Emergence of β-Lactamase Mediated Resistance among Enterobacterales: A Phenotypic Study from a Tertiary Care Hospital

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The increasing emergence of β-lactamase–mediated resistance, particularly extended-spectrum β-lactamases (ESBL), AmpC and carbapenemases, has significantly reduced the effectiveness of commonly used antibiotics and poses a major challenge for clinical management. Objective This study was conducted to determine the distribution of Enterobacterales isolated from clinical specimens as well as evaluate the frequency of ESBL, AmpC & carbapenemase production using phenotypic detection methods. Methods This study was carried out in the Department of Microbiology at Maharishi Markandeshwar Medical College and Hospital, Solan, India, from August 2024 to July 2025. A total of 486 Enterobacterales isolates obtained. Identification and AST were performed according to standard laboratory procedures and CLSI guidelines. Phenotypic methods were used to detect β-lactamase production, including the double-disk synergy test for ESBL detection, boronic acid inhibition test for AmpC detection, Modified Carba NP test for carbapenemase detection and imipenem-EDTA synergy test for metallo-β-lactamase (MBL) detection. Results Among the 486 isolates, E-coli (331) was the most frequently isolated organism, followed by Klebsiella species (87) and Citrobacter species (47). Urine was the most common clinical specimen from which isolates were obtained. Phenotypic analysis showed that 38% of isolates produced ESBL, 27% produced AmpC β-lactamase, and 17% demonstrated carbapenemase activity. Additionally, metallo-β-lactamase production was detected in 14% of isolates. A considerable proportion of isolates also exhibited multidrug resistance, particularly among Escherichia coli and Klebsiella species. Conclusion The study highlights a substantial prevalence of β-lactamase–mediated resistance among Enterobacterales in the studied healthcare setting. The presence of ESBL, AmpC, and carbapenemase-producing isolates emphasizes the need for routine laboratory detection, continuous surveillance, effective antimicrobial stewardship, and strict infection control measures to limit the spread of resistant pathogens. Health sciences/Diseases Health sciences/Health care Biological sciences/Microbiology MCNP ESBL MBL Carbapenemase Figures Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 Introduction Enterobacterales are the most significant cause of hospital acquired as well as community acquired infection across the world. Member of Enterobacterales are in order ie. Escherichia coli, Klebsiella species, Enterobacter species, Citrobacter species and Proteus species, are frequently causing infections such as UTIs, BSIs, wound infections, neonatal meningitis and intra-abdominal infections [ 1 ]. The irrational use of antibiotics in clinical settings as well as agriculture settings has enhanced the emergence & propagation of antimicrobial resistance within the organisms that leads to serious threat to global health [ 2 ]. The common mechanism of antimicrobial resistance among Enterobacterales are efflux pump, modification of target binding sites, genetic mechanism and the major mechanism to lead the resistance of antimicrobial agents and are emerged through production of Beta lactamase enzyme which hydrolyze Beta lactam antibiotics causes therapeutic failure. Extended spectrum beta lactamase are mediated by plasmid and those have ability to deactivating the 3rd generation of cephalosporins along with monobactams & are only susceptible against clavulanic acid. Widely spread of ESBL producing Enterobacterales has significantly limited the effectiveness of commonly prescribed cephalosporins has led to increased reliance on carbapenem as las resort of drugs [ 3 ]. AmpC β-lactamases is also amongst the crucial types of resistant mechanism, thus enzymes confers the resistance to broad spectrum of β-lactam antibiotic, includes penicillin & cephamycin and they are not overcome by β-lactamase inhibitors. Production of AmpC may occurs either chromosomally and plasmid mediated that facilitating horizontal gene transfer among bacterial species. Carrying of AmpC enzyme by bacteria leads to complication in routine laboratory detection and causes therapeutic failure [ 4 ]. Carbapenem resistant Enterobacterales induced due by carbapenemase enzymes are serious concern due to their ability to hydrolyse carbapenem, which are used as last resort of drug against treatment of MDR Enterobacterales. Carbapenemase producing Enterobacterales harbour enzyme ie. Klebsiella pneumoniae carbapenemase (KPC), New Delhi metallo-β-lactamase (NDM), Verona integron-encoded metallo-β-lactamase (VIM), imipenemase (IMP) and oxacillinase-48 (OXA-48). These enzymes are frequently carried on mobile genetic elements, enabling rapid dissemination across healthcare facilities and geographic regions. Infections caused by carbapenemase producers are associated with limited therapeutic options, higher mortality rates, prolonged hospitalization, and increased healthcare costs [ 5 ]. Accurate detection of β-lactamase production among Enterobacterales is essential for appropriate antimicrobial therapy and infection control. Although molecular techniques provide definitive identification of resistance genes, phenotypic methods remain widely used in routine microbiology lab because of their cost-effectiveness, accessibility and capability to reflect functional enzyme activity. Phenotypic detection of β-lactamases in Enterobacterales is routinely performed in clinical microbiology laboratories using inhibitor-based and hydrolysis-based assays that demonstrate functional enzyme activity. ESBL production is typically identified by screening for reduced susceptibility to third-generation cephalosporins and confirmation with combination disk tests or double-disk synergy tests showing clavulanic acid–mediated enhancement of inhibition zones. AmpC β-lactamases are suspected in cefoxitin-resistant isolates and confirmed using boronic acid inhibition tests or AmpC disk tests, as these enzymes are not inhibited by clavulanate. Carbapenemase production is screened by decreased susceptibility to carbapenems and confirmed by assays such as mCIM, EDTA-based synergy tests for metallo-β-lactamases, or rapid biochemical tests like the Carba NP test. Although phenotypic methods are cost-effective and suitable for routine use, interpretation may be challenging in isolates co-producing multiple β-lactamases [ 6 ]. The prevalence of ESBL, AmpC and carbapenemase production among Enterobacterales varies widely across regions and healthcare settings, influenced by antibiotic usage patterns, infection control practices, and local epidemiology. In low- and middle-income countries, the burden of these resistant pathogens is especially high. Continuous surveillance, accurate laboratory detection, molecular characterization and implementation of antimicrobial stewardship and infection prevention policies are critical to stop their spread [ 6 ]. Understanding the epidemiology and distribution of ESBL, AmpC and carbapenemase-producing Enterobacterales is essential for guiding empirical therapy, informing public health policies, and developing targeted interventions to combat antimicrobial resistance [ 7 ]. Methodology Study settings and data collection It was carried out in the department of Microbiology, MMMC&H, Solan, India, after obtaining ethical clearance from the Institutional Ethics Committee, MMMC&H (MMMCH/IEC/23/589). All methods were performed in accordance with the relevant guidelines and regulations. Written informed consent was obtained from all participants or their legally authorized representatives before inclusion in the study after explaining the study objectives and procedures. Data availability The database generated and analyzed during the present study are available from corresponding author upon reasonable request. The study was done in department of Microbiology, MMMCH in MMU, Kumarhatti Solan, Study was performed during Aug 2024 to July 2025. A total 486 enterobacterales obtained from various clinical specimens in bacteriology section. All the isolates were further proceeded as per routine standard guidelines and followed by performed AST as provided by CLSI guidelines. The drug-resistant isolates were further performed for phenotypic confirmation of ESBLs, AMPC and Carbapenemase by several method as shown in Fig. 1 [ 8 ]. Phenotypic confirmation of clinical isolates ESBLs detection This method is based upon ability of clavulanic acid which as beta lactamase inhibitor to inhibit ESBLs enzymes. When an ESBL producing isolate were tested, an enhance zone was observed between a cephalosporin disk and a disk containing amoxycillin-clavulanate due to synergistic activity. Disk containing cefotaxime 30µm and ceftazidime 30µm are used, additionally disk contain the same antibiotics combined with clavulanic acid 10 µg. After the incubation, measuring of zone size were done. If the organism produces ESBLs, clavulanic acid blocks the enzyme’s action, allowing the antibiotic to work more effectively. This results in a larger inhibition zone around the combined disk. A ˃5mm or more in the zone diameter compared with the antibiotic alone is as interpretated as confirmation of ESBL production as shown in Fig. 2 [ 6 ]. AmpC detection: Routinely used technique for the detection of AmpC among gram negative bacteria is boronic acid method. In this method, a cefoxitin 30µm disk was tested alone and alongside a cefoxitin disc combined with phenylboronic acid, which acts as an AmpC enzyme inhibitor followed by incubation. After the incubation inhibition zone was compared. If the organisms produced AmpC β-lactamases, the boronic acid inhibits enzyme and enhance the activity of cefoxitin, resulting in an increases of 5mm or more in the inhibitory size around combination disk compared to cefoxitin only, this increase zone size confirms production of AmpCs as shown in Fig. 3 [ 6 ]. Detection of Carbapenemase Rapid Carbapenemase detction The MCNP test is a rapid phenotypic method used to identify carbapenemase-producing Enterobacterales. It works by detection of hydrolysed carbapenem ring. In this test a bacterial suspension is mixed with a solution containing the antibiotic and a pH indicator such as phenol red. If the organism produces carbapenemase, the drug is