A Case Report of Complex Co-infection with Talaromyces marneffei and Rhodococcus equi in a Patient with AIDS

A Case Report of Complex Co-infection with Talaromyces marneffei and Rhodococcus equi in a Patient with AIDS | Research Square window.SnipcartSettings = { analytics: { enabled: false } }; (function() { var accessVector = localStorage.getItem('access_vector') || ''; window.dataLayer = window.dataLayer || []; if (accessVector) { window.dataLayer.push({ user: { profile: { profileInfo: { snid: accessVector } } } }); } })(); (function(w,d,s,l,i){w[l]=w[l]||[];w[l].push({'gtm.start':new Date().getTime(),event:'gtm.js'});var f=d.getElementsByTagName(s)[0],j=d.createElement(s),dl=l!='dataLayer'?'&l='+l:'';j.async=true;j.src='https://www.googletagmanager.com/gtm.js?id='+i+dl;f.parentNode.insertBefore(j,f);})(window,document,'script','dataLayer','GTM-K279D39R'); Browse Preprints In Review Journals COVID-19 Preprints AJE Video Bytes Research Tools Research Promotion AJE Professional Editing AJE Rubriq About Preprint Platform In Review Editorial Policies Our Team Advisory Board Help Center Sign In Submit a Preprint Cite Share Download PDF Case Report A Case Report of Complex Co-infection with Talaromyces marneffei and Rhodococcus equi in a Patient with AIDS Li Gao, Yanqi Peng, Zhenglun Li, Xiaorui Cai, Yue Feng, Xingqi Dong, and 1 more This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-9078351/v1 This work is licensed under a CC BY 4.0 License Status: Under Review Version 1 posted 10 You are reading this latest preprint version Abstract Background: Co-infection with Talaromyces marneffei (TM) and Rhodococcus equi in HIV-positive patients is an extremely rare but life-threatening combination of opportunistic infections. We report a scarce case of an HIV-infected patient initially suspected of pulmonary tuberculosis, who was subsequently confirmed by culture and next-generation sequencing (NGS) to have a co-infection with R. equi and TM. Case Presentation: The patient was a 32-year-old male presenting with cough, sputum production, and chest tightness after exercise. He was admitted to our hospital for further diagnosis and treatment on June 25, 2025. The sputum acid-fast stain was positive for acid-fast coccoid organisms on June 26, 2025. Following the confirmation of R. equi sepsis on June 27, the antimicrobial regimen was adjusted to a combination of levofloxacin (0.5g qd), amikacin (0.4g qd), and azithromycin (0.25g qd). On June 29, amphotericin B was initiated for anti-TM therapy, starting at 5 mg and titrated daily. Due to severe gastrointestinal reactions, azithromycin and compound sulfamethoxazole were discontinued. On June 30, the antiretroviral therapy (ART) was optimized to tenofovir disoproxil fumarate/lamivudine/dolutegravir (TDF/3TC/DTG). On July 1, the patient reported three episodes of watery diarrhea; examination revealed white pseudomembranes on the bilateral oral mucosa, suggestive of concurrent oral candidiasis, for which sodium bicarbonate mouthwash was prescribed. At 11:30 on July 7, the patient experienced sudden fatigue, chest tightness, and nausea, with blood pressure dropping to 87/56 mmHg, heart rate rising to 120 bpm, and oxygen saturation at 92%. Immediate resuscitation measures, including albumin supplementation and correction of electrolyte imbalances, stabilized his condition. By July 9, hemoglobin rose to 90 g/L, albumin was 18.0 g/L, and liver function tests showed AST at 92 U/L. With normalized body temperature and reduced coughing, the patient requested discharge. He was advised to continue oral itraconazole (0.2g bid), levofloxacin (0.5g qd), and antiviral medications, outpatient, with regular follow-ups. Conclusion: R.equi , being acid-fast positive, is easily misdiagnosed as tuberculosis; thus, clinicians must prioritize differential diagnosis for such infections. The key to success in this case lay in obtaining definitive etiological evidence through bronchoscopy and bone marrow aspiration, which prevented misdiagnosis and enabled a targeted combination therapy. This underscores the importance of employing multiple diagnostic methods to clarify clinical diagnoses. HIV Talaromyces marneffei Rhodococcus equi Co-infection Opportunistic infection Figures Figure 1 Figure 2 Figure 3 Background Co-infection with Talaromyces marneffei (TM) and Rhodococcus equi in HIV-positive individuals represents an extremely rare yet severe combination of opportunistic infections[ 1 , 2 ]. TM infection is particularly prevalent among HIV-1/AIDS populations in Southeast Asia and Southern China, whereas R. equi infection is more commonly observed in individuals with severely compromised cellular immunity[ 3 , 4 ]. Although the incidence of co-infection is low, its complex clinical presentation, diagnostic difficulties, and challenging treatment protocols pose significant challenges in clinical practice[ 5 ]. This article reports a complex clinical case of an HIV-infected patient with concurrent TM and R.equi infection, aiming to provide references for clinical practice. This study was approved by the Ethics Committee of Yunnan Provincial Infectious Diseases Hospital (Approval No.: Ke 2024050), in accordance with the Declaration of Helsinki. Case Presentation Patient Information: A 32-year-old male was diagnosed with HIV infection by the local Centers for Disease Control and Prevention (CDC) in 2018. His CD4 + T lymphocyte count at diagnosis was unknown. Three months before admission, he had been on combination antiretroviral therapy (cART) with a regimen of tenofovir disoproxil fumarate/lamivudine/efavirenz (TDF/3TC/EFV). He had a history of intravenous drug use and was diagnosed with Hepatitis C five years ago, which was cured following standardized antiviral treatment. History of Present Illness: On April 23, 2025, the patient developed fever, cough, expectoration of yellow-white viscous sputum, fatigue, and weight loss without obvious triggers. He was diagnosed at a local hospital with "AIDS with multiple infections, suspected pulmonary tuberculosis, pulmonary fungal infection, intestinal fungal infection, hypoproteinemia, and moderate anemia". He was treated with fluconazole (0.4g qd), isoniazid (0.3g qd), rifabutin (0.3g qd), ethambutol (0.75g qd), and pyrazinamide (1.0g qd). While his fever temporarily improved, cough and sputum production persisted, accompanied by chest tightness after exercise. Consequently, he was transferred to our hospital for further management on June 25, 2025. Physical Examination: Temperature 36.8℃, Pulse 82 bpm, Respiration 21 bpm, Blood Pressure 110/94 mmHg. Height 167 cm, Weight 46 kg, BMI 16.4 kg/m². The general condition was poor. The patient appeared emaciated but was conscious. He presented with an anemic appearance. No superficial lymphadenopathy was palpable. Skin and sclera were non-icteric, and lips and fingertips showed no cyanosis. The oral mucosa was smooth. Lung auscultation revealed coarse breath sounds without dry or wet rales. Heart rate was 82 bpm with a regular rhythm; no murmurs were heard in any valvular listening areas. The abdomen was flat and soft, with no tenderness, rebound tenderness, or muscle tension. Liver percussion pain was negative, and the hepatojugular reflux sign was negative. No edema was observed in the lower extremities. Laboratory and Imaging Findings: Blood Routine: WBC 11.1×10 9 /L, Neutrophils 82.6%, Hemoglobin 70 g/L, Platelets 370×10 9 /L. Biochemistry: Albumin 21.6 g/L, Globulin 52.8 g/L, ALT 19 U/L, AST 47 U/L, CRP 161.87 mg/L, PCT 0.246 ng/ml, IL-6 98.29 pg/mL. Immunology: CD4 + T cell count 72 cells/µL, CD4 + /CD8 + ratio 0.14, HIV-RNA 7.84×10 4 IU/mL. Fungal Markers: Fungal D-glucan 212.87 pg/ml, Aspergillus galactomannan antigen 0.11 µg/L. Imaging (Chest CT, 2025-06-26, Fig. 1 B ~ E): Revealed multiple infiltrative lesions in both lungs with thick-walled cavity formation, consolidation, and atelectasis in the middle and lower lobes of the right lung, possible lung abscess in the right lower lobe. Enlarged mediastinal and right hilar lymph nodes were noted. Signs of pulmonary hypertension, small pericardial effusion, bilateral pleural thickening, and multiple osteolytic destructions of the sternum, bilateral clavicles, and scapulae were observed. Abdominal ultrasound indicated splenomegaly (thickness 4.7cm), multiple stones in the right kidney, and right-sided pleural effusion. Etiological