Abstract
BACKGROUND: Klebsiella pneumoniae is a common nosocomial pathogen capable of causing invasive disease, including sepsis and meningitis, even in immunocompetent hosts. Involvement of the scrotum, manifesting as scrotal abscess or Fournier’s gangrene, is uncommon and under-recognized. We report three K. pneumoniae scrotal infections and provide microbiological characterization to highlight their clinical relevance and novelty. CASE PRESENTATION: Three elderly male patients (aged 68, 78, and 85 years) with diabetes and a history of rectal or prostate cancer presented with acute scrotal swelling, erythema, and ulceration. Two cases progressed to Fournier’s gangrene (necrotizing fasciitis). All underwent urgent surgical debridement or abscess drainage, combined with susceptibility-directed antimicrobial therapy (cefazolin, cefotaxime, or ciprofloxacin). K. pneumoniae was identified as the sole pathogen in all cases, including one hypervirulent ST23 strain. All patients achieved significant clinical improvement and were discharged with healed or healing wounds. CONCLUSION: Although rare, K. pneumoniae should be considered as a potential pathogen in scrotal infections, especially in patients with diabetes and cancer. Early recognition, prompt surgical source control and susceptibility-directed antimicrobial therapy are crucial for favorable outcomes. CLINICAL TRIAL: Clinical trial number: Not applicable. This study was not registered as a clinical trial because it was a descriptive cross-sectional study involving the analysis of bacterial isolates from clinical specimens, which did not meet the criteria for a clinical trial. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1186/s12879-026-12946-y.