Abstract: Objective To investigate the bacteriological features and the epidemiology of methicillin-resistant Staphylococcus aureus (MRSA) in patients with impetigo, and provide evidence for selection of appropriate agents for treating impetigo and its complications. Methods Two hundred and forty-six out-patients with impetigo were surveyed. Cultures were obtained from impetiginous lesions. Antibiotic susceptibility tests on 212 S.aureus isolates were performed by standard agar dilution testing (MIC). Results In a total of 246 isolates, 87.0% yielded S.aureus alone, 2.0% S.aureus and Group A beta-hemolytic streptococcus (GABHS), 1.6% GABHS alone, 4.1% Staphylococcus epidermidis. Fifteen antimicrobial agents were used in the susceptibility tests. One hundred percent of S. aureus isolates were resistant to penicillin, 87.7% were resistant to erythromycin, followed by clindamycin (75.5%), tetracycline (63.2%), chloramphenicol (54.2%), ampicillin-sulbactam (44.8%), oxacillin (30.2%), ciprofloxacin (12.8%), cefotaxime (0.9%), fusidic acid (0.9%) and gentamicin (0.9%). None of the S.aureus isolates was resistant to vancomycin, cefazolin, cefuroxime and mupirocin. Sixty-four MRSA strains were isolated. No vancomycin resistant S.aureus strain was found. Conclusions Penicillin, erythromycin, clindamycin, tetracycline, chloramphenicol and ampicillin-sulbactam prove to be no longer the appropriate therapeutic agents. Cephalosporin, mupirocin and fusidic acid might be the good choice for treatment of impetigo in our region.

Key words: Impetigo sores, Staphylococcus aureus, Staphylococcus epidermidis, Streptococcus, Drug tolerance