Characterization of Canadian cefoxitin-resistant non-typhoidal Salmonella isolates, 2005-06
Characterization of Canadian cefoxitin-resistant non-typhoidal Salmonella isolates, 2005-06
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DOI：
10.1093/jac/dkp249
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发表时间：
2009-10-01
影响因子：
5.2
通讯作者：
Mulvey, M. R.
中科院分区：
文献类型：
--
作者：
Mataseje, L. E.;Xiao, J.;Mulvey, M. R.
目的：全世界沙门氏菌对超广谱头孢菌素的耐药性有所增加，这是医院和社区环境中的一个问题。本报告的目的是调查从加拿大各地人类临床病例中鉴定出的头孢西丁耐药沙门氏菌分离株。方法：头孢西丁耐药分离株（定义为 MIC >= 32 mg/L）通过多重 PCR 筛选 ampC 类别 DHA、FOX、ENT 和 CIT，然后进行序列分析。通过限制性片段长度多态性 (RFLP) 和复制子分型对头孢西丁耐药沙门氏菌的方便样本进行质粒分析。 结果：2005 年，从加拿大各省收集的沙门氏菌分离株中，5.3% (181/3442) 和 2006 年分别有 3.1% (102/3250) 显示出头孢西丁耐药性。 283 例中的 71 例 (25.1%) 具有多重耐药性 (MDR)，定义为对至少三种不同抗生素类别的耐药性。 96.8% (274/283) 的头孢西丁耐药菌株携带 bla(CMY-2) 基因。对 CMY-2 质粒的分析显示，19.7% 的质粒含有对多种抗菌药物产生耐药性的基因。转化体 CMY-2 质粒 DNA 的复制子分型揭示了 I1-I gamma 和 A/C 的优势。在 MDR CMY-2 质粒中，75% 含有 A/C 型复制子。 CMY-2 质粒的 RFLP 模式揭示了与 I1-I gamma 和 A/C 复制子类型相对应的簇。结论：不相容组 I1-I gamma 是沙门氏菌 CMY-2 质粒中最常见的，而 A/C 与 MDR CMY-2 质粒相关。
Objectives: Resistance to extended-spectrum cephalosporins has increased in Salmonella worldwide, and is a concern in both hospital and community settings. The aim of this report was to investigate cefoxitin-resistant Salmonella isolates identified from human clinical cases across Canada.Methods: Cefoxitin-resistant isolates, defined as having an MIC >= 32 mg/L, were screened for the ampC classes DHA, FOX, ENT and CIT in a multiplex PCR followed by sequence analysis. Plasmid analysis by restriction fragment length polymorphism (RFLP) and replicon typing was performed on a convenience sample of cefoxitin-resistant Salmonella.Results: In 2005, 5.3% (181/3442) and in 2006, 3.1% (102/3250) of Salmonella isolates collected from all provinces across Canada displayed cefoxitin resistance. Seventy-one out of 283 (25.1%) were multidrug resistant (MDR), as defined by resistance to at least three different antibiotic classes. The bla(CMY-2) gene was harboured by 96.8% (274/283) of the cefoxitin-resistant isolates. Analysis of CMY-2 plasmids revealed that 19.7% contained genes conferring resistance to multiple antimicrobials. Replicon typing of transformant CMY-2 plasmid DNA revealed the predominance of I1-I gamma and A/C. Of the MDR CMY-2 plasmids, 75% contained replicon type A/C. RFLP patterns of CMY-2 plasmids revealed clusters corresponding to the I1-I gamma and A/C replicon types.Conclusions: Incompatibility group I1-I gamma is the most prevalent of the Salmonella CMY-2 plasmids, while A/C is associated with MDR CMY-2 plasmids.