金黄色葡萄球菌血液分离株毒力与耐药编码基因研究  

Study on virulence and resistance encoding genes of Staphylococcus aureus isolated from blood

作　　者：虞亦鸣[1,2] 马红映[2] 王翎[1] 汪丽[3] 吕丹[2] 孙士芳[2] 舒丽华[2] 王卫华[3] 邓在春[2] 

机构地区：[1]苏州大学附属第一医院老年科,江苏苏州215006 [2]宁波大学医学院附属医院呼吸内科,浙江宁波315020 [3]宁波大学医学院附属医院微生物室,浙江宁波315020

出　　处：《中华医院感染学杂志》2015年第19期4332-4335,共4页Chinese Journal of Nosocomiology

基　　金：宁波市医学科技计划基金资助项目(2011B13)

摘　　要：目的分析医院耐甲氧西林金黄色葡萄球菌(MRSA)及甲氧西林敏感金黄色葡萄球菌(MSSA)血液分离株临床特征及菌株分子生物学特征,了解MRSA耐药机制以控制其传播。方法对医院2012年4-12月自血液分离的19株MRSA和14株MSSA的临床特征及耐药性进行分析;采用聚合酶链式反应(PCR)对33株菌株进行23种毒力基因(sasX、fnbA、clfA、clfB、icaA、efb、cna、hla、hlb、hld、hlg、hlg2、pvl、lukE、lukM、psm-mec、ssp、eta、tst、sea、seb、cap5、cap8)与7种耐药基因[mecA、aac(6′)/aph(2″)、aph(3′)-Ⅲ、ermA、ermB、ermC、tetM]检测。结果 MRSA感染患者年龄(78.5±7.6)岁,高于MSSA感染患者的(67.6±15.3)岁,差异有统计学意义(P<0.05);MRSA检出时间为入院后(9.84±4.11)d,晚于MSSA检出时间的(6.93±3.26)d,差异有统计学意义(P<0.05);19株MRSA对万古霉素、磺胺甲噁唑/甲氧苄啶及利福平的耐药率较低,分别为0、21.1%及26.3%,14株MSSA对青霉素和红霉素的耐药率较高,分别为78.6%和42.9%;19株MRSA除hlg、lukM、eta3种毒力基因未检出外,其余20种毒力基因均有检出,耐药基因检测示MRSA阳性率高于MRSA,与抗菌药物敏感性试验相符;MRSA与MSSA均存在克隆现象。结论 MRSA与MSSA黏附素基因检出率高,提示菌株的定植特性,真性毒力基因检出率高,提示菌株具有宿主组织损伤特性,在临床处置中要特别注意医院感染的控制手段以降低感染风险。OBJECTIVE To study the clinical and molecular characteristics of methicillin‐resistant Staphylococcus aureus （MRSA） and methicillin‐sensitive S .aureus （MSSA） isolated from blood of patients ,so as to enhance the understanding of the drug resistance and transmission mechanism of MRSA .METHODS A total of 19 strains of MRSA and 14 strains of MSSA were isolated from blood of hospitalized patients in the hospital from Apr .to Dec . 2012 .The clinical characteristics and drug resistance were investigated .Furthermore ,23 virulence factors（sasX , fnbA,clfA,clfB,icaA,efb,cna,hla,hlb,hld,hlg,hlg2,pvl,lukE,lukM,psm‐mec,ssp,eta,tst,sea,seb,cap5, cap8） and 7 drug‐resistant genes [mecA ,aac（6′） /aph（2″） ,aph（3′）‐Ⅲ ,ermA ,ermB ,ermC ,tetM] were deter‐mined by PCR .RESULTS The mean age of patients infected with MRSA was older than those with MSSA （（78 .5 ± 7 .6） years vs .（67 .6 ± 15 .3） years ,P〈0 .05） .The duration of MRSA identification was longer than MSSA ,i . e .,（9 .84 ± 4 .11） days vs .（6 .93 ± 3 .26） days（P〈0 .05）from the date of patient admission .The resistant rates of 19 strains of MRSA were low to vancomycin ,sulfamethoxazole/trimethoprim and rifampicin ,being 0 ,21 .1% , and 26 .3% .The resistant rates of 14 strains of MSSA were high to penicillin and erythromycin ,being 78 .6% and 42 .9% .Twenty virulence factors were positive in MRSA strains ,except hlg ,lukM ,and eta .The positive rate of drug resistance genes of MRSA was higher than the rate of MSSA , which was identical to the results of antibacterial sensitivity tests .Clone phenomenon existed for both MRSA and MSSA .CONCLUSION The high inci‐dence of adhesion factor in MRSA and MSSA is a clue to the characteristic of colonization .The high incidence of virulence factors suggests the damnification ability of these strains to the host .This phenomenon reveals that ward infection is existed .The efficacious management should be taken as a key role to decrease nosocomial infection in

关 键 词：耐甲氧西林金黄色葡萄球菌 甲氧西林敏感金黄色葡萄球菌 分子生物学 临床特征 

分 类 号：R378.11[医药卫生—病原生物学]