Examination: Three consecutive sputum acid-fast stains upon admission were negative. However, under the microscope, acid-fast positive cocci were observed (Fig. 2DE).On June 26, bone marrow aspiration was performed, and R. equi was cultured from the bone marrow (microscopic and colony morphology shown in Fig. 2 A-C, F). The isolate was sensitive to levofloxacin, gentamicin, linezolid, and tigecycline (Table 1 ). On June 27, bronchoscopy was conducted; both R.equi and TM were cultured from the bronchoalveolar lavage fluid(BALF) (colony and microscopic morphology shown in Fig. 3 A-F). Targeted sequencing of the BALF revealed 15,134 sequence reads for R.equi and 3,264 reads for TM. Table 1 Antibiotic susceptibility test for Rhodococcus equi Antibiotics MIC(mg/L) Result Antibiotics MIC(mg/L) Result Gentamicin <=0.5 S Linezolid 4 S Ciprofloxacin =16.0 R Levofloxacin 0.5 S Tigecycline 0.5 S Moxifloxacin 0.5 S Rifampicin =8.0 R Trimethoprim/Sulfamethoxazole 1 S Quinupristin/Dalfopristin 4 R Diagnosis and Treatment Based on clinical and laboratory findings, the patient was diagnosed with: AIDS with multiple infections, Talaromycosis (TM infection), R. equi sepsis, Bacterial pneumonia, Hypoproteinemia, and Moderate anemia. Initially, the patient continued on the HRbEZ anti-tuberculosis regimen, fluconazole for antifungal coverage, and compound sulfamethoxazole for PCP prophylaxis. After confirming R.equi sepsis on June 27, the antimicrobial regimen was adjusted to levofloxacin (0.5g qd), amikacin (0.4g qd), and azithromycin (0.25g qd). On June 29, amphotericin B was added for anti-TM therapy, starting at 5 mg and increased daily. Due to severe gastrointestinal reactions, azithromycin and compound sulfamethoxazole were discontinued. On June 30, the ART regimen was optimized to TDF/3TC/DTG. On July 1, the patient reported three episodes of watery diarrhea; examination revealed white pseudomembranes on the oral mucosa, suggesting concurrent oral candidiasis, treated with sodium bicarbonate mouthwash. On July 7 at 11:30, the patient experienced sudden fatigue, chest tightness, and nausea. Vital signs deteriorated: BP 87/56 mmHg, HR 120 bpm, SpO2 92%. Immediate resuscitation, including albumin infusion and electrolyte correction, stabilized his condition. By July 9, hemoglobin increased to 90g/L, albumin was 18.0g/L, and AST was 92U/L. With normalized temperature and improved cough, the patient requested discharge. He was instructed to continue oral itraconazole(0.2g bid), levofloxacin(0.5g qd), and antiviral medications outpatient, with regular follow-ups. Discussion TM is a temperature-dependent dimorphic fungus commonly found in soil and rotting wood in nature. It is endemic in Southeast Asian countries and Southern China and is one of the most common opportunistic fungal pathogens in HIV-1 infected individuals[ 1 , 6 ]. Its pathogenic characteristics include an insidious onset and non-specific clinical manifestations, often leading to misdiagnosis[ 7 ]. Although characteristic skin lesions (such as umbilicated papules) are diagnostically significant, they do not appear in all patients[ 6 , 8 ]. This patient had a 5-year history of antiretroviral therapy but exhibited significantly suppressed immune function (CD4 + T cell count 72 cells/µL), placing him in a typical high-risk category for opportunistic infections, consistent with recent studies showing that TM infection can occur despite ART, particularly in patients with poor immune reconstitution[ 9 ]. R. equi is a Gram-positive, facultative intracellular bacterium belonging to the genus Rhodococcus . Commonly found in soil and feces of horse farms, it is a rare opportunistic pathogen primarily affecting immunocompromised individuals (such as AIDS patients), causing cavitary pneumonia, sepsis, or space-occupying lesions[ 3 , 4 , 10 ]. In primary care settings, it is frequently misdiagnosed as tuberculosis due to its acid-fast positivity, a situation that occurred in this case[ 11 ]. In conventional clinical thinking, the presence of acid-fast positivity usually directly points to Mycobacterium tuberculosis , which leads to initial misdiagnosis. Therefore, among AIDS patients, it is crucial to clearly determine whether the acid-fast positive result represents bacilli or cocci. Clinicians must pay special attention to making an early diagnosis and initiating treatment. R.equi is a classic concurrent infection in talaromycosis; it exhibits strong drug resistance and poses significant treatment challenges[ 5 , 12 ]. The isolation of R.equi from both the bone marrow and lungs in this patient suggests a profound level of immunodeficiency and potential hematogenous spread to the lungs, highlighting the severity of dual infection in advanced AIDS [ 13 ]. The definitive diagnosis of this case relied heavily on etiological diagnostics. The isolation of R.equi and TM from bone marrow aspiration and BALF cultures provided the most direct evidence for confirmation [ 5 , 14 ]. Notably, TM displayed characteristic yellow-green or light gray-green colonies on culture media (Fig. 3 A), and microscopy revealed typical broom-shaped conidiophores (Fig. 3 B, C)[ 6 , 14 ]. Targeted sequencing of BALF showed a significant number of TM reads (3,264 reads), highlighting the value of molecular biology techniques in early diagnosis, especially when traditional cultures are time-consuming[ 15 , 16 ]. Recent studies have demonstrated that mNGS significantly improves diagnostic yield in complex infections, identifying pathogens that are missed by conventional methods [ 15 , 17 ]. For this complex case, the preferred induction therapy for TM is amphotericin B (or its lipid formulation), followed by step-down therapy with itraconazole or voriconazole[ 6 , 18 ]. In this patient, due to gastrointestinal intolerance to azithromycin, amphotericin B was utilized for anti-TM treatment, adhering to the guideline-recommended principles of "adequate duration and dosage" [ 6 , 18 ]. Given the drug resistance of R.equi , the combination of levofloxacin and amikacin is currently a standard regimen, requiring close monitoring for adverse effects such as nephrotoxicity[ 5 , 12 ]. Optimizing the ART regimen to TDF/3TC/DTG helped increase CD4 + T cell counts and improve immune function, thereby enhancing the success rate of antifungal and antibacterial treatments[ 19 ]. Current guidelines recommend early ART initiation within 2 weeks of starting antifungal therapy for TM infection to improve outcomes [ 18 ]. On July 7, 2025, before the patient experienced the symptoms of shock, it was highly likely that it was an immune reconstitution inflammatory syndrome (IRIS). After initiating antiviral treatment, the patient's condition fluctuated. It was confirmed that the patient had infections caused by TM and R.equi , which were highly likely to trigger IRIS. In response to the situation where "ART was developed first, followed by infection", our strategy is no longer "delaying ART", but rather "stabilizing antiviral treatment, intensifying anti-infection efforts, and strictly preventing inflammatory storms". During the treatment process, we first need to evaluate the ART regimen and confirm whether the current antiviral drugs conflict with the anti-infective drugs (especially rifampicin-based drugs); then we need to adjust the anti-infective treatment plan: for antifungal treatment, amphotericin B is the first choice; for antibacterial treatment, rifabutin is the first choice. Thirdly, we must not interrupt the treatment and instruct the patient not to stop the ART at all; compliance is the key. Finally, we need to prepare for the use of alternative hormones and inform the patient that if the fever worsens or new rashes/shortness of breath occur after medication, they should immediately return for a follow-up visit. In case of necessity, additional hormones should be used to "put out the fire". This case presented several diagnostic and therapeutic challenges: 1. Non-specific Clinical Manifestations: the patient primarily presented with fever, cough, and weight loss. Imaging showed pulmonary infiltrates and cavities, easily leading to misdiagnosis as pulmonary tuberculosis or lung cancer, necessitating a high index of suspicion for opportunistic infections [ 7 , 11 ]. 