MRSA的7种新SCCmec型别及其抗药特性

Seven kinds of new SCCmec type in Methicillin-resistant Staphyloccus aureus and their susceptibility to the antibiotics

摘要:

为探明海口地区耐甲氧西林金黄色葡萄球菌(MRSA)的耐药性和携带的葡萄球菌染色体mec盒(SCCmec)型别,对收集的1174株金黄色葡萄球菌用PBP2a检测法确证为MRSA有686株,用多重PCR对58株进行SCCmec分型测定,并用K-B琼脂扩散法和E-test法测定其对临床常用7类抗生素的代表性药物耐药性。结果在17株中又发现了7种新的SCCmec型别,其结构特点为:New3含A、F、H、M4个位点,New4型含F、H、M3个位点,New5含D、B、M3个位点,New6型含A、B、M3个位点,New7型含H、E、C、M4个位点,New8型含A、M两个位点,New9型含A、C、M3个位点;它们均与报道型别的结构特点存在明显差异;且携带新型的MRSA菌株,其分布特点及抗药性也与已报道的菌株存在差异:多分自门诊病人,且耐药性高,抗药谱较广,值得引起高度重视和关注。

Abstract:

In order to explore the resistance and the staphylococcal chromosome cassette mec (SCCmec) types of Methicillin-resistant S. aureus (MRSA) in the area of Haikou, 686 strains of MRSA had been distinguished from 1174 strains of S. aureus using PBP2a testing. The resistance to the seven deputies of seven kinds antibiotics which in common use in clinic, including Oxacillin, Vancomycin，Doxycyclin, Amikacin, Erythromycin, Chloramphenicol，Ciprofloxacin, and SCCmec type of 58 strains had been tested using the K-B Agar diffuse，E-test and multiplex PCR strategy, and seven kinds of new SCCmec types were found in 17 strains. Their specialties of structure are: type-new3 possess four loci of A,F,H,M; New4 possess three loci of F,H,M; New5 possess three loci of D,B,M; New6 possess three loci of A,B,M; New7 possess four loci of H,E,C,M; New8 possess two loci of A,M; New9 possess three loci of A,C,M. All of them are different from the types reported. The strains carrying new SCCmec types are different from that carrying old SCCmec types in the epidemical distribution and resistance to the antibiotics: they were mostly isolated from the out-patients and have high level and wider range of resistance to antibiotics and deserve to pay more attention.