hydrolysed that leads to formation of acid byproducts. this lowers the pH of solution and cause a visible color shift from red to yellow or orange colour. If no enzyme is present, the colour remains unchanged. This test provides a quick and reliable way to confirm carbapenemase as shown in Fig. 4 [ 9 ]. MBL detection The IMP-EDTA method is a phenotypic test which is used to detect metallo- β-lactamases production in bacteria. This method is based on the principle in which MBL enzyme requires zinc ions for their activity and EDTA acts as a chelating agent that binds zinc, thereby inhibiting the enzyme. In the procedure, two disk are placed IPM and IPM+ EDTA kept it for incubation. After the incubation aones are measure, an increase of 7mm or more in the size diameter around I + E as compared to IPM indicates as MBL production as shown in Fig. 5 [ 9 ]. Results Total number of Enterobacterales obtained among all the clinical isolates were 486 and the distribution are as follows 331 were Escherichia coli followed by Klebsiella species 87, Citrobacter species 47, Proteus species 09, Enterobacter species 08, Salmonella Typhi 02 and 01 Serratia species & Morganella species . Among the 486 Enterobacterales clinical isolates, phenotypic screening revealed that presence of 38% exhibited ESBL production, 27% were AmpC producers and 17% demonstrated carbapenemase production. Also this study observed co-production of ESBL along with AmpC were14%. Collectively, these findings indicate that although β-lactamase mediated resistance remains a significant challenge among Enterobacterales in this clinical setting, the prevalence of ESBLs, AmpC and carbapenemases in our study is emphasizing the need for ongoing surveillance and tailored antibiotic policies. Table 1 Distribution of Enterobacterales among various clinical specimens. Enterobacterales Urine Pus/Swab Blood Sputum HVS Fluid Others Total E. coli 226 72 3 8 14 2 8 331 Klebsiella oxytoca 6 5 – 3 1 – – 14 Klebsiella pneumoniae 23 21 5 11 5 1 9 73 Citrobacter spp. 15 18 2 7 2 – 4 47 Enterobacter spp. 3 2 3 – – – 1 8 Proteus spp. 3 6 – – 1 – – 9 Salmonella spp. 1 – 2 – – – – 2 Serratia spp. 1 – – – – – 1 1 Morganella spp. 1 1 – – – – – 1 Total 276 122 13 28 23 3 21 486 Table 1 : illustrates maximum number of Enterobacterales isolates were obtained from urine specimens (276) followed by pus or swab (122) and lowest isolates were obtained from blood & body fluids. Maximum number of isolates was E coli (331) followed by Klebsiella species (87), Citrobacter species (47), Proteus (09) species, Enterobacter species (08) salmonella species (02) and Serratia species Morganella species were (01). Table 2 Prevalence of multidrug resistance among Enterobacterale isolates. Enterobacterales MDR XDR Escherichia coli (331) 142(43%) 35(10%) Klebsiella species (87) 49(56%) 18(20%) Citrobacter species (47) 6(12%) 01(2%) Enterobacter species (08) 01(12.5%) 00 Salmonella species (02) 01(50%) 00 Proteus species (09) 01(11%) 00 Serratia & Morganella species(01) 00 00 Table 2 : illustrates a total 485 enterobacterale isolates were evaluated for antimicrobial resistance, among these Escherichia coli (331) was showed highest resistance ie 142 isolates were MDR and 35 isolates were XDR, indicating a significant burden of antimicrobial resistance in this organism. Followed by Klebsiella species were showed 49 isolates were MDR and 18 were XDR, showing a considerable proportion of resistant strains. Among the Citrobacter species 6 were MDR and 1 were XDR, indicating relatively lower resistance as compared to E coli & Klebsiella. Enterobacter, Proteus and Salmonella species showed 01 MDR and no XDR isolates. Table 3 Distribution of ESBL, AmpC, Carbapenemase and MBL producers among Enterobacterales. Enterobacterales ESBL AmpC MCNP MBLs Escherichia coli (331) 128 94 43 34 Klebsiella species (87) 42 30 29 28 Citrobacter species (47) 09 05 04 02 Enterobacter species (08) 03 02 02 02 Salmonella species (02) - - - - Proteus species (09) - - - - Serratia & Morganella species(01) - - - - Total 484 182 131 78 66 Table 3 : Illustrate maximum number of ESBLs producing bacteria was E coli 128, 94 AmpC,43 MCNP and 34 MBL producers. This was followed by Klebsiella species which had 42 ESBLs,30 AmpCs, 29 MCNP and 28 MBL producers. Citrobacter species showed 9ESBLs,5AmpC, 4MCNP and 2 MBL producers while Enterobacter species had 3 ESBL, 2AmpC, 2 MCNP and 2MBL producers. No resistance mechanism were detected among Salmonella, Proteus, Serratia/ Morganella isolates. Overall the phenotypic methods detected 182 ESBL, 131 AmpC, 78 MCNP and 66 MBL producers with E coli contributing the largest proportion. Table 4 Distribution of Enterobacterales on the basis of gender and CA-HA infections. Gender Community-acquired infections Hospital-acquired infections Total Male 122 90 212 Female 176 98 274 Total 298 188 486 Table 4 : illustrates the distribution of Enterobacterales infections according to gender and type of acquisition. Among the 486 isolates community acquired infections were more common in females ie.176 than in males 122. Hospital acquired infections were observed in both genders, with a slightly higher number in females 98 compared to males 90. Overall community acquired infections are more frequent infections 188. Discussion Enterobacterales represent a major group of GN isolates accountable for wide spectrum of infections among both community as well as healthcare settings. These isolates are recurrently implicated among UTIs, BSIs, respiratory infections, wound infections and intra-abdominal infections. Over the past two decades, the rapid emergence & distribution of AMR among Enterobacterales has become a serious public health challenge. Resistance mechanisms mediated by β-lactamases, particularly ESBLs, AmpC and carbapenemases, have significantly compromised the effectiveness of commonly used antibiotics. The present study meant to obtained the distribution of Enterobacterales isolated among clinical specimens and to assess the occurrence of important β-lactamase–mediated resistance mechanisms using phenotypic methods in a tertiary care hospital [ 10 ]. In present investigation, total 486 Enterobacterales isolates were recovered from several clinical specimens. Among these, E-coli was major isolate, accounting for the majority of cases, followed by Klebsiella species and Citrobacter species. This distribution pattern is consistent with findings reported in many clinical microbiology studies where E. coli remains the most commonly isolated Enterobacterales member. The predominance of E. coli can largely be attributed to its role as a leading causative agent of UTIs and other community-acquired infections. In this study, the largest isolates were obtained from urine samples, further supporting the well-established association between E. coli and UTIs. The second most isolates were Klebsiella species, which are known to be significant pathogens in hospital-acquired infections including pneumonia, septicemia, and wound infections as shown in Table 1 [ 11 ]. The analysis of specimen distribution demonstrated that urine samples contributed the largest proportion of isolates, followed by pus or wound swabs, while blood and body fluids accounted for a smaller proportion. This pattern reflects the clinical prevalence of urinary tract infections and soft tissue infections in healthcare settings. Previously a similar study have been reported where urine was identified as the most common source of Enterobacterales isolates. The recovery of isolates from multiple specimen types also indicates the wide clinical spectrum of infections caused by these organisms [ 12 ] . This study revealed a considerable load of AMR among Enterobacterales isolates. A significant proportion of isolates exhibited MDR, particularly among Ecoli and Klebsiella species. The occurrence of MDR among E. coli was 43%, while Klebsiella species showed an even higher proportion of MDR isolates at 56%. Additionally, extensively drug-resistant (XDR) strains were identified, with Klebsiella species demonstrating a higher percentage compared to other organisms as shown in Table 2 . The higher resistance observed in Klebsiella species may be due to their ability to acquire and maintain multiple resistance determinants through plasmids, transposons, and integrons. The emergence of MDR and XDR strains significantly limits treatment choices and upsurges the chance of therapeutic failure, prolonged hospital stay & increased healthcare costs. One of the major objectives of this study was to evaluate the phenotypic occurrence of ESBLs production among Enterobacterales strains. The results demonstrated that ESBL was produced by 182 isolates, representing approximately 38% of the total isolates. The maximum ESBL-producing isolates was observed in Escherichia coli , followed by Klebsiella species and findings are in concordance with Sageerabanoo S et al reports that have identified E. coli and Klebsiella pneumoniae as the most common ESBL-producing organisms worldwide. ESBL enzymes are capable of hydrolyzing a wide range of β-lactam antibiotics, including third-generation cephalosporins and monobactams, which are frequently used in clinical practice. The rising occurrence of ESBL-producing organisms has therefore led to a reduction in the effectiveness of these antibiotics and has increased reliance on carbapenems for treatment [ 13 ]. In addition to ESBL production, AmpC β-lactamase production was also observed among a majority of isolates in this study. AmpC enzymes converse resistance to a broad spectrum of β-lactam antibiotics, including penicillins, cephalosporins and cephamycins, unlike ESBLs, they are not inhibited by β-lactamase inhibitors such as clavulanic acid. In the present study, 131(27%) isolates were identified as AmpC producers, with the majority being Escherichia coli followed by Klebsiella species. This study was concordance with Peter, J.A et al. ie 44.8%The detection of AmpC enzymes is particularly important because these enzymes can be either chromosomally encoded or plasmid-mediated, allowing for horizontal transfer between bacterial species. Furthermore, AmpC-producing organisms may appear susceptible to certain cephalosporins during routine susceptibility testing, which may lead to inappropriate antibiotic therapy if not properly detected [ 14 ]. Another significant finding of present study was the detection of carbapenemase production from