Polymicrobial necrotizing fasciitis involving Clostridium perfringens and Paeniclostridium sordellii: A diagnostic and therapeutic challenges

Necrotizing soft tissue infections (NSTIs) are rapidly progressing, life-threatening conditions often caused by toxin-producing organisms. While Clostridium perfringens is a well-known cause of gas gangrene, P. sordellii is a rare but highly lethal anaerobe more commonly associated with obstetric and gynecologic infections. We report a unique case of polymicrobial NSTI involving both C. perfringens and P. sordellii . A 71-year-old male presented with non-healing bilateral foot wounds, ultimately diagnosed as necrotizing fasciitis. Wound cultures revealed six organisms, Four agents were not likely to be causative for the patient's clinical symptoms, while two others— C. perfringens and P. sordellii —were in agreement with the clinical findings. The patient underwent prompt surgical debridement and broad-spectrum intravenous antibiotic therapy, including piperacillin-tazobactam, vancomycin, and clindamycin. Blood cultures were negative for septicemia, and no multidrug-resistant organisms were identified. Following two additional debridements and extended antibiotic therapy, the patient demonstrated significant clinical improvement and remained stable. While necrotizing fasciitis in and of itself prompts a rapid diagnosis, aggressive surgical management, and appropriate antimicrobial therapy to ensure patient survival, this case is notable because P. sordellii was isolated with C. perfringens, yet the patient survived despite unknown transmission dynamics amidst the unusually high fatality associated with P. sordellii. This case underscores the need for heightened clinical awareness and highlights the role of early and decisive intervention on improving outcomes and patient survival from otherwise devastating infections. • Identification of P. sordellii from a non-gynecologic, lower extremity wound expands the known clinical spectrum of this rare pathogen. • Successful management using triple antibiotic therapy and multiple surgical debridement without hyperbaric oxygen intervention. • Wound culture yielded six organisms, highlighting the importance of precise microbiologic workup in polymicrobial infections. Emphasizes the diagnostic and treatment challenges posed by P. sordellii due to unknown transmission dynamics and high associated mortality. • Demonstrates the value of early Gram staining and culture in initiating appropriate antimicrobial and surgical management in NSTIs aiding the limited literature on P. sordellii as a soft tissue pathogen and reinforces its potential role in mixed infections outside the peripartum context.