High Burden of Viridans Streptococcal Endocarditis Linked to Multidrug Resistance and Regional Risk Factors: First Report From Khyber Pakhtunkhwa, Pakistan

High Burden of Viridans Streptococcal Endocarditis Linked to Multidrug Resistance and Regional Risk Factors: First Report From Khyber Pakhtunkhwa, Pakistan | Research Square window.SnipcartSettings = { analytics: { enabled: false } }; (function() { var accessVector = localStorage.getItem('access_vector') || ''; window.dataLayer = window.dataLayer || []; if (accessVector) { window.dataLayer.push({ user: { profile: { profileInfo: { snid: accessVector } } } }); } })(); (function(w,d,s,l,i){w[l]=w[l]||[];w[l].push({'gtm.start':new Date().getTime(),event:'gtm.js'});var f=d.getElementsByTagName(s)[0],j=d.createElement(s),dl=l!='dataLayer'?'&l='+l:'';j.async=true;j.src='https://www.googletagmanager.com/gtm.js?id='+i+dl;f.parentNode.insertBefore(j,f);})(window,document,'script','dataLayer','GTM-K279D39R'); Browse Preprints In Review Journals COVID-19 Preprints AJE Video Bytes Research Tools Research Promotion AJE Professional Editing AJE Rubriq About Preprint Platform In Review Editorial Policies Our Team Advisory Board Help Center Sign In Submit a Preprint Cite Share Download PDF Research Article High Burden of Viridans Streptococcal Endocarditis Linked to Multidrug Resistance and Regional Risk Factors: First Report From Khyber Pakhtunkhwa, Pakistan Abdul Khaliq, Saadullah Khan, Noor Muhammad, Mubbashir Hussain, and 5 more This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-8071744/v1 This work is licensed under a CC BY 4.0 License Status: Published Journal Publication published 08 Jan, 2026 Read the published version in BMC Microbiology → Version 1 posted 15 You are reading this latest preprint version Abstract Background: Infective endocarditis (IE) is a life-threatening condition caused by Viridans Group Streptococci (VGS) in low and middle-income countries. Data on epidemiology and molecular resistance mechanisms in the high-risk resource-limited setting of Khyber Pakhtunkhwa (KP), Pakistan, are scarce. This study aimed to determine the prevalence, risk factors, and molecular analysis of antimicrobial resistance in VGS isolated from IE patients in KP. Methods: A cross-sectional study was done on 350 IE suspected patients admitted to tertiary care hospitals in KP. Blood cultures were performed and isolates were identified using standard microbiological methods followed by species confirmation via PCR ( sodA, gtf, gyrB, and rpoB genes). Antibiotic susceptibility testing was performed. Antibiotic resistance genes ermB , mefA , tetM , tetO , and pbp2x were analyzed by PCR. Socio-demographic and clinical data were collected, and statistical analysis was performed using logistic regression. Results: Among the 350 suspected IE patients, 62 (17.7%) were confirmed to have VGS-IE. The Streptococcus mitis group was the predominant species (41.9%) followed by S. sanguinis (19.4%), and the S. anginosus group (16.1%). A high prevalence of penicillin non-susceptibility (25.8%), alongside high resistance to erythromycin (40.3%) and tetracycline (32.3%) was observed. 38.7% of isolates were multidrug-resistant. Genotypic analysis confirmed a high prevalence of the resistance determinants pbp2x (in penicillin-resistant isolates), ermB (40.3%), and tetM (32.3%). The high prevalence of region-specific risk factors, including limited access to dental care (60.0%) and use of smokeless tobacco ( naswar ) (46.6%) was recorded. No significant independent risk factors were found by multivariate analysis, however, prosthetic heart valve implantation (aOR=2.05, 95% CI: 0.74–5.67) and prior antibiotic use (aOR=1.35, 95% CI: 0.64–2.86) showed elevated risks. Conclusion: This is the first comprehensive study from KP that demonstrates the high prevalence of VGS-IE with considerable multidrug resistance confirmed for genetic determinants. These findings emphasized the urgent need for improved antimicrobial stewardship, access to better dental care, and the integration of region-specific risk factors into preventive strategies to mitigate the burden of IE in regions with low-income settings. Infective endocarditis Viridans Group Streptococci Antimicrobial resistance Resistance genes Risk factors Pakistan Figures Figure 1 Figure 2 Introduction Infective endocarditis (IE) is a severe bacterial infection of the endocardial surface of the heart, notably the valves, and is associated with high rates of morbidity and mortality worldwide specially in developing countries [1]. Among different pathogens responsible for IE, the Viridans Group Streptococci (VGS) are well-known pathogens [2]. The prevalence is high in individuals with predisposing conditions like rheumatic heart disease (RHD), prosthetic cardiac valves, or congenital structural heart defects, infection often originating from the oral cavity following bacteremia [3]. The epidemiology of IE has evolved, notably influenced by changes in healthcare practices, the increasing use of invasive practices, and irrational use of antibiotics [4]. In high-income countries, Staphylococcus aureus is the predominant cause [5]. In contrast, VGS remains a primary cause of IE in low and middle-income countries (LMICs), the trend largely linked to the persistent high prevalence of RHD and poor oral healthcare [6, 7]. Studies from Pakistan have documented this with one five-year experience at a tertiary care hospital in Karachi Pakistan, identifying streptococci, including VGS, as a major cause of community-acquired IE [8], and another study from Buner, Khyber Pakhtunkhwa, Pakistan reported a significant proportion of culture-positive IE cases attributable to these bacteria [9]. Pakistan and the province of Khyber Pakhtunkhwa (KP), especially, present a unique and high-risk setting for VGS-associated IE. This region has reported a high burden of RHD in children [7, 8], widespread use of smokeless tobacco products like naswar (a local smokeless tobacco product for the mouth), limited access to dental care [10], and unregulated antibiotic use [11]. Despite this high-risk environment, there is a lack of comprehensive data on the prevalence, risk factors, and molecular mechanisms of antimicrobial resistance in VGS isolates from IE patients in KP. Globally, resistance in VGS is mediated by well-characterized genes, including ermB and mefA (conferring macrolide resistance) [12], tetM and tetO (mediating tetracycline resistance) [13], and alterations in pbp2x (reducing susceptibility to beta-lactams) [14]. However, most of the previous studies from this region reported only phenotypic characterization of antibiotic resistance, and the prevalence of these resistance determinants in the Pakistani population remains unreported [9]. To our knowledge, no study from KP has employed a combined culture and molecular approach to specifically investigate VGS-IE, its resistance determinants, and associated genetic profiles. This critical knowledge gap hinders the development of effective, region-specific preventive and therapeutic strategies. Methodology Ethical Approval The study was designed as a PhD research project of the principal author and was reviewed and approved by the Ethical and Research Committee of Kohat University of Science and Technology (KUST), Kohat, Pakistan, vide reference number (No. KUST/Ethical Committee/1975, dated December 02, 2024, supplementary file S1). In addition to this, formal administrative permission was also obtained from the participating hospitals. Written informed consent was obtained from all participants before enrollment in the study. Confidentiality of the patient’s data was maintained throughout the research. Study Area and Study Design This hospital-based cross-sectional study was conducted from December 2024 to September 2025 in Khyber Pakhtunkhwa (KP), Pakistan, a province with an estimated population of over 35 million comprising both urban and rural populations with limited access to healthcare. The research target was patients who were admitted and suspected of infective endocarditis to the cardiology units and cardiac surgery wards of major tertiary care and teaching hospitals across KP. Participating centers included the Lady Reading Hospital (LRH), Hayatabad Medical Complex (HMC), and Khyber Teaching Hospital (KTH), Peshawar, the three largest government tertiary hospitals with dedicated cardiology and cardiac surgery departments. Additional patient recruitment was carried out at cardiology wards at district-level hospitals of Kohat, Hangu, Bannu, Dera Ismail Khan (DI Khan) Districts, and the Peshawar Institute of Cardiology (PIC), a specialized cardiac care and interventional cardiology center serving as a provincial referral institute. These hospitals receive patients from all districts of KP and neighboring tribal regions, providing a representative cross-section of the province’s cardiac patient population. The inclusion of both general tertiary hospitals, district-level hospitals, and a specialized cardiology institute enhanced the reliability and diversity of the data, thus reflecting real patterns of infective endocarditis management in the region. Figure 1. Geographical representation of sampling areas and hospitals in Khyber Pakhtunkhwa, Pakistan. The map illustrates the districts from which samples were collected for this study. Sampling districts are highlighted in red, including Peshawar, Kohat, Hangu, Bannu, and Dera Ismail Khan. Major hospitals where specimens were obtained are indicated: Khyber Teaching Hospital (KTH), Lady Reading Hospital (LRH), and Hayatabad Medical Complex (HMC) in Peshawar. Inclusion and Exclusion Criteria The sample size was calculated using Cochran’s formula (1977) or the World Health Organization (Lwanga & Lemeshow, 1991) method: n0 = Z2×p(1−p) d2 As per the formula, a total of 350 consecutive patients were recruited. The patients were included if they were adults (≥18 years) presenting with clinical features meeting the criteria for possible or definite IE according to the modified Duke criteria [15]. Exclusion criteria comprised of individuals who had received previous antibiotic therapy for more than 48 hours before blood culture collection, those with a confirmed alternative diagnosis accounting for their symptoms, polymicrobial bacteremia, or pregnancy. Patients were excluded if they had received antibiotic therapy for more than 48 hours before blood culture collection, had a confirmed alternative diagnosis explaining their symptoms, or had polymicrobial bacteremia. In addition, patients presenting with other cardiac conditions such as ischemic heart disease, rheumatic valvular disease without active infection, cardiomyopathy, congenital heart defects, or non-infective endocarditis were excluded. As per the objective, these strict criteria ensured that only patients with a strong clinical suspicion of IE were evaluated for Viridans Group Streptococci infection. Data Collection Sociodemographic and clinical information were obtained from all enrolled patients using a pre-tested, self structured questionnaire (Supplementry file S2) and review of available medical records. The data included age, gender, area of residence (urban/rural), socioeconomic status, and medical history relevant to infective endocarditis. Clinical parameters included history of rheumatic heart disease (RHD), presence of a prosthetic cardiac valve, oral hygiene status, recent antibiotic exposure within the preceding three months, intravenous drug use (IVDU), and nutritional status assessed by Body Mass Index (BMI). Data was collected by the PhD scholar through patient interviews, clinical examination, and chart reviews, assisted by a trained nurse or cardiologist to ensure accuracy and uniformity across participating centers. Sample Collection and Bacterial Identification Under aseptic conditions, 5-10 mL of venous blood was collected from each patient and inoculated into BACTEC™ aerobic blood culture bottles. The Isolates were identified based on colony morphology, hemolysis patterns, Gram staining, and catalase reaction. Presumptive VGS isolates were confirmed via PCR targeting the sodA, gyrB, gtf , and rpoB genes [16]. Antimicrobial Susceptibility Testing Antibiotic susceptibility testing was performed for antibiotics includingPenicillin G (Pen); Amoxicillin (AMX); Ceftriaxone (CRO); Erythromycin (ERY); Clindamycin (CLI); Tetracycline (TET), Doxycycline (DOX); Azithromycin (AZM); Vancomycin (VAN); Linezolid (LZN) using the Kirby-Bauer disk diffusion method on Mueller-Hinton agar supplemented with 5% sheep blood, followed by determination of Minimum Inhibitory Concentrations (MICs) using E-test strips as per guidelines of Clinical and Laboratory Standards Institute guidelines (CLSI M100, 2024) [17]. Molecular Identification of Isolates Genomic DNA was extracted from overnight fresh cultures of presumptive viridans group streptococci (VGS) using a commercial bacterial DNA extraction kit (Thermo Fisher Scientific, USA). Species identification was performed by amplification of sodA , rpoB , gtf and gyrB gene fragments using previously published primers [18-20]. Each 25 µL reaction contained 12.5 µL of 2× PCR Master Mix (Thermo Fisher Scientific), 10 pmol of each primer (Table 1), 2 µL of DNA template, and nuclease-free water. Thermocycling conditions are mentioned in Supplementary file S3. PCR products were resolved by electrophoresis on 1.5% agarose gels stained with ethidium bromide and visualized under UV transillumination. Detection of Resistance Genes In the second part of the experiment, detection of antimicrobial resistance determinants targeted to ermB and mefA (macrolide resistance), tetM and tetO (tetracycline resistance), and pbp2x (β-lactam resistance) genes using already used primer sets [21-23, Supplementary file S2]. PCR composition and cycling parameters were identical except for annealing temperatures (45–58 °C) optimized per primer pair (Supplementary file, Table S3). Amplicons were analyzed on 1.5% agarose gels alongside a 100 bp and 1 kb molecular size markers. Statistical Analysis Data was analyzed using SPSS Statistics (version 26.0). Descriptive statistics were presented as frequencies and percentages for the variables recorded. Associations between potential risk factors and VGS-IE were analyzed using the Chi-square test or Fisher's exact test, where applicable. Variables with a p-value < 0.2 in univariate analysis were further used in a multivariate logistic regression model to identify independent predictors that were presented as adjusted odds ratios (aOR) with 95% confidence intervals (CI). A p-value of < 0.05 was considered statistically significant. The control group for the risk factor analysis was defined as patients with clinically suspected IE who were negative for VGS by both culture and PCR (n = 288). Results