A Case Report of Wound Infection Caused by Mycobacterium porcinum

Mycobacterium porcinum is a rapidly growing non-tuberculous mycobacterium that requires 3 to 5 days of cultivation for colonies to become visible to the naked eye, with most exhibiting vigorous growth during this initial week. It does not readily grow in standard bacterial culture conditions, posing challenges that often result in missed or incorrect diagnoses, and necessitating an extended course of anti-infective treatment.

This case report describes a rare instance of wound infection caused by Mycobacterium porcinum in a 64-year-old female patient who underwent mitral valve bioprosthesis replacement and temporary cardiac pacemaker implantation. In the postoperative period, the patient exhibited signs of infection, including elevated leukocyte count and neutrophil percentage, along with serous discharge from the surgical wound. Mycobacterium porcinum was definitively identified using 16sRNA gene sequencing. The patient responded well to a combination therapy consisting of amikacin, azithromycin, and moxifloxacin, complemented by surgical debridement.

Rapidly growing mycobacteria, which require extended cultivation periods for visible colony formation, often result in underdetection. The atypical presentation of clinical symptoms can further delay the initiation of appropriate antibiotic therapy. This case underscores the critical role of prolonged cultivation time in detecting rapidly growing mycobacteria and highlights the importance of confirming genuine infections and the precision of clinical medication based on clinical symptoms and treatment outcomes.