Case Report: Fournier's gangrene caused by Gleimia hominis

Fournier's gangrene is typically polymicrobial necrotizing fasciitis of the perineal/genital regions. Gleimia hominis (Actinomycetaceae) is a rare anaerobic Gram-positive rod whose clinical role remains poorly defined.

A 71-year-old man with Parkinson disease, dementia, and chronic obstructive pulmonary disease was transferred for worsening fever and perineal swelling despite 6 days of piperacillin-tazobactam. Computed tomography showed a rim-enhancing fluid collection extending from the left lower abdominal wall to the left hemiscrotum with gas formation. Fournier's gangrene was diagnosed, and empiric meropenem was started together with surgical incision and drainage. G. hominis was isolated from the abscess culture and identified by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry. Antimicrobial therapy was de-escalated to ampicillin-sulbactam, followed by oral amoxicillin-clavulanate, with clinical improvement.

This case highlights the pathogenic potential of G. hominis in necrotizing soft tissue infection and the value of precise microbiologic identification for antimicrobial de-escalation.