摘要
目的检测11株耐万古霉素肠球菌(VRE)的耐药表型、基因型以及多耐基因。方法采用纸片扩散法、微量稀释法、自动化仪器、浓度梯度法测定11株VRE对万古霉素(Van)、替考拉宁(Tec)的耐药表型,微量稀释法测定11株VRE对10种抗菌药物的最低抑菌浓度;多重聚合酶链反应检测vanA、vanB、vanC1、vanC2并对van基因产物进行测序,聚合酶链反应检测TEM、tetM、ermB、aac(6′)/aph(2′′)、ant(6)Ⅰ、aph(3′)Ⅲ基因。结果不同药敏方法测得11株VRE对Van、Tec的药敏结果有差异;11株VRE对红霉素(9/11)、环丙沙星(7/11)、左氧氟沙星(7/11)、利福平(8/11)、氯霉素(7/11)耐药程度较高,高水平庆大霉素耐药株(HLGR)、高水平链霉素耐药株(HLSR)分别占10/11和9/11。11株VRE检出1株VanA、4株VanB、5株VanC1,1株VanC2,基因型和表型一致;耐药基因TEM(8/11)、tetM(6/11)、ermB(7/11)、aac(6′)/aph(2′′)(7/11)、ant(6)I(5/11)、aph(3′)Ⅲ(9/11)检出率高。结论VRE确证试验以及准确检测其MIC值是筛查VRE不漏诊的可靠方法;van基因的检测是从分子水平确定VRE准确特异的方法;耐药基因的高检出率体现了VRE复杂的耐药机制。
Objective To detect the phenotype and genotype of 11 vancomycin-resistant enterococci(VRE).Methods Disk diffusion test,microdilution broth method,VITEK-2 and Etest were used to determin the susceptibility of 11 VRE to vancomycin and teicoplanin. MIC to 10 antimicrobial agents were determined with microdiluton broth method. vanA, vanB ,vanC_1, vanC_2 were detected with multiplex PCR and were further confirmed by DNA sequencing. TEM, tetM,ermB,aac(6′)/aph(2′′),ant(6)- I,aph(3′)-Ⅲ were detected with PCR.Results Susceptibilities of 11 VRE to vancomycin and teicoplanin were different in four vitro susceptibility testing methods. VRE showed resistance to erythromycin(9/11),ciprfloxacin(7/11),levofloxacin(7/11),rifampin(8/11) and chloramphenicol(7/11). HLGR and HLSR is 10/11 and 9/11 respectively. 1 VanA,4 VanB,5 VanC_1 and 1 VanC_2 were detected and their phenotypes confirmed to the genotypes. High rate of TEM(8/11), tetM(6/11), ermB(7/11), aac(6′)/aph(2′′)(7/11), ant(6)- I(5/11) and aph(3′)-III(9/11) were detected in 11 VRE.Conclusions VRE screening test and the determination of MIC are reliable in finding VRE. PCR is precise and specific in the testing and confirmation of VRE. The high rates of drug resistance genes showed the complicated mechanisms of drug resistance in VRE.
出处
《中华检验医学杂志》
CAS
CSCD
北大核心
2005年第4期426-429,共4页
Chinese Journal of Laboratory Medicine
基金
北京市自然科学基金资助项目(7012013)
CLONEGEN细菌耐药基因研究专项基金资助