2. Diagnosis of Co-infection: TM often co-occurs with other opportunistic pathogens (such as non-tuberculous mycobacteria or R.equi ). Etiological examinations must be comprehensive; diagnosis cannot rely solely on blood cultures or a single specimen type [ 5 , 12 , 20 ]. The use of mNGS in this case enabled rapid identification of both pathogens from BALF, demonstrating its utility in complex co-infections[ 15 , 16 ]. 3. Drug Interactions: During treatment, interactions between antifungal and antiviral drugs, as well as potential nephrotoxicity (e.g., from the combination of amphotericin B and amikacin), must be managed. This requires clinicians to possess extensive experience in pharmaceutical care[ 21 ]. The combination of amphotericin B and aminoglycosides requires careful monitoring of renal function and electrolytes. This case highlights the overlapping clinical and radiological features of R.equi and TM co-infection in patients with advanced AIDS, emphasizing the critical importance of timely etiological diagnosis and individualized combination therapy. In conclusion, the success of this case hinged on obtaining clear etiological evidence through bronchoscopy and bone marrow aspiration, which prevented misdiagnosis and facilitated the formulation of a targeted combination treatment plan[ 15 , 17 ]. Abbreviations TM Talaromyces marneffei HIV Human Immunodeficiency Virus AIDS Acquired Immune Deficiency Syndrome cART combination Antiretroviral Therapy HAART Highly Active Antiretroviral Therapy TDF Tenofovir Disoproxil Fumarate 3TC Lamivudine EFV Efavirenz HCV Hepatitis C Virus tNGS targeted Next-Generation Sequencing TMP-SMX trimethoprim-sulfamethoxazole DTG dolutegravir Declarations Supplementary Information Acknowledgements We thank the members of the department of infectious diseases and clinical laboratory in Yunnan Provincial Infectious Diseases Hospital for clinical data and sample collection. Authors’ contributions Li Gao, Yanqi Peng, Zhenglun Li, Xiaorui Cai, and Xingqi Dong designed the study, analyzed the data, and wrote the manuscript. Yue Feng and Xueshan Xia analyzed the data and reviewed the manuscript. All authors read and approved the final manuscript. Funding This work was supported financially by Yunnan Clinical Research Center for Infectious Disease (AIDS)“Precision-oriented research on key technologies of AIDS diagnosis and treatment”(grant number202405AJ310002). Data Availability The raw sequencing data reported in this paper have been deposited in the NCBI Sequence Read Archive (SRA) database (BioProject: PRJNA1444575). All other data from this study are presented in full in the manuscript. Ethics approval and consent to participate. Ethical approval was obtained from the Ethics Committee of Yunnan Provincial Hospital of Infectious Disease (Ref: Ke 2024050), and written informed consent for publication was obtained directly from the patient. He was fully informed about the nature of the publication, including the use of potentially identifying clinical information and medical images, and voluntarily agreed to participate. Consent for publication Written informed consent was obtained from the patients and their families for publication of this report and any accompanying images. Competing interests The authors declare no competing interests. References Wang L, Huang Y, Yan H, et al. Clinical characteristics and outcomes of Talaromyces marneffei infection in HIV-negative patients: a retrospective study. BMC Infect Dis. 2019;19:491. Zhu H, Guo Y, Chen H, et al. A case of pulmonary infection caused by Rhodococcus equi in an AIDS patient and literature review. Infect Drug Resist. 2025;18:2021-2027. Val-Calvo J, Darcy J, Gibbons J, et al. International spread of multidrug-resistant Rhodococcus equi. Emerg Infect Dis. 2022;28(9):1862-1866. Donisi A, Suardi MG, Casari S, et al. Rhodococcus equi infection in HIV-infected patients. AIDS. 1996;10(4):359-363. Chan JF, Lau SK, Yuen KY, Woo PC. Talaromyces (Penicillium) marneffei: an emerging pathogen in the era of HIV/AIDS and beyond. Virulence. 2016;7(3):273-284. Guidelines for the Prevention and Treatment of Opportunistic Infections in HIV-Infected Adults and Adolescents. NIH HIV Guidelines. 2024. Qin J, Deng Y, Huang Y, et al. Development and validation of a prognostic model for in-hospital mortality in patients with HIV-associated talaromycosis: a dynamic prediction study. PLoS Negl Trop Dis. 2025;19(1):e0013672. Hu Y, Zhang J, Li X, et al. Talaromyces marneffei infection in non-HIV-infected patients: a systematic review and meta-analysis. Emerg Microbes Infect. 2020;9(1):281-287. Chen Y, Li X, Wang L, et al. Clinical characteristics and prognosis of AIDS complicated with Talaromyces marneffei infection: a single-center retrospective study. Infect Dis Ther. 2025. Weinstock DM, Brown AE. Rhodococcus equi: an emerging pathogen. Clin Infect Dis. 2002;34(10):1379-1385. Hsueh PR, Hung CC, Teng LJ, et al. Report of invasive Rhodococcus equi infections in Taiwan, with an emphasis on the emergence of multidrug-resistant strains. Clin Infect Dis. 1998;27(2):370-375. Prescott JF. Rhodococcus equi: an animal and human pathogen. Clin Microbiol Rev. 1991;4(1):25-35. Arlotti M, Zoboli G, Moscatelli GL, et al. Rhodococcus equi infection in HIV-positive subjects: a retrospective analysis of 24 cases. Scand J Infect Dis. 1996;28(5):463-467. Le T, Wolbers M, Chi NH, et al. Epidemiology, seasonality, and predictors of outcome of AIDS-associated Penicillium marneffei infection in Ho Chi Minh City, Viet Nam. Clin Infect Dis. 2011;52(7):945-952. Han D, Li Z, Li R, et al. Seven-year performance of a clinical metagenomic next-generation sequencing test for diagnosis of central nervous system infections. Nat Med. 2024;30(11):3285-3295. Chiu CY, Miller SA. Clinical metagenomics. Nat Rev Genet. 2019;20(6):341-355. Han D, Yu F, Chen Y, et al. Effectiveness of metagenomic next-generation sequencing in the diagnosis of infectious diseases: a systematic review and meta-analysis. Int J Infect Dis. 2024;138:107-115. Guidelines for the Prevention and Treatment of Opportunistic Infections in Adults and Adolescents with HIV. Centers for Disease Control and Prevention (CDC). Updated 2024. Zhang C, Wang L, Liu X, et al. Advancements in diagnosing talaromycosis: exploring novel strategies and emerging technologies. J Fungi (Basel). 2025;11(6):434. Vinh DC, Maschmeyer G, Patterson TF. Emerging fungal pathogens in the immunocompromised host. Nat Rev Microbiol. 2015;13(11):717-729. Limper AH, Knox KS, Sarosi GA, et al. An official American Thoracic Society statement: Treatment of fungal infections in adult pulmonary and critical care patients. Am J Respir Crit Care Med. 2011;183(1):96-128. Additional Declarations No competing interests reported. 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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-9078351","acceptedTermsAndConditions":true,"allowDirectSubmit":false,"archivedVersions":[],"articleType":"Case Report","associatedPublications":[],"authors":[{"id":627429835,"identity":"58e2cd1f-11ff-42b4-b6b8-a3753d3b6b29","order_by":0,"name":"Li Gao","email":"","orcid":"","institution":"Kunming University of Science and Technology","correspondingAuthor":false,"prefix":"","firstName":"Li","middleName":"","lastName":"Gao","suffix":""},{"id":627429837,"identity":"71d7076d-0bfa-4f11-a497-ae573f6c0fa7","order_by":1,"name":"Yanqi Peng","email":"","orcid":"","institution":"Yunnan Provincial Infectious Diseases Hospital","correspondingAuthor":false,"prefix":"","firstName":"Yanqi","middleName":"","lastName":"Peng","suffix":""},{"id":627429839,"identity":"202ea676-7eb5-4991-a517-b8153dde7083","order_by":2,"name":"Zhenglun Li","email":"","orcid":"","institution":"Yunnan Provincial Infectious Diseases Hospital","correspondingAuthor":false,"prefix":"","firstName":"Zhenglun","middleName":"","lastName":"Li","suffix":""},{"id":627429841,"identity":"8274c2fe-a411-4104-8c90-d67a09801bdf","order_by":3,"name":"Xiaorui Cai","email":"","orcid":"","institution":"Yunnan Provincial Infectious Diseases Hospital","correspondingAuthor":false,"prefix":"","firstName":"Xiaorui","middleName":"","lastName":"Cai","suffix":""},{"id":627429842,"identity":"2e2a564c-2fa2-4c7a-84f8-70059a317631","order_by":4,"name":"Yue Feng","email":"data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAZAAAAAyAQMAAABI0h/eAAAABlBMVEX///8AAABVwtN+AAAACXBIWXMAAA7EAAAOxAGVKw4bAAAAz0lEQVRIiWNgGAWjYBAC9gY2BoYPBhL1/MzMhx8QpYXnABsD44wKmwTJdrY0A6K1MPOcSUswOM+jIEGcFom0NAnetsN5xod5GAwYamyiidFyTEKy7XCx2WHeAw8YjqXlNhDSYi+R3iZh2HaYcdthvgQDxobDhLXwgLQkArVsbuYxkCBSC9BhB86kJW5gJloLz7Nky4YKG2OJw8BATiDGLzzsaYa3/xhIyPH3Hz784EONDWEtDAIJLIjoSCCoHAT4DzB/IErhKBgFo2AUjFwAADgLPzv+90K6AAAAAElFTkSuQmCC","orcid":"","institution":"Kunming