Prevalence and Diagnostic Confirmation Out of 350 clinically suspected IE patients, 62 (17.7%) were confirmed to have VGS-IE based on culture and/or PCR results and constituted the final study cohort for all subsequent analyses (Table 1). Hospital wise distribution of viridans group streptocci positive cases are shown in supplementry file S4. Table 1. Diagnostic Yield of Culture and PCR for Viridans Group Streptococci (n=350) Method Positive cases (n) Percentage (%) Blood culture 58 16.6 PCR ( sodA, gtf, gyrB, rpoB ) 55 15.7 Combined detection (culture + PCR) 62 17.7 Species Distribution Among the 62 confirmed VGS isolates, the Streptococcus mitis group was the most prevalent, accounting for 41.9% (n=26) of cases, followed by S. sanguinis (19.4%, n=12), and the S. anginosus group (16.1%, n=10). Other species identified included S. salivarius (9.7%, n=6), S. mutans (8.1%, n=5), and S. oralis (4.8%, n=3) (Table 2). Table 2. Species distribution of viridans-group streptococci (VGS) isolated from IE patients (n=62) Species identified Frequency (n) Percentage (%) Streptococcus mitis group 26 41.9% Streptococcus sanguinis 12 19.4% Streptococcus anginosus group 10 16.1% Streptococcus salivarius 6 9.7% Streptococcus mutans 5 8.1% Streptococcus oralis 3 4.8% Total 62 100% Antimicrobial Susceptibility and Resistance Genetics The overall resistance profile of the 62 isolates showed high rates of resistance to different classes of antibiotics. Resistance to penicillin was observed in 16 isolates (25.8%), with corresponding resistance rates of 24.2% to amoxicillin and 19.4% to ceftriaxone. High resistance was also observed to macrolides (erythromycin 40.3%, azithromycin 27.4%) and tetracyclines (tetracycline 32.3%, doxycycline 25.8%). All isolates remained fully susceptible to vancomycin and linezolid (Table 4). Molecular analysis of the 62 isolates was performed. PCR amplification of housekeeping and resistance-associated genes was successfully achieved in the isolates included in this study. Clear and specific amplicons were obtained for the housekeeping genes rpoB (~700 bp), gyrB (~1100 bp), and gtf (~517 bp). Likewise, resistance genes were reliably amplified, yielding expected product sizes for mefA (~350 bp), ermB (~648 bp), tetM (~406 bp), tetO (~171 bp), and pbp2x (~2.1 kb). The amplified products demonstrated sharp, distinct bands upon agarose gel electrophoresis, confirming the presence of the respective genetic determinants. Representative gel images for all amplified genes are provided in Supplementary File S5. As detailed in Table 3, 4 and Figure 2, the Streptococcus mitis group, being the most prevalent (n=26), showed the highest absolute number of resistant isolates and significant resistance rates across all drug classes. It showed significant resistance to beta-lactams (penicillin 34.6%, ceftriaxone 23.1%), macrolides (erythromycin 50.0%), and tetracyclines (tetracycline 34.6%). The S. sanguinis group (n=12) and the S. anginosus group (n=10) also showed considerable resistance to these drug classes. All isolates, regardless of species, remained fully susceptible to vancomycin and linezolid. Table 3 . Antibiotic resistance profile of Viridans Group Streptococci isolates (n = 62) and correlation with resistance genes Antibiotic Resistant isolates MIC range of resistant isolates (µg/mL) Key resistance genes detected Penicillin G 16 (25.8%) 0.5 -- 8.0 pbp2x (16, 100%) Amoxicillin 15 (24.2%) 0.5 -- 4.0 pbp2x (15, 100%) Ceftriaxone 12 (19.4%) 0.5 -- 4.0 pbp2x (10, 83.3%) + other mechanisms Erythromycin 25 (40.3%) 1 -- 8 ermB (20, 80.0%), mefA (12, 48.0%) Azithromycin 17 (27.4%) 1 -- 4 ermB (12, 70.6%), mefA (9, 52.9%) Clindamycin 13 (21.0%) 0.5 -- 2.0 ermB (10, 76.9%) Tetracycline 20 (32.3%) 2 -- 16 tetM (13, 65.0%), tetO (7, 35.0%) Doxycycline 16 (25.8%) 1 -- 8 tetM (11, 68.8%), tetO (5, 31.3%) Vancomycin 0 (0.0%) ≤0.5 None detected Linezolid 0 (0.0%) ≤1.0 None detected Multidrug resistance 24 (38.7%) --- Combinations of ermB , mefA , tetM , tetO , pbp2x Figure 2. (A) Prevalence (%) of resistance among isolates to various antibiotics. (B) Antibiotic resistance prevalence (%) of different Streptococcus species against tested antibiotics. Table 4. Antibiotic resistance of viridans group streptococci stratified by species (n = 62) Species (n) PEN R n (%) AMX R n (%) CRO R n (%) ERY R n (%) AZM R n (%) CLI R n (%) TET R n (%) DOX R n (%) VAN R n (%) LZD R n (%) S. mitis group (26) 9 (34.6) 8 (30.8) 6 (23.1) 13 (50.0) 9 (34.6) 6 (23.1) 9 (34.6) 7 (26.9) 0 (0.0) 0 (0.0) S. sanguinis (12) 2 (16.7) 2 (16.7) 2 (16.7) 5 (41.7) 4 (33.3) 2 (16.7) 4 (33.3) 3 (25.0) 0 (0.0) 0 (0.0) S. anginosus group (10) 3 (30.0) 3 (30.0) 2 (20.0) 4 (40.0) 2 (20.0) 2 (20.0) 3 (30.0) 2 (20.0) 0 (0.0) 0 (0.0) S. salivarius (6) 1 (16.7) 1 (16.7) 1 (16.7) 2 (33.3) 1 (16.7) 1 (16.7) 2 (33.3) 1 (16.7) 0 (0.0) 0 (0.0) S. mutans (5) 1 (20.0) 1 (20.0) 1 (20.0) 1 (20.0) 1 (20.0) 1 (20.0) 1 (20.0) 1 (20.0) 0 (0.0) 0 (0.0) S. oralis (3) 0 (0.0) 0 (0.0) 0 (0.0) 0 (0.0) 0 (0.0) 1 (33.3) 1 (33.3) 1 (33.3) 0 (0.0) 0 (0.0) Total (62) 16 (25.8) 15 (24.2) 12 (19.4) 25 (40.3) 17 (27.4) 13 (21.0) 20 (32.3) 15 (24.2) 0 (0.0) 0 (0.0) PEN=Penicillin, AMX=Amoxicillin, CRO=Ceftriaxone, ERY=Erythromycin, AZM=Azithromycin, CLI=Clindamycin, TET=Tetracycline, DOX=Doxycycline, VAN=Vancomycin, LZD=Linezolid Minimum Inhibitory Concentration (MIC) Distribution MIC testing was done to confirm concerning resistance trends. The MIC₉₀ values for penicillin and ceftriaxone were recorded as 4.0 µg/mL and 2.0 µg/mL respectively indicating that a significant subset of the population had MICs at or approaching near the CLSI resistance breakpoints. This confirms a significant level of reduced susceptibility to beta-lactams. In contrast, elevated MIC₉₀ values were observed for erythromycin (8.0 µg/mL), tetracycline (16.0 µg/mL), and doxycycline (8.0 µg/mL) thus confirming the high-level resistance evident in the disk diffusion assay. All MICs for vancomycin and linezolid were within the susceptible range (Table 5). Table 5. Minimum inhibitory concentrations (MICs) of Viridans Group Streptococci isolates (n = 62) Antibiotic MIC range (µg/mL) MIC 50 (µg/mL) MIC 90 (µg/mL) CLSI 2024 resistance breakpoint (µg/mL) Penicillin G 0.03 – 8.0 0.12 4.0 ≥4.0 Amoxicillin 0.03 – 4.0 0.12 2.0 ≥2.0 Ceftriaxone 0.06 – 4.0 0.25 2.0 ≥4.0 Erythromycin 0.06 – 16.0 0.5 8.0 ≥1.0 Azithromycin 0.06 – 8.0 0.5 4.0 ≥2.0 Clindamycin 0.03 – 4.0 0.25 2.0 ≥1.0 Tetracycline 0.12 – 32.0 2.0 16.0 ≥8.0 Doxycycline 0.06 – 16.0 1.0 8.0 ≥4.0 Vancomycin 0.25 – 1.0 0.5 0.5 ≥2.0 Linezolid 0.12 – 1.0 0.5 1.0 ≥4.0 Demographic and Clinical Characteristics of the IE Patients The present study cohort consisted of 350 patients with a clinical suspicion of infective endocarditis. The mean age of the participants was 42.7 years, with the largest proportion (42.6%, n =149) included within the 31-50 years age group. A male predominance was observed, accounting for 62.0% (n =218) of the cohort. Most patients were urban residents (58.0%, n=203). Significant clinical risk factors included a history of rheumatic heart disease (RHD) in 30.0% (n=105) of patients and intravenous drug use (IVDU) in 10.0% (n=35). Contextual risk factors were highly prevalent that as most patients were of low socioeconomic status (52.0%, n =182) reported limited access to dental care (60.0%, n=210), and used local tobacco or naswar (46.6%, n=163). Additionally, 21.4% (n=75) of the patients were underweight, indicating a notable prevalence of malnutrition within the cohort (Table 6). Table 6. Demographic and clinical characteristics of infective endocarditis patients (n=350) Variable Category Frequency (n) Percentage (%) Age group 18–30 years 89 25.4 31–50 years 149 42.6 51–70 years 84 24.0 >70 years 28 8.0 Gender Male 218 62.0 Female 134 38.0 Residence Urban 203 58.0 Rural 147 42.0 Rheumatic heart disease Yes 105 30.0 No 245 70.0 IV drug use Yes 35 10.0 No 315 90.0 Socioeconomic status Low 182 52.0 Middle/High 168 48.0 Access to dental care Limited 210 60.0 Adequate 140 40.0 Tobacco/naswar chewing Yes 163 46.6 No 187 53.4 Nutritional status (BMI) Underweight 75 21.4 Normal/High 275 78.6 Risk Factor Analysis Analysis by univariate logistic regression of the 350 patient cohort (62 cases versus 288 controls) showed several factors with significantly elevated crude odds ratios for VGS-IE. These included prosthetic heart valves implantation (OR=2.56, 95% CI: 1.12–5.85, p=0.03), IVDU (OR=2.33, 95% CI: 1.08–5.03, p=0.03) low socioeconomic status (OR=1.85, 95% CI: 1.08–3.18, p=0.03) and limited access to dental care (OR=2.12, 95% CI: 1.21–3.72, p=0.01). However, upon multivariate adjustment, none of these factors retained formal statistical significance as an independent predictor. Despite this, prosthetic valve implantation (aOR=2.05, 95% CI: 0.74–5.67) and prior antibiotic use (aOR=1.35, 95% CI: 0.64–2.86) continued to demonstrate notably elevated, although non-significant odds. Limited access to dental care was marginally significant (aOR=2.10, 95% CI: 1.01–4.38, p=0.05) (Table 7). Table 7: Univariate and multivariate logistic regression of risk factors for Viridans Group Streptococci infective endocarditis (n=62 cases vs. 288 controls) Predictor Crude OR (95% CI) p-value Adjusted OR (95% CI) p-value Poor oral hygiene 0.87 (0.38–1.98) 0.74 0.92 (0.44–1.90) 0.81 Rheumatic heart disease 0.98 (0.42–2.29) 0.97 0.75 (0.36–1.56) 0.45 Prosthetic valve 2.56 (1.12–5.85) 0.03 2.05 (0.74–5.67) 0.15 Prior antibiotic use 1.01 (0.43–2.36) 0.99 1.35 (0.64–2.86) 0.43 Urban residence 1.05 (0.61–1.82) 0.86 0.69 (0.35–1.35) 0.28 Male sex 1.02 (0.59–1.76) 0.95 1.20 (0.61–2.34) 0.58 IV drug use 2.33 (1.08–5.03) 0.03 1.95 (0.63–6.00) 0.25 Low socioeconomic status 1.85 (1.08–3.18) 0.03 1.95 (0.98–3.89) 0.06 Limited access to dental care 2.12 (1.21–3.72) 0.01 2.10 (1.01–4.38) 0.05 Tobacco/naswar chewing 1.54 (0.90–2.63) 0.11 1.65 (0.82–3.32) 0.12 Malnutrition (low BMI) 1.37 (0.76–2.47) 0.30 1.40 (0.66–2.95) 0.35 *Variables with p<0.2 in univariate analysis entered into the multivariate logistic regression model. Controls were defined as VGS culture / PCR-negative patients. Discussion This study represents the first molecular epidemiological analysis of Viridans Group Streptococci infective endocarditis (IE) from the Khyber Pakhtunkhwa (KP) region of Pakistan. While previous reports from this province have reported the bacteriological profile of IE that were largely based on phenotypic methods and did not focus specifically on the molecular characterization of VGS [9]. Our data integrates the culture, PCR based species confirmation and resistance gene detection affirms an overall VGS-IE prevalence of 17.7% and establishes this bacterial group as a significant etiological agent in the local population suffering from IE. This finding aligns with national data from other provinces indicate that the streptococci are responsible for a considerable proportion of IE cases in Pakistan, particularly among individuals with predisposing conditions like RHD and improper dental hygiene [8, 9]. In contrast to the epidemiological shift towards Staphylococcus aureus in high-income countries [24]. the enduring predominance of VGS in this low-income setting emphasizes the persistent influence of regional risk factors pervasive in LMICs, including a high RHD burden, limited access to oral healthcare, and unregulated antibiotic use [25-27]. The species distribution in our cohort was dominated by the S. mitis group (41.9%) and S. sanguinis (19.4%) and the finding is consistent with regional and global profiles. A study from Quetta, in Pakistan's Balochistan province, also reported a high prevalence of oral streptococci, including S. mutans (25.6%) and S. mitis (19.4%) in dental caries [28]. Similarly, research from South India has identified the S. mitis group as a predominant cause of VGS bacteremia [29]. As commensals of the oropharyngeal region, these species are well-recognized pathogens in subacute IE [30]. The high prevalence of the S. mitis group reinforces its emerging role as a leading cause of VGS-IE, a trend supported by studies highlighting its significant virulence potential in community-acquired infections [31,32]. The notable detection of the S. anginosus group (16.1%) is also significant, as this group is frequently associated with abscess formation and may indicate a more invasive disease phenotype [33]. The antibiotic sensitivity profile recorded in this study presents an alarming picture that aligns with the rising trends observed across South Asia. A key finding of our study is the reporting of a high prevalence of penicillin non susceptibility (25.8%), which we confirmed with the detection of the pbp2x gene in samples. This provides the first genetic confirmation of beta-lactam resistance mechanisms in VGS from KP. This finding is in consistence with the 32.14% reported in a recent study from Lahore, Pakistan [34] and falls within the 20-65% range documented in other Pakistani reports [35, 36]. It is also in accordance with high rates of 34-60% reported from neighboring India and China [37, 38], although it is higher than the 15.4% reported from Jordan [39]. This data highlights that penicillin resistance in VGS is a severe and widespread problem in the region likely propelled by decades of unregulated and irrational antibiotic use. The clinical relevance of this finding is confirmed by the elevated MIC₉₀ value for penicillin (4.0 µg/mL), approaching the CLSI resistance breakpoint and suggesting that empirical treatment with penicillin only may be inadequate for a substantial proportion of IE patients in KP. Conversely, we recorded higher levels of resistance to macrolides (erythromycin 40.3%) and tetracyclines (tetracycline 32.3%) with 38.7% of isolates classified as multidrug resistant (MDR). To our knowledge, this is the first report from KP to document the genetic determinants of this MDR phenotypes in viridans streptococci revealing high carriage of ermB (40.3%) and tetM (32.3%) genes. These rates substantially exceed the 18.5% macrolide resistance reported from Karachi [9] and are higher than the 15-25% range typical in Western nations; for instance, a study from Finland found resistance to erythromycin and tetracycline in 22.4% and 27.3% of isolates, respectively [34, 35]. The elevated MIC₉₀ values for erythromycin (8.0 µg/mL) and tetracycline (16.0 µg/mL) confirmed the presence of a high level clinically relevant resistance likely to be driven by widespread use of non prescription antibiotic in the community and agricultural sectors across South Asia [40]. Molecular analysis provided a genetic confirmation of phenotypic characterization of antibiotic resistance. The pbp2x gene was detected in all penicillin-resistant isolates, confirming the role of altered penicillin-binding proteins. Furthermore the high co