Enterobacterales isolates. Carbapenems are considered outmost effective group of antibiotics for the therapy of MDRGNB. However, the emergence of CPE has become a major concern for global health. In current study, carbapenemase production was detected in 78 (16%) isolates using the Modified Carba NP test this study was concordance with Kumar A et al. showed prevalence of Carbapenemase among Enterobacterales were 150 (15.4%) by MCNP method. Among these, a large proportion were identified as metallo-β-lactamase (MBL) producers through the imipenem-EDTA synergy test. MBL zinc ions for enzymatic activity and are accomplished of hydrolyzing nearly all β-lactam antibiotics, including carbapenems as shown in Table 3 [ 9 ]. The detection of MBL production in 66 (14%) isolates indicates the growing presence of carbapenem resistance in the clinical setting this study was concordance with Kumar A et al. showed (13%) of MBL among total enterobacterales isolates. The majority of carbapenemase producers in this study were Escherichia coli and Klebsiella species, which are known to harbour carbapenemase genes ie. NDM, VIM, IMP and OXA-48. The presence of enzymes poses a serious therapeutic challenge because infections caused by such isolates are accompanying with inadequate treatment options increased mortality. The dissemination of carbapenemase genes through mobile genetic elements ie. plasmids & integrons further facilitates the quick spread of resistance within hospitals and across geographical regions as shown in hospital 4[ 9 , 15 ]. In this study the occurrence of multiple β-lactamase mechanisms within the same bacterial population. The co-existence of ESBL & AmpC enzymes in certain isolates indicates the complication of resistant mechanisms among Enterobacterales. The presence of multiple resistance determinants can complicate phenotypic detection and may lead to underestimation of resistance if appropriate tests are not performed. Therefore, routine laboratory screening for β-lactamase production is essential for accurate detection and appropriate antimicrobial therapy [ 16 ]. The phenotypic methods used in this study, including the double-disk synergy test for ESBL detection, boronic acid inhibition test for AmpC detection, Modified Carba NP test for carbapenemase detection and imipenem-EDTA synergy test for MBL detection, proved to be effective and practical for routine use in clinical microbiology laboratories. These methods are relatively inexpensive, simple to perform, and suitable for laboratories with limited access to molecular diagnostic facilities. Although molecular techniques provide definitive identification of resistance genes, phenotypic assays remain valuable tools for the functional detection of enzyme activity in resource-limited settings [ 17 , 18 , 19 ]. The current study highlights crucial need for continuous monitoring of antimicrobial resistance among Enterobacterales. The high occurrence of ESBL, AmpC and carbapenemase producers emphasizes the importance of implementing effective antimicrobial stewardship programs to promote rational antibiotic use. Additionally, strict infection control procedures such as hand hygiene, surveillance cultures, isolation precautions should be executed to avoid the spread of resistant organisms within healthcare facilities. Thus integrating molecular methods such as PCR & sequencing would help in identifying the exact resistance genes and understanding their epidemiological distribution [ 20 , 21 ]. Overall, the results of this study demonstrate that β-lactamase-mediated resistance is widely prevalent among Enterobacterales isolates in the studied healthcare setting. The predominance of ESBL producers, along with the increasing occurrence of AmpC and carbapenemase-producing isolates, highlights the growing challenge of antimicrobial resistance. Continuous surveillance, accurate laboratory detection, rational antibiotic prescribing, and effective infection control strategies are essential to limit the spread of these resistant pathogens and improve clinical outcomes. Limitation Current study as several limitation which considered while interpretation of the findings. The current observation was obtained in only a tertiary care hospital while that can reduce the generalizability of the outcomes to other healthcare settings or geographic regions. Second, the detection of beta lactamases production was based only on phenotypic methods, molecular technique such as PCR were not performed to identify specific resistance genes. Additionally detailed clinical data and patient risk factors associated with resistant infections were not analyzed, despite these limitations, this observation showed valuable perception into the occurrence of ESBL, AmpC and carbapenemase producing Enterobacterales in the studied healthcare sittings. Declarations Acknowledgement The authors would like to thank the Department of Microbiology and the laboratory staff of the study institution for their technical assistance and support during sample collection, processing and analysis. We also extend our sincere gratitude to all participants involved in this study Conflict of Interest There is no conflicts of interest among authors regarding the given manuscript. Funding The author declare that no financial support was received for the conduct of this study. Consent for publication All authors have read and approved the final version of the manuscript and consent to its publication, all author agree to submission and take responsibility for the consent of the manuscript. Ethical declaration It was carried out in the department of Microbiology, Maharishi Markandeshwar Medical College and Hospital, Solan, India, after obtaining ethical clearance from the Institutional Ethics Committee, Maharishi Markandeshwar Medical College and Hospital (MMMCH/IEC/23/589). Data availability The database generated and analyzed during the present study are available from corresponding author upon reasonable request. All methods were performed in accordance with the relevant guidelines and regulations Author contribution Manika Sharma : Conceptualization, Methodology, Investigation, Data Curation, Formal Analysis, Supervision, Writing – Review & Editing. Ajay kumar : Methodology, Investigation, Data Curation, Formal Analysis, Writing. References Guentzel, M. N. & Escherichia Klebsiella, Enterobacter, Serratia, Citrobacter, and Proteus. In: Baron S, editor. Medical Microbiology. 4th edition. Galveston (TX): University of Texas Medical Branch at Galveston; Chapter 26. 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Khadse, S. N., Ugemuge, S. & Singh, C. Impact of Antimicrobial Stewardship on Reducing Antimicrobial Resistance. Cureus 15 (12), e49935. 10.7759/cureus.49935 (2023). PMID: 38179391; PMCID: PMC10765068. Additional Declarations No competing interests reported. Cite Share Download PDF Status: Posted Version 1 posted 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. As a division of Research Square Company, we’re committed to making research communication faster, fairer, and more useful. We do this by developing innovative software and high quality services for the global research community. Our growing team is made up of researchers and industry professionals working together to solve the most critical problems facing scientific publishing. Also discoverable on Platform About Our Team In Review Editorial Policies Advisory Board Help Center Resources Author Services Accessibility API Access RSS feed Manage Cookie Preferences © Research Square 2026 | ISSN 2693-5015 (online) Privacy Policy Terms of Service Do Not Sell My Personal Information {"props":{"pageProps":{"initialData":{"identity":"rs-9358923","acceptedTermsAndConditions":true,"allowDirectSubmit":true,"archivedVersions":[],"articleType":"Article","associatedPublications":[],"authors":[{"id":627883210,"identity":"f79a7bd4-f96f-4162-bbc9-057f02bfc2d5","order_by":0,"name":"Manika Sharma","email":"","orcid":"","institution":"Maharishi Markandeshwar University, Mullana","correspondingAuthor":false,"prefix":"","firstName":"Manika","middleName":"","lastName":"Sharma","suffix":""},{"id":627883211,"identity":"eeda4b39-b255-4e05-b55f-4b079d4116c9","order_by":1,"name":"Ajay kumar","email":"data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAZAAAAAyAQMAAABI0h/eAAAABlBMVEX///8AAABVwtN+AAAACXBIWXMAAA7EAAAOxAGVKw4bAAABBklEQVRIie3RMUvEMBjG8ZRCl0vpmlCoX+E9AwFRua/SUHHyQHE9MFLJdDi3030GEZxbAplEV6UgBw6udXM4PKOO2nBuDvnP+RF4H4R8vn9YRIr2eQV7OEnKdtnPNN6qUNC/qmGSEFMAPj7MaGWKcWVesoigkNZ3w4TWc05wrxk0RzyN5ZpZEo3i92ECHWZAIBSyueXpvuyEsiSMbxzkKTpZAkTivFSnu9PNSHgNOWBRIn3VTS83IJMOcdIAEQrlkO4offZNHBeDxwtOJQDD6GA7DZT++mXkJA+mYAjyjNhrj+fmkwQlrZ3ETolWazy5t1O+zbRYLHTrnPK3Avm39z6fz+f70QfX7132lmC2SgAAAABJRU5ErkJggg==","orcid":"","institution":"Maharishi Markandeshwar University, Mullana","correspondingAuthor":true,"prefix":"","firstName":"Ajay","middleName":"","lastName":"kumar","suffix":""}],"badges":[],"createdAt":"2026-04-08 15:27:07","currentVersionCode":1,"declarations":"","doi":"10.21203/rs.3.rs-9358923/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-9358923/v1","draftVersion":[],"editorialEvents":[],"editorialNote":"","failedWorkflow":false,"files":[{"id":107662912,"identity":"a938d8dc-e39e-4c5f-8183-601637529e36","added_by":"auto","created_at":"2026-04-23 17:40:53","extension":"png","order_by":1,"title":"Figure 1","display":"","copyAsset":false,"role":"figure","size":583914,"visible":true,"origin":"","legend":"\u003cp\u003epresence of gram negative bacilli with no specific arrangement.