Infection最新文献

{"title":"Concordance of five large language models with infectious diseases physicians on clinical decision-making: a multi-model comparative survey study.","authors":"Yakup Demir, Hüsameddin Atay, Eren Öztürk","doi":"10.1007/s15010-026-03006-3","DOIUrl":"https://doi.org/10.1007/s15010-026-03006-3","url":null,"abstract":"<p><strong>Purpose: </strong>To evaluate the accuracy of five large language models (LLMs) on a set of infectious diseases (ID) case-based multiple-choice questions and to compare their performance with that of practising ID physicians.</p><p><strong>Methods: </strong>A cross-sectional, web-based comparative survey was conducted among ID physicians and residents across Turkey. Ten original case scenarios (30 five-option multiple-choice questions; stratified by difficulty) were validated by a five-expert Delphi consensus panel (two rounds) using IDSA guidelines and EUCAST 2024 breakpoints as the reference standard. The same questions were put to five LLMs - Grok, ChatGPT-4o, Gemini 2.5, Claude Sonnet, and DeepSeek-V3 - via a standardised prompt in a single session. Primary outcomes were accuracy rate (%), Cohen's κ computed from observed response marginals, and an exact one-sided binomial test comparing each model's score against the observed physician-group accuracy, with Cohen's h as the effect-size measure for the difference between proportions.</p><p><strong>Results: </strong>Of 129 respondents, 112 were included; 17 were excluded for self-reported AI use during the case section (this exclusion criterion was empirically supported: excluded participants scored significantly higher than included participants, 68.8% vs. 61.6%, Mann-Whitney p = 0.0015). Physician accuracy was 61.6% (18.5/30; SD 8.2; κ = 0.41 relative to a chance rate of 20%, interpreted descriptively). Four of five LLMs showed statistically significant superiority over the physician group: Grok 90.0% (κ = 0.806; Cohen's h = 0.69; binomial p < 0.001), ChatGPT-4o 83.3% (κ = 0.682; h = 0.50; p = 0.009), Gemini 2.5 83.3% (κ = 0.700; h = 0.50; p = 0.009), Claude Sonnet 80.0% (κ = 0.646; h = 0.41; p = 0.026); DeepSeek-V3 (76.7%; κ = 0.573; h = 0.33) did not reach statistical significance (p = 0.062). In Turkey-specific endemic cases, all models scored 100% versus 73% for physicians. Two items showed low concordance with the guideline-derived reference in both physicians and all LLMs; post-hoc review indicated that one of these items (prosthetic valve endocarditis) reflected a timing-dependent guideline nuance not fully captured by the original vignette, rather than a clear guideline violation. No correlation was found between physician AI-trust scores and clinical accuracy (Spearman ρ=-0.008; p = 0.937).</p><p><strong>Conclusion: </strong>On this case-based multiple-choice assessment, most evaluated LLMs achieved higher guideline concordance than a physician comparison group, particularly for guideline-standard and regionally endemic scenarios. These findings should be interpreted as evidence of accuracy on a structured test format rather than of general clinical decision-making superiority, and do not establish that LLMs should be used unsupervised in real clinical practice, which typically involves collaborative, multidisciplinary input rather than unilateral decisions.</p>","PeriodicalId":13600,"journal":{"name":"Infection","volume":" ","pages":""},"PeriodicalIF":3.9,"publicationDate":"2026-10-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149109047","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Asymptomatic bacteriuria in patients receiving SGLT2 inhibitors: methodological considerations and clinical implications.","authors":"Ahmad Alam, Mohd Salman, Bushra Amer","doi":"10.1007/s15010-026-03005-4","DOIUrl":"https://doi.org/10.1007/s15010-026-03005-4","url":null,"abstract":"<p><p>Hussain et al. reported a higher prevalence of culture-detected asymptomatic bacteriuria (ASB) among sodium-glucose cotransporter-2 inhibitor (SGLT2i) users than among non-users with type 2 diabetes mellitus. This observation is important but requires cautious interpretation. Culture-detected ASB is distinct from symptomatic urinary tract infection (UTI), and evidence from randomized trials and real-world studies has generally not shown a clinically meaningful increase in symptomatic UTI with SGLT2i use. Moreover, the single-time-point assessment cannot distinguish transient, persistent, or incident bacteriuria, and a single voided urine specimen may not confirm ASB in women. Unmeasured differences in background antidiabetic therapy and lower urinary tract risk factors may also have contributed to the observed association. Most importantly, the study did not determine whether detecting ASB predicts clinically significant infection or improves patient-important outcomes. Therefore, the available findings do not support routine urine screening in asymptomatic SGLT2i users.