Antibiotic-associated diarrhoea and methicillin-resistant Staphylococcus aureus.

Methicillin-resistant Staphylococcus aureus was thought to be the cause of 10 cases of antibiotic-associated diarrhoea observed over a 12-month period at The Royal Melbourne Hospital. Each patient had significant underlying disease, and all had been treated with multiple, broad-spectrum antibiotic agents. The diagnosis was made on the distinctive Gram-stain appearance of faecal smears, the heavy predominant growth of methicillin-resistant Staph. aureus from stool cultures, and the absence of other bowel pathogens, including toxigenic Clostridium difficile. Diarrhoea usually responded to treatment with vancomycin or bacitracin, and, in patients whose condition improved, the stools cleared of staphylococci. Patients with staphylococcal diarrhoea present a significant crossinfection risk, and early diagnosis, treatment, and isolation are essential.