High incidence of multidrug-resistant Escherichia coli coharboring mcr-1 and blaCTX-M-15 recovered from pigs
High incidence of multidrug-resistant Escherichia coli coharboring mcr-1 and blaCTX-M-15 recovered from pigs
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猪体内同时含有 mcr-1 和 bla(CTX)-(M-15) 的多重耐药大肠杆菌的高发生率
DOI：
10.2147/idr.s209473
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发表时间：
2019-01-01
影响因子：
3.9
通讯作者：
Wang, Liping
中科院分区：
文献类型：
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作者：
Shafiq, Muhammad;Huang, Jinhu;Wang, Liping
目的：大肠杆菌中移动粘菌素（COL）抗性基因mcr-1与超广谱β-内酰胺酶（ESBL）基因的共存已成为全球的严重威胁。本研究的目的是调查对 COL 日益增强的耐药性，特别是其与从中国养猪场回收的产 ESBL 大肠杆菌的共存情况。材料和方法：从中国江苏的 14 个养猪场分离出大肠杆菌。药敏试验采用微量稀释法鉴定。 PCR检测和核苷酸测序用于检测COL耐药基因mcr-1至-5，以及ESBL基因bla(CTX-M)、bla(SHV)和bla(TEM)。通过接合实验、多药耐药性 (MDR) 质粒复制子分型、S1-PFGE 和 DNA Southern 杂交来研究这些基因的可转移性。 结果：总共从 432 个泄殖腔和鼻拭子中回收了 275 个大肠杆菌分离株。 90%以上的分离株具有MDR，其中70.18%对COL耐药。在这 275 个分离株中，mcr-1 被确定为最主要的基因，71.63% (197/275) 的分离株携带 mcr-1，39.59% (78/197) 的分离株同时携带 mcr-1 和 ESBL 基因（bla(CTX-M)、bla(SHV) 和 bla(TEM)）。 ESBL 基因分型显示 bla(CTX-M) 是最主要的 ESBL (68.49%)，其次是 bla(SHV) (16.4%) 和 bla(TEM) (15%)。测序显示，最常见的 blaCTX-M 变体是 bla(CTX-M-15) (69%)、bla(CTX-M-55) (29%) 和 bla(CTX-M-1) (1.8%)。 IncHI2、IncFIB、IncFIC、IncN 和 IncX4 被发现是在供体和转接合子中最常见的 Inc 型，并且与 mcr-1 和 ESBL 编码基因的转移相关。六株菌株总共携带五种不同的质粒：大约 97-、130-、160-、227-和 242-kb 质粒。结论：从猪源大肠杆菌中回收的、携带 mcr-1 和 bla(CTX-M-15) 的分离株具有高 MDR，其共存是人类和兽医学的主要关注点。
Purpose: The coexistence of mobile colistin (COL)-resistant gene mcr-1 with extended-spectrum beta-lactamase (ESBL) gene in Escherichia coli has become a serious threat globally. The aim of this study was to investigate the increasing resistance to COL and in particular its coexistence with ESBL-producing E. coli recovered from pig farms in China.Materials and methods: E. coli were isolated from 14 pig farms in Jiangsu China. Susceptibility testing was identified by micro-dilution method. PCR assay and nucleotide sequencing were used to detect COL-resistant genes, mcr-1 to -5, as well as ESBL genes, bla(CTX-M), bla(SHV) and bla(TEM). Conjugation experiment, plasmid replicon typing of the multidrug resistance (MDR), S1-PFGE and DNA southern hybridization were performed to study the transferability of these genes.Results: Overall, 275 E. coli isolates were recovered from a total of 432 cloacal and nasal swabs. More than 90% of the isolates were MDR, of which 70.18% were resistant to COL. Of these 275 isolates, mcr-1 was identified as the most predominant gene carried by 71.63% (197/275) of isolates, 39.59% (78/197) of the isolates were harboring both mcr-1 and ESBL genes (bla(CTX-M), bla(SHV) and bla(TEM)). ESBL genotyping showed that bla(CTX-M) was the most predominant ESBL (68.49%) followed by bla(SHV) (16.4%) and bla(TEM) (15%). Sequencing revealed that the most common variants of blaCTX-M identified were, bla(CTX-M-15) (69%), bla(CTX-M-55) (29%) and bla(CTX-M-1) (1.8%). IncHI2, IncFIB, IncFIC, IncN and IncX4 were found to be the most common Inc-types found both in donors and in transconjugants and were associated with the transfer of the mcr-1 and ESBL encoding genes. Six strains carried a total of five different plasmids: approximately 97-, 130-, 160-, 227-and 242-kb plasmids.Conclusion: The coexistence of the mcr-1- and bla(CTX-M-15)-carrying isolates displaying high MDR, recovered from E. coli of pig origin, is a major concern for both humans and veterinary medicine.