</p>","PeriodicalId":13600,"journal":{"name":"Infection","volume":" ","pages":""},"PeriodicalIF":3.9,"publicationDate":"2026-10-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149108715","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Secondary syphilis with impetiginized lesions in untreated HIV infection.","authors":"Annika P Schnell, Britta F Zecher, Stefan Schmiedel","doi":"10.1007/s15010-026-02996-4","DOIUrl":"https://doi.org/10.1007/s15010-026-02996-4","url":null,"abstract":"<p><p>Syphilis may present with atypical cutaneous manifestations in immunodeficient patients and is easily misdiagnosed. We report a 39-year-old man with untreated HIV infection presenting with widespread non-pruritic lesions initially mistaken for impetigo contagiosa. Serology confirmed secondary syphilis with Lues maligna and palmoplantar hyperkeratosis (Clavi syphilitici). This case highlights the importance of considering syphilis in patients with atypical skin lesions and HIV-related immunodeficiency.</p>","PeriodicalId":13600,"journal":{"name":"Infection","volume":" ","pages":""},"PeriodicalIF":3.9,"publicationDate":"2026-10-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149109216","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Best picture award \"Infektionsmedizin menschennah\".","authors":"Indrajit Ghosh, Oliver Wolff","doi":"10.1007/s15010-026-02972-y","DOIUrl":"https://doi.org/10.1007/s15010-026-02972-y","url":null,"abstract":"","PeriodicalId":13600,"journal":{"name":"Infection","volume":" ","pages":""},"PeriodicalIF":3.9,"publicationDate":"2026-10-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149108983","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Factors associated with 90-day mortality in adults with cryptococcal meningoencephalitis across HIV, solid organ transplant, and non-HIV, non-transplant populations.","authors":"Bayard A Taylor, Ameera Jamshad, Andrés F Henao-Martínez, Charlie Garcia, David B Cluck, Daniel B Chastain","doi":"10.1007/s15010-026-02997-3","DOIUrl":"https://doi.org/10.1007/s15010-026-02997-3","url":null,"abstract":"<p><strong>Purpose: </strong>Predictors of mortality in cryptococcal meningoencephalitis (CM) across HIV, solid organ transplant (SOT), and non-HIV, non-transplant (NHNT) populations remain incompletely defined. We compared clinical characteristics and 90-day mortality across host groups and evaluated factors associated with mortality.</p><p><strong>Methods: </strong>Adults with CM were identified in TriNetX (2003-2024) using ICD-10-CM codes or cerebrospinal fluid cryptococcal antigen or DNA evidence. Analyses were restricted to amphotericin B-treated patients to improve diagnostic specificity. Patients with available host-group information were categorized as HIV, SOT, or NHNT. Multivariable Cox regression evaluated 90-day mortality, adjusting for age, sex, ethnicity, Charlson Comorbidity Index, pre-index glucocorticoid exposure, and calendar year.</p><p><strong>Results: </strong>Among 650 patients in the final analytic cohort, 26.0% had HIV, 22.2% were SOT recipients, and 51.8% were NHNT. Overall 90-day mortality was 19.5% (n=127), and was highest among NHNT patients (23.1%), followed by SOT recipients (19.4%) and patients with HIV (12.4%). Non-survivors were older and more frequently had neoplasms, hematologic malignancy, aplastic anemia, and liver disease. NHNT status was associated with higher mortality than HIV in unadjusted analysis (HR 1.98, 95% CI 1.22-3.20). In the multivariable model (n = 608, 113 deaths), this association was attenuated (aHR 1.16, 95% CI 0.36-3.69), while advancing age remained independently associated with mortality (aHR 1.02/year, 95% CI 1.01-1.04).</p><p><strong>Conclusions: </strong>NHNT adults had the highest crude mortality, but this association was attenuated after adjustment. Advancing age remained independently associated with mortality, while the independent association between host group and mortality remained uncertain.