University of Science and Technology","correspondingAuthor":true,"prefix":"","firstName":"Yue","middleName":"","lastName":"Feng","suffix":""},{"id":627429843,"identity":"5f27173a-0e8f-463f-8c2b-3fb7b817e432","order_by":5,"name":"Xingqi Dong","email":"","orcid":"","institution":"Yunnan Provincial Infectious Diseases Hospital","correspondingAuthor":false,"prefix":"","firstName":"Xingqi","middleName":"","lastName":"Dong","suffix":""},{"id":627429844,"identity":"8e7f3e46-7787-4019-a12a-4bb6e03117a3","order_by":6,"name":"Xueshan Xia","email":"","orcid":"","institution":"Kunming University of Science and Technology","correspondingAuthor":false,"prefix":"","firstName":"Xueshan","middleName":"","lastName":"Xia","suffix":""}],"badges":[],"createdAt":"2026-03-10 02:54:38","currentVersionCode":1,"declarations":"","doi":"10.21203/rs.3.rs-9078351/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-9078351/v1","draftVersion":[],"editorialEvents":[],"editorialNote":"","failedWorkflow":false,"files":[{"id":107834079,"identity":"a8618837-360f-4f59-8116-afef0b348b31","added_by":"auto","created_at":"2026-04-26 15:42:51","extension":"png","order_by":1,"title":"Figure 1","display":"","copyAsset":false,"role":"figure","size":14090970,"visible":true,"origin":"","legend":"\u003cp\u003eTimeline and imaging. (A)A timeline of the patient’s clinical progress. (B)(C)Chest CT image shows pulmonary infection. (D)Enlarged spleen. (E)Right-sided pleural effusion.\u003c/p\u003e","description":"","filename":"Fig1.png","url":"https://assets-eu.researchsquare.com/files/rs-9078351/v1/5c7f40449b09544d914ade95.png"},{"id":107870160,"identity":"5876bb3e-f599-4905-8c79-c6c94db47d9d","added_by":"auto","created_at":"2026-04-27 07:38:58","extension":"png","order_by":2,"title":"Figure 2","display":"","copyAsset":false,"role":"figure","size":3278441,"visible":true,"origin":"","legend":"\u003cp\u003eColony and microscopic morphology of \u003cem\u003eR.equi. \u003c/em\u003e(A) Colony of \u003cem\u003eR.equi\u003c/em\u003e. (B)After 2 days of cultivation, the microscopic morphology under Gram staining showed that it was mainly Gram-positive(Gram stain, ×1000). (C)After 10 days of cultivation, the microscopic morphology under Gram staining showed that it was mainly Gram-negative(Gram stain,×1000). (D)(E)Concentration of sputum for bacterial collection, acid-fast staining, and microscopic morphology examination showed acid-fast positive cocci(acid-fast staining, ×1000). (F)The morphology of the colonies after 2 days of cultivation under acid-fast staining by microscope showed acid-fast negative cocci (acid-fast staining,×1000).\u003c/p\u003e","description":"","filename":"Fig2.png","url":"https://assets-eu.researchsquare.com/files/rs-9078351/v1/202cccdaf0c6b7c8b51fc090.png"},{"id":107834081,"identity":"96c7ba69-b7a8-43d5-ad69-8cf6bffaf25c","added_by":"auto","created_at":"2026-04-26 15:42:51","extension":"png","order_by":3,"title":"Figure 3","display":"","copyAsset":false,"role":"figure","size":101055267,"visible":true,"origin":"","legend":"\u003cp\u003eColony and microscopic morphology of TM\u003cem\u003e. \u003c/em\u003e(A)Wine-red colonies after 7 days at 25℃ on SDA. (B)(C)Typical characteristics of \u003cem\u003eTalaromyces marneffei\u003c/em\u003e with penicillus and phialides with spherical conidia in chains (brush-like structures typical of the genus Penicillium; lactophenol cotton blue stain; original magnification (B)×400, (C)×1000). (D)White, yeast-like colonies at 37℃. (E) Microscopic examination of the colonies revealed oval, yeast-like cells with a central septum. (F)After 2 days of cultivation at 37℃, the morphology of the colonies under Gram staining showed that the main form was Gram-negative bacilli (Gram stain,×1000). (F)After 10 days of cultivation at 37℃, the morphology of the colonies under Gram staining showed Gram-positive bacilli. (Gram stain,×1000)\u003c/p\u003e","description":"","filename":"Fig3.png","url":"https://assets-eu.researchsquare.com/files/rs-9078351/v1/bcbd0d05d2dc08d011bc8243.png"},{"id":108181053,"identity":"a6baeb8e-5098-4cc9-b548-1bb4c31f627e","added_by":"auto","created_at":"2026-04-30 08:56:43","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":100329455,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-9078351/v1/a5392dc5-9e6a-4112-a410-9dcfda49fb12.pdf"}],"financialInterests":"No competing interests reported.","formattedTitle":"A Case Report of Complex Co-infection with Talaromyces marneffei and Rhodococcus equi in a Patient with AIDS","fulltext":[{"header":"Background","content":"\u003cp\u003eCo-infection with \u003cem\u003eTalaromyces marneffei\u003c/em\u003e (TM) and \u003cem\u003eRhodococcus equi\u003c/em\u003e in HIV-positive individuals represents an extremely rare yet severe combination of opportunistic infections[\u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e, \u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2\u003c/span\u003e]. TM infection is particularly prevalent among HIV-1/AIDS populations in Southeast Asia and Southern China, whereas \u003cem\u003eR. equi\u003c/em\u003e infection is more commonly observed in individuals with severely compromised cellular immunity[\u003cspan citationid=\"CR3\" class=\"CitationRef\"\u003e3\u003c/span\u003e, \u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e4\u003c/span\u003e]. Although the incidence of co-infection is low, its complex clinical presentation, diagnostic difficulties, and challenging treatment protocols pose significant challenges in clinical practice[\u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e5\u003c/span\u003e]. This article reports a complex clinical case of an HIV-infected patient with concurrent TM and \u003cem\u003eR.equi\u003c/em\u003e infection, aiming to provide references for clinical practice. This study was approved by the Ethics Committee of Yunnan Provincial Infectious Diseases Hospital (Approval No.: Ke 2024050), in accordance with the Declaration of Helsinki.\u003c/p\u003e"},{"header":"Case Presentation","content":"\u003cp\u003ePatient Information: A 32-year-old male was diagnosed with HIV infection by the local Centers for Disease Control and Prevention (CDC) in 2018. His CD4\u003csup\u003e+\u003c/sup\u003eT lymphocyte count at diagnosis was unknown. Three months before admission, he had been on combination antiretroviral therapy (cART) with a regimen of tenofovir disoproxil fumarate/lamivudine/efavirenz (TDF/3TC/EFV). He had a history of intravenous drug use and was diagnosed with Hepatitis C five years ago, which was cured following standardized antiviral treatment.\u003c/p\u003e \u003cp\u003eHistory of Present Illness: On April 23, 2025, the patient developed fever, cough, expectoration of yellow-white viscous sputum, fatigue, and weight loss without obvious triggers. He was diagnosed at a local hospital with \"AIDS with multiple infections, suspected pulmonary tuberculosis, pulmonary fungal infection, intestinal fungal infection, hypoproteinemia, and moderate anemia\". He was treated with fluconazole (0.4g qd), isoniazid (0.3g qd), rifabutin (0.3g qd), ethambutol (0.75g qd), and pyrazinamide (1.0g qd). While his fever temporarily improved, cough and sputum production persisted, accompanied by chest tightness after exercise. Consequently, he was transferred to our hospital for further management on June 25, 2025.\u003c/p\u003e \u003cp\u003ePhysical Examination: Temperature 36.8℃, Pulse 82 bpm, Respiration 21 bpm, Blood Pressure 110/94 mmHg. Height 167 cm, Weight 46 kg, BMI 16.4 kg/m\u0026sup2;. The general condition was poor. The patient appeared emaciated but was conscious. He presented with an anemic appearance. No superficial lymphadenopathy was palpable. Skin and sclera were non-icteric, and lips and fingertips showed no cyanosis. The oral mucosa was smooth. Lung auscultation revealed coarse breath sounds without dry or wet rales. Heart rate was 82 bpm with a regular rhythm; no murmurs were heard in any valvular listening areas. The abdomen was flat and soft, with no tenderness, rebound tenderness, or muscle tension. Liver percussion pain was negative, and the hepatojugular reflux sign was negative. No edema was observed in the lower extremities.