\u003c/p\u003e","description":"","filename":"1.png","url":"https://assets-eu.researchsquare.com/files/rs-9358923/v1/8d9bc4c9f88ffefcc37a7add.png"},{"id":107708079,"identity":"43401bcf-788e-48b3-a2b6-c26dff508a1c","added_by":"auto","created_at":"2026-04-24 09:21:51","extension":"png","order_by":2,"title":"Figure 2","display":"","copyAsset":false,"role":"figure","size":428214,"visible":true,"origin":"","legend":"\u003cp\u003eESBL detection by double disc diffusion method\u003c/p\u003e","description":"","filename":"2.png","url":"https://assets-eu.researchsquare.com/files/rs-9358923/v1/50984db86cf2f1a530e6f133.png"},{"id":107662913,"identity":"b8504bed-cb14-4498-a5c5-372ccfb74e8d","added_by":"auto","created_at":"2026-04-23 17:40:53","extension":"png","order_by":3,"title":"Figure 3","display":"","copyAsset":false,"role":"figure","size":561771,"visible":true,"origin":"","legend":"\u003cp\u003eAmpC detection by cefoxitin-cloxacillin method\u003c/p\u003e","description":"","filename":"3.png","url":"https://assets-eu.researchsquare.com/files/rs-9358923/v1/86a346a3606fd8ede7ca27e0.png"},{"id":107707418,"identity":"3bd35626-2d45-41fa-ac4e-152ead664d2c","added_by":"auto","created_at":"2026-04-24 09:20:15","extension":"png","order_by":4,"title":"Figure 4","display":"","copyAsset":false,"role":"figure","size":538173,"visible":true,"origin":"","legend":"\u003cp\u003eModified carbaNP test for the detection of carbapenemase eznyme\u003c/p\u003e","description":"","filename":"4.png","url":"https://assets-eu.researchsquare.com/files/rs-9358923/v1/63a29bc0b16d53e8bcbe6db9.png"},{"id":107662915,"identity":"0e163d19-d2b8-49c5-960f-bad17ba51d98","added_by":"auto","created_at":"2026-04-23 17:40:53","extension":"png","order_by":5,"title":"Figure 5","display":"","copyAsset":false,"role":"figure","size":219222,"visible":true,"origin":"","legend":"\u003cp\u003eIPM+EDTA method for the detection of MBL.\u003c/p\u003e","description":"","filename":"5.png","url":"https://assets-eu.researchsquare.com/files/rs-9358923/v1/f633619190b06c6049c57ce7.png"},{"id":108492616,"identity":"d44ee8f8-b197-4153-829c-e7e224c13201","added_by":"auto","created_at":"2026-05-05 09:58:11","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":3329808,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-9358923/v1/656c5725-796d-4d37-9b3e-a6d85965acf0.pdf"}],"financialInterests":"No competing interests reported.","formattedTitle":"Emergence of β-Lactamase Mediated Resistance among Enterobacterales: A Phenotypic Study from a Tertiary Care Hospital","fulltext":[{"header":"Introduction","content":"\u003cp\u003eEnterobacterales are the most significant cause of hospital acquired as well as community acquired infection across the world. Member of Enterobacterales are in order ie. \u003cem\u003eEscherichia coli, Klebsiella species, Enterobacter species, Citrobacter\u003c/em\u003e species and \u003cem\u003eProteus\u003c/em\u003e species, are frequently causing infections such as UTIs, BSIs, wound infections, neonatal meningitis and intra-abdominal infections [\u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e]. The irrational use of antibiotics in clinical settings as well as agriculture settings has enhanced the emergence \u0026amp; propagation of antimicrobial resistance within the organisms that leads to serious threat to global health [\u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2\u003c/span\u003e].\u003c/p\u003e \u003cp\u003eThe common mechanism of antimicrobial resistance among Enterobacterales are efflux pump, modification of target binding sites, genetic mechanism and the major mechanism to lead the resistance of antimicrobial agents and are emerged through production of Beta lactamase enzyme which hydrolyze Beta lactam antibiotics causes therapeutic failure. Extended spectrum beta lactamase are mediated by plasmid and those have ability to deactivating the 3rd generation of cephalosporins along with monobactams \u0026amp; are only susceptible against clavulanic acid. Widely spread of ESBL producing Enterobacterales has significantly limited the effectiveness of commonly prescribed cephalosporins has led to increased reliance on carbapenem as las resort of drugs [\u003cspan citationid=\"CR3\" class=\"CitationRef\"\u003e3\u003c/span\u003e].\u003c/p\u003e \u003cp\u003eAmpC β-lactamases is also amongst the crucial types of resistant mechanism, thus enzymes confers the resistance to broad spectrum of β-lactam antibiotic, includes penicillin \u0026amp; cephamycin and they are not overcome by β-lactamase inhibitors. Production of AmpC may occurs either chromosomally and plasmid mediated that facilitating horizontal gene transfer among bacterial species. Carrying of AmpC enzyme by bacteria leads to complication in routine laboratory detection and causes therapeutic failure [\u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e4\u003c/span\u003e].\u003c/p\u003e \u003cp\u003eCarbapenem resistant Enterobacterales induced due by carbapenemase enzymes are serious concern due to their ability to hydrolyse carbapenem, which are used as last resort of drug against treatment of MDR Enterobacterales. Carbapenemase producing Enterobacterales harbour enzyme ie. Klebsiella pneumoniae carbapenemase (KPC), New Delhi metallo-β-lactamase (NDM), Verona integron-encoded metallo-β-lactamase (VIM), imipenemase (IMP) and oxacillinase-48 (OXA-48). These enzymes are frequently carried on mobile genetic elements, enabling rapid dissemination across healthcare facilities and geographic regions. Infections caused by carbapenemase producers are associated with limited therapeutic options, higher mortality rates, prolonged hospitalization, and increased healthcare costs [\u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e5\u003c/span\u003e].\u003c/p\u003e \u003cp\u003eAccurate detection of β-lactamase production among Enterobacterales is essential for appropriate antimicrobial therapy and infection control. Although molecular techniques provide definitive identification of resistance genes, phenotypic methods remain widely used in routine microbiology lab because of their cost-effectiveness, accessibility and capability to reflect functional enzyme activity.\u003c/p\u003e \u003cp\u003ePhenotypic detection of β-lactamases in Enterobacterales is routinely performed in clinical microbiology laboratories using inhibitor-based and hydrolysis-based assays that demonstrate functional enzyme activity. ESBL production is typically identified by screening for reduced susceptibility to third-generation cephalosporins and confirmation with combination disk tests or double-disk synergy tests showing clavulanic acid\u0026ndash;mediated enhancement of inhibition zones. AmpC β-lactamases are suspected in cefoxitin-resistant isolates and confirmed using boronic acid inhibition tests or AmpC disk tests, as these enzymes are not inhibited by clavulanate. Carbapenemase production is screened by decreased susceptibility to carbapenems and confirmed by assays such as mCIM, EDTA-based synergy tests for metallo-β-lactamases, or rapid biochemical tests like the Carba NP test. Although phenotypic methods are cost-effective and suitable for routine use, interpretation may be challenging in isolates co-producing multiple β-lactamases [\u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e6\u003c/span\u003e].\u003c/p\u003e \u003cp\u003eThe prevalence of ESBL, AmpC and carbapenemase production among Enterobacterales varies widely across regions and healthcare settings, influenced by antibiotic usage patterns, infection control practices, and local epidemiology. In low- and middle-income countries, the burden of these resistant pathogens is especially high. Continuous surveillance, accurate laboratory detection, molecular characterization and implementation of antimicrobial stewardship and infection prevention policies are critical to stop their spread [\u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e6\u003c/span\u003e].\u003c/p\u003e \u003cp\u003eUnderstanding the epidemiology and distribution of ESBL, AmpC and carbapenemase-producing Enterobacterales is essential for guiding empirical therapy, informing public health policies, and developing targeted interventions to combat antimicrobial resistance [\u003cspan citationid=\"CR7\" class=\"CitationRef\"\u003e7\u003c/span\u003e].\u003c/p\u003e"},{"header":"Methodology","content":"\u003cdiv id=\"Sec3\" class=\"Section2\"\u003e \u003ch2\u003eStudy settings and data collection\u003c/h2\u003e \u003cp\u003eIt was carried out in the department of Microbiology, MMMC\u0026amp;H, Solan, India, after obtaining ethical clearance from the Institutional Ethics Committee, MMMC\u0026amp;H (MMMCH/IEC/23/589).\u003c/p\u003e \u003cp\u003eAll methods were performed in accordance with the relevant guidelines and regulations.\u003c/p\u003e \u003cp\u003eWritten informed consent was obtained from all participants or their legally authorized representatives before inclusion in the study after explaining the study objectives and procedures.\u003c/p\u003e \u003c/div\u003e\n\u003ch3\u003eData availability\u003c/h3\u003e\n\u003cp\u003eThe database generated and analyzed during the present study are available from corresponding author upon reasonable request.\u003c/p\u003e \u003cp\u003eThe study was done in department of Microbiology, MMMCH in MMU, Kumarhatti Solan, Study was performed during Aug 2024 to July 2025. A total 486 enterobacterales obtained from various clinical specimens in bacteriology section. All the isolates were further proceeded as per routine standard guidelines and followed by performed AST as provided by CLSI guidelines. The drug-resistant isolates were further performed for phenotypic confirmation of ESBLs, AMPC and Carbapenemase by several method as shown in Fig.\u0026nbsp;\u003cspan refid=\"Fig1\" class=\"InternalRef\"\u003e1\u003c/span\u003e [\u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e8\u003c/span\u003e].\u003c/p\u003e\n\u003ch3\u003ePhenotypic confirmation of clinical isolates\u003c/h3\u003e\n\u003cdiv id=\"Sec6\" class=\"Section2\"\u003e \u003ch2\u003eESBLs detection\u003c/h2\u003e \u003cp\u003eThis method is based upon ability of clavulanic acid which as beta lactamase inhibitor to inhibit ESBLs enzymes. When an ESBL producing isolate were tested, an enhance zone was observed between a cephalosporin disk and a disk containing amoxycillin-clavulanate due to synergistic activity. Disk containing cefotaxime 30\u0026micro;m and ceftazidime 30\u0026micro;m are used, additionally disk contain the same antibiotics combined with clavulanic acid 10 \u0026micro;g. After the incubation, measuring of zone size were done. If the organism produces ESBLs, clavulanic acid blocks the enzyme\u0026rsquo;s action, allowing the antibiotic to work more effectively. This results in a larger inhibition zone around the combined disk. A ˃5mm or more in the zone diameter compared with the antibiotic alone is as interpretated as confirmation of ESBL production as shown in Fig.\u0026nbsp;\u003cspan refid=\"Fig2\" class=\"InternalRef\"\u003e2\u003c/span\u003e [\u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e6\u003c/span\u003e].