occurance and co carriage of macrolide ( ermB , mefA ) and tetracycline ( tetM , tetO ) resistance genes facilitates the observed MDR phenotype. The prevalence of ermB (40.3%) and tetM (32.3%) in our isolates is markedly higher than rates reported in a Tunisian pediatric population (12.84% for ermB and 9.17% for tetM ), though tetO was more common there (27.52%) [41], the reason being the target population was pediatric, while in our study sampling population was adults over 18 years age. The tetM and tetO genes confer tetracycline resistance through ribosomal protection [42]. Similar resistance genetics have been reported elsewhere, a study from Turkey found ermB in 56% and pbp2x in 20% of resistant VGS isolates [43, 44]. While the current clinical impact of pbp2x may be limited, its presence is a critical warning that necessitates ongoing surveillance for rising beta-lactam resistance. The 100% susceptibility to vancomycin and linezolid confirms that these agents as reliable last line options for treatment of severe or MDR cases. However, their high cost and limited availability in Pakistan's public health sector render them inaccessible for patients from remote areas, highlights the urgent need to revise local empirical treatment guidelines and implement stringent antibiotic stewardship programs. Although multivariate analysis of risk factors in present study did not identify statistically significant independent predictors, several factors showed strong epidemiological associations with VGS-IE. Prosthetic heart valve implantation was linked to a two-fold increased risk (aOR = 2.05) which is in accordance with a study from Karachi, Pakistan that identified prosthetic valve endocarditis as a complex entity with higher morbidity and mortality (OR = 3.74) [45]. The trend observed with IVDU (aOR = 1.95), although less common in our cohort remains a biologically possible risk factor due to the potential for direct inoculation of oral flora in blood stream as supported by previous literature [46]. The high prevalence of region specific risk factors in our cohort, including limited dental care access (60%), low socioeconomic status (52%), and particularly the use of naswar (46.6%), likely plays a critical role in facilitating oral colonization and subsequent bacteremia. Poor oral health is a well-established risk factor for transient streptococcal bacteremia, especially in individuals with underlying valvular damage [47]. The common practice of naswar chewing a smokeless tobacco product is of particular concern in KP. Its use causes chronic mucosal irritation and damage to the oral mucosa thus disrupting the normal microflora and creating portals of entry for bacteria into the bloodstream and thereby predisposing users to infections [48, 49]. The persistently elevated, though non-significant, odds ratios for these factors in our multivariate model highlight their potential contributory role and warrant further investigation in larger, prospective studies. Limitations This study has various limitations. Its cross-sectional design impedes causal interpretation between risk factors and outcome. Although PCR was used for gene detection, the absence of whole-genome or Sanger sequencing, which couldn’t be performed due to the resource constraints of this PhD research project that limited our ability to explore novel mutations, perform detailed phylogenetic analysis or identify undiscovered resistance mechanisms. The recruitment of participants from tertiary care centers may introduce selection bias, potentially underrepresenting community-acquired cases or those managed in rural settings. Furthermore, despite the use of combined culture and PCR diagnostics and exclusion of participants who received prior antibiotic therapy, the true burden of IE may be miscalculated due to culture-negative cases, often resulting from antecedent antibiotic therapy. Conclusion In conclusion, this study offers the first comprehensive evidence from Khyber Pakhtunkhwa, Pakistan on the molecular epidemiology of VGS-IE. We report a significant disease burden characterized by considerable multidrug resistance, the genetic basis of which including the prevalence of ermB , mefA , tetM , tetO , and pbp2x genes is reported for the first time in clinical VGS isolates from this region. The endemicity of VGS-IE in KP appears to be driven by regional factors, including inadequate dental care, a high burden of RHD, unregulated antibiotic use, and the common practice of naswar chewing. These findings emphasize at the urgent need for region-specific interventions including vigorous antibiotic stewardship programs, enhanced oral health infrastructure, and the development of context aware clinical guidelines to minimize AMR. Future research should be employ for genomic surveillance to fully explore the resistance profiles and transmission dynamics of these bacteria and to evaluate the impact of public health steps aimed at mitigating these unique, region-specific risk factors. Declarations Author Contributions: Conceptualization, A.K. and M.H.; methodology, A.K., S.K., and M.H.; software, A.K. and H.N.; validation, N.M., A.B., and K.J.A.; formal analysis, A.K. and K.F.A.; investigation, A.K., S.K., and H.N.; resources, M.H., S.K., and F.M.A.; data curation, A.K. and A.B.; writing and original draft preparation, A.K.; writing, review and editing, M.H., S.K., K.J.A., and F.M.A.; visualization, A.K. and K.F.A.; supervision, M.H. and S.K.; project administration, M.H.; funding acquisition, K.J.A. and F.M.A. All authors have read and agreed to the published version of the manuscript. Funding: This research was funded by Taif University, Taif, Saudi Arabia, grant number (TU-DSPP-2024-26). Ethics approval and consent to participate: The study was approved by the Ethical and Research Committee of Kohat University of Science and Technology (KUST), Kohat, Pakistan (Approval No. KUST/Ethical Committee/1975, dated 02 December 2024). All procedures involving human participants were performed in accordance with the ethical standards of the institutional committee and with the Declaration of Helsinki. Written informed consent was obtained from all individual participants (or their legal guardians, where applicable) prior to sample collection. Consent for Publication: Not applicable Data Availability Statement: The data presented in this study is available on request from the corresponding author. The data is not publicly available due to privacy and ethical restrictions. Acknowledgments: The authors extend their sincere appreciation to Taif University, Saudi Arabia, for supporting this work through project number (TU-DSPP-2024-26). The authors are also profoundly grateful to the doctors, nurses, and laboratory staff at the participating hospitals Lady Reading Hospital (LRH), Hayatabad Medical Complex (HMC), Khyber Teaching Hospital (KTH), Peshawar Institute of Cardiology (PIC), and the district headquarters hospitals in Kohat, Hangu, Bannu, and Dera Ismail Khan for their invaluable assistance in patient recruitment and sample collection. Finally, we sincerely thank all the patients who participated in this study. Conflicts of Interest: The authors declare no conflicts of interest. The funders had no role in the design of the study; in the collection, analyses, or interpretation of data; in the writing of the manuscript; or in the decision to publish the results References Cahill TJ, Prendergast BD. Infective endocarditis. Lancet. 2016;387(10021):882–93. Wang A, Gaca JG, Chu VH. Management Considerations in Infective Endocarditis: A Review. JAMA. 2018;320(1):72–83. 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Adv Dent Res. 2019;30(1):4–10. Additional Declarations No competing interests reported. Supplementary Files SupplementryfileS1Ethicalcertificate.pdf SupplementryfilS2Questionairre.pdf SupplementryfileS3tablefilePrimersKhaliqetal.pdf SupplementryfileS4SamplingfromdifferenthospitalsKhaliqatal.pdf supplementryfileS5Gelpictureskhaliqetal3.pdf Cite Share Download PDF Status: Published Journal Publication published 08 Jan, 2026 Read the published version in BMC Microbiology → Version 1 posted Editorial decision: Revision requested 08 Dec, 2025 Reviews received at journal 07 Dec, 2025 Reviewers agreed at journal 07 Dec, 2025 Reviewers agreed at journal 07 Dec, 2025 Reviews received at journal 05 Dec, 2025 Reviewers agreed at journal 04 Dec, 2025 Reviewers agreed at journal 04 Dec, 2025 Reviewers agreed at journal 04 Dec, 2025 Reviewers agreed at journal 04 Dec, 2025 Reviewers agreed at journal 04 Dec, 2025 Reviewers invited by journal 04 Dec, 2025 Editor assigned by journal 04 Dec, 2025 Editor invited by journal 19 Nov, 2025 Submission checks completed at journal 19 Nov, 2025 First submitted to journal 19 Nov, 2025 You are reading this latest preprint version Research Square lets you share your work early, gain feedback from the community, and start making changes to your manuscript prior to peer review in a journal. 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1","display":"","copyAsset":false,"role":"figure","size":85653,"visible":true,"origin":"","legend":"\u003cp\u003e\u003cstrong\u003eGeographical representation of sampling areas and hospitals in Khyber Pakhtunkhwa, Pakistan.\u003c/strong\u003e The map illustrates the districts from which samples were collected for this study. Sampling districts are highlighted in red, including Peshawar, Kohat, Hangu, Bannu, and Dera Ismail Khan. Major hospitals where specimens were obtained are indicated: Khyber Teaching Hospital (KTH), Lady Reading Hospital (LRH), and Hayatabad Medical Complex (HMC) in Peshawar.\u003c/p\u003e","description":"","filename":"Picture1.jpg","url":"https://assets-eu.researchsquare.com/files/rs-8071744/v1/bf67ea342c91917093016d8a.jpg"},{"id":97894537,"identity":"dd7cfb32-539f-407b-a327-466d7651bb48","added_by":"auto","created_at":"2025-12-10 15:32:41","extension":"jpg","order_by":2,"title":"Figure 2","display":"","copyAsset":false,"role":"figure","size":92731,"visible":true,"origin":"","legend":"\u003cp\u003e(A) Prevalence (%) of resistance among isolates to various antibiotics. (B) Antibiotic resistance prevalence (%) of different \u003cem\u003eStreptococcus\u003c/em\u003e species against tested antibiotics.\u003c/p\u003e","description":"","filename":"Picture2.jpg","url":"https://assets-eu.researchsquare.com/files/rs-8071744/v1/d227e20cfd4e2430fd9566c9.jpg"},{"id":100069122,"identity":"ff856ef8-0fa6-4867-96df-7ad35be55495","added_by":"auto","created_at":"2026-01-12 16:09:58","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":1982820,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-8071744/v1/8d17ee98-dc13-416b-9855-e73ce7d56f20.pdf"},{"id":97895268,"identity":"d76aae1c-fe54-415c-86a7-156e9d1d23f4","added_by":"auto","created_at":"2025-12-10 15:33:55","extension":"pdf","order_by":1,"title":"","display":"","copyAsset":false,"role":"supplement","size":101286,"visible":true,"origin":"","legend":"","description":"","filename":"SupplementryfileS1Ethicalcertificate.pdf","url":"https://assets-eu.researchsquare.com/files/rs-8071744/v1/2591cc9ba21fdf5be9bf3c90.pdf"},{"id":97894460,"identity":"639e55d7-9f38-4241-bf11-736f62b4fbe1","added_by":"auto","created_at":"2025-12-10 15:32:32","extension":"pdf","order_by":2,"title":"","display":"","copyAsset":false,"role":"supplement","size":559361,"visible":true,"origin":"","legend":"","description":"","filename":"SupplementryfilS2Questionairre.pdf","url":"https://assets-eu.researchsquare.com/files/rs-8071744/v1/4a5d831ae73d151760043ecf.pdf"},{"id":97894917,"identity":"40a3deaa-73b5-4fca-afe4-86f17d1bf8de","added_by":"auto","created_at":"2025-12-10 15:33:13","extension":"pdf","order_by":3,"title":"","display":"","copyAsset":false,"role":"supplement","size":291409,"visible":true,"origin":"","legend":"","description":"","filename":"SupplementryfileS3tablefilePrimersKhaliqetal.pdf","url":"https://assets-eu.researchsquare.com/files/rs-8071744/v1/98719ea56467df178b805ced.pdf"},{"id":97704412,"identity":"e1536918-ea35-4e69-afec-316c6efca4b4","added_by":"auto","created_at":"2025-12-08 12:48:31","extension":"pdf","order_by":4,"title":"","display":"","copyAsset":false,"role":"supplement","size":293359,"visible":true,"origin":"","legend":"","description":"","filename":"SupplementryfileS4SamplingfromdifferenthospitalsKhaliqatal.pdf","url":"https://assets-eu.researchsquare.com/files/rs-8071744/v1/9901faa03108e97a3963fcdd.pdf"},{"id":97704424,"identity":"4b5955c3-78ee-4ff3-a5e6-8dda5390c021","added_by":"auto","created_at":"2025-12-08 12:48:32","extension":"pdf","order_by":5,"title":"","display":"","copyAsset":false,"role":"supplement","size":715842,"visible":true,"origin":"","legend":"","description":"","filename":"supplementryfileS5Gelpictureskhaliqetal3.pdf","url":"https://assets-eu.researchsquare.com/files/rs-8071744/v1/c14c49d5370f86b7a8ccdcee.pdf"}],"financialInterests":"No competing interests reported.","formattedTitle":"\u003cp\u003eHigh Burden of Viridans Streptococcal Endocarditis Linked to Multidrug Resistance and Regional Risk Factors: First Report From Khyber Pakhtunkhwa, Pakistan\u003c/p\u003e","fulltext":[{"header":"Introduction","content":"\u003cp\u003eInfective endocarditis (IE) is a severe bacterial infection of the endocardial surface of the heart, notably the valves, and is associated with high rates of morbidity and mortality worldwide specially in developing countries [1]. Among different pathogens responsible for IE, the Viridans Group Streptococci (VGS) are well-known pathogens [2]. The prevalence is high in individuals with predisposing conditions like rheumatic heart disease (RHD), prosthetic cardiac valves, or congenital structural heart defects, infection often originating from the oral cavity following bacteremia [3].\u003c/p\u003e\n\u003cp\u003eThe epidemiology of IE has evolved, notably influenced by changes in healthcare practices, the increasing use of invasive practices, and irrational use of antibiotics [4]. In high-income countries, \u003cem\u003eStaphylococcus aureus\u003c/em\u003e is the predominant cause [5]. In contrast, VGS remains a primary cause of IE in low and middle-income countries (LMICs), the trend largely linked to the persistent high prevalence of RHD and poor oral healthcare [6, 7]. Studies from Pakistan have documented this with one five-year experience at a tertiary care hospital in Karachi Pakistan, identifying streptococci, including VGS, as a major cause of community-acquired IE [8], and another study from Buner, Khyber Pakhtunkhwa, Pakistan reported a significant proportion of culture-positive IE cases attributable to these bacteria [9].