Molecular characterisation of the NDM-1-encoding plasmid p2189-NDM in an Escherichia coli ST410 clinical isolate from Ghana
Molecular characterisation of the NDM-1-encoding plasmid p2189-NDM in an Escherichia coli ST410 clinical isolate from Ghana
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DOI：
10.1371/journal.pone.0209623
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发表时间：
2018-12-21
期刊：
影响因子：
3.7
通讯作者：
Saito, Ryoichi
中科院分区：
文献类型：
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作者：
Ayibieke, Alafate;Sato, Wakana;Saito, Ryoichi
新德里产金属β-内酰胺酶(NDM)细菌的全球传播已成为主要的健康威胁。然而，关于包括加纳在内的西非产NDM细菌的鉴定和特性的报道很少。从加纳塔马莱教学医院分离到一株对美罗培南耐药的大肠杆菌。使用商业系统进行其鉴定和药敏图谱的测定。通过表型检测试剂盒、聚合酶链式反应和DNA测序分析耐药机制。接合实验、S1核酸酶脉冲场凝胶电泳和Southern blotting。最后，利用下一代测序和系统发育分析对携带NDM-1基因的质粒进行了鉴定。耐美罗培南的大肠埃希菌EC2189含有BLA(NDM-1)，属于410序列类型。Bla(NDM-1)位于Inchi类型可转移质粒p2189-NDM上，共携带bla(CTX-M-15)、aadA1、aac(6‘)-Ib、sul3、dfrA12和cmlA1等多个抗性基因。P2189-NDM与以前发现的BLA(NDM-1)阳性Inchi类型的质粒在系统发育上是不同的。含有blA(NDM-1)的Tn125片段上游被类似ISSM-1的插入序列包围，下游被位点特异性整合酶包围。据我们所知，我们首次在加纳鉴定了一株产NDM-1的肠杆菌科菌株，并对其进行了分子特征分析，该菌株具有BLA(NDM-1)具有新的遗传结构。我们的发现表明NDM-1有可能在加纳传播，并强调了对碳青霉烯酶产生菌进行持续监测的必要性。
Global dissemination of New Delhi metallo-beta-lactamase (NDM)-producing bacteria has become a major health threat. However, there are few reports regarding the identification and characterisation of NDM-producing bacteria from West Africa, including Ghana. An Escherichia coli strain with resistance to meropenem was isolated from the Tamale Teaching Hospital in Ghana. Its identification and determination of antibiotic susceptibility profile were carried out using commercial systems. The antibiotic resistance mechanism was analysed by phenotypic detection kits, PCR, and DNA sequencing. Conjugation experiments, S1 nuclease pulsed field gel electrophoresis, and Southern blotting were performed. Finally, the NDM-1-harbouring plasmid was characterised using next-generation sequencing and phylogenetic analysis. The meropenem-resistant Escherichia coli strain EC2189 harboured bla(NDM-1) and belonged to sequence type 410. bla(NDM-1) was located on the IncHI type transferrable plasmid p2189-NDM (248,807 bp long), which co-carried multiple resistance genes, such as bla(CTX-M-15), aadA1, aac(6')-Ib, sul3, dfrA12, and cmlA1. p2189-NDM phylogenetically differed from previously identified bla(NDM-1)-positive IncHI type plasmids. A truncated Tn125 containing bla(NDM-1) was bracketed by an ISSm-1-like insertion sequence upstream and by a site-specific integrase downstream. To the best of our knowledge, we have, for the first time identified and molecularly characterised an NDM-1-producing Enterobacteriaceae strain in Ghana with bla(NDM-1) that had a novel genetic structure. Our findings indicate a possibility of NDM-1 dissemination in Ghana and underscore the need for constant monitoring of carbapenemase-producing bacteria.