\u003c/p\u003e \u003c/div\u003e\n\u003ch3\u003eAmpC detection:\u003c/h3\u003e\n\u003cp\u003eRoutinely used technique for the detection of AmpC among gram negative bacteria is boronic acid method. In this method, a cefoxitin 30\u0026micro;m disk was tested alone and alongside a cefoxitin disc combined with phenylboronic acid, which acts as an AmpC enzyme inhibitor followed by incubation. After the incubation inhibition zone was compared. If the organisms produced AmpC β-lactamases, the boronic acid inhibits enzyme and enhance the activity of cefoxitin, resulting in an increases of 5mm or more in the inhibitory size around combination disk compared to cefoxitin only, this increase zone size confirms production of AmpCs as shown in Fig.\u0026nbsp;\u003cspan refid=\"Fig3\" class=\"InternalRef\"\u003e3\u003c/span\u003e[\u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e6\u003c/span\u003e].\u003c/p\u003e \u003cdiv id=\"Sec8\" class=\"Section2\"\u003e \u003ch2\u003eDetection of Carbapenemase\u003c/h2\u003e \u003cdiv id=\"Sec9\" class=\"Section3\"\u003e \u003ch2\u003eRapid Carbapenemase detction\u003c/h2\u003e \u003cp\u003eThe MCNP test is a rapid phenotypic method used to identify carbapenemase-producing Enterobacterales. It works by detection of hydrolysed carbapenem ring. In this test a bacterial suspension is mixed with a solution containing the antibiotic and a pH indicator such as phenol red. If the organism produces carbapenemase, the drug is hydrolysed that leads to formation of acid byproducts. this lowers the pH of solution and cause a visible color shift from red to yellow or orange colour. If no enzyme is present, the colour remains unchanged. This test provides a quick and reliable way to confirm carbapenemase as shown in Fig.\u0026nbsp;\u003cspan refid=\"Fig4\" class=\"InternalRef\"\u003e4\u003c/span\u003e [\u003cspan citationid=\"CR9\" class=\"CitationRef\"\u003e9\u003c/span\u003e].\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e\n\u003ch3\u003eMBL detection\u003c/h3\u003e\n\u003cp\u003eThe IMP-EDTA method is a phenotypic test which is used to detect metallo- β-lactamases production in bacteria. This method is based on the principle in which MBL enzyme requires zinc ions for their activity and EDTA acts as a chelating agent that binds zinc, thereby inhibiting the enzyme. In the procedure, two disk are placed IPM and IPM+ EDTA kept it for incubation. After the incubation aones are measure, an increase of 7mm or more in the size diameter around I\u0026thinsp;+\u0026thinsp;E as compared to IPM indicates as MBL production as shown in Fig.\u0026nbsp;\u003cspan refid=\"Fig5\" class=\"InternalRef\"\u003e5\u003c/span\u003e [\u003cspan citationid=\"CR9\" class=\"CitationRef\"\u003e9\u003c/span\u003e].\u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003cp\u003e \u003c/p\u003e"},{"header":"Results","content":"\u003cp\u003eTotal number of Enterobacterales obtained among all the clinical isolates were 486 and the distribution are as follows 331 were \u003cem\u003eEscherichia coli\u003c/em\u003e followed by \u003cem\u003eKlebsiella\u003c/em\u003e species 87, \u003cem\u003eCitrobacter species\u003c/em\u003e 47, \u003cem\u003eProteus species\u003c/em\u003e 09, \u003cem\u003eEnterobacter species\u003c/em\u003e 08, \u003cem\u003eSalmonella Typhi\u003c/em\u003e 02 and 01 \u003cem\u003eSerratia species \u0026amp; Morganella species\u003c/em\u003e.\u003c/p\u003e \u003cp\u003eAmong the 486 Enterobacterales clinical isolates, phenotypic screening revealed that presence of 38% exhibited ESBL production, 27% were AmpC producers and 17% demonstrated carbapenemase production.\u003c/p\u003e \u003cp\u003eAlso this study observed co-production of ESBL along with AmpC were14%. Collectively, these findings indicate that although β-lactamase mediated resistance remains a significant challenge among Enterobacterales in this clinical setting, the prevalence of ESBLs, AmpC and carbapenemases in our study is emphasizing the need for ongoing surveillance and tailored antibiotic policies.\u003c/p\u003e \u003cp\u003e \u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab1\" border=\"1\"\u003e \u003ccaption language=\"En\"\u003e \u003cdiv class=\"CaptionNumber\"\u003eTable 1\u003c/div\u003e \u003cdiv class=\"CaptionContent\"\u003e \u003cp\u003eDistribution of Enterobacterales among various clinical specimens.\u003c/p\u003e \u003c/div\u003e \u003c/caption\u003e \u003ccolgroup cols=\"9\"\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c4\" colnum=\"4\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c5\" colnum=\"5\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c6\" colnum=\"6\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c7\" colnum=\"7\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c8\" colnum=\"8\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c9\" colnum=\"9\"\u003e\u003c/div\u003e \u003cthead\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c1\"\u003e \u003cp\u003eEnterobacterales\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c2\"\u003e \u003cp\u003eUrine\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c3\"\u003e \u003cp\u003ePus/Swab\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c4\"\u003e \u003cp\u003eBlood\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c5\"\u003e \u003cp\u003eSputum\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c6\"\u003e \u003cp\u003eHVS\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c7\"\u003e \u003cp\u003eFluid\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c8\"\u003e \u003cp\u003eOthers\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c9\"\u003e \u003cp\u003eTotal\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cem\u003eE. coli\u003c/em\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e226\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e72\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e3\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e8\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e14\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e2\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003e8\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c9\"\u003e \u003cp\u003e331\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cem\u003eKlebsiella oxytoca\u003c/em\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e6\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e5\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e\u0026ndash;\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e3\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e1\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e\u0026ndash;\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003e\u0026ndash;\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c9\"\u003e \u003cp\u003e14\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cem\u003eKlebsiella pneumoniae\u003c/em\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e23\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e21\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e5\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e11\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e5\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e1\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003e9\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c9\"\u003e \u003cp\u003e73\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cem\u003eCitrobacter spp.\u003c/em\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e15\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e18\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e2\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e7\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e2\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e\u0026ndash;\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003e4\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c9\"\u003e \u003cp\u003e47\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cem\u003eEnterobacter spp.\u003c/em\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e3\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e2\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e3\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e\u0026ndash;\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e\u0026ndash;\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e\u0026ndash;\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003e1\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c9\"\u003e \u003cp\u003e8\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cem\u003eProteus spp.\u003c/em\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e3\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e6\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e\u0026ndash;\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e\u0026ndash;\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e1\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e\u0026ndash;\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003e\u0026ndash;\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c9\"\u003e \u003cp\u003e9\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cem\u003eSalmonella spp.\u003c/em\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e1\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e\u0026ndash;\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e2\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e\u0026ndash;\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e\u0026ndash;\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e\u0026ndash;\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003e\u0026ndash;\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c9\"\u003e \u003cp\u003e2\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cem\u003eSerratia spp.\u003c/em\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e1\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e\u0026ndash;\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e\u0026ndash;\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e\u0026ndash;\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e\u0026ndash;\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e\u0026ndash;\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003e1\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c9\"\u003e \u003cp\u003e1\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cem\u003eMorganella spp.