Plasmid typing and genetic context of AmpC β-lactamases in Enterobacteriaceae lacking inducible chromosomal ampC genes: findings from a Spanish hospital 1999-2007
Plasmid typing and genetic context of AmpC β-lactamases in Enterobacteriaceae lacking inducible chromosomal ampC genes: findings from a Spanish hospital 1999-2007
复制标题
DOI：
10.1093/jac/dkr412
复制
发表时间：
2012-01-01
影响因子：
5.2
通讯作者：
Navarro, Ferran
中科院分区：
文献类型：
--
作者：
Mata, Caterina;Miro, Elisenda;Navarro, Ferran
目的：为了深入了解细菌strains.Methods之间的ampC传输：我们研究了117收购ampC基因从27119肠杆菌科收集1999年和2007年之间的遗传背景。质粒分析通过基于PCR的复制子或松弛酶分型、S1-PFGE和Southern杂交进行。I-CeuI/PFGE用于未通过质粒分析表征的分离株。结果：81.2%的ampC基因位于已知的Inc/MOB群质粒上，7.7%位于染色体上，11.1%未确定。在携带bla（CMY-2）的质粒中，A/C、I1和K是最常见的复制子，而L/M复制子与bla（DHA-1）相关。bla（ACC-1）与I1和MOBF 11质粒相连; bla（CMY-27）与IncF和MOBP 12质粒相连;携带bla（CMY-25）的质粒不能分型，bla（CMY-40）位于染色体上。所有87个携带bla（CMY-2）、bla（CMY-4）、bla（CMY-25）、bla（CMY-27）、bla（CMY-40）或bla（ACC-1）的菌株均显示转座子样结构ISEcp 1/Delta ISEcp 1-bla（CMY）-blc-sugE或Delta ISEcp 1-bla（ACC-1）-gdha。bla（DHA-1）中最常见的结构（93.3%的病例）与肺炎克雷伯氏菌pTN 60013质粒中描述的结构相同。值得注意的是，在三个分离株含有染色体bla（CMY-2），这个基因被动员conjugation.Conclusions：虽然质粒是细菌之间的ampC基因的快速传播的主要原因，我们需要知道，其他移动的遗传因素，如整合和接合元件（ICE）可以参与这些基因的动员。
Objectives: To gain insights into ampC transmission between bacterial strains.Methods: We examined the genetic context of 117 acquired ampC genes from 27119 Enterobacteriaceae collected between 1999 and 2007. Plasmid analysis was carried out by PCR-based replicon or relaxase typing, S1-PFGE and Southern hybridization. I-CeuI/PFGE was used for isolates not characterized by plasmid analysis. PCR reactions were used to map the genetic organization of the ampC genes.Results: Among the isolates studied, 81.2% of ampC genes were located on plasmids of known Inc/MOB groups, 7.7% were chromosomally located and 11.1% were not determined. A/C, I1 and K were the most commonly found replicons in plasmids carrying bla(CMY-2), while L/M replicons were associated with bla(DHA-1). bla(ACC-1) was linked to I1 and MOBF11 plasmids; bla(CMY-27) was associated with IncF and MOBP12 plasmids; the plasmid carrying bla(CMY-25) could not be typed, and bla(CMY-40) was chromosomally located. All 87 isolates carrying bla(CMY-2), bla(CMY-4), bla(CMY-25), bla(CMY-27), bla(CMY-40) or bla(ACC-1) displayed the transposon-like structures ISEcp1/Delta ISEcp1-bla(CMY)-blc-sugE or Delta ISEcp1-bla(ACC-1)-gdha. The most prevalent structure in bla(DHA-1) (93.3% of cases) was identical to that described in the Klebsiella pneumoniae pTN60013 plasmid. Remarkably, in three isolates containing chromosomal bla(CMY-2), this gene was mobilized by conjugation.Conclusions: Although plasmids are the main cause of the rapid dissemination of ampC genes among bacteria, we need to be aware that other mobile genetic elements such as integrative and conjugative elements (ICEs) can be involved in the mobilization of these genes.