Methicillin-resistant Staphylococcus aureus in community-acquired pyoderma

Background. Methicillin-resistant Staphylococcus aureus (MRSA) is an important nosocomial pathogen. It can also cause community-acquired infections. Indian reports about MRSA in community-acquired infections are rare. Aim. To evaluate the rate of MRSA in community-acquired pyoderma and the nasal colonisation with S. aureus in such patients. Methods. Two hundred and fifty patients with community-acquired pyoderma, who attended outreach camps around Mangalore, south India between January 2000 and July 2001, were studied. Swabs collected from the skin lesions and anterior nares were inoculated onto blood agar and MacConkey's agar. Antimicrobial sensitivity testing was performed using Kirby-Bauer disk diffusion, agar dilution, and agar screen. Results. Of 250 pyoderma cases, S. aureus was isolated from 202 (80.8%) patients. Twenty-two (10.9%) S. aureus isolates were methicillin resistant, 179 (88.6%) were resistant to penicillin, and 114 (56.4%) were resistant to erythromycin. S. aureus colonization in the anterior nares was observed in 136 (54.4%) cases, 11.8% of which were MRSA. Antibiograms of clinical isolates of S. aureus matched with nasal isolates in 99 (49%) cases. Conclusion. The emergence of MRSA in the community is a warning. A high nasal carriage rate may contribute to recurrent pyoderma. A correct antimicrobial policy and the avoidance of inappropriate antimicrobial usage are mandatory to reduce the spread of MRSA in the community.