</p>","PeriodicalId":13600,"journal":{"name":"Infection","volume":" ","pages":""},"PeriodicalIF":3.9,"publicationDate":"2026-10-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149109028","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Integrated analysis of HIV-1 drug resistance across reverse transcriptase, protease and integrase in india: gene-region-corrected prevalence and threshold-specific scoring from public sequence data.","authors":"Amlan Das, Bhoomika Patel, Alfeena Topiwala, Priyanshi Yadav, Tanvi Suthar, Vijay Kevlani","doi":"10.1007/s15010-026-02968-8","DOIUrl":"https://doi.org/10.1007/s15010-026-02968-8","url":null,"abstract":"<p><strong>Purpose: </strong>India carries the third-largest HIV-1 burden globally. The 2021 national transition to Tenofovir/Lamivudine/Dolutegravir (TLD) makes Integrase Strand Transfer Inhibitor resistance surveillance an urgent programmatic priority, yet no prior Indian study has simultaneously characterised all three pol gene regions using gene-region-corrected denominators or multi-threshold algorithmic scoring.</p><p><strong>Methods: </strong>We retrieved 4,375 HIV-1 subtype C pol sequences from LANL and NCBI GenBank (November 2024). Gene-region-specific denominators were applied (RT, n = 2,879; Protease, n = 2,373; Integrase, n = 1,084). Mutations were classified per 2022 IAS-USA criteria; drug-level resistance was scored across four Stanford HIVdb v9.4 thresholds with Benjamini-Hochberg FDR correction. Mutation co-occurrence was assessed across 231 pairs simultaneously.</p><p><strong>Results: </strong>NNRTI resistance was 36.7% (95% CI: 35.0-38.5%), NRTI resistance 25.4%, and dual-class resistance 23.0%; predominant mutations were M184V (19.2%), K103N (11.9%), and Y181C (8.7%). Composite HIVdb scoring detected TDF resistance in 12.1% (≥ Level 3) - four-fold higher than K65R-based counting alone (3.0%) - reflecting Thymidine Analogue Mutation cross-resistance. Nevirapine, Efavirenz, and Protease Inhibitor major resistance were 32.9%, 31.7%, and 4.0%, respectively. INSTI major resistance was 1.6% (95% CI: 0.9-2.4%); Q148H/K/R was entirely absent, and Dolutegravir/Bictegravir resistance was 0% at ≥Level 3. L74M prevalence was 11.3% (9.5-13.3%). Threshold sensitivity reached 9.4-fold for etravirine; co-occurrence analysis identified K65R+V106M enrichment (8.4-fold, FDR q < 0.001).</p><p><strong>Conclusions: </strong>Among publicly available Indian sequences enriched for treatment-failure submissions, the complete absence of Q148-pathway mutations provides a bounded baseline among available pre-/early-TLD integrase sequences. The four-fold TDF resistance underestimation by conventional mutation counting and up to 9.4-fold threshold-dependent prevalence variation support composite algorithm-scored, threshold-specified reporting as a standard for database-level HIV drug resistance analyses.</p>","PeriodicalId":13600,"journal":{"name":"Infection","volume":" ","pages":""},"PeriodicalIF":3.9,"publicationDate":"2026-10-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149109304","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Gut resilience and clinical homeostasis following administration of neomycin and albendazole in soil-transmitted helminth-infected adults living in Lambaréné, Gabon.","authors":"Ayodele Alabi, Mirabeau M Ngwese, Paulin N Essone, Armel V Mbouna, Anita Lumeka Kabwende, Fabrice Lotola-Mougeni, Saidou Mahmoudou, Kossiwa Kokou, Meral Esen, Bertrand Lell, Ayola A Adegnika, Michael Ramharter, Martin P Grobusch, Ruth E Ley, Peter G Kremsner, Selidji T Agnandji","doi":"10.1007/s15010-026-02906-8","DOIUrl":"https://doi.org/10.1007/s15010-026-02906-8","url":null,"abstract":"<p><strong>Purpose: </strong>Gut resilience and systemic homeostasis are interrelated dynamic functions. A gut that fails to regulate intestinal barrier integrity, metabolite production, and immune regulation will lead to systemic pathogenic invasion and susceptibility to infections. Gut resilience withstands stressors that can induce gut failure, and even when disturbances occur, it quickly restores its composition and functions. There is a paucity of data on the microbiome of people living in low- and middle-income settings. We therefore assessed the local and systemic conditions of gut resilience following neomycin treatment in individuals with intestinal soil-transmitted helminth infections.</p><p><strong>Methods: </strong>A randomised, placebo-controlled, participant-blinded study was conducted in adults up to 40 years with known soil-transmitted helminth infections (STH) living in Lambaréné, Gabon. Participants were randomly assigned to the intervention or placebo groups. The intervention group received neomycin 2000 mg per os (p.o) three times daily for 10 days and fluconazole 150 mg p.o once weekly for two weeks. On day 90, all study participants were treated with 400 mg of albendazole for three days. Outcome measures included egg counts of Ascaris lumbricoides, Necator americanus and Trichuris trichiura, a dual marker of gut barrier permeability and metabolite production (FABP2), incidence of adverse events, and assessment of pathogen proliferation.