Transmission of plasmid-borne and chromosomal blaCTX-M-64 among Escherichia coli and Salmonella isolates from food-producing animals via ISEcp1-mediated transposition
Transmission of plasmid-borne and chromosomal blaCTX-M-64 among Escherichia coli and Salmonella isolates from food-producing animals via ISEcp1-mediated transposition
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通过 ISEcp1 介导的转座，质粒携带的染色体 blaCTX-M-64 在食品动物的大肠杆菌和沙门氏菌分离株中传播
DOI：
10.1093/jac/dkaa044
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发表时间：
2020
影响因子：
5.2
通讯作者：
Hong-Xia Jiang
中科院分区：
文献类型：
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作者：
Qiu-Yun Zhao;Pin-Xian Chen;Ling Yang;Run-Mao Cai;Jia-Hang Zhu;Liang-Xing Fang;Mark A Webber;Hong-Xia Jiang
目的研究食品动物源大肠埃希菌和沙门氏菌之间blaCTX-M-64基因的传播机制。对2016年从食用动物中分离的60株沙门氏菌和60株大肠杆菌进行了blaCTX-M-64基因筛查。对阳性菌株进行基因分型、质粒和染色体DNA测序，以确定blaCTX-M-64基因的遗传背景和质粒类型。大肠杆菌菌株中为优势基因，而沙门氏菌菌株中为优势基因（n=9）。这12株CTX-M-64阳性菌株对氨苄西林、头孢噻肟、头孢噻呋、头孢曲松、头孢他啶和氟苯尼考均耐药，9株对环丙沙星耐药。将blaCTX-M-64基因定位在可转移的IncI 2质粒和IncHI 2质粒上。coli和1株沙门氏菌。其余8株沙门氏菌CTX-M-64整合到染色体上。BlaCTX-M-64基因在12株分离株中存在不同的遗传背景：3E的IncI 2质粒上有ISEcp 1-blaCTX-M-64-orf 477-A/C。大肠杆菌分离株;结论本研究首次报道了CTX-M-64基因在沙门氏菌中的染色体编码。ISEcp 1介导的转座可能是肠杆菌科尤其是大肠杆菌中blaCTX-M-64在不同质粒和染色体间传播的主要原因。大肠杆菌和沙门氏菌。
ObjectivesTo clarify the transmission mechanism of theblaCTX-M-64gene betweenEscherichia coliandSalmonellaisolates from food animals.MethodsA total of 329E. coliand 60Salmonellaisolates collected from food animals in 2016 were screened for the presence ofblaCTX-M-64genes. TheblaCTX-M-64-positive isolates were typed and plasmid and chromosome DNA was sequenced to determine the genetic context ofblaCTX-M-64and the plasmid types present.ResultsTheblaCTX-M-64gene was identified in only threeE. coliisolates but was the predominant gene in theSalmonellaisolates (n=9). These 12 CTX-M-64-positive isolates were all resistant to ampicillin, cefotaxime, ceftiofur, ceftriaxone, ceftazidime and florfenicol and 9 were resistant to ciprofloxacin. TheblaCTX-M-64gene was located on transferable IncI2 plasmids and an IncHI2 plasmid in threeE. coliand oneSalmonellaisolate, respectively. The remaining eightSalmonellaisolates containedblaCTX-M-64integrated into the chromosome. Different genetic contexts ofblaCTX-M-64genes were found among the 12 isolates: ISEcp1-blaCTX-M-64-orf477-A/C on IncI2 plasmids of 3E. coliisolates; ΔISEcp1-blaCTX-M-64-orf477-A/C in the chromosome of 1Salmonellaisolate; and ISEcp1-blaCTX-M-64-orf477on the IncHI2 plasmid and chromosome of 8Salmonellaisolates.ConclusionsTo the best of our knowledge, this is the first report of chromosomally encoded CTX-M-64 inSalmonellaisolates. ISEcp1-mediated transposition is likely to be responsible for the spread ofblaCTX-M-64between different plasmids and chromosomes in Enterobacteriaceae especiallyE. coliandSalmonella.