In vitro antimicrobial efficacy of a silver-containing wound dressing against mycobacteria associated with atypical skin ulcers.

Mycobacterium ulcerans, the etiological agent in Buruli and related ulcers, is a major threat to public health in many tropical countries. Recommended treatment that is accessible and affordable for affected individuals includes surgical debridement and combination antibiotics. The potential benefits in the use of antimicrobial wound dressings has not been demonstrated to date, and consequently the efficacy of a silver-containing absorbent dressing was investigated against a pathogenic wound mycobacterium using stringent in vitro models. The in vitro models were designed to simulate a variety of challenging wound conditions. Mycobacterium fortuitum was used as a fast-growing surrogate for M. ulcerans, a physiologically similar but slower-growing and more significant wound pathogen. Collectively, the studies showed that the silver-containing dressing was bactericidal against M. fortuitum, it maintained killing effect over a prolonged period (7 days) under conditions simulating excessive exudate, and killed an average of 100% of the bacterial population inoculated directly beneath the dressing in a simulated, colonized, shallow wound model. Based on the in vitro data generated in the current research, use of the silver-containing dressing as part of a protocol-of-care in the management of Buruli and related ulcers may help to alleviate wound infection caused by pathogenic mycobacteria, improve quality of life, and provide infection protection in endemic and at-risk regions. .