\u003c/em\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e1\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e1\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e\u0026ndash;\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e\u0026ndash;\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e\u0026ndash;\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e\u0026ndash;\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003e\u0026ndash;\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c9\"\u003e \u003cp\u003e1\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cb\u003eTotal\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e\u003cb\u003e276\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e\u003cb\u003e122\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e\u003cb\u003e13\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e\u003cb\u003e28\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e\u003cb\u003e23\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e\u003cb\u003e3\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003e\u003cb\u003e21\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c9\"\u003e \u003cp\u003e\u003cb\u003e486\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003c/tbody\u003e \u003c/colgroup\u003e \u003c/table\u003e\u003c/div\u003e \u003c/p\u003e \u003cp\u003eTable\u0026nbsp;\u003cspan refid=\"Tab1\" class=\"InternalRef\"\u003e1\u003c/span\u003e: illustrates maximum number of Enterobacterales isolates were obtained from urine specimens (276) followed by pus or swab (122) and lowest isolates were obtained from blood \u0026amp; body fluids. Maximum number of isolates was E coli (331) followed by Klebsiella species (87), Citrobacter species (47), Proteus (09) species, Enterobacter species (08) salmonella species (02) and Serratia species Morganella species were (01).\u003c/p\u003e \u003cp\u003e \u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab2\" border=\"1\"\u003e \u003ccaption language=\"En\"\u003e \u003cdiv class=\"CaptionNumber\"\u003eTable 2\u003c/div\u003e \u003cdiv class=\"CaptionContent\"\u003e \u003cp\u003ePrevalence of multidrug resistance among Enterobacterale isolates.\u003c/p\u003e \u003c/div\u003e \u003c/caption\u003e \u003ccolgroup cols=\"3\"\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e \u003cthead\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c1\"\u003e \u003cp\u003eEnterobacterales\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c2\"\u003e \u003cp\u003eMDR\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c3\"\u003e \u003cp\u003eXDR\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eEscherichia coli (331)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e142(43%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e35(10%)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eKlebsiella species (87)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e49(56%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e18(20%)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eCitrobacter species (47)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e6(12%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e01(2%)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eEnterobacter species (08)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e01(12.5%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e00\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eSalmonella species (02)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e01(50%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e00\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eProteus species (09)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e01(11%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e00\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eSerratia \u0026amp; Morganella species(01)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e00\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e00\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003c/tbody\u003e \u003c/colgroup\u003e \u003c/table\u003e\u003c/div\u003e \u003c/p\u003e \u003cp\u003eTable\u0026nbsp;\u003cspan refid=\"Tab2\" class=\"InternalRef\"\u003e2\u003c/span\u003e: illustrates a total 485 enterobacterale isolates were evaluated for antimicrobial resistance, among these Escherichia coli (331) was showed highest resistance ie 142 isolates were MDR and 35 isolates were XDR, indicating a significant burden of antimicrobial resistance in this organism. Followed by Klebsiella species were showed 49 isolates were MDR and 18 were XDR, showing a considerable proportion of resistant strains. Among the Citrobacter species 6 were MDR and 1 were XDR, indicating relatively lower resistance as compared to E coli \u0026amp; Klebsiella. Enterobacter, Proteus and Salmonella species showed 01 MDR and no XDR isolates.\u003c/p\u003e \u003cp\u003e \u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab3\" border=\"1\"\u003e \u003ccaption language=\"En\"\u003e \u003cdiv class=\"CaptionNumber\"\u003eTable 3\u003c/div\u003e \u003cdiv class=\"CaptionContent\"\u003e \u003cp\u003eDistribution of ESBL, AmpC, Carbapenemase and MBL producers among Enterobacterales.\u003c/p\u003e \u003c/div\u003e \u003c/caption\u003e \u003ccolgroup cols=\"5\"\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c4\" colnum=\"4\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c5\" colnum=\"5\"\u003e\u003c/div\u003e \u003cthead\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c1\"\u003e \u003cp\u003eEnterobacterales\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c2\"\u003e \u003cp\u003eESBL\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c3\"\u003e \u003cp\u003eAmpC\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c4\"\u003e \u003cp\u003eMCNP\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c5\"\u003e \u003cp\u003eMBLs\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eEscherichia coli (331)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e128\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e94\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e43\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e34\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eKlebsiella species (87)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e42\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e30\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e29\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e28\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eCitrobacter species (47)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e09\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e05\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e04\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e02\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eEnterobacter species (08)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e03\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e02\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e02\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e02\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eSalmonella species (02)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eProteus species (09)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eSerratia \u0026amp; Morganella species(01)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eTotal 484\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e182\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e131\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e78\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e66\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003c/tbody\u003e \u003c/colgroup\u003e \u003c/table\u003e\u003c/div\u003e \u003c/p\u003e \u003cp\u003eTable\u0026nbsp;\u003cspan refid=\"Tab3\" class=\"InternalRef\"\u003e3\u003c/span\u003e: Illustrate maximum number of ESBLs producing bacteria was E coli 128, 94 AmpC,43 MCNP and 34 MBL producers. This was followed by Klebsiella species which had 42 ESBLs,30 AmpCs, 29 MCNP and 28 MBL producers. Citrobacter species showed 9ESBLs,5AmpC, 4MCNP and 2 MBL producers while Enterobacter species had 3 ESBL, 2AmpC, 2 MCNP and 2MBL producers. No resistance mechanism were detected among Salmonella, Proteus, Serratia/ Morganella isolates. Overall the phenotypic methods detected 182 ESBL, 131 AmpC, 78 MCNP and 66 MBL producers with E coli contributing the largest proportion.\u003c/p\u003e \u003cp\u003e \u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab4\" border=\"1\"\u003e \u003ccaption language=\"En\"\u003e \u003cdiv class=\"CaptionNumber\"\u003eTable 4\u003c/div\u003e \u003cdiv class=\"CaptionContent\"\u003e \u003cp\u003eDistribution of Enterobacterales on the basis of gender and CA-HA infections.\u003c/p\u003e \u003c/div\u003e \u003c/caption\u003e \u003ccolgroup cols=\"4\"\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c4\" colnum=\"4\"\u003e\u003c/div\u003e \u003cthead\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c1\"\u003e \u003cp\u003eGender\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c2\"\u003e \u003cp\u003eCommunity-acquired infections\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c3\"\u003e \u003cp\u003eHospital-acquired infections\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c4\"\u003e \u003cp\u003eTotal\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eMale\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e122\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e90\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e212\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eFemale\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e176\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e98\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e274\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cb\u003eTotal\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e\u003cb\u003e298\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e\u003cb\u003e188\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e\u003cb\u003e486\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003c/tbody\u003e \u003c/colgroup\u003e \u003c/table\u003e\u003c/div\u003e \u003c/p\u003e \u003cp\u003eTable\u0026nbsp;\u003cspan refid=\"Tab4\" class=\"InternalRef\"\u003e4\u003c/span\u003e: illustrates the distribution of Enterobacterales infections according to gender and type of acquisition. Among the 486 isolates community acquired infections were more common in females ie.176 than in males 122. Hospital acquired infections were observed in both genders, with a slightly higher number in females 98 compared to males 90. Overall community acquired infections are more frequent infections 188.