A Rare Catch in a Nonhealing Wound.

Area of Science:

• Medical Microbiology
• Dermatology
• Infectious Diseases

Background:

• Mycobacterium smegmatis is a ubiquitous, non-pathogenic environmental bacterium.
• Infections caused by M. smegmatis are rare in immunocompetent individuals.
• Chronic nonhealing wounds pose a diagnostic challenge, often requiring consideration of atypical pathogens.

Observation:

• A 45-year-old male with hypertension presented with a chronic, nonhealing anterior chest wall surgical wound.
• Wound cultures identified Mycobacterium smegmatis as the causative agent.
• The wound measured 0.5 cm x 0.5 cm x 0.3 cm with minimal serosanguinous drainage.

Findings:

• A 3-month course of antibiotic therapy was initiated.
• Advanced wound care included silver-alginate and iodoform packing, later transitioning to collagen dressings.
• The patient showed a positive response, with complete ulcer closure after 3 months of treatment.

Implications:

• This case highlights the importance of suspecting atypical microbial infections, such as M. smegmatis, in non-healing wounds.
• Early and appropriate treatment can lead to successful resolution of challenging infections.
• Consideration of environmental mycobacteria is crucial in the differential diagnosis of chronic wounds.