한국에서 분리된 methicillin 내성 포도상구균(MRSA)에서 multoplex PCR에 의한 nuc, mecA, enterotoxon 유전자들과 tst 유전자의 분포에 관한 연구

Abstract

In this study we attempted multiplex PCR for rapid detection of genes for nuc, mecA, enterotoxin A to E and TSST-l(tst) in bacterial lysates extracted from human strains of S. aureus. In 210 isolates of methicillin-resistant Staphylococcus aureus (MRSA), all strains showed both nuc gene and mecA gene positive except two strains that showed only nuc gene positive. One hundred sixty nine(80.5%) of 210 MRSA isolates tested produced one or more toxins. Other 41(19.5%) isolates did not produce any of the toxins. Enterotoxin A gene(sea) was amplified in 50.5%(n=105) of the isolates, enterotoxin B(seb) in 14.3%(n=30), enterotoxin C(sec) in 23.3%(n=49), enterotoxin D(sed) in 10.0%(n=21) and TSST-l(tst) in 12.4%(n=26). Fifty eight strains(27.6%) amplified more than two enteroxin genes. The most common combination of toxin gene was sea and seb, which was found in 26(12.4%) strains, and the next frequent combination was sec and tst in 14(6.7%) strains from 210 isolates among which 109 MRSA strains tested were isolated in Seoul area and 101 in Pusan area. The frequency rate of enterotoxin A in Pusan was twice higher than that of Seoul with 57.1% to 23.6%. But the frequency rates of enterotoxins C and D genes in Seoul area are analogous with relatively narrow margin while those rates in Pusan area were almost negligible with less than 2% each. Apparent difference of enterotoxin type distribution was also found between the countries. Beside enterotoxin A which was most predominantely found in both European countries and Korea, enterotoxin C was the subsequently prevalent type of toxin in Korea instead of enterotoxin b which was found as the second most prevalent enterotoxin in some European countries