Staphylococcus aureus in patients with Buruli ulcer and burns in Ghana

Wounds of the skin are highly susceptible to secondary infections by bacteria, especially in healthcare settings with limited resources and lack of infection prevention and control practices. To assess the possible implications of bacterial wound colonization in a resource-limited setting, this PhD research addressed the colonization of Buruli ulcers and burn wounds in Ghana by the bacterial pathogen Staphylococcus aureus. Buruli ulcer is a serious necrotizing skin disease caused by Mycobacterium ulcerans, a close relative of the bacteria causing tuberculosis and leprosy. Burn injuries are the most devastating of all injuries, and ~90% of burns occur in low- and middle-income countries. Previous studies showed that wounds of Buruli ulcer and burn patients are colonized with a variety of microorganisms including S. aureus, which may interfere with wound healing. Advanced tools to distinguish related bacteria, especially whole-genome sequencing, were used to track temporal changes of Staphylococcus aureus in wounds of Buruli ulcer and burn patients, as well as in-hospital transmission events between patients and healthcare workers during wound care. In addition, genome sequencing allowed an assessment of the potential of different S. aureus isolates to cause disease. The results provide novel insights into the molecular epidemiology of S. aureus in Buruli ulcer and burns in Ghana. Importantly, they demonstrate transmission events and unnoticed outbreaks of highly drug-resistant forms of S. aureus, such as MRSA. This emphasizes a critical need for implementation of appropriate wound care, hospital hygiene, and preventive measures to limit the risks of infections by highly drug-resistant microorganisms.