</p><p><strong>Results: </strong>Thirty-eight participants were enrolled and followed up for 180 days. At the gut level, the intestinal STH egg counts decreased on day 7 after neomycin administration. From day 14 onward, intestinal STH egg counts began to increase, reaching the initial counts by day 90. There was no difference in FABP2 marker concentration between the two groups. Adverse events occurred more frequently in the intervention group, most commonly side effects of neomycin and fluconazole. There was no pathogen proliferation.</p><p><strong>Conclusion: </strong>Broad-spectrum antibiotic-induced changes in laying of STH helminth eggs in STH-infected adults, which occurred at the peak of the drug concentration observed in the blood, corresponding to a high availability in the gut. These changes support that the antibiotic-induced changes were transient and did not induce occurrence of clinical peripheral changes. The local resilience of the gut translated into peripheral-maintained homeostasis.</p><p><strong>Trial registration: </strong>The study was registered at the Pan African Clinical Trial Registry (https//pactr.samrc.ac.za/) database with identification numberPACTR201707002361207.</p>","PeriodicalId":13600,"journal":{"name":"Infection","volume":" ","pages":""},"PeriodicalIF":3.9,"publicationDate":"2026-10-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149109111","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"30-day mortality and antifungal resistance in confirmed Candida auris bloodstream infections (BSI): a systematic review and meta-analysis.","authors":"Muhammad Kamran, Muhammad Ali, Afreenish Amir, Naseer Ali Shah","doi":"10.1007/s15010-026-02983-9","DOIUrl":"https://doi.org/10.1007/s15010-026-02983-9","url":null,"abstract":"<p><strong>Background: </strong>Candida auris is a potentially multidrug-resistant nosocomial fungus that was classified as a WHO critical priority pathogen in 2022. Individual cohort studies report 30-day bloodstream infection mortality; however, prior meta-analyses have not restricted their primary pool to confirmed bloodstream infection cases.</p><p><strong>Methods: </strong>A PROSPERO-registered systematic review and meta-analysis was conducted (CRD420261418844). Studies enrolling patients with confirmed C. auris bloodstream infection and reporting 30-day or in-hospital all-cause mortality were included. Freeman-Tukey double arcsine transformation with DerSimonian-Laird random-effects modelling was applied to all proportion pools. Fluconazole and amphotericin B resistance were combined. Echinocandin resistance was synthesised narratively because of the zero-event problem. Subgroup analyses were pre-specified by geographic region and study designs.</p><p><strong>Results: </strong>Sixteen studies (N = 1,069 patients; 2016-2026) met the inclusion criteria. Pooled 30-day mortality from 13 studies (N = 813) was 39.6% (95% CI 32.4-47.0%; I² = 75.5%). In-hospital mortality from three studies (N = 256) was 45.1% (95% CI 30.9-59.7). Pooled fluconazole resistance was 95.0% (95% CI 86.7-99.7%; I² = 92.6%). Pooled amphotericin B resistance was 45.5% (95% CI 22.6-69.4%; I² = 97.5%), with extreme heterogeneity driven by clade-specific variations. Echinocandin resistance ranged from 0 to 16% across the individual cohorts. Multinational consortia showed the highest regional mortality estimate (52.4%, 95% CI 41.4-63.3%).</p><p><strong>Conclusions: </strong>Confirmed C. auris bloodstream infections have a pooled 30-day mortality rate of approximately 40%, along with near-universal fluconazole resistance. Echinocandins remain the first-line therapy, although mortality rates remain high. Susceptibility-guided therapy and enhanced infection control are essential.</p>","PeriodicalId":13600,"journal":{"name":"Infection","volume":" ","pages":""},"PeriodicalIF":3.9,"publicationDate":"2026-10-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149108792","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Hantavirus cardiopulmonary syndrome: an emerging fatal zoonotic infection.","authors":"Amina Rao, Hassan Tariq","doi":"10.1007/s15010-026-02994-6","DOIUrl":"https://doi.org/10.1007/s15010-026-02994-6","url":null,"abstract":"<p><p>Hantavirus cardiopulmonary syndrome is a potentially fatal respiratory zoonotic infection caused by New World hantaviruses, and it is acquired mostly via inhaling aerosolized excreta from infected rodents. Over the past 30 years, HCPS has expanded beyond its initial foci, and recent events suggest a potential for spread beyond traditionally