\u003c/p\u003e \u003cp\u003eLaboratory and Imaging Findings:\u003c/p\u003e \u003cp\u003eBlood Routine: WBC 11.1\u0026times;10\u003csup\u003e9\u003c/sup\u003e/L, Neutrophils 82.6%, Hemoglobin 70 g/L, Platelets 370\u0026times;10\u003csup\u003e9\u003c/sup\u003e/L.\u003c/p\u003e \u003cp\u003eBiochemistry: Albumin 21.6 g/L, Globulin 52.8 g/L, ALT 19 U/L, AST 47 U/L, CRP 161.87 mg/L, PCT 0.246 ng/ml, IL-6 98.29 pg/mL.\u003c/p\u003e \u003cp\u003eImmunology: CD4\u003csup\u003e+\u003c/sup\u003eT cell count 72 cells/\u0026micro;L, CD4\u003csup\u003e+\u003c/sup\u003e/CD8\u003csup\u003e+\u003c/sup\u003e ratio 0.14, HIV-RNA 7.84\u0026times;10\u003csup\u003e4\u003c/sup\u003eIU/mL.\u003c/p\u003e \u003cp\u003eFungal Markers: Fungal D-glucan 212.87 pg/ml, Aspergillus galactomannan antigen 0.11 \u0026micro;g/L.\u003c/p\u003e \u003cp\u003eImaging (Chest CT, 2025-06-26, Fig.\u0026nbsp;\u003cspan refid=\"Fig1\" class=\"InternalRef\"\u003e1\u003c/span\u003eB\u0026thinsp;~\u0026thinsp;E): Revealed multiple infiltrative lesions in both lungs with thick-walled cavity formation, consolidation, and atelectasis in the middle and lower lobes of the right lung, possible lung abscess in the right lower lobe. Enlarged mediastinal and right hilar lymph nodes were noted. Signs of pulmonary hypertension, small pericardial effusion, bilateral pleural thickening, and multiple osteolytic destructions of the sternum, bilateral clavicles, and scapulae were observed. Abdominal ultrasound indicated splenomegaly (thickness 4.7cm), multiple stones in the right kidney, and right-sided pleural effusion.\u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003cp\u003eEtiological Examination: Three consecutive sputum acid-fast stains upon admission were negative. However, under the microscope, acid-fast positive cocci were observed (Fig.\u0026nbsp;2DE).On June 26, bone marrow aspiration was performed, and \u003cem\u003eR. equi\u003c/em\u003e was cultured from the bone marrow (microscopic and colony morphology shown in Fig.\u0026nbsp;\u003cspan refid=\"Fig2\" class=\"InternalRef\"\u003e2\u003c/span\u003eA-C, F). The isolate was sensitive to levofloxacin, gentamicin, linezolid, and tigecycline (Table\u0026nbsp;\u003cspan refid=\"Tab1\" class=\"InternalRef\"\u003e1\u003c/span\u003e). On June 27, bronchoscopy was conducted; both \u003cem\u003eR.equi\u003c/em\u003e and TM were cultured from the bronchoalveolar lavage fluid(BALF) (colony and microscopic morphology shown in Fig.\u0026nbsp;\u003cspan refid=\"Fig3\" class=\"InternalRef\"\u003e3\u003c/span\u003eA-F). Targeted sequencing of the BALF revealed 15,134 sequence reads for \u003cem\u003eR.equi\u003c/em\u003e and 3,264 reads for TM.\u003c/p\u003e \u003cp\u003e \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\u003eAntibiotic susceptibility test for \u003cem\u003eRhodococcus equi\u003c/em\u003e\u003c/p\u003e \u003c/div\u003e \u003c/caption\u003e \u003ccolgroup cols=\"6\"\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 \u003cdiv align=\"left\" class=\"colspec\" colname=\"c6\" colnum=\"6\"\u003e\u003c/div\u003e \u003cthead\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c1\"\u003e \u003cp\u003eAntibiotics\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c2\"\u003e \u003cp\u003eMIC(mg/L)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c3\"\u003e \u003cp\u003eResult\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c4\"\u003e \u003cp\u003eAntibiotics\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c5\"\u003e \u003cp\u003eMIC(mg/L)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c6\"\u003e \u003cp\u003eResult\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eGentamicin\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e\u0026lt;=0.5\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003eS\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003eLinezolid\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e4\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003eS\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eCiprofloxacin\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e\u0026lt;=0.5\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003eS\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003eTetracycline\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e\u0026gt;=16.0\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003eR\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eLevofloxacin\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e0.5\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003eS\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003eTigecycline\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e0.5\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003eS\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eMoxifloxacin\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e0.5\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003eS\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003eRifampicin\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e\u0026lt;=0.5\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003eS\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eErythromycin\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e\u0026gt;=8.0\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003eR\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003eTrimethoprim/Sulfamethoxazole\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e1\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003eS\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eQuinupristin/Dalfopristin\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e4\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003eR\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003c/tbody\u003e \u003c/colgroup\u003e \u003c/table\u003e\u003c/div\u003e \u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003cdiv id=\"Sec3\" class=\"Section2\"\u003e \u003ch2\u003eDiagnosis and Treatment\u003c/h2\u003e \u003cp\u003eBased on clinical and laboratory findings, the patient was diagnosed with: AIDS with multiple infections, Talaromycosis (TM infection), \u003cem\u003eR. equi\u003c/em\u003e sepsis, Bacterial pneumonia, Hypoproteinemia, and Moderate anemia. Initially, the patient continued on the HRbEZ anti-tuberculosis regimen, fluconazole for antifungal coverage, and compound sulfamethoxazole for PCP prophylaxis. After confirming \u003cem\u003eR.equi\u003c/em\u003e sepsis on June 27, the antimicrobial regimen was adjusted to levofloxacin (0.5g qd), amikacin (0.4g qd), and azithromycin (0.25g qd). On June 29, amphotericin B was added for anti-TM therapy, starting at 5 mg and increased daily. Due to severe gastrointestinal reactions, azithromycin and compound sulfamethoxazole were discontinued. On June 30, the ART regimen was optimized to TDF/3TC/DTG. On July 1, the patient reported three episodes of watery diarrhea; examination revealed white pseudomembranes on the oral mucosa, suggesting concurrent oral candidiasis, treated with sodium bicarbonate mouthwash. On July 7 at 11:30, the patient experienced sudden fatigue, chest tightness, and nausea. Vital signs deteriorated: BP 87/56 mmHg, HR 120 bpm, SpO2 92%. Immediate resuscitation, including albumin infusion and electrolyte correction, stabilized his condition. By July 9, hemoglobin increased to 90g/L, albumin was 18.0g/L, and AST was 92U/L. With normalized temperature and improved cough, the patient requested discharge. He was instructed to continue oral itraconazole(0.2g bid), levofloxacin(0.5g qd), and antiviral medications outpatient, with regular follow-ups.\u003c/p\u003e \u003c/div\u003e"},{"header":"Discussion","content":"\u003cp\u003eTM is a temperature-dependent dimorphic fungus commonly found in soil and rotting wood in nature. It is endemic in Southeast Asian countries and Southern China and is one of the most common opportunistic fungal pathogens in HIV-1 infected individuals[\u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e, \u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e6\u003c/span\u003e]. Its pathogenic characteristics include an insidious onset and non-specific clinical manifestations, often leading to misdiagnosis[\u003cspan citationid=\"CR7\" class=\"CitationRef\"\u003e7\u003c/span\u003e]. Although characteristic skin lesions (such as umbilicated papules) are diagnostically significant, they do not appear in all patients[\u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e6\u003c/span\u003e, \u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e8\u003c/span\u003e]. This patient had a 5-year history of antiretroviral therapy but exhibited significantly suppressed immune function (CD4\u003csup\u003e+\u003c/sup\u003eT cell count 72 cells/\u0026micro;L), placing him in a typical high-risk category for opportunistic infections, consistent with recent studies showing that TM infection can occur despite ART, particularly in patients with poor immune reconstitution[\u003cspan citationid=\"CR9\" class=\"CitationRef\"\u003e9\u003c/span\u003e].