某院耐甲氧西林金黄色葡萄球菌MLVA基因分型及流行状况研究

目的通过构建适合临床实验室常规应用的耐甲氧西林金黄色葡萄球菌(MRSA)菌株同源性多位点可变数目串联重复序列分析(MLVA)分型方法,建立昆明地区临床分离MRSA菌株的MLVA基因分型基础数据库,分析医院MRSA感染流行情况。方法收集昆明市第一人民医院临床微生物室2010年10月至2013年12月分离的111株MRSA菌株,对7个可变数目串联重复序列(VNTR)位点进行聚合酶链式反应(PCR)扩增和产物电泳分析,归类各菌株的基因型别。结果 VNTR09-01位点测序结果显示9bp的重复子,重复规律性不强、易突变;111株分离株被分为25个基因型别(A~Y),其中G、A、B为主要型别,分别占47.7%、13.5%、8.1%;呼吸内科、神经外科、重症监护室(ICU)和乳腺科存在MRSA集中流行趋势。结论 MLVA分型方法可推广应用于本研究中7个VNTR位点多态性检测,部分科室存在MRSA同源菌集中流行情况,值得高度关注。

MLVA genotyping and the prevalence status analysis of methicillin-resistant Staphylococcus aureus isolated from a hospital

Objective To establish multiple‐locus variable‐number tandem repeat assay(MLVA) genotyping database for clinical isolates of methicillin‐resistant Staphylococcus aureus(MRSA) in Kunming area and analyse the prevalence status of MRSA in hos‐pital ,through establishing a classification method for MRSA by homology MLVA which was appropriate to routine application in clinical laboratory .Methods A total of 111 strains of MRSA isolated by the Clinical Microbiology Chamber of the First People′s Hospital of Kunming City from October 2010 to December 2013 were collected .The polymerase chain reaction(PCR) amplification and electrophoresis for analysis of PCR products were carried out for the seven sites of variable number tandem repeats(VNTR) , classification of strain based on genotypes was carried out ,as well .Results The sequencing results of VNTR09‐01 site showed 9 bp repetitive sequence elements whose regularity was not strong ,and the repetitive elements was mutable .The 111 isolates were divid‐ed into 25 kinds of genotypes(A -Y) ,among which genotype G ,A and B were the main types ,accounted for 47 .7% ,13 .5% and 8 .1% respectively .Conclusion MLVA could be generally applied in the seven sites of VNTR in this study .Some departments might exit concentrated epidemic of homologous MRSA strains ,which is worthy of being paid more attention .