产超广谱β-内酰胺酶大肠埃希菌及肺炎克雷伯菌的耐药基因序列分析

目的　了解四川大学华西医院产超广谱 β 内酰胺酶 (ESBLs)肺炎克雷伯菌和大肠埃希菌的TEM及SHV型ESBLs亚型 ,并分析其耐药性。方法　采用聚合酶链反应 (PCR)扩增分离四川大学华西医院住院患者的产ESBLs大肠埃希菌与肺炎克雷伯菌株的TEM型及SHV型ESBLs基因并测序 ,用琼脂稀释法测定头孢他啶和头孢噻肟等 8种抗菌药物的最小抑菌浓度 (MIC)值。结果　所有产ESBLs株均耐头孢噻肟 ,11株耐氨曲南 ,2株分别耐头孢他啶和头孢吡肟 ,对环丙沙星、阿米卡星及头孢西丁耐药的分别为 11株、5株和 3株。 12株ESBLs菌中 10株产SHV 2 ,2株产TEM 19。结论　本研究中的产ESBLs株以耐头孢噻肟和氨曲南为主 ,其中绝大多数为多重耐药株 ,产SHV 2和TEM 19是其对头孢噻肟及氨曲南等氧亚胺基 β 内酰胺酶类抗生素耐药的原因之一

Molecular epidemiology of TEM and SHV extended-spectrum β-lactamases in Klebsiella pneumoniae and Escherichia coli clinical isolates from Chengdu, China

Objective To investigate TEM and SHV ESBLs in Klebsiella pneumoniae and Escherichia coli clinical isolates from West China Hospital of Sichuan University and detect resistance of ESBLs-producing isolates. Methods The TEM and SHV ESBLs-encoding gene was amplified by PCR and was sequenced. And the MIC of eight antibiotics against the ESBLs-producing strains were detected by agar dilution. Results All strains were resistant to cefotaxime; eleven strains were resistant to aztreonam; two were resistant to ceftizidime; eleven, five and three were resistant to ciprofloxacin, amikacin and cefoxidine respectively; All strains were susceptible to imipenem. Ten strains of twelve ESBLs-producing strains carried bla SHV-2, two carried bla TEM-19. Conclusions ESBLs producers were mainly resistant to cefotaxime and aztreonam and most of them were multi-drug resistance; Cefotaxime resistance is partially due to production of SHV-2 and TEM-19 in this study.