The trend of epidemiological study against MRSA stains which were isolated in 1992 and in 1993 was investigated. Number of stains tested yearly consisted of 30 isolates that were considered to play pathogenic roles for inpatients in clinical departments at our institute. In comparing with biological studies on MRSA stains and the epidemilogical surveillance of the background of the isolation, the data summerizes as followings;
1) No.of MRSA stains which were producible for TSST increased from 24/30, 80% up to 30/30, 100%.
2) No.of enterotoxin type harbouring bitype of B/C increased 0/30, 0% up to 12/30, 40%.
3) No.of type of plasmid DNA profile increased in varying from 3 types (A, B, C) to 8 types (A-H).
4) The in vitro activity of antimicrobials, as such MINO, GM, IPM, CMZ was less potent than that of the prior year, and even for VCM, ABK, the activity proved less potent in 1-2 tubes in MIC₉₀.
5) No.significant hospital acquired infection was detected between the inpatients, with MRSA infection and isolates from plasmid DNA profiles.
6) Since the ratio of the coincidence of plasmid DNA profiles of MRSA was only in 4 patients out of 27, 14.9 &, nosocomial infections with MRSA brought to patients have not only been considered by medical, paramedical staff, but that the infection may be caused by broad contamination at the institute.