[Incidence and antimicrobial susceptibility of clinical isolates of MRSA from 1988 to 1990, from the results of 26 clinical laboratories in Tokyo and the surrounding area].

We made a survey to investigate the incidence of clinical isolation and the trend of antimicrobial susceptibility of Methicillin-resistant Staphylococcus aureus (MRSA), isolated in 26 clinical laboratories. Among the 26 institutions, the frequency of MRSA was 22 to 64% (average: 42.1%) in 1988, 22 to 69% (average: 55.3%) in 1989 and 29 to 76% (average: 56.9%) in 1990, and increasing year by year. MRSA showed poor sensitivity to beta-lactam antibiotics, gentamicin, toburamycin and clindamycin. There was a significant difference in frequency of the minocycline-resistant strains and the ofloxacin-resistant strains among the 26 institutions. Albekacin, netilmicin, and vancomycin were most active against MRSA with a MIC90 of 1, 8 and 1 microgram/ml, respectively.