endemic regions. The disease rapidly progresses from a vague prodrome to acute cardiopulmonary failure with a high fatality rate despite optimum supportive treatment. Pathophysiology involves endothelial failure, increased vascular permeability, acute thrombocytopenia and excessive immunological responses resulting in capillary leak syndrome and cardiogenic shock. It is still hard to clinically suspect early since the prodromal symptoms are vague and mirror common viral infections and respiratory disorders. Diagnostic confirmation needs serological testing or genetic approaches, which are typically unavailable in resource-limited endemic situations, leading to considerable diagnostic delays. Management is generally supportive, with early ICU admission, judicious hydration management, mechanical breathing and cardiopulmonary support including extracorporeal membrane oxygenation in refractory patients. The recent multi-country Andes virus epidemic on a cruise ship in May 2026 highlights the potential for fast worldwide transmission of HCPS outside of usual endemic settings. This review summarizes the current information on the epidemiology, pathophysiology, clinical presentation, diagnostic techniques, and treatment options for HCPS. We also highlight the pressing need for improved global surveillance, rapid point-of-care diagnostics, global awareness among health care workers, and ongoing development of preventive vaccines and effective antiviral therapies to address this significant public health threat.</p>","PeriodicalId":13600,"journal":{"name":"Infection","volume":" ","pages":""},"PeriodicalIF":3.9,"publicationDate":"2026-10-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149109025","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Emerging Corynebacterium diphtheriae ST-212 cluster with truncated tox gene linked by possible sexual transmission.","authors":"Alexandra Dangel, Anja Berger, Stefanie Schindler, Vladimira Hinic, Frank Imkamp, Helena M B Seth-Smith, Peter W Schreiber, Carola Berger, Marion Blaschitz, Alexander Indra, Adrian Egli, Andreas Sing","doi":"10.1007/s15010-026-02973-x","DOIUrl":"https://doi.org/10.1007/s15010-026-02973-x","url":null,"abstract":"<p><strong>Purpose: </strong>Despite low incidence, Corynebacterium (C.) diphtheriae remains a pathogen of concern, particularly due to emerging clusters of toxigenic and non-toxigenic strains causing respiratory, wound or invasive infections, and even recent fatal cases. This study aimed to investigate genetic relationships, characteristics, and epidemiological links among recent C. diphtheriae isolates of sequence type (ST)-212 from Germany, Austria, and Switzerland, focusing on their tox gene status and transmission routes.</p><p><strong>Methods: </strong>Four isolates collected 2022-2024 underwent whole genome sequencing (WGS). Analyses included multi locus sequence typing (MLST) and core genome MLST (cgMLST). Toxigenicity was assessed by qPCR, Elek, and lateral flow immunoassay (LFIA). Comparative genomic analyses used virulence factor databases and insertion sequence identification. Epidemiological data were gathered through patient interviews.</p><p><strong>Results: </strong>The four isolates belonged to the rare ST-212 and showed close genetic relatedness (cgMLST allelic distances 0-8, compared to a default cluster threshold of 14). Each harboured an identical truncated tox gene with a 5' deletion of 336 nucleotides and an upstream insertion sequence (IS) element (IS1132) disrupting the gene. The isolates were tox PCR positive but negative for diphtheria toxin (DT) production (non-toxigenic tox gene bearing; NTTB). Epidemiological investigation revealed shared exposure of two cases at a Berlin nightclub and suggested transmission through close or sexual contacts or indirect transmission via a contaminated environment within the nightclub. Comparison with historical and public ST-212 genomes confirmed the unique tox truncation and IS element insertion.</p><p><strong>Conclusion: </strong>WGS led to the discovery of previously unknown epidemiological links and unexpected genetic markers in C. diphtheriae. The findings could indicate fort sexual transmission and form the basis for the hypothesis that tox gene truncation and its consequence of NTTB strains may attenuate clinical severity. Molecular-epidemiological integration is vital for surveillance and outbreak control.</p>","PeriodicalId":13600,"journal":{"name":"Infection","volume":" ","pages":""},"PeriodicalIF":3.9,"publicationDate":"2026-10-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149109018","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}