\u003c/p\u003e\n\u003cp\u003ePakistan and the province of Khyber Pakhtunkhwa (KP), especially, present a unique and high-risk setting for VGS-associated IE. This region has reported a high burden of RHD in children [7, 8], widespread use of smokeless tobacco products like \u003cem\u003enaswar\u003c/em\u003e (a local smokeless tobacco product for the mouth), limited access to dental care [10], and unregulated antibiotic use [11]. Despite this high-risk environment, there is a lack of comprehensive data on the prevalence, risk factors, and molecular mechanisms of antimicrobial resistance in VGS isolates from IE patients in KP.\u003c/p\u003e\n\u003cp\u003eGlobally, resistance in VGS is mediated by well-characterized genes, including \u003cem\u003eermB\u003c/em\u003e and \u003cem\u003emefA\u0026nbsp;\u003c/em\u003e(conferring macrolide resistance) [12], \u003cem\u003etetM\u003c/em\u003e and \u003cem\u003etetO\u003c/em\u003e (mediating tetracycline resistance) [13], and alterations in \u003cem\u003epbp2x\u003c/em\u003e (reducing susceptibility to beta-lactams) [14]. However, most of the previous studies from this region reported only phenotypic characterization of antibiotic resistance, and the prevalence of these resistance determinants in the Pakistani population remains unreported [9].\u003c/p\u003e\n\u003cp\u003eTo our knowledge, no study from KP has employed a combined culture and molecular approach to specifically investigate VGS-IE, its resistance determinants, and associated genetic profiles. This critical knowledge gap hinders the development of effective, region-specific preventive and therapeutic strategies.\u003c/p\u003e"},{"header":"Methodology","content":"\u003cp\u003e\u003cstrong\u003eEthical Approval\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe study was designed as a PhD research project of the principal author and was reviewed and approved by the Ethical and Research Committee of Kohat University of Science and Technology (KUST), Kohat, Pakistan, vide reference number (No. KUST/Ethical Committee/1975, dated December 02, 2024, supplementary file S1). In addition to this, formal administrative permission was also obtained from the participating hospitals. Written informed consent was obtained from all participants before enrollment in the study. Confidentiality of the patient\u0026rsquo;s data was maintained throughout the research.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eStudy Area and Study Design\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThis hospital-based cross-sectional study was conducted from December 2024 to September 2025 in\u0026nbsp;Khyber Pakhtunkhwa (KP), Pakistan, a province with an estimated population of over 35 million comprising both urban and rural populations with limited access to healthcare. The research target was patients who were admitted and suspected of infective endocarditis to the\u0026nbsp;cardiology units and cardiac surgery wards\u0026nbsp;of major tertiary care and teaching hospitals across KP. Participating centers included the\u0026nbsp;Lady Reading Hospital (LRH), Hayatabad Medical Complex (HMC), and Khyber Teaching Hospital (KTH), Peshawar, the three largest government tertiary hospitals with dedicated cardiology and cardiac surgery departments. Additional patient recruitment was carried out at cardiology wards at\u0026nbsp;district-level hospitals of Kohat, Hangu, Bannu, Dera Ismail Khan (DI Khan) Districts, and the\u0026nbsp;Peshawar Institute of Cardiology (PIC), a specialized cardiac care and interventional cardiology center serving as a provincial referral institute. These hospitals receive patients from all districts of KP and neighboring tribal regions, providing a representative cross-section of the province\u0026rsquo;s cardiac patient population. The inclusion of both general tertiary hospitals, district-level hospitals, and a specialized cardiology institute enhanced the reliability and diversity of the data, thus reflecting real patterns of infective endocarditis management in the region.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eFigure 1.\u003c/strong\u003e \u003cstrong\u003eGeographical representation of sampling areas and hospitals in Khyber Pakhtunkhwa, Pakistan.\u003c/strong\u003e The map illustrates the districts from which samples were collected for this study. Sampling districts are highlighted in red, including Peshawar, Kohat, Hangu, Bannu, and Dera Ismail Khan. Major hospitals where specimens were obtained are indicated: Khyber Teaching Hospital (KTH), Lady Reading Hospital (LRH), and Hayatabad Medical Complex (HMC) in Peshawar.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eInclusion and Exclusion Criteria\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe sample size was calculated using\u0026nbsp;Cochran\u0026rsquo;s formula (1977)\u0026nbsp;or the\u0026nbsp;World Health Organization (Lwanga \u0026amp; Lemeshow, 1991)\u0026nbsp;method:\u003c/p\u003e\n\u003cp\u003e\u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; n0 = \u003cu\u003eZ2\u0026times;p(1\u0026minus;p)\u003c/u\u003e\u003c/p\u003e\n\u003cp\u003e\u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp;d2\u003c/p\u003e\n\u003cp\u003eAs per the formula, a total of 350 consecutive patients were recruited. The patients were included if they were adults (\u0026ge;18 years) presenting with clinical features meeting the criteria for possible or definite IE according to the modified Duke criteria [15]. Exclusion criteria comprised of individuals who had received previous antibiotic therapy for more than 48 hours before blood culture collection, those with a confirmed alternative diagnosis accounting for their symptoms, polymicrobial bacteremia, or pregnancy. Patients were excluded if they had received antibiotic therapy for more than 48 hours before blood culture collection, had a confirmed alternative diagnosis explaining their symptoms, or had polymicrobial bacteremia. In addition, patients presenting with other cardiac conditions such as ischemic heart disease, rheumatic valvular disease without active infection, cardiomyopathy, congenital heart defects, or non-infective endocarditis were excluded. \u0026nbsp;As per the objective, these strict criteria ensured that only patients with a strong clinical suspicion of IE were evaluated for \u003cem\u003eViridans Group Streptococci\u003c/em\u003e infection.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eData Collection\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eSociodemographic and clinical information were obtained from all enrolled patients using a\u0026nbsp;pre-tested, self structured questionnaire (Supplementry file S2)\u0026nbsp;and review of available medical records. The data included\u0026nbsp;age, gender, area of residence (urban/rural), socioeconomic status, and medical history\u0026nbsp;relevant to infective endocarditis. Clinical parameters included history of rheumatic heart disease (RHD), presence of a prosthetic cardiac valve, oral hygiene status, recent antibiotic exposure within the preceding three months, intravenous drug use (IVDU), and nutritional status assessed by Body Mass Index (BMI). Data was collected by the PhD scholar through\u0026nbsp;patient interviews, clinical examination, and chart reviews,\u0026nbsp;assisted by a trained nurse or cardiologist to ensure accuracy and uniformity across participating centers.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eSample Collection and Bacterial Identification\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eUnder aseptic conditions, 5-10 mL of venous blood was collected from each patient and inoculated into BACTEC\u0026trade; aerobic blood culture bottles. The Isolates were identified based on colony morphology, hemolysis patterns, Gram staining, and catalase reaction. Presumptive VGS isolates were confirmed via PCR targeting the \u003cem\u003esodA, gyrB, gtf\u003c/em\u003e, and\u003cem\u003e\u0026nbsp;rpoB\u003c/em\u003e genes [16].\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAntimicrobial Susceptibility Testing\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eAntibiotic susceptibility testing was performed for antibiotics includingPenicillin G (Pen); Amoxicillin (AMX); Ceftriaxone (CRO); Erythromycin (ERY); Clindamycin (CLI); Tetracycline (TET), Doxycycline (DOX); Azithromycin (AZM); Vancomycin (VAN); Linezolid (LZN) using the Kirby-Bauer disk diffusion method on Mueller-Hinton agar supplemented with 5% sheep blood, followed by determination of Minimum Inhibitory Concentrations (MICs) using E-test strips as per guidelines of Clinical and Laboratory Standards Institute guidelines (CLSI M100, 2024) [17].\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eMolecular Identification of Isolates\u0026nbsp;\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eGenomic DNA was extracted from overnight fresh cultures of presumptive \u003cem\u003eviridans group streptococci (VGS)\u003c/em\u003e using a commercial bacterial DNA extraction kit (Thermo Fisher Scientific, USA). \u0026nbsp;Species identification was performed by amplification of \u003cem\u003esodA\u003c/em\u003e, \u003cem\u003erpoB\u003c/em\u003e, \u003cem\u003egtf\u003c/em\u003e and \u003cem\u003egyrB\u003c/em\u003e gene fragments using previously published primers [18-20]. Each 25 \u0026micro;L reaction contained 12.5 \u0026micro;L of 2\u0026times; PCR Master Mix (Thermo Fisher Scientific), 10 pmol of each primer (Table 1), 2 \u0026micro;L of DNA template, and nuclease-free water. Thermocycling conditions are mentioned in Supplementary file S3. PCR products were resolved by electrophoresis on 1.5% agarose gels stained with ethidium bromide and visualized under UV transillumination.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eDetection of Resistance Genes\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eIn the second part of the experiment, detection of antimicrobial resistance determinants targeted to \u003cem\u003eermB\u003c/em\u003e and \u003cem\u003emefA\u003c/em\u003e (macrolide resistance), \u003cem\u003etetM\u003c/em\u003e and \u003cem\u003etetO\u0026nbsp;\u003c/em\u003e(tetracycline resistance), and \u003cem\u003epbp2x\u003c/em\u003e (\u0026beta;-lactam resistance) genes using already used primer sets [21-23, Supplementary file S2]. PCR composition and cycling parameters were identical except for annealing temperatures (45\u0026ndash;58 \u0026deg;C) optimized per primer pair (Supplementary file, Table S3). Amplicons were analyzed on 1.5% agarose gels alongside a 100 bp and 1 kb molecular size markers.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eStatistical Analysis\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eData was analyzed using SPSS Statistics (version 26.0). Descriptive statistics were presented as frequencies and percentages for the variables recorded. Associations between potential risk factors and VGS-IE were analyzed using the Chi-square test or Fisher\u0026apos;s exact test, where applicable. Variables with a p-value \u0026lt; 0.2 in univariate analysis were further used in a multivariate logistic regression model to identify independent predictors that were presented as adjusted odds ratios (aOR) with 95% confidence intervals (CI). A p-value of \u0026lt; 0.05 was considered statistically significant. The control group for the risk factor analysis was defined as patients with clinically suspected IE who were negative for VGS by both culture and PCR (n = 288).\u003c/p\u003e"},{"header":"Results","content":"\u003cp\u003e\u003cstrong\u003ePrevalence and Diagnostic Confirmation\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eOut of 350 clinically suspected IE patients, 62 (17.7%) were confirmed to have VGS-IE based on culture and/or PCR results and constituted the final study cohort for all subsequent analyses (Table 1). Hospital wise distribution of viridans group streptocci positive cases are shown in supplementry file S4.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eTable 1. Diagnostic Yield of Culture and PCR for Viridans Group Streptococci (n=350)\u003c/strong\u003e\u003c/p\u003e\n\u003ctable border=\"1\" cellspacing=\"0\" cellpadding=\"0\" width=\"592\"\u003e\n \u003cthead\u003e\n \u003ctr\u003e\n \u003ctd\u003e\n \u003cp\u003e\u003cstrong\u003eMethod\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e\u003cstrong\u003ePositive cases (n)\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e\u003cstrong\u003ePercentage (%)\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/thead\u003e\n \u003ctbody\u003e\n \u003ctr\u003e\n \u003ctd\u003e\n \u003cp\u003eBlood culture\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e58\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e16.6\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd\u003e\n \u003cp\u003ePCR (\u003cem\u003esodA, gtf, gyrB, rpoB\u003c/em\u003e)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e55\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e15.7\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd\u003e\n \u003cp\u003eCombined detection (culture + PCR)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e62\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e17.7\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tbody\u003e\n\u003c/table\u003e\n\u003cp\u003e\u003cstrong\u003eSpecies Distribution\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eAmong the 62 confirmed VGS isolates, the \u003cem\u003eStreptococcus mitis\u003c/em\u003e group was the most prevalent, accounting for 41.9% (n=26) of cases, followed by \u003cem\u003eS. sanguinis\u003c/em\u003e (19.4%, n=12), and the \u003cem\u003eS. anginosus\u003c/em\u003e group (16.1%, n=10). Other species identified included \u003cem\u003eS. salivarius\u003c/em\u003e (9.7%, n=6), \u003cem\u003eS. mutans\u003c/em\u003e (8.1%, n=5), and \u003cem\u003eS. oralis\u003c/em\u003e (4.8%, n=3) (Table 2).