\u003c/p\u003e \u003cp\u003e \u003cem\u003eR. equi\u003c/em\u003e is a Gram-positive, facultative intracellular bacterium belonging to the genus \u003cem\u003eRhodococcus\u003c/em\u003e. Commonly found in soil and feces of horse farms, it is a rare opportunistic pathogen primarily affecting immunocompromised individuals (such as AIDS patients), causing cavitary pneumonia, sepsis, or space-occupying lesions[\u003cspan citationid=\"CR3\" class=\"CitationRef\"\u003e3\u003c/span\u003e, \u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e4\u003c/span\u003e, \u003cspan citationid=\"CR10\" class=\"CitationRef\"\u003e10\u003c/span\u003e]. In primary care settings, it is frequently misdiagnosed as tuberculosis due to its acid-fast positivity, a situation that occurred in this case[\u003cspan citationid=\"CR11\" class=\"CitationRef\"\u003e11\u003c/span\u003e]. In conventional clinical thinking, the presence of acid-fast positivity usually directly points to \u003cem\u003eMycobacterium tuberculosis\u003c/em\u003e, which leads to initial misdiagnosis. Therefore, among AIDS patients, it is crucial to clearly determine whether the acid-fast positive result represents bacilli or cocci. Clinicians must pay special attention to making an early diagnosis and initiating treatment.\u003cem\u003eR.equi\u003c/em\u003e is a classic concurrent infection in talaromycosis; it exhibits strong drug resistance and poses significant treatment challenges[\u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e5\u003c/span\u003e, \u003cspan citationid=\"CR12\" class=\"CitationRef\"\u003e12\u003c/span\u003e]. The isolation of \u003cem\u003eR.equi\u003c/em\u003e from both the bone marrow and lungs in this patient suggests a profound level of immunodeficiency and potential hematogenous spread to the lungs, highlighting the severity of dual infection in advanced AIDS [\u003cspan citationid=\"CR13\" class=\"CitationRef\"\u003e13\u003c/span\u003e].\u003c/p\u003e \u003cp\u003eThe definitive diagnosis of this case relied heavily on etiological diagnostics. The isolation of \u003cem\u003eR.equi\u003c/em\u003e and TM from bone marrow aspiration and BALF cultures provided the most direct evidence for confirmation [\u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e5\u003c/span\u003e, \u003cspan citationid=\"CR14\" class=\"CitationRef\"\u003e14\u003c/span\u003e]. Notably, TM displayed characteristic yellow-green or light gray-green colonies on culture media (Fig.\u0026nbsp;\u003cspan refid=\"Fig3\" class=\"InternalRef\"\u003e3\u003c/span\u003eA), and microscopy revealed typical broom-shaped conidiophores (Fig.\u0026nbsp;\u003cspan refid=\"Fig3\" class=\"InternalRef\"\u003e3\u003c/span\u003eB, C)[\u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e6\u003c/span\u003e, \u003cspan citationid=\"CR14\" class=\"CitationRef\"\u003e14\u003c/span\u003e]. Targeted sequencing of BALF showed a significant number of TM reads (3,264 reads), highlighting the value of molecular biology techniques in early diagnosis, especially when traditional cultures are time-consuming[\u003cspan citationid=\"CR15\" class=\"CitationRef\"\u003e15\u003c/span\u003e, \u003cspan citationid=\"CR16\" class=\"CitationRef\"\u003e16\u003c/span\u003e]. Recent studies have demonstrated that mNGS significantly improves diagnostic yield in complex infections, identifying pathogens that are missed by conventional methods [\u003cspan citationid=\"CR15\" class=\"CitationRef\"\u003e15\u003c/span\u003e, \u003cspan citationid=\"CR17\" class=\"CitationRef\"\u003e17\u003c/span\u003e].\u003c/p\u003e \u003cp\u003eFor this complex case, the preferred induction therapy for TM is amphotericin B (or its lipid formulation), followed by step-down therapy with itraconazole or voriconazole[\u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e6\u003c/span\u003e, \u003cspan citationid=\"CR18\" class=\"CitationRef\"\u003e18\u003c/span\u003e]. In this patient, due to gastrointestinal intolerance to azithromycin, amphotericin B was utilized for anti-TM treatment, adhering to the guideline-recommended principles of \"adequate duration and dosage\" [\u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e6\u003c/span\u003e, \u003cspan citationid=\"CR18\" class=\"CitationRef\"\u003e18\u003c/span\u003e]. Given the drug resistance of \u003cem\u003eR.equi\u003c/em\u003e, the combination of levofloxacin and amikacin is currently a standard regimen, requiring close monitoring for adverse effects such as nephrotoxicity[\u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e5\u003c/span\u003e, \u003cspan citationid=\"CR12\" class=\"CitationRef\"\u003e12\u003c/span\u003e]. Optimizing the ART regimen to TDF/3TC/DTG helped increase CD4\u003csup\u003e+\u003c/sup\u003eT cell counts and improve immune function, thereby enhancing the success rate of antifungal and antibacterial treatments[\u003cspan citationid=\"CR19\" class=\"CitationRef\"\u003e19\u003c/span\u003e]. Current guidelines recommend early ART initiation within 2 weeks of starting antifungal therapy for TM infection to improve outcomes [\u003cspan citationid=\"CR18\" class=\"CitationRef\"\u003e18\u003c/span\u003e].\u003c/p\u003e \u003cp\u003eOn July 7, 2025, before the patient experienced the symptoms of shock, it was highly likely that it was an immune reconstitution inflammatory syndrome (IRIS). After initiating antiviral treatment, the patient's condition fluctuated. It was confirmed that the patient had infections caused by TM and \u003cem\u003eR.equi\u003c/em\u003e, which were highly likely to trigger IRIS. In response to the situation where \"ART was developed first, followed by infection\", our strategy is no longer \"delaying ART\", but rather \"stabilizing antiviral treatment, intensifying anti-infection efforts, and strictly preventing inflammatory storms\". During the treatment process, we first need to evaluate the ART regimen and confirm whether the current antiviral drugs conflict with the anti-infective drugs (especially rifampicin-based drugs); then we need to adjust the anti-infective treatment plan: for antifungal treatment, amphotericin B is the first choice; for antibacterial treatment, rifabutin is the first choice. Thirdly, we must not interrupt the treatment and instruct the patient not to stop the ART at all; compliance is the key. Finally, we need to prepare for the use of alternative hormones and inform the patient that if the fever worsens or new rashes/shortness of breath occur after medication, they should immediately return for a follow-up visit. In case of necessity, additional hormones should be used to \"put out the fire\".\u003c/p\u003e \u003cp\u003eThis case presented several diagnostic and therapeutic challenges: 1. Non-specific Clinical Manifestations: the patient primarily presented with fever, cough, and weight loss. Imaging showed pulmonary infiltrates and cavities, easily leading to misdiagnosis as pulmonary tuberculosis or lung cancer, necessitating a high index of suspicion for opportunistic infections [\u003cspan citationid=\"CR7\" class=\"CitationRef\"\u003e7\u003c/span\u003e, \u003cspan citationid=\"CR11\" class=\"CitationRef\"\u003e11\u003c/span\u003e]. 2. Diagnosis of Co-infection: TM often co-occurs with other opportunistic pathogens (such as non-tuberculous mycobacteria or \u003cem\u003eR.equi\u003c/em\u003e). Etiological examinations must be comprehensive; diagnosis cannot rely solely on blood cultures or a single specimen type [\u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e5\u003c/span\u003e, \u003cspan citationid=\"CR12\" class=\"CitationRef\"\u003e12\u003c/span\u003e, \u003cspan citationid=\"CR20\" class=\"CitationRef\"\u003e20\u003c/span\u003e]. The use of mNGS in this case enabled rapid identification of both pathogens from BALF, demonstrating its utility in complex co-infections[\u003cspan citationid=\"CR15\" class=\"CitationRef\"\u003e15\u003c/span\u003e, \u003cspan citationid=\"CR16\" class=\"CitationRef\"\u003e16\u003c/span\u003e]. 