临床分离耐甲氧西林溶血性葡萄球菌的SCCmec分型及同源性分析

目的了解临床分离耐甲氧西林溶血性葡萄球菌（MRSH）的SCCmec基因型别及相同SCCmec型别菌株的同源性。方法多重PCR进行SCCmec分型，ERIC-PCR法对相同SCCmec型别菌株进行同源性分析。结果83株临床分离MRSH菌株中，SCCmecI型有23株（27．7％），SCCmecⅡ型有10株（12．1％），SCCmecm型有24株（28．9％），SCCmecIV型有1株（1．2％），I、Ⅱ混合型有8株（9．6％），I、Ⅲ混合型有6株（7．2％），Ⅱ、11混合型有5株（6．0％），I、Ⅱ、Ⅲ混合型有3株（3．6％），未分型3株（3．6％）。ERIC—PCR结果显示，23株SCCmecI型分为11型，其中A型5株，B型5株，C型3株，其余8株各为1型，2株未分型；10株SCCmecⅡ型分为6型，其中D型4株，E型2株，3株各为1型，1株未分型；24株SCCmecm型分为9型，其中F型11株，G型2株，H型2株，I型2株，5株各为1型，2株未分型。结论临床分离MRSH中，SCCmecI、Ⅲ型为多，部分菌株呈混合型别；相同SCCmec型别的部分菌株之间可能存在克隆传播。

Analysis of SCCmec typing and homology in MRSH isolates

Objective To analyse the subtypes of Staphylococcal Cassette Chromosome mec(SCCmec) and the homology of subtypes in methicillin-resistant hStaphylococcus haemolyticush(MRSH).Method SCCmec types were indentifed by multiplex PCR.The homology of subtypes was analyzed by Enterobacterial Repetitive Intergenic Consensus polymerase chain reaction(ERIC-PCR).Result Of the 83 strains isolated,there were 23 strains(27.7%) of SCCmec I,10 strains(12.1%) of SCCmec II,24 strains(28.9%) of SCCmec III and 1 strain(1.2%) of SCCmec IV.The mixing type of I and II,I and III,II and III,I,II and III were 8 strains(9.6%),6 strains(7.2%),5 strains(6.0%),and 3 strains(3.6%) respectively.The results of ERIC-PCR manifested that there were 5 strains of subtype A,5 strains of subtype B,3 strains of subtype C,2 unclassified subtypes,and 8 other subtypes in the 23 strains of SCCmec I.The 10 strains of SCCmec II contained 4 strains of subtype D,2 strains of subtype E,1 unclassified strains,and 3 other subtypes.The 24 strains of SCCmec III included 11 strains of subtype F,2 strains of subtype G,2 strains of subtype H,2 strains of I,2 unclassified strains,and 5 other subtypes.Conclusion The type I and III are the predominant types of SCCmec and part of them are mixing types that include two or more types.Clonal spread was found in some of the strains that have the same type of SCCmec.