\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eTable 2. Species distribution of viridans-group streptococci (VGS) isolated from IE patients (n=62)\u003c/strong\u003e\u003c/p\u003e\n\u003ctable border=\"1\" cellspacing=\"0\" cellpadding=\"0\" width=\"588\"\u003e\n \u003cthead\u003e\n \u003ctr\u003e\n \u003ctd\u003e\n \u003cp\u003e\u003cstrong\u003eSpecies identified\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e\u003cstrong\u003eFrequency (n)\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e\u003cstrong\u003ePercentage (%)\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/thead\u003e\n \u003ctbody\u003e\n \u003ctr\u003e\n \u003ctd\u003e\n \u003cp\u003e\u003cem\u003eStreptococcus mitis\u003c/em\u003e group\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e26\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e41.9%\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd\u003e\n \u003cp\u003e\u003cem\u003eStreptococcus sanguinis\u003c/em\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e12\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e19.4%\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd\u003e\n \u003cp\u003e\u003cem\u003eStreptococcus anginosus\u003c/em\u003e group\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e10\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e16.1%\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd\u003e\n \u003cp\u003e\u003cem\u003eStreptococcus salivarius\u003c/em\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e6\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e9.7%\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd\u003e\n \u003cp\u003e\u003cem\u003eStreptococcus mutans\u003c/em\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e5\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e8.1%\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd\u003e\n \u003cp\u003e\u003cem\u003eStreptococcus oralis\u003c/em\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e3\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e4.8%\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd\u003e\n \u003cp\u003eTotal\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e62\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e100%\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tbody\u003e\n\u003c/table\u003e\n\u003cp\u003e\u003cstrong\u003e\u0026nbsp;Antimicrobial Susceptibility and Resistance Genetics\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe overall resistance profile of the 62 isolates showed high rates of resistance to different classes of antibiotics. Resistance to penicillin was observed in\u0026nbsp;16 isolates (25.8%), with corresponding resistance rates of\u0026nbsp;24.2% to amoxicillin\u0026nbsp;and\u0026nbsp;19.4% to ceftriaxone. High resistance was also observed to macrolides (erythromycin\u0026nbsp;40.3%, azithromycin\u0026nbsp;27.4%) and tetracyclines (tetracycline\u0026nbsp;32.3%, doxycycline\u0026nbsp;25.8%). All isolates remained fully susceptible to vancomycin and linezolid (Table 4).\u003c/p\u003e\n\u003cp\u003eMolecular analysis of the 62 isolates was performed. PCR amplification of housekeeping and resistance-associated genes was successfully achieved in the isolates included in this study. Clear and specific amplicons were obtained for the housekeeping genes \u003cem\u003erpoB\u003c/em\u003e (~700 bp), \u003cem\u003egyrB\u003c/em\u003e (~1100 bp), and \u003cem\u003egtf\u003c/em\u003e (~517 bp). Likewise, resistance genes were reliably amplified, yielding expected product sizes for \u003cem\u003emefA\u003c/em\u003e (~350 bp), \u003cem\u003eermB\u003c/em\u003e (~648 bp), \u003cem\u003etetM\u003c/em\u003e (~406 bp), \u003cem\u003etetO\u003c/em\u003e (~171 bp), and \u003cem\u003epbp2x\u003c/em\u003e (~2.1 kb). The amplified products demonstrated sharp, distinct bands upon agarose gel electrophoresis, confirming the presence of the respective genetic determinants. Representative gel images for all amplified genes are provided in Supplementary File S5. As detailed in Table 3, 4 and Figure 2, the \u003cem\u003eStreptococcus mitis\u003c/em\u003e group, being the most prevalent (n=26), showed the highest absolute number of resistant isolates and significant resistance rates across all drug classes. It showed significant resistance to beta-lactams (penicillin 34.6%, ceftriaxone 23.1%), macrolides (erythromycin 50.0%), and tetracyclines (tetracycline 34.6%). The \u003cem\u003eS. sanguinis\u003c/em\u003e group (n=12) and the \u003cem\u003eS. anginosus\u003c/em\u003e group (n=10) also showed considerable resistance to these drug classes. All isolates, regardless of species, remained fully susceptible to vancomycin and linezolid.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eTable\u0026nbsp;\u003c/strong\u003e\u003cstrong\u003e3\u003c/strong\u003e\u003cstrong\u003e. Antibiotic resistance profile of Viridans Group Streptococci isolates (n = 62) and correlation with resistance genes\u003c/strong\u003e\u003c/p\u003e\n\u003ctable border=\"1\" cellspacing=\"0\" cellpadding=\"0\" width=\"619\"\u003e\n \u003ctbody\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e\u003cstrong\u003e\u0026nbsp;\u003c/strong\u003e\u003c/p\u003e\n \u003cp\u003e\u003cstrong\u003eAntibiotic\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e\u003cstrong\u003e\u0026nbsp;\u003c/strong\u003e\u003c/p\u003e\n \u003cp\u003e\u003cstrong\u003eResistant isolates\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e\u003cstrong\u003e\u0026nbsp;\u003c/strong\u003e\u003c/p\u003e\n \u003cp\u003e\u003cstrong\u003eMIC range of resistant isolates (\u0026micro;g/mL)\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e\u003cstrong\u003e\u0026nbsp;\u003c/strong\u003e\u003c/p\u003e\n \u003cp\u003e\u003cstrong\u003eKey resistance genes detected\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003ePenicillin G\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e16 (25.8%)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e0.5 -- 8.0\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e\u003cem\u003epbp2x\u003c/em\u003e (16, 100%)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003eAmoxicillin\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e15 (24.2%)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e0.5 -- 4.0\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e\u003cem\u003epbp2x\u003c/em\u003e (15, 100%)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003eCeftriaxone\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e12 (19.4%)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e0.5 -- 4.0\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e\u003cem\u003epbp2x\u003c/em\u003e (10, 83.3%) + other mechanisms\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003eErythromycin\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e25 (40.3%)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e1 -- 8\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e\u003cem\u003eermB\u003c/em\u003e (20, 80.0%), \u003cem\u003emefA\u003c/em\u003e (12, 48.0%)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003eAzithromycin\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e17 (27.4%)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e1 -- 4\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e\u003cem\u003eermB\u003c/em\u003e (12, 70.6%), \u003cem\u003emefA\u003c/em\u003e (9, 52.9%)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003eClindamycin\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e13 (21.0%)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e0.5 -- 2.0\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e\u003cem\u003eermB\u003c/em\u003e (10, 76.9%)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003eTetracycline\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e20 (32.3%)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e2 -- 16\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e\u003cem\u003etetM\u003c/em\u003e (13, 65.0%), \u003cem\u003etetO\u003c/em\u003e (7, 35.0%)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003eDoxycycline\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e16 (25.8%)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e1 -- 8\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e\u003cem\u003etetM\u003c/em\u003e (11, 68.8%), \u003cem\u003etetO\u003c/em\u003e (5, 31.3%)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003eVancomycin\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e0 (0.0%)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e\u0026le;0.5\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003eNone detected\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003eLinezolid\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e0 (0.0%)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e\u0026le;1.0\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003eNone detected\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003eMultidrug resistance\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e24 (38.7%)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e---\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003eCombinations of \u003cem\u003eermB\u003c/em\u003e, \u003cem\u003emefA\u003c/em\u003e, \u003cem\u003etetM\u003c/em\u003e, \u003cem\u003etetO\u003c/em\u003e, \u003cem\u003epbp2x\u003c/em\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tbody\u003e\n\u003c/table\u003e\n\u003cp\u003eFigure 2. (A) Prevalence (%) of resistance among isolates to various antibiotics. (B) Antibiotic resistance prevalence (%) of different \u003cem\u003eStreptococcus\u003c/em\u003e species against tested antibiotics.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eTable 4. Antibiotic resistance of viridans group streptococci stratified by species (n = 62)\u003c/strong\u003e\u003c/p\u003e\n\u003ctable border=\"1\" cellspacing=\"0\" cellpadding=\"0\" width=\"616\"\u003e\n \u003ctbody\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e\u003cstrong\u003eSpecies (n)\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e\u003cstrong\u003ePEN R n (%)\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e\u003cstrong\u003eAMX R n (%)\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e\u003cstrong\u003eCRO R n (%)\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e\u003cstrong\u003eERY R n (%)\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e\u003cstrong\u003eAZM R n (%)\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e\u003cstrong\u003eCLI R n (%)\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e\u003cstrong\u003eTET R n (%)\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e\u003cstrong\u003eDOX R n (%)\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e\u003cstrong\u003eVAN R\u0026nbsp;\u003c/strong\u003e\u003c/p\u003e\n \u003cp\u003e\u003cstrong\u003en (%)\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e\u003cstrong\u003eLZD R n (%)\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e\u003cem\u003eS. mitis\u003c/em\u003e group (26)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e9\u0026nbsp;\u003c/p\u003e\n \u003cp\u003e(34.6)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e8\u0026nbsp;\u003c/p\u003e\n \u003cp\u003e(30.8)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e6\u0026nbsp;\u003c/p\u003e\n \u003cp\u003e(23.1)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e13 (50.0)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e9 (34.6)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e6 (23.1)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e9\u003c/p\u003e\n \u003cp\u003e\u0026nbsp;(34.6)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e7\u003c/p\u003e\n \u003cp\u003e\u0026nbsp;(26.9)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e0\u0026nbsp;\u003c/p\u003e\n \u003cp\u003e(0.0)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e0\u0026nbsp;\u003c/p\u003e\n \u003cp\u003e(0.0)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e\u003cem\u003eS. sanguinis\u003c/em\u003e\u0026nbsp;\u003c/p\u003e\n \u003cp\u003e(12)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e2\u0026nbsp;\u003c/p\u003e\n \u003cp\u003e(16.7)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e2\u003c/p\u003e\n \u003cp\u003e\u0026nbsp;(16.7)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e2\u0026nbsp;\u003c/p\u003e\n \u003cp\u003e(16.7)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e5\u003c/p\u003e\n \u003cp\u003e\u0026nbsp;(41.7)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e4 (33.3)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e2 (16.7)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e4\u003c/p\u003e\n \u003cp\u003e\u0026nbsp;(33.3)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e3\u003c/p\u003e\n \u003cp\u003e\u0026nbsp;(25.0)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e0\u0026nbsp;\u003c/p\u003e\n \u003cp\u003e(0.0)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e0\u0026nbsp;\u003c/p\u003e\n \u003cp\u003e(0.0)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e\u003cem\u003eS. anginosus\u003c/em\u003e group (10)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e3\u003c/p\u003e\n \u003cp\u003e\u0026nbsp;(30.0)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e3\u003c/p\u003e\n \u003cp\u003e\u0026nbsp;(30.0)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e2\u003c/p\u003e\n \u003cp\u003e\u0026nbsp;(20.0)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e4\u0026nbsp;\u003c/p\u003e\n \u003cp\u003e(40.0)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e2 (20.0)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e2 (20.0)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e3\u003c/p\u003e\n \u003cp\u003e\u0026nbsp;(30.0)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e2\u003c/p\u003e\n \u003cp\u003e\u0026nbsp;(20.0)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e0\u0026nbsp;\u003c/p\u003e\n \u003cp\u003e(0.0)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e0\u0026nbsp;\u003c/p\u003e\n \u003cp\u003e(0.0)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e\u003cem\u003eS. salivarius\u003c/em\u003e\u0026nbsp;\u003c/p\u003e\n \u003cp\u003e(6)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e1\u003c/p\u003e\n \u003cp\u003e\u0026nbsp;(16.7)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e1\u003c/p\u003e\n \u003cp\u003e\u0026nbsp;(16.7)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e1\u003c/p\u003e\n \u003cp\u003e\u0026nbsp;(16.7)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e2\u0026nbsp;\u003c/p\u003e\n \u003cp\u003e(33.3)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e1 (16.7)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e1 (16.7)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e2\u003c/p\u003e\n \u003cp\u003e\u0026nbsp;(33.3)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e1\u003c/p\u003e\n \u003cp\u003e\u0026nbsp;(16.7)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e0\u0026nbsp;\u003c/p\u003e\n \u003cp\u003e(0.0)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e0\u0026nbsp;\u003c/p\u003e\n \u003cp\u003e(0.0)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e\u003cem\u003eS. mutans\u003c/em\u003e\u0026nbsp;\u003c/p\u003e\n \u003cp\u003e(5)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e1\u003c/p\u003e\n \u003cp\u003e\u0026nbsp;(20.0)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e1\u003c/p\u003e\n \u003cp\u003e\u0026nbsp;(20.0)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e1\u003c/p\u003e\n \u003cp\u003e\u0026nbsp;(20.0)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e1\u003c/p\u003e\n \u003cp\u003e\u0026nbsp;(20.0)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e1 (20.0)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e1 (20.0)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e1\u003c/p\u003e\n \u003cp\u003e\u0026nbsp;(20.0)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e1\u003c/p\u003e\n \u003cp\u003e\u0026nbsp;(20.0)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e0\u0026nbsp;\u003c/p\u003e\n \u003cp\u003e(0.0)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e0\u003c/p\u003e\n \u003cp\u003e\u0026nbsp;(0.0)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e\u003cem\u003eS. oralis\u003c/em\u003e\u003c/p\u003e\n \u003cp\u003e\u0026nbsp;(3)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e0\u0026nbsp;\u003c/p\u003e\n \u003cp\u003e(0.0)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e0\u003c/p\u003e\n \u003cp\u003e\u0026nbsp;(0.0)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e0\u003c/p\u003e\n \u003cp\u003e\u0026nbsp;(0.0)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e0\u003c/p\u003e\n \u003cp\u003e\u0026nbsp;(0.0)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e0\u0026nbsp;\u003c/p\u003e\n \u003cp\u003e(0.0)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e1 (33.3)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e1\u003c/p\u003e\n \u003cp\u003e\u0026nbsp;(33.3)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e1\u003c/p\u003e\n \u003cp\u003e\u0026nbsp;(33.3)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e0\u0026nbsp;\u003c/p\u003e\n \u003cp\u003e(0.0)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e0\u0026nbsp;\u003c/p\u003e\n \u003cp\u003e(0.0)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003eTotal\u0026nbsp;\u003c/p\u003e\n \u003cp\u003e(62)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e16 (25.8)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e15\u003c/p\u003e\n \u003cp\u003e\u0026nbsp;(24.2)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e12\u003c/p\u003e\n \u003cp\u003e\u0026nbsp;(19.4)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e25 (40.3)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e17 (27.4)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e13 (21.0)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e20\u0026nbsp;\u003c/p\u003e\n \u003cp\u003e(32.3)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e15\u003c/p\u003e\n \u003cp\u003e\u0026nbsp;(24.2)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e0\u0026nbsp;\u003c/p\u003e\n \u003cp\u003e(0.0)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\"\u003e\n \u003cp\u003e0\u0026nbsp;\u003c/p\u003e\n \u003cp\u003e(0.0)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tbody\u003e\n\u003c/table\u003e\n\u003cp\u003e\u003cstrong\u003e\u003cem\u003ePEN=Penicillin, AMX=Amoxicillin, CRO=Ceftriaxone, ERY=Erythromycin, AZM=Azithromycin, CLI=Clindamycin, TET=Tetracycline, DOX=Doxycycline, VAN=Vancomycin, LZD=Linezolid\u003c/em\u003e\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eMinimum Inhibitory Concentration (MIC) Distribution\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eMIC testing was done to confirm concerning resistance trends. The MIC₉₀ values for penicillin and ceftriaxone were recorded as 4.0 \u0026micro;g/mL and 2.0 \u0026micro;g/mL respectively indicating that a significant subset of the population had MICs at or approaching near the CLSI resistance breakpoints. This confirms a significant level of reduced susceptibility to beta-lactams. In contrast, elevated MIC₉₀ values were observed for erythromycin (8.0 \u0026micro;g/mL), tetracycline (16.0 \u0026micro;g/mL), and doxycycline (8.0 \u0026micro;g/mL) thus confirming the high-level resistance evident in the disk diffusion assay. All MICs for vancomycin and linezolid were within the susceptible range (Table 5).\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eTable 5. Minimum inhibitory concentrations (MICs) of Viridans Group Streptococci isolates (n = 62)\u003c/strong\u003e\u003c/p\u003e\n\u003ctable border=\"1\" cellspacing=\"0\" cellpadding=\"0\"\u003e\n \u003cthead\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 189px;\"\u003e\n \u003cp\u003e\u003cstrong\u003eAntibiotic\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 132px;\"\u003e\n \u003cp\u003e\u003cstrong\u003eMIC range (\u0026micro;g/mL)\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 85px;\"\u003e\n \u003cp\u003e\u003cstrong\u003eMIC 50 (\u0026micro;g/mL)\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 85px;\"\u003e\n \u003cp\u003e\u003cstrong\u003eMIC 90 (\u0026micro;g/mL)\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 110px;\"\u003e\n \u003cp\u003e\u003cstrong\u003eCLSI 2024 resistance breakpoint (\u0026micro;g/mL)\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/thead\u003e\n \u003ctbody\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 189px;\"\u003e\n \u003cp\u003ePenicillin G\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 132px;\"\u003e\n \u003cp\u003e0.03 \u0026ndash; 8.0\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 85px;\"\u003e\n \u003cp\u003e0.12\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 85px;\"\u003e\n \u003cp\u003e4.0\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 110px;\"\u003e\n \u003cp\u003e\u0026ge;4.0\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 189px;\"\u003e\n \u003cp\u003eAmoxicillin\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 132px;\"\u003e\n \u003cp\u003e0.03 \u0026ndash; 4.0\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 85px;\"\u003e\n \u003cp\u003e0.12\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 85px;\"\u003e\n \u003cp\u003e2.0\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 110px;\"\u003e\n \u003cp\u003e\u0026ge;2.0\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 189px;\"\u003e\n \u003cp\u003eCeftriaxone\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 132px;\"\u003e\n \u003cp\u003e0.06 \u0026ndash; 4.0\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 85px;\"\u003e\n \u003cp\u003e0.25\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 85px;\"\u003e\n \u003cp\u003e2.0\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 110px;\"\u003e\n \u003cp\u003e\u0026ge;4.0\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 189px;\"\u003e\n \u003cp\u003eErythromycin\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 132px;\"\u003e\n \u003cp\u003e0.06 \u0026ndash; 16.0\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 85px;\"\u003e\n \u003cp\u003e0.5\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 85px;\"\u003e\n \u003cp\u003e8.0\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 110px;\"\u003e\n \u003cp\u003e\u0026ge;1.0\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 189px;\"\u003e\n \u003cp\u003eAzithromycin\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 132px;\"\u003e\n \u003cp\u003e0.06 \u0026ndash; 8.0\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 85px;\"\u003e\n \u003cp\u003e0.5\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 85px;\"\u003e\n \u003cp\u003e4.0\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 110px;\"\u003e\n \u003cp\u003e\u0026ge;2.0\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 189px;\"\u003e\n \u003cp\u003eClindamycin\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 132px;\"\u003e\n \u003cp\u003e0.03 \u0026ndash; 4.0\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 85px;\"\u003e\n \u003cp\u003e0.25\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 85px;\"\u003e\n \u003cp\u003e2.0\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 110px;\"\u003e\n \u003cp\u003e\u0026ge;1.0\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 189px;\"\u003e\n \u003cp\u003eTetracycline\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 132px;\"\u003e\n \u003cp\u003e0.12 \u0026ndash; 32.0\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 85px;\"\u003e\n \u003cp\u003e2.0\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 85px;\"\u003e\n \u003cp\u003e16.0\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 110px;\"\u003e\n \u003cp\u003e\u0026ge;8.0\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 189px;\"\u003e\n \u003cp\u003eDoxycycline\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 132px;\"\u003e\n \u003cp\u003e0.06 \u0026ndash; 16.0\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 85px;\"\u003e\n \u003cp\u003e1.0\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 85px;\"\u003e\n \u003cp\u003e8.0\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 110px;\"\u003e\n \u003cp\u003e\u0026ge;4.0\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 189px;\"\u003e\n \u003cp\u003eVancomycin\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 132px;\"\u003e\n \u003cp\u003e0.25 \u0026ndash; 1.0\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 85px;\"\u003e\n \u003cp\u003e0.5\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 85px;\"\u003e\n \u003cp\u003e0.5\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 110px;\"\u003e\n \u003cp\u003e\u0026ge;2.0\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 189px;\"\u003e\n \u003cp\u003eLinezolid\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 132px;\"\u003e\n \u003cp\u003e0.12 \u0026ndash; 1.0\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 85px;\"\u003e\n \u003cp\u003e0.5\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 85px;\"\u003e\n \u003cp\u003e1.0\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 110px;\"\u003e\n \u003cp\u003e\u0026ge;4.0\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tbody\u003e\n\u003c/table\u003e\n\u003cp\u003e\u003cstrong\u003eDemographic and Clinical Characteristics of the IE Patients\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe present study cohort consisted of 350 patients with a clinical suspicion of infective endocarditis. The mean age of the participants was 42.7 years, with the largest proportion (42.6%, n =149) included within the 31-50 years age group. A male predominance was observed, accounting for 62.0% (n =218) of the cohort. Most patients were urban residents (58.0%, n=203). Significant clinical risk factors included a history of rheumatic heart disease (RHD) in 30.0% (n=105) of patients and intravenous drug use (IVDU) in 10.0% (n=35). Contextual risk factors were highly prevalent that as most patients were of low socioeconomic status (52.0%, n =182) reported limited access to dental care (60.0%, n=210), and used local tobacco or \u003cem\u003enaswar\u003c/em\u003e (46.6%, n=163). Additionally, 21.4% (n=75) of the patients were underweight, indicating a notable prevalence of malnutrition within the cohort (Table 6).\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eTable 6. Demographic and clinical characteristics of infective endocarditis patients (n=350)\u003c/strong\u003e\u003c/p\u003e\n\u003cdiv align=\"center\"\u003e\n \u003ctable border=\"1\" cellspacing=\"0\" cellpadding=\"0\" width=\"564\"\u003e\n \u003cthead\u003e\n \u003ctr\u003e\n \u003ctd\u003e\n \u003cp\u003e\u003cstrong\u003eVariable\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e\u003cstrong\u003eCategory\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e\u003cstrong\u003eFrequency (n)\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e\u003cstrong\u003ePercentage (%)\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/thead\u003e\n \u003ctbody\u003e\n \u003ctr\u003e\n \u003ctd rowspan=\"4\"\u003e\n \u003cp\u003e\u003cstrong\u003eAge group\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e18\u0026ndash;30 years\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e89\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e25.4\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd\u003e\n \u003cp\u003e31\u0026ndash;50 years\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e149\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e42.6\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd\u003e\n \u003cp\u003e51\u0026ndash;70 years\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e84\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e24.0\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd\u003e\n \u003cp\u003e\u0026gt;70 years\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e28\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e8.0\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd rowspan=\"2\"\u003e\n \u003cp\u003e\u003cstrong\u003eGender\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003eMale\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e218\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e62.0\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd\u003e\n \u003cp\u003eFemale\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e134\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e38.0\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd rowspan=\"2\"\u003e\n \u003cp\u003e\u003cstrong\u003eResidence\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003eUrban\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e203\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e58.0\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd\u003e\n \u003cp\u003eRural\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e147\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e42.0\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd rowspan=\"2\"\u003e\n \u003cp\u003e\u003cstrong\u003eRheumatic heart disease\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003eYes\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e105\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e30.0\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd\u003e\n \u003cp\u003eNo\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e245\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e70.0\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd rowspan=\"2\"\u003e\n \u003cp\u003e\u003cstrong\u003eIV drug use\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003eYes\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e35\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e10.0\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd\u003e\n \u003cp\u003eNo\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e315\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e90.0\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd rowspan=\"2\"\u003e\n \u003cp\u003e\u003cstrong\u003eSocioeconomic status\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003eLow\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e182\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e52.0\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd\u003e\n \u003cp\u003eMiddle/High\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e168\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e48.0\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd rowspan=\"2\"\u003e\n \u003cp\u003e\u003cstrong\u003eAccess to dental care\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003eLimited\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e210\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e60.0\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd\u003e\n \u003cp\u003eAdequate\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e140\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e40.0\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd rowspan=\"2\"\u003e\n \u003cp\u003e\u003cstrong\u003eTobacco/naswar chewing\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003eYes\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e163\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e46.6\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd\u003e\n \u003cp\u003eNo\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e187\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e53.4\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd rowspan=\"2\"\u003e\n \u003cp\u003e\u003cstrong\u003eNutritional status (BMI)\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003eUnderweight\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e75\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e21.4\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd\u003e\n \u003cp\u003eNormal/High\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e275\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e78.6\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tbody\u003e\n \u003c/table\u003e\n\u003c/div\u003e\n\u003cp\u003e\u003cstrong\u003eRisk Factor Analysis\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eAnalysis by univariate logistic regression of the 350 patient cohort (62 cases versus 288 controls) showed several factors with significantly elevated crude odds ratios for VGS-IE. These included prosthetic heart valves implantation (OR=2.56, 95% CI: 1.12\u0026ndash;5.85, p=0.03), IVDU (OR=2.33, 95% CI: 1.08\u0026ndash;5.03, p=0.03) low socioeconomic status (OR=1.85, 95% CI: 1.08\u0026ndash;3.18, p=0.03) and limited access to dental care (OR=2.12, 95% CI: 1.21\u0026ndash;3.72, p=0.01). However, upon multivariate adjustment, none of these factors retained formal statistical significance as an independent predictor. Despite this, prosthetic valve implantation (aOR=2.05, 95% CI: 0.74\u0026ndash;5.67) and prior antibiotic use (aOR=1.35, 95% CI: 0.64\u0026ndash;2.86) continued to demonstrate notably elevated, although non-significant odds. Limited access to dental care was marginally significant (aOR=2.10, 95% CI: 1.01\u0026ndash;4.38, p=0.05) (Table 7).\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eTable 7: Univariate and multivariate logistic regression of risk factors for Viridans Group Streptococci infective endocarditis (n=62 cases vs. 288 controls)\u003c/strong\u003e\u003c/p\u003e\n\u003ctable border=\"1\" cellspacing=\"0\" cellpadding=\"0\"\u003e\n \u003cthead\u003e\n \u003ctr\u003e\n \u003ctd\u003e\n \u003cp\u003e\u003cstrong\u003ePredictor\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e\u003cstrong\u003eCrude OR (95% CI)\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e\u003cstrong\u003ep-value\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e\u003cstrong\u003eAdjusted OR (95% CI)\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e\u003cstrong\u003ep-value\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/thead\u003e\n \u003ctbody\u003e\n \u003ctr\u003e\n \u003ctd\u003e\n \u003cp\u003e\u003cstrong\u003ePoor oral hygiene\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e0.87 (0.38\u0026ndash;1.98)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e0.74\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e0.92 (0.44\u0026ndash;1.90)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e0.81\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd\u003e\n \u003cp\u003e\u003cstrong\u003eRheumatic heart disease\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e0.98 (0.42\u0026ndash;2.29)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e0.97\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e0.75 (0.36\u0026ndash;1.56)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e0.45\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd\u003e\n \u003cp\u003e\u003cstrong\u003eProsthetic valve\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e2.56 (1.12\u0026ndash;5.85)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e0.03\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e2.05 (0.74\u0026ndash;5.67)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e0.15\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd\u003e\n \u003cp\u003e\u003cstrong\u003ePrior antibiotic use\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e1.01 (0.43\u0026ndash;2.36)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e0.99\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e1.35 (0.64\u0026ndash;2.86)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e0.43\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd\u003e\n \u003cp\u003e\u003cstrong\u003eUrban residence\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e1.05 (0.61\u0026ndash;1.82)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e0.86\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e0.69 (0.35\u0026ndash;1.35)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e0.28\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd\u003e\n \u003cp\u003e\u003cstrong\u003eMale sex\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e1.02 (0.59\u0026ndash;1.76)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e0.95\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e1.20 (0.61\u0026ndash;2.34)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e0.58\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd\u003e\n \u003cp\u003e\u003cstrong\u003eIV drug use\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e2.33 (1.08\u0026ndash;5.03)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e0.03\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e1.95 (0.63\u0026ndash;6.00)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e0.25\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd\u003e\n \u003cp\u003e\u003cstrong\u003eLow socioeconomic status\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e1.85 (1.08\u0026ndash;3.18)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e0.03\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e1.95 (0.98\u0026ndash;3.89)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e0.06\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd\u003e\n \u003cp\u003e\u003cstrong\u003eLimited access to dental care\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e2.12 (1.21\u0026ndash;3.72)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e0.01\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e2.10 (1.01\u0026ndash;4.38)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e0.05\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd\u003e\n \u003cp\u003e\u003cstrong\u003eTobacco/naswar chewing\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e1.54 (0.90\u0026ndash;2.63)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e0.11\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e1.65 (0.82\u0026ndash;3.32)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e0.12\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd\u003e\n \u003cp\u003e\u003cstrong\u003eMalnutrition (low BMI)\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e1.37 (0.76\u0026ndash;2.47)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e0.30\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e1.40 (0.66\u0026ndash;2.95)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e0.35\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tbody\u003e\n\u003c/table\u003e\n\u003cp\u003e*Variables with p\u0026lt;0.2 in univariate analysis entered into the multivariate logistic regression model. Controls were defined as VGS culture / PCR-negative patients.\u003c/p\u003e"},{"header":"Discussion","content":"\u003cp\u003eThis study represents the first molecular epidemiological analysis of Viridans Group Streptococci infective endocarditis (IE) from the Khyber Pakhtunkhwa (KP) region of Pakistan. While previous reports from this province have reported the bacteriological profile of IE that were largely based on phenotypic methods and did not focus specifically on the molecular characterization of VGS [9]. Our data integrates the culture, PCR based species confirmation and resistance gene detection affirms an overall VGS-IE prevalence of 17.7% and establishes this bacterial group as a significant etiological agent in the local population suffering from IE. This finding aligns with national data from other provinces indicate that the streptococci are responsible for a considerable proportion of IE cases in Pakistan, particularly among individuals with predisposing conditions like RHD and improper dental hygiene [8, 9]. In contrast to the epidemiological shift towards \u003cem\u003eStaphylococcus aureus\u003c/em\u003e in high-income countries [24]. the enduring predominance of VGS in this low-income setting emphasizes the persistent influence of regional risk factors pervasive in LMICs, including a high RHD burden, limited access to oral healthcare, and unregulated antibiotic use [25-27].\u003c/p\u003e\n\u003cp\u003eThe species distribution in our cohort was dominated by the \u003cem\u003eS. mitis\u003c/em\u003e group (41.9%) and \u003cem\u003eS. sanguinis\u003c/em\u003e(19.4%) and the finding is consistent with regional and global profiles. A study from Quetta, in Pakistan's Balochistan province, also reported a high prevalence of oral streptococci, including \u003cem\u003eS. mutans\u003c/em\u003e (25.6%) and \u003cem\u003eS. mitis\u0026nbsp;\u003c/em\u003e(19.4%) in dental caries [28]. Similarly, research from South India has identified the \u003cem\u003eS. mitis\u003c/em\u003e group as a predominant cause of VGS bacteremia [29]. As commensals of the oropharyngeal region, these species are well-recognized pathogens in subacute IE [30]. The high prevalence of the \u003cem\u003eS. mitis\u003c/em\u003e group reinforces its emerging role as a leading cause of VGS-IE, a trend supported by studies highlighting its significant virulence potential in community-acquired infections [31,32]. The notable detection of the \u003cem\u003eS. anginosus\u003c/em\u003e group (16.1%) is also significant, as this group is frequently associated with abscess formation and may indicate a more invasive disease phenotype [33].\u003c/p\u003e\n\u003cp\u003eThe antibiotic sensitivity profile recorded in this study presents an alarming picture that aligns with the rising trends observed across South Asia. A key finding of our study is the reporting of a high prevalence of penicillin non susceptibility (25.8%), which we confirmed with the detection of the \u003cem\u003epbp2x\u003c/em\u003e gene in samples. This provides the first genetic confirmation of beta-lactam resistance mechanisms in VGS from KP. This finding is in consistence with the 32.14% reported in a recent study from Lahore, Pakistan [34] and falls within the 20-65% range documented in other Pakistani reports [35, 36]. It is also in accordance with high rates of 34-60% reported from neighboring India and China [37, 38], although it is higher than the 15.4% reported from Jordan [39]. This data highlights that penicillin resistance in VGS is a severe and widespread problem in the region likely propelled by decades of unregulated and irrational antibiotic use. The clinical relevance of this finding is confirmed by the elevated MIC₉₀ value for penicillin (4.0 µg/mL), approaching the CLSI resistance breakpoint and suggesting that empirical treatment with penicillin only may be inadequate for a substantial proportion of IE patients in KP.\u003c/p\u003e\n\u003cp\u003eConversely, we recorded higher levels of resistance to macrolides (erythromycin 40.3%) and tetracyclines (tetracycline 32.3%) with 38.7% of isolates classified as multidrug resistant (MDR). To our knowledge, this is the first report from KP to document the genetic determinants of this MDR phenotypes in viridans streptococci revealing high carriage of \u003cem\u003eermB\u003c/em\u003e (40.3%) and \u003cem\u003etetM\u003c/em\u003e (32.3%) genes. These rates substantially exceed the 18.5% macrolide resistance reported from Karachi [9] and are higher than the 15-25% range typical in Western nations; for instance, a study from Finland found resistance to erythromycin and tetracycline in 22.4% and 27.3% of isolates, respectively [34, 35]. The elevated MIC₉₀ values for erythromycin (8.0 µg/mL) and tetracycline (16.0 µg/mL) confirmed the presence of a high level clinically relevant resistance likely to be driven by widespread use of non prescription antibiotic in the community and agricultural sectors across South Asia [40].\u003c/p\u003e\n\u003cp\u003eMolecular analysis provided a genetic confirmation of phenotypic characterization of antibiotic resistance. The \u003cem\u003epbp2x\u003c/em\u003e gene was detected in all penicillin-resistant isolates, confirming the role of altered penicillin-binding proteins. Furthermore the high co occurance and co carriage of macrolide (\u003cem\u003eermB\u003c/em\u003e, \u003cem\u003emefA\u003c/em\u003e) and tetracycline (\u003cem\u003etetM\u003c/em\u003e, \u003cem\u003etetO\u003c/em\u003e) resistance genes facilitates the observed MDR phenotype. The prevalence of \u003cem\u003eermB\u003c/em\u003e (40.3%) and \u003cem\u003etetM\u003c/em\u003e (32.3%) in our isolates is markedly higher than rates reported in a Tunisian pediatric population (12.84% for \u003cem\u003eermB\u003c/em\u003e and 9.17% for \u003cem\u003etetM\u003c/em\u003e), though \u003cem\u003etetO\u003c/em\u003e was more common there (27.52%) [41], the reason being the target population was pediatric, while in our study sampling population was adults over 18 years age. The \u003cem\u003etetM\u003c/em\u003e and \u003cem\u003etetO\u003c/em\u003e genes confer tetracycline resistance through ribosomal protection [42]. Similar resistance genetics have been reported elsewhere, a study from Turkey found \u003cem\u003eermB\u003c/em\u003e in 56% and \u003cem\u003epbp2x\u003c/em\u003e in 20% of resistant VGS isolates [43, 44]. While the current clinical impact of \u003cem\u003epbp2x\u003c/em\u003e may be limited, its presence is a critical warning that necessitates ongoing surveillance for rising beta-lactam resistance. The 100% susceptibility to vancomycin and linezolid confirms that these agents as reliable last line options for treatment of severe or MDR cases. However, their high cost and limited availability in Pakistan's public health sector render them inaccessible for patients from remote areas, highlights the urgent need to revise local empirical treatment guidelines and implement stringent antibiotic stewardship programs.