无菌部位金黄色葡萄球菌耐药性及分子流行病学特征

Antibiotic resistance and molecular epidemiology characteristics of Staphylococcus aureus isolated from sterile sites

目的:了解无菌部位分离的金黄色葡萄球菌对常用抗菌药物的耐药性及分子流行病学特征,为临床预防和控制其感染以及合理使用抗菌药物提供实验依据。方法:收集2011年8月至2012年6月某三甲医院无菌部位分离的非重复金黄色葡萄球菌50株。VITEK-2微生物分析系统进行菌株鉴定,PCR检测耐甲氧西林的金黄色葡萄球菌(MRSA)杀白细胞毒素(PVL)基因,多重PCR对MRSA进行SCCmec基因分型。结果:在18种抗菌药物中,青霉素和红霉素的耐药率最高,分别为90.0%和62.0%;尚无对万古霉素、替加环素、替考拉宁、利奈唑胺、达托霉素的耐药菌株。50株金葡菌中,MRSA 15株(30.0%),MSSA35株(70.0%),MRSA对12种抗菌药物的敏感率明显低于MSSA。15株MRSA中,SCCmecⅢ型11株(73.3%),SCCmecⅣ型4株(26.7%),PVL基因扩增均为阴性。结论:该院无菌部位分离的金黄色葡萄球菌以MSSA为主;MRSA对抗菌药物呈多重耐药性,且以SCCmecⅢ型为主。

Objective To understand antibiotic resistance and molecular epidemiology characteristics of Staphylococcus aureus isolated from sterile sites, thus provide evidence for prevention and control of Staphylococ-cus aureus infections, and for the rational use of antibiotics in clinical settings. Methods A total of 50 non-dupli-cate clinical isolates of Staphylococcus aureus from sterile sites were collected from August 2011 to June 2012 in a hospital and then identified by Vitek-2 microbiological analysis system.The Panton-Valentine leukocidin (PVL) gene was detected by simple PCR and the genotypes of staphylococcals chromosomal cassette mec(SCCmec) were determined by multiplex PCR. Results Among the 18 antibiotics, resistance rates to penicillin and erythromycin were the highest (90.0% and 62.0% respectively). No isolates resistant to vancomycin, tigecycline, teicoplanin, linezolid and daptomycin were found. Among the 50 Staphylococcus aureus strains, there were 15 strains of MR-SA(30.0%) and 35 strains of MSSA(70.0%). The sensitivities of MRSA to the other 12 antibiotics were much lower than that of MSSA. Among the 15 strains of MRSA, 11 (73.3%) strains belonged to SCCmec typeⅢ,4 (26.7%) strains belonged to SCCmec typeⅣ, PVL genes were all negative. Conclusions Staphylococcus aureus isolated from sterile sites were major MSSA, but MRSA presented with multi-drug resistance to antibiotics and a major genotype of SCCmec typeⅢ.