Distribution of CTX-M β-lactamase Genes Among Escherichia coli Strains Isolated from Patients in Iran
Distribution of CTX-M β-lactamase Genes Among Escherichia coli Strains Isolated from Patients in Iran
复制标题
DOI：
10.1309/lmuuwbhmzedytbw5
复制
发表时间：
2009-12-01
期刊：
影响因子：
--
通讯作者：
Mansouri, Sadegh
中科院分区：
文献类型：
--
作者：
Mirzaee, Mohsen;Owlia, Parviz;Mansouri, Sadegh
背景：产生 CTX-M-β-内酰胺酶的生物体正在世界范围内出现，作为对氧亚氨基头孢菌素（例如头孢噻肟）的耐药性来源。在这项研究中，我们使用多重聚合酶链式反应（PCR）作为快速方法来鉴定来自德黑兰医院的超广谱β-内酰胺酶（ESBL）基因bla（CTX-M），产生大肠杆菌（E. coli）临床分离株。方法：在6个月（2007年9月至2008年2月）期间，从3所大学医院收集了250个大肠杆菌临床分离株。在德黑兰。 ESBL 检测的表型筛选和确认测试是根据临床和实验室标准研究所 (CLSI) 指南进行的。通过多重 PCR 检查所有产生 ESBL 的分离株是否存在 bla(CTX-M) 基因。结果：初步表型测试显示 56% (n=140) 的大肠杆菌分离株产生 ESBL。在使用克拉维酸的验证试验中，96% (n=135) 的初次阳性试验菌株中确认了 ESBL 的产生。 3.5% (n=5) 筛查呈阳性的患者中，未证实 ESBL 的存在。在所有筛选阳性分离株中，来自 CTX-M 组 1 的 50 个分离株对 bla(CTX-M) 基因呈阳性；来自 CTX-M 第 9 组的 5 个分离株对 bla(CTX-M) 基因呈阳性； 1 株分离株对 CTX-M 组 25/26 呈阳性。结论：我们的研究证明使用多重 PCR 可以快速检测临床分离株中的 bla(CTX-M)。这种基因型方法可以在实验室中快速有效地分化 ESBL。
Background: Organisms producing CTX-M-beta-lactamase are emerging around the world as a source of resistance to oxyimino-cephalosporins such as cefotaxime. In this study, we used a multiplex polymerase chain reaction (PCR) as a rapid method to identify genes bla(CTX-M) for Extended-spectrum beta-lactamase (ESBLs) producing clinical isolates of Escherichia coli (E. coli) from hospitals of Tehran.Methods: During 6 months (September 2007 to February 2008), 250 clinical isolates of E. coli were collected from 3 university hospitals in Tehran. Phenotypic screening and confirmation tests for ESBL detection were performed according to Clinical and Laboratory Standards Institute (CLSI) guidelines. All of the ESBL-producing isolates were examined by multiplex PCR for presence of bla(CTX-M) genes.Results: Primary phenotypic tests revealed that 56% (n=140) of E coli isolates produced ESBLs. In confirmatory tests using clavulanic acid, ESBL production was confirmed in 96% (n=135) of isolates with a primary positive test. The presence of ESBL was not confirmed in 3.5% (n=5) of those that screened positive. Of all screen positive isolates, 50 isolates were positive for bla(CTX-M) genes from the CTX-M group 1; 5 isolates were positive for bla(CTX-M) genes from the CTX-M group 9; and 1 isolate was positive for CTX-M group 25/26.Conclusions: Our study demonstrated rapid detection of bla(CTX-M) in clinical isolates using multiplex PCR. This genotypic method provided a rapid and efficient differentiation of ESBLs in the laboratory.