\u003c/p\u003e\n\u003cp\u003eAlthough multivariate analysis of risk factors in present study did not identify statistically significant independent predictors, several factors showed strong epidemiological associations with VGS-IE. Prosthetic heart valve implantation was linked to a two-fold increased risk (aOR = 2.05) which is in accordance with a study from Karachi, Pakistan that identified prosthetic valve endocarditis as a complex entity with higher morbidity and mortality (OR = 3.74) [45]. The trend observed with IVDU (aOR = 1.95), although less common in our cohort remains a biologically possible risk factor due to the potential for direct inoculation of oral flora in blood stream as supported by previous literature [46].\u003c/p\u003e\n\u003cp\u003eThe high prevalence of region specific risk factors in our cohort, including limited dental care access (60%), low socioeconomic status (52%), and particularly the use of \u003cem\u003enaswar\u003c/em\u003e (46.6%), likely plays a critical role in facilitating oral colonization and subsequent bacteremia. Poor oral health is a well-established risk factor for transient streptococcal bacteremia, especially in individuals with underlying valvular damage [47]. The common practice of \u003cem\u003enaswar\u003c/em\u003e chewing a smokeless tobacco product is of particular concern in KP. Its use causes chronic mucosal irritation and damage to the oral mucosa thus disrupting the normal microflora and creating portals of entry for bacteria into the bloodstream and thereby predisposing users to infections [48, 49]. The persistently elevated, though non-significant, odds ratios for these factors in our multivariate model highlight their potential contributory role and warrant further investigation in larger, prospective studies.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eLimitations\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThis study has various limitations. Its cross-sectional design impedes causal interpretation between risk factors and outcome. Although PCR was used for gene detection, the absence of whole-genome or Sanger sequencing, which couldn’t be performed due to the resource constraints of this PhD research project that limited our ability to explore novel mutations, perform detailed phylogenetic analysis or identify undiscovered resistance mechanisms. The recruitment of participants from tertiary care centers may introduce selection bias, potentially underrepresenting community-acquired cases or those managed in rural settings. Furthermore, despite the use of combined culture and PCR diagnostics and exclusion of participants who received prior antibiotic therapy, the true burden of IE may be miscalculated due to culture-negative cases, often resulting from antecedent antibiotic therapy.\u003c/p\u003e"},{"header":"Conclusion","content":"\u003cp\u003eIn conclusion, this study offers the first comprehensive evidence from Khyber Pakhtunkhwa, Pakistan on the molecular epidemiology of VGS-IE. We report a significant disease burden characterized by considerable multidrug resistance, the genetic basis of which including the prevalence of \u003cem\u003eermB\u003c/em\u003e, \u003cem\u003emefA\u003c/em\u003e, \u003cem\u003etetM\u003c/em\u003e, \u003cem\u003etetO\u003c/em\u003e, and \u003cem\u003epbp2x\u003c/em\u003e genes is reported for the first time in clinical VGS isolates from this region. The endemicity of VGS-IE in KP appears to be driven by regional factors, including inadequate dental care, a high burden of RHD, unregulated antibiotic use, and the common practice of \u003cem\u003enaswar\u003c/em\u003e chewing. These findings emphasize at the urgent need for region-specific interventions including vigorous antibiotic stewardship programs, enhanced oral health infrastructure, and the development of context aware clinical guidelines to minimize AMR. Future research should be employ for genomic surveillance to fully explore the resistance profiles and transmission dynamics of these bacteria and to evaluate the impact of public health steps aimed at mitigating these unique, region-specific risk factors.\u003c/p\u003e"},{"header":"Declarations","content":"\u003cp\u003e\u003cstrong\u003eAuthor Contributions:\u003c/strong\u003e Conceptualization, A.K. and M.H.; methodology, A.K., S.K., and M.H.; software, A.K. and H.N.; validation, N.M., A.B., and K.J.A.; formal analysis, A.K. and K.F.A.; investigation, A.K., S.K., and H.N.; resources, M.H., S.K., and F.M.A.; data curation, A.K. and A.B.; writing and original draft preparation, A.K.; writing, review and editing, M.H., S.K., K.J.A., and F.M.A.; visualization, A.K. and K.F.A.; supervision, M.H. and S.K.; project administration, M.H.; funding acquisition, K.J.A. and F.M.A.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eAll authors have read and agreed to the published version of the manuscript.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eFunding:\u003c/strong\u003e This research was funded by Taif University, Taif, Saudi Arabia, grant number (TU-DSPP-2024-26).\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eEthics approval and consent to participate:\u0026nbsp;\u003c/strong\u003eThe study was approved by the Ethical and Research Committee of Kohat University of Science and Technology (KUST), Kohat, Pakistan (Approval No. KUST/Ethical Committee/1975, dated 02 December 2024). All procedures involving human participants were performed in accordance with the ethical standards of the institutional committee and with the Declaration of Helsinki. Written informed consent was obtained from all individual participants (or their legal guardians, where applicable) prior to sample collection.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eConsent for Publication:\u003c/strong\u003e Not applicable\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eData Availability Statement:\u003c/strong\u003e The data presented in this study is available on request from the corresponding author. The data is not publicly available due to privacy and ethical restrictions.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAcknowledgments:\u003c/strong\u003e The authors extend their sincere appreciation to Taif University, Saudi Arabia, for supporting this work through project number (TU-DSPP-2024-26). The authors are also profoundly grateful to the doctors, nurses, and laboratory staff at the participating hospitals Lady Reading Hospital (LRH), Hayatabad Medical Complex (HMC), Khyber Teaching Hospital (KTH), Peshawar Institute of Cardiology (PIC), and the district headquarters hospitals in Kohat, Hangu, Bannu, and Dera Ismail Khan for their invaluable assistance in patient recruitment and sample collection. Finally, we sincerely thank all the patients who participated in this study.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eConflicts of Interest:\u003c/strong\u003e The authors declare no conflicts of interest. The funders had no role in the design of the study; in the collection, analyses, or interpretation of data; in the writing of the manuscript; or in the decision to publish the results\u003c/p\u003e"},{"header":"References","content":"\u003col\u003e\u003cli\u003e\u003cspan\u003eCahill TJ, Prendergast BD. Infective endocarditis. 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Adv Dent Res. 2019;30(1):4\u0026ndash;10.\u003c/span\u003e\u003c/li\u003e\u003c/ol\u003e"}],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":true,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":false,"hideJournal":false,"highlight":"","institution":"","isAcceptedByJournal":true,"isAuthorSuppliedPdf":false,"isDeskRejected":"","isHiddenFromSearch":false,"isInQc":false,"isInWorkflow":false,"isPdf":false,"isPdfUpToDate":true,"isWithdrawnOrRetracted":false,"journal":{"display":true,"email":"[email protected]","identity":"bmc-microbiology","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"mcro","sideBox":"Learn more about [BMC Microbiology](http://bmcmicrobiol.biomedcentral.com/)","snPcode":"","submissionUrl":"https://www.editorialmanager.com/mcro","title":"BMC Microbiology","twitterHandle":"#bmcmicrobiology","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"em","reportingPortfolio":"BMC Series","inReviewEnabled":true,"inReviewRevisionsEnabled":true},"keywords":"Infective endocarditis, Viridans Group Streptococci, Antimicrobial resistance, Resistance genes, Risk factors, Pakistan","lastPublishedDoi":"10.21203/rs.3.rs-8071744/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-8071744/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003cp\u003e\u003cstrong\u003eBackground:\u003c/strong\u003e Infective endocarditis (IE) is a life-threatening condition caused by Viridans Group Streptococci (VGS) in low and middle-income countries. Data on epidemiology and molecular resistance mechanisms in the high-risk resource-limited setting of Khyber Pakhtunkhwa (KP), Pakistan, are scarce. This study aimed to determine the prevalence, risk factors, and molecular analysis of antimicrobial resistance in VGS isolated from IE patients in KP.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eMethods:\u003c/strong\u003e A cross-sectional study was done on 350 IE suspected patients admitted to tertiary care hospitals in KP. Blood cultures were performed and isolates were identified using standard microbiological methods followed by species confirmation via PCR (\u003cem\u003esodA, gtf, gyrB, \u003c/em\u003eand\u003cem\u003e rpoB \u003c/em\u003egenes). Antibiotic susceptibility testing was performed. Antibiotic resistance genes \u003cem\u003eermB\u003c/em\u003e, \u003cem\u003emefA\u003c/em\u003e, \u003cem\u003etetM\u003c/em\u003e, \u003cem\u003etetO\u003c/em\u003e, and \u003cem\u003epbp2x\u003c/em\u003e\u003cstrong\u003e \u003c/strong\u003ewere analyzed by PCR. Socio-demographic and clinical data were collected, and statistical analysis was performed using logistic regression.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eResults:\u003c/strong\u003e \u003cbr\u003e\nAmong the 350 suspected IE patients, 62 (17.7%) were confirmed to have VGS-IE. The \u003cem\u003eStreptococcus mitis\u003c/em\u003e group was the predominant species (41.9%) followed by \u003cem\u003eS. sanguinis\u003c/em\u003e (19.4%), and the \u003cem\u003eS. anginosus\u003c/em\u003e group (16.1%). A high prevalence of penicillin non-susceptibility (25.8%), alongside high resistance to erythromycin (40.3%) and tetracycline (32.3%) was observed. 38.7% of isolates were multidrug-resistant. Genotypic analysis confirmed a high prevalence of the resistance determinants \u003cem\u003epbp2x\u003c/em\u003e (in penicillin-resistant isolates), \u003cem\u003eermB\u003c/em\u003e (40.3%), and \u003cem\u003etetM\u003c/em\u003e (32.3%). The high prevalence of region-specific risk factors, including limited access to dental care (60.0%) and use of smokeless tobacco (\u003cem\u003enaswar\u003c/em\u003e) (46.6%) was recorded. No significant independent risk factors were found by multivariate analysis, however, prosthetic heart valve implantation (aOR=2.05, 95% CI: 0.74–5.67) and prior antibiotic use (aOR=1.35, 95% CI: 0.64–2.86) showed elevated risks.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eConclusion:\u003c/strong\u003e This is the first comprehensive study from KP that demonstrates the high prevalence of VGS-IE with considerable multidrug resistance confirmed for genetic determinants. These findings emphasized the urgent need for improved antimicrobial stewardship, access to better dental care, and the integration of region-specific risk factors into preventive strategies to mitigate the burden of IE in regions with low-income settings.\u003c/p\u003e","manuscriptTitle":"High Burden of Viridans Streptococcal Endocarditis Linked to Multidrug Resistance and Regional Risk Factors: First Report From Khyber Pakhtunkhwa, Pakistan","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2025-12-08 12:48:26","doi":"10.21203/rs.3.rs-8071744/v1","editorialEvents":[{"type":"communityComments","content":0},{"type":"decision","content":"Revision requested","date":"2025-12-08T07:47:48+00:00","index":"","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2025-12-07T20:15:01+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"312806097488195681255264904285263806143","date":"2025-12-07T12:04:23+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"62716672695607914232437958357997519233","date":"2025-12-07T07:34:51+00:00","index":"hide","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2025-12-05T11:53:36+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"212736832325373048424042210032944300006","date":"2025-12-04T14:30:25+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"120613576453142210592625174601530779051","date":"2025-12-04T14:22:58+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"211134620898241821780673905009078735408","date":"2025-12-04T09:15:24+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"152938859280545256013040306645954649424","date":"2025-12-04T08:17:49+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"46512173263127342271572782368759646700","date":"2025-12-04T08:15:39+00:00","index":"hide","fulltext":""},{"type":"reviewersInvited","content":"","date":"2025-12-04T08:10:20+00:00","index":"","fulltext":""},{"type":"editorAssigned","content":"","date":"2025-12-04T08:07:50+00:00","index":"","fulltext":""},{"type":"editorInvited","content":"","date":"2025-11-20T04:47:00+00:00","index":"","fulltext":""},{"type":"checksComplete","content":"","date":"2025-11-20T04:29:33+00:00","index":"","fulltext":""},{"type":"submitted","content":"BMC Microbiology","date":"2025-11-20T04:26:18+00:00","index":"","fulltext":""}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"bmc-microbiology","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"mcro","sideBox":"Learn more about [BMC Microbiology](http://bmcmicrobiol.biomedcentral.com/)","snPcode":"","submissionUrl":"https://www.editorialmanager.com/mcro","title":"BMC Microbiology","twitterHandle":"#bmcmicrobiology","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"em","reportingPortfolio":"BMC Series","inReviewEnabled":true,"inReviewRevisionsEnabled":true}}],"origin":"","ownerIdentity":"4bd8b8cd-f531-458d-85bf-12d1e940a52d","owner":[],"postedDate":"December 8th, 2025","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"published-in-journal","subjectAreas":[],"tags":[],"updatedAt":"2026-01-12T16:01:19+00:00","versionOfRecord":{"articleIdentity":"rs-8071744","link":"https://doi.org/10.1186/s12866-025-04648-3","journal":{"identity":"bmc-microbiology","isVorOnly":false,"title":"BMC Microbiology"},"publishedOn":"2026-01-08 15:57:29","publishedOnDateReadable":"January 8th, 2026"},"versionCreatedAt":"2025-12-08 12:48:26","video":"","vorDoi":"10.1186/s12866-025-04648-3","vorDoiUrl":"https://doi.org/10.1186/s12866-025-04648-3","workflowStages":[]},"version":"v1","identity":"rs-8071744","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-8071744","identity":"rs-8071744","version":["v1"]},"buildId":"8U1c8b4HqxoKbykW_rLl7","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}