\u003c/p\u003e"},{"header":"Discussion","content":"\u003cp\u003eEnterobacterales represent a major group of GN isolates accountable for wide spectrum of infections among both community as well as healthcare settings. These isolates are recurrently implicated among UTIs, BSIs, respiratory infections, wound infections and intra-abdominal infections. Over the past two decades, the rapid emergence \u0026amp; distribution of AMR among Enterobacterales has become a serious public health challenge. Resistance mechanisms mediated by β-lactamases, particularly ESBLs, AmpC and carbapenemases, have significantly compromised the effectiveness of commonly used antibiotics. The present study meant to obtained the distribution of Enterobacterales isolated among clinical specimens and to assess the occurrence of important β-lactamase\u0026ndash;mediated resistance mechanisms using phenotypic methods in a tertiary care hospital [\u003cspan citationid=\"CR10\" class=\"CitationRef\"\u003e10\u003c/span\u003e].\u003c/p\u003e \u003cp\u003eIn present investigation, total 486 Enterobacterales isolates were recovered from several clinical specimens. Among these, \u003cem\u003eE-coli\u003c/em\u003e was major isolate, accounting for the majority of cases, followed by \u003cem\u003eKlebsiella\u003c/em\u003e species and \u003cem\u003eCitrobacter\u003c/em\u003e species. This distribution pattern is consistent with findings reported in many clinical microbiology studies where \u003cem\u003eE. coli\u003c/em\u003e remains the most commonly isolated Enterobacterales member. The predominance of \u003cem\u003eE. coli\u003c/em\u003e can largely be attributed to its role as a leading causative agent of UTIs and other community-acquired infections. In this study, the largest isolates were obtained from urine samples, further supporting the well-established association between \u003cem\u003eE. coli\u003c/em\u003e and UTIs. The second most isolates were \u003cem\u003eKlebsiella\u003c/em\u003e species, which are known to be significant pathogens in hospital-acquired infections including pneumonia, septicemia, and wound infections as shown in Table \u003cspan refid=\"Tab1\" class=\"InternalRef\"\u003e1\u003c/span\u003e[\u003cspan citationid=\"CR11\" class=\"CitationRef\"\u003e11\u003c/span\u003e].\u003c/p\u003e \u003cp\u003eThe analysis of specimen distribution demonstrated that urine samples contributed the largest proportion of isolates, followed by pus or wound swabs, while blood and body fluids accounted for a smaller proportion. This pattern reflects the clinical prevalence of urinary tract infections and soft tissue infections in healthcare settings. Previously a similar study have been reported where urine was identified as the most common source of Enterobacterales isolates. The recovery of isolates from multiple specimen types also indicates the wide clinical spectrum of infections caused by these organisms [\u003cspan citationid=\"CR12\" class=\"CitationRef\"\u003e12\u003c/span\u003e] .\u003c/p\u003e \u003cp\u003eThis study revealed a considerable load of AMR among Enterobacterales isolates. A significant proportion of isolates exhibited MDR, particularly among \u003cem\u003eEcoli\u003c/em\u003e and \u003cem\u003eKlebsiella\u003c/em\u003e species. The occurrence of MDR among \u003cem\u003eE. coli\u003c/em\u003e was 43%, while \u003cem\u003eKlebsiella\u003c/em\u003e species showed an even higher proportion of MDR isolates at 56%. Additionally, extensively drug-resistant (XDR) strains were identified, with \u003cem\u003eKlebsiella\u003c/em\u003e species demonstrating a higher percentage compared to other organisms as shown in Table \u003cspan refid=\"Tab2\" class=\"InternalRef\"\u003e2\u003c/span\u003e. The higher resistance observed in \u003cem\u003eKlebsiella\u003c/em\u003e species may be due to their ability to acquire and maintain multiple resistance determinants through plasmids, transposons, and integrons. The emergence of MDR and XDR strains significantly limits treatment choices and upsurges the chance of therapeutic failure, prolonged hospital stay \u0026amp; increased healthcare costs.\u003c/p\u003e \u003cp\u003eOne of the major objectives of this study was to evaluate the phenotypic occurrence of ESBLs production among Enterobacterales strains. The results demonstrated that ESBL was produced by 182 isolates, representing approximately 38% of the total isolates. The maximum ESBL-producing isolates was observed in \u003cem\u003eEscherichia coli\u003c/em\u003e, followed by \u003cem\u003eKlebsiella\u003c/em\u003e species and findings are in concordance with Sageerabanoo S \u003cem\u003eet al\u003c/em\u003e reports that have identified \u003cem\u003eE. coli\u003c/em\u003e and \u003cem\u003eKlebsiella pneumoniae\u003c/em\u003e as the most common ESBL-producing organisms worldwide. ESBL enzymes are capable of hydrolyzing a wide range of β-lactam antibiotics, including third-generation cephalosporins and monobactams, which are frequently used in clinical practice. The rising occurrence of ESBL-producing organisms has therefore led to a reduction in the effectiveness of these antibiotics and has increased reliance on carbapenems for treatment [\u003cspan citationid=\"CR13\" class=\"CitationRef\"\u003e13\u003c/span\u003e].\u003c/p\u003e \u003cp\u003eIn addition to ESBL production, AmpC β-lactamase production was also observed among a majority of isolates in this study. AmpC enzymes converse resistance to a broad spectrum of β-lactam antibiotics, including penicillins, cephalosporins and cephamycins, unlike ESBLs, they are not inhibited by β-lactamase inhibitors such as clavulanic acid. In the present study, 131(27%) isolates were identified as AmpC producers, with the majority being \u003cem\u003eEscherichia coli\u003c/em\u003e followed by \u003cem\u003eKlebsiella\u003c/em\u003e species. This study was concordance with Peter, J.A \u003cem\u003eet al.\u003c/em\u003e ie 44.8%The detection of AmpC enzymes is particularly important because these enzymes can be either chromosomally encoded or plasmid-mediated, allowing for horizontal transfer between bacterial species. Furthermore, AmpC-producing organisms may appear susceptible to certain cephalosporins during routine susceptibility testing, which may lead to inappropriate antibiotic therapy if not properly detected [\u003cspan citationid=\"CR14\" class=\"CitationRef\"\u003e14\u003c/span\u003e].\u003c/p\u003e \u003cp\u003eAnother significant finding of present study was the detection of carbapenemase production from Enterobacterales isolates. Carbapenems are considered outmost effective group of antibiotics for the therapy of MDRGNB. However, the emergence of CPE has become a major concern for global health. In current study, carbapenemase production was detected in 78 (16%) isolates using the Modified Carba NP test this study was concordance with Kumar A \u003cem\u003eet al.\u003c/em\u003e showed prevalence of Carbapenemase among Enterobacterales were 150 (15.4%) by MCNP method. Among these, a large proportion were identified as metallo-β-lactamase (MBL) producers through the imipenem-EDTA synergy test. MBL zinc ions for enzymatic activity and are accomplished of hydrolyzing nearly all β-lactam antibiotics, including carbapenems as shown in Table \u003cspan refid=\"Tab3\" class=\"InternalRef\"\u003e3\u003c/span\u003e [\u003cspan citationid=\"CR9\" class=\"CitationRef\"\u003e9\u003c/span\u003e].\u003c/p\u003e \u003cp\u003eThe detection of MBL production in 66 (14%) isolates indicates the growing presence of carbapenem resistance in the clinical setting this study was concordance with Kumar A \u003cem\u003eet al.\u003c/em\u003e showed (13%) of MBL among total enterobacterales isolates. The majority of carbapenemase producers in this study were \u003cem\u003eEscherichia coli\u003c/em\u003e and \u003cem\u003eKlebsiella\u003c/em\u003e species, which are known to harbour carbapenemase genes ie. NDM, VIM, IMP and OXA-48. The presence of enzymes poses a serious therapeutic challenge because infections caused by such isolates are accompanying with inadequate treatment options increased mortality. The dissemination of carbapenemase genes through mobile genetic elements ie. plasmids \u0026amp; integrons further facilitates the quick spread of resistance within hospitals and across geographical regions as shown in hospital 4[\u003cspan citationid=\"CR9\" class=\"CitationRef\"\u003e9\u003c/span\u003e, \u003cspan citationid=\"CR15\" class=\"CitationRef\"\u003e15\u003c/span\u003e].\u003c/p\u003e \u003cp\u003eIn this study the occurrence of multiple β-lactamase mechanisms within the same bacterial population. The co-existence of ESBL \u0026amp; AmpC enzymes in certain isolates indicates the complication of resistant mechanisms among Enterobacterales. The presence of multiple resistance determinants can complicate phenotypic detection and may lead to underestimation of resistance if appropriate tests are not performed. Therefore, routine laboratory screening for β-lactamase production is essential for accurate detection and appropriate antimicrobial therapy [\u003cspan citationid=\"CR16\" class=\"CitationRef\"\u003e16\u003c/span\u003e].\u003c/p\u003e \u003cp\u003eThe phenotypic methods used in this study, including the double-disk synergy test for ESBL detection, boronic acid inhibition test for AmpC detection, Modified Carba NP test for carbapenemase detection and imipenem-EDTA synergy test for MBL detection, proved to be effective and practical for routine use in clinical microbiology laboratories. These methods are relatively inexpensive, simple to perform, and suitable for laboratories with limited access to molecular diagnostic facilities. Although molecular techniques provide definitive identification of resistance genes, phenotypic assays remain valuable tools for the functional detection of enzyme activity in resource-limited settings [\u003cspan citationid=\"CR17\" class=\"CitationRef\"\u003e17\u003c/span\u003e, \u003cspan citationid=\"CR18\" class=\"CitationRef\"\u003e18\u003c/span\u003e, \u003cspan citationid=\"CR19\" class=\"CitationRef\"\u003e19\u003c/span\u003e].