摘要
目的调查福建地区猪源大肠杆菌耐药基因oqxAB流行性及阳性菌中其重要耐药基因的流行情况,以期为本地区抗菌药的合理应用提供依据。方法采集腹泻仔猪肛门拭子分离大肠杆菌,通过琼脂二倍稀释法测定分离株的药物敏感性,并用PCR法检测PMQR(包括oqxAB)、ESBLs及其他耐药基因;对oqxAB阳性菌进行接合转移试验,测定接合子的药物敏感性变化;对阳性菌的种系发育及毒力基因分布进行测定。结果本研究共分离鉴定大肠杆菌133株,分离株对磺胺甲噁唑/甲氧苄啶的耐药率最高(90.2%),对多粘菌素的耐药率最低(24.8%),其余药物的耐药率在26.3%~85.7%;耐药基因检测结果显示,oqxAB基因检出率为29.3%(39/133),在oqxAB阳性菌中还检测出floR(76.9%)、qnrS(71.8%)、CTX-M-1G(59.0%)、mcr-1(56.4%)、fosA3(28.2%)和acc(6′)-Ib-cr(23.1%)等耐药基因,其中59.0%携带6种以上耐药基因,以oqxA+oqxB+qnrS+CTX-M-1G+mcr-1+floR基因型最为流行(38.5%);种系发育显示分离株主要分布在A组(46.2%),毒力基因主要分布在B2和D组,其毒力基因平均个数分别为3.43和2.64。69.2%(27/39)oqxAB阳性菌成功将耐药质粒传给受体菌(C600),其接合子的MIC值较受体菌均有不同程度的提高。结论福建地区猪源大肠杆菌中oqxAB耐药基因携带率较高,在oqxAB阳性菌中携带多种耐药基因,种系发育主要分布在共生型(A组),毒力基因主要分布在B2和D群;携带oqxAB基因的阳性质粒可通过接合转移的方式进行水平传播。
This study investigated the prevalence of the oqxAB resistance gene and other important resistance genes in oqxAB positive E.coli in pigs in Fujian,to provide a basis for the rational application of antibiotics in this area.Anal swabs of piglets with diarrhea were collected;E.coli was isolated;the drug sensitivity of the isolates was determined with the agar double dilution method;and PMQR(including oqxAB),ESBLs and other antibiotic resistance genes were detected by PCR.Conjugation experiments were performed on oqxAB positive strains,and changes in drug sensitivity of the transconjugants were measured.The phylogeny and distribution of virulence genes in oqxAB-positive strains were analyzed.A total of 133 E.coli strains were isolated.The drug resistance rate of the isolates was highest to sulfamethoxazole/trimethoprim(90.2%)and lowest to polymyxin(24.8%).The drug resistance rates to other drugs ranged from 26.3%to 85.7%.The detection rate of the oqxAB gene was 29.3%(39/133).The resistance genes floR(76.9%),qnrS(71.8%),CTX-M-1G(59.0%),mcr-1(56.4%),fosA3(28.2%)and acc(6′)-Ib-cr(23.1%)were detected in oqxAB positive strains.Among them,59.0%of strains carried more than six drug resistance genes,and the oqxA+oqxB+qnrS+CTX-M-1G+mcr-1+floR genotype was the most frequent(38.5%).Phylogenetic analysis indicated that the isolates were distributed mainly in the A group(46.2%),and the virulence genes were distributed primarily in the B2 and D groups;the average numbers of virulence genes were 3.43 and 2.64,respectively.A total of 69.2%(27/39)isolates successfully transmitted oqxAB-carrying plasmids to recipient bacteria(C600),and the transconjugants showed different degrees of increases in the minimum inhibitory concentrations with respect to the recipient strain.The carriage rate of the oqxAB resistance gene was high in E.coli isolated from pigs in Fujian.Multiple drug-resistance genes were found in those positive strains and were distributed primarily in symbiotic group A,whereas virulence genes were distributed mainly in
作者
杨守深
范潇悦
江妤丹
林欣
张雅红
涂小梅
杨光庭
王娟
郭荣荣
黄翠琴
YANG Shou-shen;FAN Xiao-yue;JIANG Yu-dan;LIN Xin;ZHANG Ya-hong;TU Xiao-mei;YANG Guang-ting;WANG Juan;GUO Rong-rong;HUANG Cui-qin(College of Life Sciences,Longyan University,Longyan 364012,China;Fujian Provincial Key Laboratory for the Prevention and Control of Animal Infectious Diseases and Biotechnology,College of Life Sciences,Longyan 364012,China)
出处
《中国人兽共患病学报》
CAS
CSCD
北大核心
2023年第2期185-191,199,共8页
Chinese Journal of Zoonoses
基金
福建省自然科学基金项目(No.2022J011156)
漳平市奇迈科技创新基金项目(No.漳工科[2021]123号)
大学生创新创业训练计划项目(No.S202211312035)联合资助。
关键词
药物敏感性
毒力基因
水平传播
种系发育
antimicrobial susceptibility
virulence gene
horizontal transmission
phylogeny
