大肠埃希菌与肺炎克雷伯菌产碳青霉烯酶的表型检测及耐药分析

Detection of phenotypes of carbapenem enzyme-producing Escherichia coli and Klebsiella pneumoniae and drug resistance

目的了解临床分离的大肠埃希菌与肺炎克雷伯菌碳青霉烯酶和金属酶的携带情况,并进行相关耐药机制分析。方法采用VITEK-2型全自动微生物检测系统鉴定细菌;用微量稀释法筛选耐碳青霉烯类抗菌药物的大肠埃希菌和肺炎克雷伯菌共36株;通过Hodge试验检测碳青霉烯酶,以EDTA/IMP、EDTA/CAZ复合纸片,亚胺培南和头孢他啶为底物,进行协同试验检测B类碳青霉烯酶(金属酶),统计分析16种抗菌药物的MIC。结果 36株病原菌对头孢菌素类、碳青霉烯类和喹诺酮类抗菌药物耐药,有5株肺炎克雷伯菌对氨基糖苷类敏感;Hodge试验通过36株病原菌筛选,阳性菌株共30株,其中大肠埃希菌3株,阳性率为37.5%,肺炎克雷伯菌26株,阳性率为92.8%;只发现1株肺炎克雷伯菌金属酶阳性,A方法对金属酶的检测优于B方法。结论在ICU和呼吸科产碳青霉烯酶是细菌耐药的主要原因。

OBJECTIVE To study the drug resistance of Escherichia coli and Klebsiella pneumoniae, and the existance of the carbapene-mase and metal enzymes,in order to provid the basis for rational use of antimicrobial. METHODS These isolates were identified by the automatic VITEK2 system and their carbapenem-resistant E. coli and K. pneumoniae were tested by microdilution; carbapenem enzyme was tested by Hodge and the carbapenem class B enzymes （metallo） was tested by EDTA/IMP, EDTA/CAZ complex paper and imipenem and ceftazidime for joint experiments. The MIC to 16 kinds of drug were statistoc analyzed. RESULTS Totally 8 strains of E. coli and 28 strains of K. pneumoniae were drug resistance the cephalosporins, carbapenems and fluoroquinolones. 5strains of K. pneumoniae were sensitived aminoglycosides, by Hodge testing were screen 8 strains of E. coli and 28 strains of K. pneurnoniae, a total of 30 strains for positive, 3 strains of E. coli, the positive rate was 37.5%. 26 strains of K. pneurnoniae for positive, the positive rate was 92.8%. Synergy experiments to test 36 strains of bacteria, only founds a metal enzyme-positive strains, belonging the K. pneumoniae, A method was detecting of metal enzyme better than the B methods. CONCLUSION The ICU and respiratory production carbapenemase is mainly reason by drug resistance of bacteria.