甲氧西林耐药葡萄球菌精氨酸代谢可移动原件研究

目的:研究临床分离的甲氧西林耐药葡萄球菌ACME携带情况以及阳性菌株流行特点。方法:收集2009年1月-2011年12月临床分离的葡萄球菌共363株,包括275株MRSA和88株MRSE,采用PCR方法对ACME编码基因arcA进行扩增。结果:275株MRSA中未发现ACME阳性菌株;88株MRSE中检测到ACME阳性菌株28株,阳性率31.8%,其中血液中分离率最高,占42.3%(11/26)。药敏结果显示,ACME阳性菌株除对利福平的耐药率较低外,对红霉素、氯洁霉素、庆大霉素、复方新诺明、四环素、左旋氧氟沙星的耐药率较高(均>30%),未发现耐利奈唑脘和万古霉素的菌株;ACME阳性菌株和阴性菌株对抗菌药物的耐药性没有显著差异(P>0.05)。结论:ACME阳性MRSE菌株在血流感染中有一定程度的流行;ACME具有广泛的水平转移功能,应加强该类菌株的监测。

Study on arginine catabolic mobile element from methicillin-resistant Staphylococcus isolates

Objective:To investigate the prevalence of arginine catabolic mobile element(ACME) of methicillin-resistant staphylococcus isolates.Methods:A total of 363 staphylococcus isolates were collected from clinical sources from January 2009 to December 2011,including 275 Methicillin-resistant Staphylococcus aureus(MRSA) strains and 88 Methicillin-resistant Staphylococcus epidermidis(MRSE) strains.The ACME-arcA gene of staphylococcus strains were amplified using PCR.Results:ACME gene was not detected in all MRSA strains;In 88 MRSE strains,28 strains carried ACME-arcA gene(31.8%).Most positive strains were isolated from blood,accounting for 42.3%(11/26).The results of antibiotic susceptibility test displayed that the resistance rates of the ACME positive strains to rifampicin were lower,but to erythromycin,clindamycin,gentamicin,trimethoprim/sulfamethoxazole,tetracycline and levofloxacin were higher,and no isolate was resistant to linezolid and vancomycin;The resistance was not significantly different between the ACME positive and negative strains(P>0.05).Conclusion:There was the prevalence of ACME positive MRSE strains in blood stream infection,and the ACME gene has a ability of lateral mobility,which should be reinforced the surveillance of this kind of strains.