羊腹泻大肠杆菌整合子及ESBLs携带情况检测  

Detection of Integrons and ESBLs in Diarrheagenic Escherichia coli from Sheep

作　　者：宋晨 苏建国 郝普国 顾珂瑞 王琪 徐文琦 樊宏亮 赵红霞[1] SONG Chen;SU Jianguo;HAO Puguo;GU Kerui;WANG Qi;XU Wenqi;FAN Hongliang;ZHAO Hongxia(College of Veterinary Medicine,Inner Mongolia Agricultural University,Huhhot 010010,China;Department of Biotechnology,Erdos Vocational College of Ecological Environment,Ordos 017000,China;Inner Mongolia Yili Industrial Group Co.,Ltd.,Huhhot 010010,China)

机构地区：[1]内蒙古农业大学兽医学院,内蒙古呼和浩特010010 [2]鄂尔多斯生态环境职业学院生物技术系,内蒙古鄂尔多斯017000 [3]内蒙古伊利实业集团股份有限公司,内蒙古呼和浩特010010

出　　处：《中国兽医杂志》2024年第8期18-23,共6页Chinese Journal of Veterinary Medicine

基　　金：内蒙古自治区科技重大专项(2021ZD0013);内蒙古自治区高等学校科学研究项目(NJZY21451)。

摘　　要：为了确定内蒙古自治区羊腹泻大肠杆菌的耐药机制,本试验采用PCR方法检测呼和浩特市周边牧场分离菌株中整合酶基因(Ⅰ、Ⅱ、Ⅲ型)、耐药基因盒和编码超广谱β-内酰胺酶(ESBLs)基因的携带情况。结果显示,108株羊腹泻大肠杆菌中,Ⅰ型整合酶基因和耐药基因盒插入区扩增呈阳性的菌株为42株,检出率为38.9%,未检出Ⅱ、Ⅲ型整合酶基因;菌株中有5类基因盒流行,主要携带甲氧苄氨嘧啶(dfr)和氨基糖苷类(aadA)耐药基因;分离菌株的bla_(TEM)基因检出数为83株,占比76.9%,bla SHV和bla_(CTX)基因PCR扩增均为阴性;质粒DNA上成功扩增出携带bla TEM型ESBLs基因的Ⅰ型整合子阳性菌株40株。结果表明,内蒙古自治区羊腹泻大肠杆菌Ⅰ型整合子的携带率较高,菌株对磺胺类、甲氧苄氨嘧啶和氨基糖苷类药物的耐受性与其携带的耐药基因盒密切相关,分离菌株中ESBLs的产生和传播由菌株自身质粒所介导,这可能是其对β-内酰胺类抗菌药物耐药的主要原因,且Ⅰ型整合子在ESBLs阳性菌株中的广泛分布,也使得菌株携带的耐药基因更易散播。本试验通过对羊腹泻大肠杆菌耐药性的产生和传播进行分析,以指导临床合理用药。To determine the resistance mechanisms of diarrheagenic Escherichia coli in sheep in Inner Mongolia Autonomous Region,this study utilized PCR methods to detect integrase genes(types I,II,III),resistance gene cassettes,and genes encoding extended-spectrumβ-lactamases(ESBLs)in bacterial strains isolated from farms around Hohhot.The results showed that out of 108 diarrheagenic E.coli strains from sheep,42 strains tested positive for type I integrase genes and resistance gene cassette insertion regions,with a detection rate of 38.9%.Type II and III integrase genes were not detected.Five types of gene cassettes were prevalent among the strains,mainly carrying resistance genes for trimethoprim(dfr)and aminoglycosides(aadA).The bla_(TEM)gene was detected in 83 strains(76.9%),while bla_(SHV)and bla_(CTX)genes were not amplified by PCR.Plasmid DNA successfully amplified bla TEM-type ESBLs genes in 40 strains of type I integron-positive bacteria.The results indicate a high carriage rate of type I integrons in diarrheagenic E.coli from sheep in Inner Mongolia.The resistance of these strains to sulfonamides,trimethoprim,and aminoglycosides is closely related to the carried resistance gene cassettes.The production and dissemination of ESBLs in these isolates are mediated by their plasmids,which may be the main reason for their resistance toβ-lactam antibiotics.The widespread distribution of type I integrons in ESBL-positive strains also facilitates the dissemination of resistance genes carried by these bacteria.This study analyzes the production and transmission of antibiotic resistance in diarrheagenic E.coli from sheep to guide clinical rational drug use.

关 键 词：腹泻大肠杆菌 羊腹泻 Ⅰ型整合子 耐药基因盒 超广谱β-内酰胺酶(ESBLs) 

分 类 号：S855.1[农业科学—临床兽医学]