耐甲氧西林金黄色葡萄球菌相关致病因子的检测

Study on virulence factors of methicillin-resistant Staphylococuus aureus

目的了解医院相关性耐甲氧西林金黄色葡萄球菌(MRSA)(HA-MRSA)和社区相关性MRSA(CA-MRSA)的相关致病因子及其分布规律,为医院关于MRSA的感染学控制提供相关依据。方法收集2010年1月-2011年12月医院门诊和住院患者分离的53株MRSA,应用聚合酶链反应技术(PCR)检测MRSA中杀白细胞毒素(PVL)及α-溶血素(α-HL)。结果临床分离的53株MRSA中,PVL毒素15株CA-MRSA中5株阳性,阳性率为33.3%,38株HA-MRSA中1株阳性,阳性率为2.6%(P≤0.05);15株CA-MRSA进行α-溶血素检测,其中9株阳性,阳性率为60.0%;38株HA-MRSA,其中23株阳性,阳性率为60.5%(P>0.05)。结论 PVL毒素和α-溶血素是MRSA主要的致病因子,在携带率方面,CA-MRSA比HA-MRSA更容易携带PVL毒素,差异有统计学意义;而α-溶血素在两者之间差异无统计学意义。

OBJECTIVE To explore the related virulence factors of the hospital-associated methicillin-resistant Staph ylococuus aureus （ HA-MRSA ） and the community-associated methicillin-resistant Staph ylococuus aureus （CA-MRSA） so as to provide basis for the control of MRSA infections. METHODS A total of 53 strains of MRSA isolated from the outpatients and inpatients between Jan 2010 and Dec 2011 were collected, and the PVL and a-HL in the MRSA strains were detected with PCR. RESULTS Of 53 strains of clinical isolates of MRSA, there were 5 in 15 （33.3%） strains of CA-MRSA with PVL tested positive and 1 in 38（2.6% ） strains of HA-MRSA with PVL tested positive （P〈0.05）. There were 9 in 15 （60.0%） strains of CA-MRSA with a-HL tested positive and 23 in 38 （60.5%） strains of HA-MRSA with α-HL tested positive （P〉0.05）. CONCLUSION PVL and α-HL are the important virulence factors of MRSA. CA-MRSA is more likely than HA-MRSA to carry PVL toxin, the difference is statistically significant,however, the difference in the carrier rate of α-HL between the CA-MRSA and HA-MRSA is not statistically significant.