3. Drug Interactions: During treatment, interactions between antifungal and antiviral drugs, as well as potential nephrotoxicity (e.g., from the combination of amphotericin B and amikacin), must be managed. This requires clinicians to possess extensive experience in pharmaceutical care[\u003cspan citationid=\"CR21\" class=\"CitationRef\"\u003e21\u003c/span\u003e]. The combination of amphotericin B and aminoglycosides requires careful monitoring of renal function and electrolytes.\u003c/p\u003e \u003cp\u003eThis case highlights the overlapping clinical and radiological features of \u003cem\u003eR.equi\u003c/em\u003e and TM co-infection in patients with advanced AIDS, emphasizing the critical importance of timely etiological diagnosis and individualized combination therapy. In conclusion, the success of this case hinged on obtaining clear etiological evidence through bronchoscopy and bone marrow aspiration, which prevented misdiagnosis and facilitated the formulation of a targeted combination treatment plan[\u003cspan citationid=\"CR15\" class=\"CitationRef\"\u003e15\u003c/span\u003e, \u003cspan citationid=\"CR17\" class=\"CitationRef\"\u003e17\u003c/span\u003e].\u003c/p\u003e"},{"header":"Abbreviations","content":"\u003cdiv class=\"DefinitionList\"\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003eTM\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003e \u003cem\u003eTalaromyces marneffei\u003c/em\u003e \u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003eHIV\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003eHuman Immunodeficiency Virus\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003eAIDS\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003eAcquired Immune Deficiency Syndrome\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003ecART\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003ecombination Antiretroviral Therapy\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003eHAART\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003eHighly Active Antiretroviral Therapy\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003eTDF\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003eTenofovir Disoproxil Fumarate\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003e3TC\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003eLamivudine\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003eEFV\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003eEfavirenz\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003eHCV\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003eHepatitis C Virus\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003etNGS\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003etargeted Next-Generation Sequencing\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003eTMP-SMX\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003etrimethoprim-sulfamethoxazole\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003eDTG\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003edolutegravir\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003c/div\u003e"},{"header":"Declarations","content":"\u003cp\u003e\u003cstrong\u003eSupplementary Information\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAcknowledgements\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eWe thank the members of the department of infectious diseases and clinical laboratory in Yunnan Provincial Infectious Diseases Hospital for clinical data and sample collection.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAuthors\u0026rsquo; contributions\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eLi Gao, Yanqi Peng, Zhenglun Li, Xiaorui Cai, and Xingqi Dong designed the study, analyzed the data, and wrote the manuscript. Yue Feng and Xueshan Xia analyzed the data and reviewed the manuscript. All authors read and approved the final manuscript.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eFunding\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThis work was supported financially by Yunnan Clinical Research Center for Infectious Disease (AIDS)\u0026ldquo;Precision-oriented research on key technologies of AIDS diagnosis and treatment\u0026rdquo;(grant number202405AJ310002).\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eData Availability\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe raw sequencing data reported in this paper have been deposited in the NCBI Sequence Read Archive (SRA) database (BioProject: PRJNA1444575). All other data from this study are presented in full in the manuscript.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eEthics approval and consent to participate.\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eEthical approval was obtained from the Ethics Committee of Yunnan Provincial Hospital of Infectious Disease (Ref: Ke 2024050), and written informed consent for publication was obtained directly from the patient. He was fully informed about the nature of the publication, including the use of potentially identifying clinical information and medical images, and voluntarily agreed to participate.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eConsent for publication\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eWritten informed consent was obtained from the patients and their families for publication of this report and any accompanying images.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eCompeting interests\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe authors declare no competing interests.\u003c/p\u003e"},{"header":"References","content":"\u003col\u003e\n \u003cli\u003eWang L, Huang Y, Yan H, et al. Clinical characteristics and outcomes of Talaromyces marneffei infection in HIV-negative patients: a retrospective study. BMC Infect Dis. 2019;19:491.\u0026nbsp;\u003c/li\u003e\n \u003cli\u003e\u0026nbsp;Zhu H, Guo Y, Chen H, et al. A case of pulmonary infection caused by Rhodococcus equi in an AIDS patient and literature review. Infect Drug Resist. 2025;18:2021-2027.\u0026nbsp;\u003c/li\u003e\n \u003cli\u003eVal-Calvo J, Darcy J, Gibbons J, et al. International spread of multidrug-resistant Rhodococcus equi. Emerg Infect Dis. 2022;28(9):1862-1866.\u003c/li\u003e\n \u003cli\u003eDonisi A, Suardi MG, Casari S, et al. Rhodococcus equi infection in HIV-infected patients. AIDS. 1996;10(4):359-363.\u0026nbsp;\u003c/li\u003e\n \u003cli\u003eChan JF, Lau SK, Yuen KY, Woo PC. Talaromyces (Penicillium) marneffei: an emerging pathogen in the era of HIV/AIDS and beyond. Virulence. 2016;7(3):273-284.\u003c/li\u003e\n \u003cli\u003eGuidelines for the Prevention and Treatment of Opportunistic Infections in HIV-Infected Adults and Adolescents. NIH HIV Guidelines. 2024.\u0026nbsp;\u003c/li\u003e\n \u003cli\u003eQin J, Deng Y, Huang Y, et al. Development and validation of a prognostic model for in-hospital mortality in patients with HIV-associated talaromycosis: a dynamic prediction study. PLoS Negl Trop Dis. 2025;19(1):e0013672.\u0026nbsp;\u003c/li\u003e\n \u003cli\u003eHu Y, Zhang J, Li X, et al. Talaromyces marneffei infection in non-HIV-infected patients: a systematic review and meta-analysis. Emerg Microbes Infect. 2020;9(1):281-287.\u003c/li\u003e\n \u003cli\u003eChen Y, Li X, Wang L, et al. Clinical characteristics and prognosis of AIDS complicated with \u003cem\u003eTalaromyces marneffei\u003c/em\u003e infection: a single-center retrospective study. Infect Dis Ther. 2025.\u0026nbsp;\u003c/li\u003e\n \u003cli\u003eWeinstock DM, Brown AE. Rhodococcus equi: an emerging pathogen. Clin Infect Dis. 2002;34(10):1379-1385.\u0026nbsp;\u003c/li\u003e\n \u003cli\u003eHsueh PR, Hung CC, Teng LJ, et al. Report of invasive Rhodococcus equi infections in Taiwan, with an emphasis on the emergence of multidrug-resistant strains. Clin Infect Dis. 1998;27(2):370-375.\u0026nbsp;\u003c/li\u003e\n \u003cli\u003ePrescott JF. Rhodococcus equi: an animal and human pathogen. Clin Microbiol Rev. 1991;4(1):25-35.\u0026nbsp;\u003c/li\u003e\n \u003cli\u003eArlotti M, Zoboli G, Moscatelli GL, et al. Rhodococcus equi infection in HIV-positive subjects: a retrospective analysis of 24 cases. Scand J Infect Dis. 1996;28(5):463-467.