\u003c/p\u003e \u003cp\u003eThe current study highlights crucial need for continuous monitoring of antimicrobial resistance among Enterobacterales. The high occurrence of ESBL, AmpC and carbapenemase producers emphasizes the importance of implementing effective antimicrobial stewardship programs to promote rational antibiotic use. Additionally, strict infection control procedures such as hand hygiene, surveillance cultures, isolation precautions should be executed to avoid the spread of resistant organisms within healthcare facilities. Thus integrating molecular methods such as PCR \u0026amp; sequencing would help in identifying the exact resistance genes and understanding their epidemiological distribution [\u003cspan citationid=\"CR20\" class=\"CitationRef\"\u003e20\u003c/span\u003e, \u003cspan citationid=\"CR21\" class=\"CitationRef\"\u003e21\u003c/span\u003e].\u003c/p\u003e \u003cp\u003eOverall, the results of this study demonstrate that β-lactamase-mediated resistance is widely prevalent among Enterobacterales isolates in the studied healthcare setting. The predominance of ESBL producers, along with the increasing occurrence of AmpC and carbapenemase-producing isolates, highlights the growing challenge of antimicrobial resistance. Continuous surveillance, accurate laboratory detection, rational antibiotic prescribing, and effective infection control strategies are essential to limit the spread of these resistant pathogens and improve clinical outcomes.\u003c/p\u003e \u003cdiv id=\"Sec13\" class=\"Section2\"\u003e \u003ch2\u003eLimitation\u003c/h2\u003e \u003cp\u003eCurrent study as several limitation which considered while interpretation of the findings. The current observation was obtained in only a tertiary care hospital while that can reduce the generalizability of the outcomes to other healthcare settings or geographic regions. Second, the detection of beta lactamases production was based only on phenotypic methods, molecular technique such as PCR were not performed to identify specific resistance genes. Additionally detailed clinical data and patient risk factors associated with resistant infections were not analyzed, despite these limitations, this observation showed valuable perception into the occurrence of ESBL, AmpC and carbapenemase producing Enterobacterales in the studied healthcare sittings.\u003c/p\u003e \u003c/div\u003e"},{"header":"Declarations","content":"\u003cp\u003e\u003cstrong\u003eAcknowledgement\u0026nbsp;\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe authors would like to thank the Department of Microbiology and the laboratory staff of the study institution for their technical assistance and support during sample collection, processing and analysis. We also extend our sincere gratitude to all participants involved in this study\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eConflict of Interest\u0026nbsp;\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThere is no conflicts of interest among authors regarding the given manuscript.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eFunding\u0026nbsp;\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe author declare that no financial support was received for the conduct of this study.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eConsent for publication\u0026nbsp;\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003e\u0026nbsp;All authors have read and approved the final version of the manuscript and consent to its publication, all author agree to submission and take responsibility for the consent of the manuscript.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eEthical declaration\u0026nbsp;\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eIt was carried out in the department of Microbiology, Maharishi Markandeshwar Medical College and Hospital, Solan, India, after obtaining ethical clearance from the Institutional Ethics Committee, Maharishi Markandeshwar Medical College and Hospital (MMMCH/IEC/23/589).\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eData\u0026nbsp;\u003c/strong\u003e\u003cstrong\u003eavailability\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe database generated and analyzed during the present study are available from corresponding author upon reasonable request.\u0026nbsp;All methods were performed in accordance with the relevant guidelines and regulations\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAuthor contribution\u0026nbsp;\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eManika Sharma : Conceptualization, Methodology, Investigation, Data Curation, Formal Analysis,\u0026nbsp;Supervision, Writing \u0026ndash; Review \u0026amp; Editing.\u003c/p\u003e\n\u003cp\u003eAjay kumar : Methodology, Investigation, Data Curation, Formal Analysis, Writing.\u003c/p\u003e"},{"header":"References","content":"\u003col\u003e\u003cli\u003e\u003cspan\u003eGuentzel, M. 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Impact of Antimicrobial Stewardship on Reducing Antimicrobial Resistance. \u003cem\u003eCureus\u003c/em\u003e \u003cb\u003e15\u003c/b\u003e (12), e49935. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.7759/cureus.49935\u003c/span\u003e\u003cspan address=\"10.7759/cureus.49935\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e (2023). PMID: 38179391; PMCID: PMC10765068.\u003c/span\u003e\u003c/li\u003e\u003c/ol\u003e"}],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":true,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":false,"hideJournal":true,"highlight":"","institution":"","isAcceptedByJournal":false,"isAuthorSuppliedPdf":false,"isDeskRejected":"","isHiddenFromSearch":false,"isInQc":false,"isInWorkflow":false,"isPdf":false,"isPdfUpToDate":true,"isWithdrawnOrRetracted":false,"journal":{"display":true,"email":"[email protected]","identity":"researchsquare","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":true,"externalIdentity":"","sideBox":"","snPcode":"","submissionUrl":"/submission","title":"Research Square","twitterHandle":"researchsquare","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"","reportingPortfolio":"","inReviewEnabled":false,"inReviewRevisionsEnabled":true},"keywords":"MCNP, ESBL, MBL, Carbapenemase","lastPublishedDoi":"10.21203/rs.3.rs-9358923/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-9358923/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003ch2\u003eBackground\u003c/h2\u003e \u003cp\u003eMembers of the order Enterobacterales are among the most common causes of both community-acquired and healthcare associated infections. The increasing emergence of β-lactamase\u0026ndash;mediated resistance, particularly extended-spectrum β-lactamases (ESBL), AmpC and carbapenemases, has significantly reduced the effectiveness of commonly used antibiotics and poses a major challenge for clinical management.\u003c/p\u003e\u003ch2\u003eObjective\u003c/h2\u003e \u003cp\u003eThis study was conducted to determine the distribution of Enterobacterales isolated from clinical specimens as well as evaluate the frequency of ESBL, AmpC \u0026amp; carbapenemase production using phenotypic detection methods.\u003c/p\u003e\u003ch2\u003eMethods\u003c/h2\u003e \u003cp\u003eThis study was carried out in the Department of Microbiology at Maharishi Markandeshwar Medical College and Hospital, Solan, India, from August 2024 to July 2025. A total of 486 Enterobacterales isolates obtained. Identification and AST were performed according to standard laboratory procedures and CLSI guidelines. Phenotypic methods were used to detect β-lactamase production, including the double-disk synergy test for ESBL detection, boronic acid inhibition test for AmpC detection, Modified Carba NP test for carbapenemase detection and imipenem-EDTA synergy test for metallo-β-lactamase (MBL) detection.\u003c/p\u003e\u003ch2\u003eResults\u003c/h2\u003e \u003cp\u003eAmong the 486 isolates, \u003cem\u003eE-coli\u003c/em\u003e (331) was the most frequently isolated organism, followed by \u003cem\u003eKlebsiella\u003c/em\u003e species (87) and \u003cem\u003eCitrobacter\u003c/em\u003e species (47). Urine was the most common clinical specimen from which isolates were obtained. Phenotypic analysis showed that 38% of isolates produced ESBL, 27% produced AmpC β-lactamase, and 17% demonstrated carbapenemase activity. Additionally, metallo-β-lactamase production was detected in 14% of isolates. A considerable proportion of isolates also exhibited multidrug resistance, particularly among \u003cem\u003eEscherichia coli\u003c/em\u003e and \u003cem\u003eKlebsiella\u003c/em\u003e species.\u003c/p\u003e\u003ch2\u003eConclusion\u003c/h2\u003e \u003cp\u003eThe study highlights a substantial prevalence of β-lactamase\u0026ndash;mediated resistance among Enterobacterales in the studied healthcare setting. The presence of ESBL, AmpC, and carbapenemase-producing isolates emphasizes the need for routine laboratory detection, continuous surveillance, effective antimicrobial stewardship, and strict infection control measures to limit the spread of resistant pathogens.\u003c/p\u003e","manuscriptTitle":"Emergence of β-Lactamase Mediated Resistance among Enterobacterales: A Phenotypic Study from a Tertiary Care Hospital","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2026-04-23 17:40:49","doi":"10.21203/rs.3.rs-9358923/v1","editorialEvents":[{"type":"communityComments","content":0}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"researchsquare","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":true,"externalIdentity":"","sideBox":"","snPcode":"","submissionUrl":"/submission","title":"Research Square","twitterHandle":"researchsquare","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"","reportingPortfolio":"","inReviewEnabled":false,"inReviewRevisionsEnabled":true}}],"origin":"","ownerIdentity":"839ede0a-ac2f-4d61-b5c4-d5d8858363f5","owner":[],"postedDate":"April 23rd, 2026","published":true,"recentEditorialEvents":[{"type":"decision","content":"Rejected","date":"2026-05-04T11:20:36+00:00","index":"","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2026-04-30T17:20:19+00:00","index":44,"fulltext":""}],"rejectedJournal":[],"revision":"","amendment":"","status":"posted","subjectAreas":[{"id":66831495,"name":"Health sciences/Diseases"},{"id":66831496,"name":"Health sciences/Health care"},{"id":66831497,"name":"Biological sciences/Microbiology"}],"tags":[],"updatedAt":"2026-05-04T11:26:15+00:00","versionOfRecord":[],"versionCreatedAt":"2026-04-23 17:40:49","video":"","vorDoi":"","vorDoiUrl":"","workflowStages":[]},"version":"v1","identity":"rs-9358923","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-9358923","identity":"rs-9358923","version":["v1"]},"buildId":"XKTyCvWXoU3ODBz1xrDgd","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}