Campylobacter ureolyticus-associated Fournier's Gangrene Following Anal Fissure Infection in a Patient with Diabetes and Immunosuppression.

Fournier's gangrene (FG) is a rapidly progressive necrotizing fasciitis of the perineal and genital regions associated with high mortality. Prompt intervention is crucial, particularly in patients with predisposing risk factors. A 75-year-old man with type 2 diabetes mellitus receiving long-term corticosteroid therapy presented with progressive scrotal pain and left thigh swelling. Physical examination revealed scrotal necrosis, and contrast-enhanced computed tomography demonstrated a perianal abscess with extensive subcutaneous emphysema. Emergency surgical debridement and bilateral orchiectomy were performed. Pus cultures demonstrated polymicrobial infection, whereas blood cultures yielded additional organisms, including Campylobacter ureolyticus, resulting in microbiological discordance between the two specimen types. The patient recovered without major complications following broad-spectrum antimicrobial therapy and intensive glycemic control. C. ureolyticus, which was identified in the present case, has previously been associated with necrotizing soft tissue infections, perianal abscesses, and bacteremia, and may cause severe infections, particularly in patients with underlying comorbidities or immunosuppression. The spatially heterogeneous and polymicrobial nature of FG may have contributed to the discordant culture results between the local specimen and blood cultures. This case highlights the complementary value of obtaining both pus and blood cultures for identifying uncommon pathogens in severe polymicrobial FG.