CTX-M-12编码基因的克隆、表达及序列分析

Cloning and sequencing of the CTX-M-12 encoding gene of β-lactamase

目的 研究上海市华山医院临床分离的肺炎克雷伯菌K99 44 2菌株产生的超广谱 β 内酰胺酶 (ESBLs)的基因型。方法 采用聚合酶链反应 (PCR)扩增K99 44 2转移接合子中的ESBLs全编码基因 ,克隆入 pHSG398质粒、表达 ,并对PCR产物进行测序 ,分析其基因型。 结果 K99 44 2转移接合子所产生ESBLs编码基因序列与GeneBank中CTX M 12编码基因序列的同源性为 10 0 %。结论 临床分离的肺炎克雷伯菌K99 44 2菌株产生CTX M 12型酶 ,可对多数的 β 内酰胺类抗菌药物产生耐药性。

Objective To investigate the ESBL gene in a Klebsiella pneumoniae strain isolated from a patient in Huashan Hospital, Shanghai. Methods ESBL gene in the transconjugant from Klebsiella pneumoniae isolate was amplified by PCR. The PCR products were cloned into pHSG398 vector. The antibiotic susceptiblity and β-lactamases activity of the clone strain were tested; The PCR product was sequenced and analyzed. Results The ESBL gene was identified as CTX-M-12 gene and CTX-M-12 is much more active against cefotaxime than against ceftazidine.Conclusions A clinical isolate of Klebsiella pneumoniae k99-442 isolated from a patient in Huashan Hospital, Shanghai produced ESBL type CTX-M-12 which caused this isolate resistant to most β-lactams.