摘要
为分析河北地区水貂源大肠杆菌的致病性与耐药性,本研究对河北地区送检病死水貂采集组织样品,经分离鉴定、生化鉴定和16S rDNA基因序列分析,共分离得到24株水貂大肠杆菌。对分离菌株进行致病性试验、药敏试验、毒力基因和耐药基因检测。结果显示,24株大肠杆菌感染小鼠后小鼠死亡率为20%~100%;24株分离菌中有22株检测到毒力基因,fimC毒力基因检出率最高,为70.83%(17/24);分离的24株株大肠杆菌耐药性较强,对替米考星、土霉素、磺胺间甲氧嘧啶、磺胺二甲氧嘧啶、复方新诺明耐药的菌株占80%以上,对头孢曲松最敏感,敏感菌株占66.67%(16/24),且分离菌均具有多重耐药性,耐5种以上药物的菌株占比高达100%;24株大肠杆菌均检测到耐药基因,耐药基因检出率为4.17%~79.17%,其中氨基糖苷类耐药基因addA1(79.17%)、喹诺酮类耐药基因gyrA(75%)、gyrB(70.83%)检出率较高,β-内酰胺类耐药基因ctx-M(20.83%)和SHV(4.17%)检出率较低;未检测到tetA、tetC、sul1、mefA耐药基因。上述结果表明,分离菌对小鼠均具有一定的致病力,且毒力基因检出数越多的菌株对小鼠的致病力越强;β-内酰胺类、氨基糖苷类和喹诺酮类的耐药基因与耐药表型基本相符,分离菌的其余耐药基因与耐药表型不符,提示分离的大肠杆菌可能存在其他耐药机制。本研究为河北地区水貂大肠杆菌病的防治提供参考依据,为大肠杆菌的致病机制和耐药机制的研究奠定基础。
The objective of this study is to analyze the pathogenicity and drug resistance of E.coli from mink in Hebei province.The pathogenicity test,drug sensitivity test,virulence gene and drug resistance gene detection were performed.The results showed that the mortality rate of mice infected with the 24 strains of E.coli was 20%-100%;virulence genes were detected in 22 of the 24 isolates,with fimC showing the highest detection rate,accounting for 70.83%(17/24).All 24 E.coli strains display multiple drug resistance,more than 80%of the strains were resistant to tilmicosin,oxytetracycline,sulfamonomethoxine,sulfamethazine and compound neoforman;and 66.67%(16/24)of the strains were sensitive to ceftriaxone;resistance genes were detected in all the 24 E.coli strains,the detection rate of resistance genes was 4.17%-79.17%;among them,the detection rates of aminoglycoside resistant gene addA1(79.17%),quinolone resistant gene gyrA(75%),and gyrB(70.83%)were high,and the detection rates of ctx-M(20.83%)and SHV(4.17%)were low,while tetracycline resistant genes tetA and tetC,sulfanilamide resistant gene sul1 and macrolides resistant gene mefA were not detected.The results showed that the isolates had certain pathogenicity to mice,and the more virulence genes were detected,the stronger pathogenicity to mice.The resistance phenotypes ofβ-lactams,aminoglycosides and quinolones were basically correlated with the resistance genes,while those of tetracyclines,macrolides and sulfonamides were basically not correlated with their resistance phenotypes,suggesting that there might be multiple resistance mechanisms in the isolated Escherichia coli strains.This study provides a reference for the prevention and treatment of mink colibacillosis in Hebei province and lays a foundation for the study of pathogenesis and drug resistance mechanisms of Escherichia coli.
作者
刘勃兴
赵安奇
柳翠翠
付祥
刘畅
李浩
史秋梅
张志强
LIU Bo-xing;ZHAO An-qi;LIU Cui-cui;FU Xiang;LIU Chang;LI Hao;SHI Qiu-mei;ZHANG Zhi-qiang(Hebei Normal University of Science&Technology,Hebei key Laboratory of Preventive Veterinary Medicine,Qinhuangdao 066004,China)
出处
《中国预防兽医学报》
CAS
CSCD
北大核心
2020年第6期561-566,共6页
Chinese Journal of Preventive Veterinary Medicine
基金
秦皇岛市科技创新平台建设运行项目(201702B001)
河北省科技厅项目(18246629G)
河北省教育厅项目(ZD2017234)
农业部特种动物疫病重点试验室开放课题(01830)。
关键词
水貂
大肠杆菌
致病性
耐药性
耐药基因
毒力基因
mink
E.coli
pathogenic
drug resistance
resistance genes
virulence genes