\u0026nbsp;\u003c/li\u003e\n \u003cli\u003eLe T, Wolbers M, Chi NH, et al. Epidemiology, seasonality, and predictors of outcome of AIDS-associated Penicillium marneffei infection in Ho Chi Minh City, Viet Nam. Clin Infect Dis. 2011;52(7):945-952.\u003c/li\u003e\n \u003cli\u003eHan D, Li Z, Li R, et al. Seven-year performance of a clinical metagenomic next-generation sequencing test for diagnosis of central nervous system infections. Nat Med. 2024;30(11):3285-3295.\u003c/li\u003e\n \u003cli\u003eChiu CY, Miller SA. Clinical metagenomics. Nat Rev Genet. 2019;20(6):341-355.\u0026nbsp;\u003c/li\u003e\n \u003cli\u003eHan D, Yu F, Chen Y, et al. Effectiveness of metagenomic next-generation sequencing in the diagnosis of infectious diseases: a systematic review and meta-analysis. Int J Infect Dis. 2024;138:107-115.\u003c/li\u003e\n \u003cli\u003eGuidelines for the Prevention and Treatment of Opportunistic Infections in Adults and Adolescents with HIV. Centers for Disease Control and Prevention (CDC). Updated 2024.\u0026nbsp;\u003c/li\u003e\n \u003cli\u003eZhang C, Wang L, Liu X, et al. Advancements in diagnosing talaromycosis: exploring novel strategies and emerging technologies. J Fungi (Basel). 2025;11(6):434.\u003c/li\u003e\n \u003cli\u003eVinh DC, Maschmeyer G, Patterson TF. Emerging fungal pathogens in the immunocompromised host. Nat Rev Microbiol. 2015;13(11):717-729.\u003c/li\u003e\n \u003cli\u003eLimper AH, Knox KS, Sarosi GA, et al. An official American Thoracic Society statement: Treatment of fungal infections in adult pulmonary and critical care patients. Am J Respir Crit Care Med. 2011;183(1):96-128.\u003c/li\u003e\n\u003c/ol\u003e"}],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":true,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":false,"hideJournal":false,"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":"bmc-infectious-diseases","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"infd","sideBox":"Learn more about [BMC Infectious Diseases](http://bmcinfectdis.biomedcentral.com/)","snPcode":"","submissionUrl":"https://www.editorialmanager.com/infd","title":"BMC Infectious Diseases","twitterHandle":"#bmcinfectdis","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"em","reportingPortfolio":"BMC Series","inReviewEnabled":true,"inReviewRevisionsEnabled":true},"keywords":"HIV, Talaromyces marneffei, Rhodococcus equi, Co-infection, Opportunistic infection","lastPublishedDoi":"10.21203/rs.3.rs-9078351/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-9078351/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003cp\u003e\u003cstrong\u003eBackground: \u003c/strong\u003eCo-infection with \u003cem\u003eTalaromyces marneffei \u003c/em\u003e(TM) and \u003cem\u003eRhodococcus equi\u003c/em\u003ein HIV-positive patients is an extremely rare but life-threatening combination of opportunistic infections. We report a scarce case of an HIV-infected patient initially suspected of pulmonary tuberculosis, who was subsequently confirmed by culture and next-generation sequencing (NGS) to have a co-infection with \u003cem\u003eR. equi\u003c/em\u003e and TM.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eCase Presentation: \u003c/strong\u003eThe patient was a 32-year-old male presenting with cough, sputum production, and chest tightness after exercise. He was admitted to our hospital for further diagnosis and treatment on June 25, 2025. The sputum acid-fast stain was positive for acid-fast coccoid organisms on June 26, 2025. Following the confirmation of \u003cem\u003eR. equi\u003c/em\u003e sepsis on June 27, the antimicrobial regimen was adjusted to a combination of levofloxacin (0.5g qd), amikacin (0.4g qd), and azithromycin (0.25g qd). On June 29, amphotericin B was initiated for anti-TM therapy, starting at 5 mg and titrated daily. Due to severe gastrointestinal reactions, azithromycin and compound sulfamethoxazole were discontinued. On June 30, the antiretroviral therapy (ART) was optimized to tenofovir disoproxil fumarate/lamivudine/dolutegravir (TDF/3TC/DTG). On July 1, the patient reported three episodes of watery diarrhea; examination revealed white pseudomembranes on the bilateral oral mucosa, suggestive of concurrent oral candidiasis, for which sodium bicarbonate mouthwash was prescribed. At 11:30 on July 7, the patient experienced sudden fatigue, chest tightness, and nausea, with blood pressure dropping to 87/56 mmHg, heart rate rising to 120 bpm, and oxygen saturation at 92%. Immediate resuscitation measures, including albumin supplementation and correction of electrolyte imbalances, stabilized his condition. By July 9, hemoglobin rose to 90 g/L, albumin was 18.0 g/L, and liver function tests showed AST at 92 U/L. With normalized body temperature and reduced coughing, the patient requested discharge. He was advised to continue oral itraconazole (0.2g bid), levofloxacin (0.5g qd), and antiviral medications, outpatient, with regular follow-ups.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eConclusion:\u003c/strong\u003e \u003cem\u003eR.equi\u003c/em\u003e, being acid-fast positive, is easily misdiagnosed as tuberculosis; thus, clinicians must prioritize differential diagnosis for such infections. The key to success in this case lay in obtaining definitive etiological evidence through bronchoscopy and bone marrow aspiration, which prevented misdiagnosis and enabled a targeted combination therapy. This underscores the importance of employing multiple diagnostic methods to clarify clinical diagnoses.\u003c/p\u003e","manuscriptTitle":"A Case Report of Complex Co-infection with Talaromyces marneffei and Rhodococcus equi in a Patient with AIDS","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2026-04-26 15:42:45","doi":"10.21203/rs.3.rs-9078351/v1","editorialEvents":[{"type":"communityComments","content":0},{"type":"editorInvitedReview","content":"","date":"2026-05-16T07:59:17+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"174276037331358383055639493554634852811","date":"2026-05-16T04:42:10+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"256944240249420081068578469046651806340","date":"2026-05-16T03:56:33+00:00","index":"hide","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2026-04-21T12:33:32+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"47814528483665314649642883869780904102","date":"2026-04-17T01:16:28+00:00","index":"hide","fulltext":""},{"type":"reviewersInvited","content":"","date":"2026-04-16T17:00:19+00:00","index":"","fulltext":""},{"type":"editorInvited","content":"","date":"2026-04-08T05:54:21+00:00","index":"","fulltext":""},{"type":"editorAssigned","content":"","date":"2026-03-30T06:21:56+00:00","index":"","fulltext":""},{"type":"checksComplete","content":"","date":"2026-03-29T09:25:43+00:00","index":"","fulltext":""},{"type":"submitted","content":"BMC Infectious Diseases","date":"2026-03-29T09:20:35+00:00","index":"","fulltext":""}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"bmc-infectious-diseases","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"infd","sideBox":"Learn more about [BMC Infectious Diseases](http://bmcinfectdis.biomedcentral.com/)","snPcode":"","submissionUrl":"https://www.editorialmanager.com/infd","title":"BMC Infectious Diseases","twitterHandle":"#bmcinfectdis","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"em","reportingPortfolio":"BMC Series","inReviewEnabled":true,"inReviewRevisionsEnabled":true}}],"origin":"","ownerIdentity":"656aec60-663c-408f-bf07-50a8eb157225","owner":[],"postedDate":"April 26th, 2026","published":true,"recentEditorialEvents":[{"type":"editorInvitedReview","content":"","date":"2026-05-16T07:59:17+00:00","index":112,"fulltext":""},{"type":"reviewerAgreed","content":"174276037331358383055639493554634852811","date":"2026-05-16T04:42:10+00:00","index":110,"fulltext":""},{"type":"reviewerAgreed","content":"256944240249420081068578469046651806340","date":"2026-05-16T03:56:33+00:00","index":109,"fulltext":""}],"rejectedJournal":[],"revision":"","amendment":"","status":"under-review","subjectAreas":[],"tags":[],"updatedAt":"2026-04-26T15:42:46+00:00","versionOfRecord":[],"versionCreatedAt":"2026-04-26 15:42:45","video":"","vorDoi":"","vorDoiUrl":"","workflowStages":[]},"version":"v1","identity":"rs-9078351","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-9078351","identity":"rs-9078351","version":["v1"]},"buildId":"XKTyCvWXoU3ODBz1xrDgd","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}