内蒙古地区样本MRSA和MSSA临床分离株agr分型特征研究  

Study on the Agr genotyping features of MRSA and MSSA clinical isolates from Inner Mongolia

作　　者：薛东力 王俊瑞[2] 额尔德木图[3] 孙鹏[4] 兰海霞[5] 

机构地区：[1]内蒙古医科大学,内蒙古呼和浩特010110 [2]内蒙古医科大学附属医院检验科,内蒙古呼和浩特010050 [3]内蒙古医科大学科技处,内蒙古呼和浩特010110 [4]内蒙古医科大学病原生物学实验室,内蒙古呼和浩特010059 [5]中国人民解放军第253医院,内蒙古呼和浩特010051

出　　处：《转化医学电子杂志》2017年第4期55-60,共6页E-Journal of Translational Medicine

基　　金：内蒙古科技计划项目(20140144);内蒙古自然科学基金项目(2016MS0829);内蒙古自治区卫生和计划生育委员会科研项目(201303061)

摘　　要：目的:探究金黄色葡萄球菌附属基因调节子(agr)在耐甲氧西林金黄色葡萄球菌(MRSA)和甲氧西林敏感金黄色葡萄球菌(MSSA)临床株中的分布特征.方法:以50株MSSA株和40株MRSA株作为研究对象,采用多位点序列分型方法(MLST)检测这些菌株的ST型,进一步采用PCR方法检测agrⅠ~Ⅳ型基因在2组金黄色葡萄球菌以及不同ST型金黄色葡萄球菌中的分布.结果:MLST结果显示,MRSA株主要为ST-239型(36株,90.0%),MSSA主要为ST-5型(10株,20.0%),其次为ST-7型(9株,18.0%).90株金黄色葡萄球菌中agr-Ⅰ基因占86.7%(78株),agr-Ⅱ基因占24.4%(22株),agr-Ⅲ基因占3.3%(3株),agr-Ⅳ基因占3.3%(3株).MRSA株主要携带agr-Ⅰ基因(97.5%/78.0%,P<0.05),而agr-Ⅱ基因携带率明显低于MSSA,差异具有统计学意义(P<0.05).Agr基因调控的毒力基因中,hla和fnbA基因表达率均为100%(90株,90/90),sea基因表达率为47.8%(43株,43/90).结论:MRSA株和MSSA株agr基因分型特征差异显著,agr-I型基因在MRSA株中呈优势表达,其对MRSA株毒力调控基因表达的影响机制值得进一步研究.AIM： To investigate the distribution characteristics of accessory gene regulator（ agr） in clinical strains of methicillinresistant staphylococcus aureus（ MRSA） and methicillin sensitive staphylococcus aureus（ MSSA）. METHODS： A total of 50 strains of MRSA and 40 strains of MSSA were selected as the research objects. The multilocus sequence typing（ MLST） was used to detect the ST types, then polymerase chain reaction（ PCR） was used to detect the distribution of agrⅠ ~ Ⅳgenes in these 2 groups of staphylococcus strains and staphylococcus aureus with different ST types. RESULTS： The MLST showed that MRSA strains were mainly clustered into ST-239 type（ 36 strains,90%）,and MSSA strains mainly belonged to ST-5（ 10 strains,20%）,followed by ST-7（ 9 strains,18%）. Among the 90 strains of staphylococcus aureus tested,the positive rate agr-Ⅰ genes was86. 7%（ 78 strains）,and positive rates of the other three agr genes were respectively 24. 4%（ 22 strains）,3. 3%（ 3 strains）and 3.3%（ 3 strains）. MRSA strains carried higher rate of agr-Ⅰgene（ 97.5%/78%,P〈0.05）,while the carrying rate of agr-Ⅱgene in the MRSA strains was significantly lower than that of theMSSA（ P〈0.05）. As one of the virulence genes regulated by agr regulatary system,expression rate of both hla and fnbA were100%（ 90 strains,90/90）,while the carrying rate of sea gene was 47. 8%（ 43 strains,43/90）. CONCLUSION： Agr genotyping features of MRSA and MSSA strains tested in this study are significantly different. Agr-Ⅰ gene is predominatly expressed in MRSA strains,and the regulatory mechanism of this regulating system in MRSA strains is still needed to be further investigated.

关 键 词：金黄色葡萄球菌 agr分型 多位点序列分型 

分 类 号：R446.5[医药卫生—诊断学]