宿州市大肠埃希菌和肺炎克雷伯菌ESBLs的检测及基因型分布

Detection of Extended-spectrum Beta-lactamases and its Genotypes in Escherichia coli and Klebsiella Pneumoniae Isolates in Suzhou City

目的探讨安徽省宿州市临床分离菌中大肠埃希菌和肺炎克雷伯菌ESBLs的检出率、耐药性及基因型分布。方法采用2005年CLSI推荐方法对收集菌株进行ESBLs确证试验;平皿琼脂对倍稀释法测定产ESBLs大肠埃希菌和肺炎克雷伯菌对13种抗菌药物的耐药性;用PCR法对产ESBLs菌株使用8对引物进行β内酰胺酶基因的扩增,扩增产物回收纯化后测序。结果宿州市临床分离大肠埃希菌和肺炎克雷伯菌中产ESBLs株的检出率分别为64.7%和60.5%。ESBLs产生株对三代头孢菌素头孢曲松、头孢塞肟、头孢他啶的耐药率为41.9%～86.3%,对环丙沙星、左氧沙星的耐药率为48.4%～85.5%,对哌拉西林/他唑巴坦、头孢哌酮/舒巴坦的耐药率为4.2%～25.8%,对亚胺培南和美洛培南100.0%敏感。PCR及测序结果显示产ESBLs菌株中,β内酰胺酶基因型以TEM和CTX-M13型为主,分别为61株和55株;亚胺培南和美洛培南是治疗产ESBLs大肠埃希菌和肺炎克雷伯菌感染的首选药物。结论宿州市临床分离大肠埃希菌和肺炎克雷伯菌中产ESBLs株的检出率和对头孢菌素类及喹诺酮类的耐药率均达到很高水平,应加强对产ESBLs株的临床监测。

Objective To investigate the ESBL-producing isolates and its resistance and genotypes in Escherichia coli and Klebsiella pneurnonlae at the hospital of Suzhou city. Methods The confirmation test was used to detect ESBL- producing strains according to CLSI 2005. The MIC of 13 antimicrobials against ESBL-producing strains of Escherichla coli and Klebsiella pneurnonlae were determined by 2-fold agar dilution method. PCR method was used to amplify beta-lactamases of ESBL-producing isolates by 8 premiers,PCR products were puffed and then sequencing was performed. Results The ESBL-producing rates in Escherichia coli and Klebsiella pneumoniae at the hospital of Suzhou city was 64.7 % and 60.5 % respectively. Resistance rates to CRO,CTX,CAZ and CIP,LEV of ESBL-producing strains were 41.9 % to 86.3 % and 48. 4 % to 85. 5%. ESBL-producing strains resistance rate to Piperacillin-tazobactam and Cefoperazone-sulbactam were 4.2 % to 25.8% ;all isolates were susceptible to merpenem and imipenem. PCR indicates that the major genotypes of ESBL-producing Escherichia coli and Klebsiella pneurnoniae at the hospital of Suzhou city were TEM and CHXM13; imipenem and merpenem were the best antibiotics for treatment of infections caused by ESBL-producing Escherichia coli and Klebsiella pneurnonlae. Conclusions The separate rates of ESBL-producing Escherichia coli and Klebsiella pneurnoniae as well as their resistance rates to cephalosporins and quinolones at the hospital of Suzhou city were very high.