건강인의 비인강내 MRSA 보균율과 methicillin 내성 포도구균에서의 mecA와 femA 유전자의 검출 = Nasal Carriage of MRSA among Hea1thy Individual and Detection of mecA and femA Gene from Methicillin-Resistant Staphylococcus aureus

다국어 초록 (Multilingual Abstract)

Nasal carriage rate and methici11in resistance of Staphνlococcus aureus in healthy adults are not well known in Korea. In this study, nasal specimens collected from college students during March to June, 1998 were cultured for S. aureus and the susceptibility of the isolates was determined by agar di1ution method and the relationship of methici11in resistance level and 서 -lactamase production was analyzed. Also, presence of mecA and femA was detected from the isolates by PCR. Isolation rate of S. aureus from the 339 subjects was 20%, and the rate was higher in female (21%) than in male (12%). Among the isolates, 2.1% were MRSAs. Against MSSA, clindamycin, fusidic acid, mupirocin and vancomycin were most active (MICso50 ≤1 μgjml and MIC90 2 μgj ml) and the resistancerates to cephalothin, eηthromycin ， gentamicin and tetracyc1ine 20% and to chloramphenicol and penicillin G, were 73%. The MIC range of oxacillin against MRSA was 16-≥ 128 μgj ml, while MICso and MIC90 were 32 μgjml and 128 μgjml, respectively. Fusidic acid, mupirocin and vancomycin were most active against MRSA (both MICso and MIC90 were 1 μgjml). Resistance rate of MRSA to c1indamycin was 18%, but they were ~59% to 6 other antibiotics. ß -lactamase-producing strains were more prevalent among the low level methicillin-resistant isolates. mecA was detected from all MRSAs, but none from MSSAs. femA was detected from all of the MRSAs and MSSAs and none in coagulase-negative staphylococcus. In conc1usion, hea1thy adults occasiona11y carη MRSAs, but they may have acquired them in hospitals. Fusidic acid and vancomycin should be useful to treat MRSA infection, while mupirocin should be useful to control nasal carriage. me때 and femA may be used to differentiate MRSA from MSSA, and S. aureus from coagulsae-negative staphylococcus, respectively.