四川省食品动物源大肠埃希菌产ESBLs菌株blaCTX–M基因的分子流行特征  

Molecular epidemiologic characteristics of bla genes of ESBLs-producing Escherichia coli isolates from food animals in Sichuan province

作　　者：杨承霖 吴聪明[2] 王爽[1] 林居纯[1] YANG Chenglin;WU Congming;WANG Shuang;LIN Juchun(College of Veterinary Medicine,Sichuan Agricultural University,Chengdu,Sichuan 611130,China;College of Veterinary Medicine,China Agricultural University,Beijing 100193,China)

机构地区：[1]四川农业大学动物医学院,四川成都611130 [2]中国农业大学动物医学院,北京100193

出　　处：《湖南农业大学学报（自然科学版）》2020年第4期456-460,共5页Journal of Hunan Agricultural University(Natural Sciences)

基　　金：国家重点研发计划专项(2018YFD0500300)。

摘　　要：2010—2016年,从四川省不同养殖场的食品动物源(猪源、鸡源)中分离和纯化并最终获得123株大肠埃希菌产超广谱β–内酰胺酶(ESBL–EC)菌株,采用PCR法,并通过测序检测其blaCTX–M基因,采用脉冲场凝胶电泳法(PFGE)分析33株不同来源菌株的亲缘关系。结果显示:123株菌株中blaCTX–M检出率高达91.9%(113/123),其中以blaCTX–M–55和blaCTX–M–65基因型为主;blaCTX–M流行率呈逐年上升的趋势;不同动物源菌株中blaCTX–M流行情况不同;12株菌中blaCTX–M基因发生了9种类型的突变,其中有10株菌为有义突变,导致7种类型氨基酸被取代;33株不同来源菌株共有32种PFGE型。可见,四川省食品动物源产ESBLs大肠埃希菌中blaCTX–M基因型复杂且存在变异,在不同遗传背景的ESBL–EC菌株间广泛流行。123 extended-spectrum β-lactamase-producing Escherichia coli(ESBL-EC) were isolated and collected from food-producing animals(swine and chicken) of different farms in Sichuan province from 2010 to 2016. PCR and DNA sequencing were performed to detection blaCTX-M genes. Pulsed-field gel electrophoresis(PFGE) was used for molecular typing of 33 isolates of the 123 isolates with different sources. The results showed that prevalence of blaCTX-M was 91.9%(113/123) in ESBL-EC isolates, among which blaCTX-M-55 and blaCTX-M-65 were the dominant genotypes. The occurrence of blaCTX-M was increasing yearly;blaCTX-M variants were observed in isolates from chicken and swine;9 types of mutations of blaCTX-M genes were found in 12 isolates, in which 10 were sense mutations, which made 7 types of amino acid substitutions;33 isolates were classified into 32 types by PFGE. In sumary, blaCTX-M genotypes were mutated, and had spread widely among different molecular types of ESBL-EC isolates from food animals in Sichuan province.

关 键 词：猪 鸡 食品动物源 大肠埃希菌 β–内酰胺酶 blaCTX–M 分子流行特征 四川 

分 类 号：S852.61[农业科学—基础兽医学]