VanC型肠球菌与屎肠球菌对常用抗菌药的耐药状况研究

Study on the resistance rate of Van C type Enterococcus and Enterococcus faecium to antibiotics

目的比较Van C型肠球菌及屎肠球菌对常用抗菌药物的敏感性。方法针对56株Van C型肠球菌及299株屎肠球菌,用琼脂二倍稀释法进行药物敏感性分析;检测高水平耐万古霉素屎肠球菌的万古霉素耐药基因型。结果Van C型肠球菌万古霉素最低抑菌浓度(MIC)众数为4 mg·L-1,未发现对氨苄西林、万古霉素、替考拉宁及利奈唑胺耐药的Van C型肠球菌。屎肠球菌对氨苄西林、左氧氟沙星、红霉素及利福平的耐药率均达85%以上;对万古霉素和替考拉宁的耐药率分别为1.7%和0.7%;未发现对利奈唑胺和替加环素耐药的屎肠球菌。屎肠球菌万古霉素MIC众数为0.5 mg·L-1。5株万古霉素屎肠球菌万古霉素耐药基因均为van A型。结论屎肠球菌对万古霉素尚保持较高敏感性,万古霉素对Van C型肠球菌最低抑菌浓度较屎肠球菌高。

Objective To compare susceptibility of the VanC phenotype Enterococcus and Enterococcus faecium to antibiotics normally used in clinical.Method The antimicrobial susceptibility of 53 isolates of VanC type Enterococcus and 299 isolates of E.faecium were determined by argar dilution.The vancomycin resistance genes were analysis of high-level vancomycin- resistant E.faecium.Results The median minimum inhibitory concentration（ MIC） distribution of VanC phenotype Enterococcus to wancomycin was 4 mg · L^-1,no VanC phenotype Enterococcus were found resistant to ampicilin,vancomycin,teicoplanin and linizolid.The resistant rates of E.faecium to ampicillin,levofloxacin,erythromycin and rifampin were above 85%.The resistant rates of E.faecium to vancomycin and teicoplanin were 1.7% and 0.7%,sepreately.No E.faecium isolates were found resistant to linizolid.The median MIC distribution of E.faecium to vancomycin was 0.5 mg·L^-1.van A gene were found in 5 isolates of vancomycin resistant E.faeciums.Conclusion E.faecium remained sensitive to vancomycin,the MIC of vancomycin to VanC phenotype Enterococcus were higher than that of E.faecium.