闽西地区猪源大肠杆菌耐药基因blaCTX-M-9G的流行性分析

Investigation of blaCTX-M-9 Gresistance gene in Escherichia coli isolated from pig origin in the west of Fujian Province

为了解闽西地区猪源大肠杆菌耐药基因blaCTX-M-9G流行性以及对β-内酰胺类药物的耐药情况,以期为本地区抗菌药的合理应用提供依据。从闽西地区规模化猪场采集腹泻仔猪肛门拭子分离大肠杆菌,对分离株进行β-内酰胺类药物敏感性测定及耐药基因检测。结果显示,共分离大肠杆菌213株;分离株对氨苄西林、阿莫西林/克拉维酸、头孢噻呋和头孢噻肟表现出较高的耐药率,分别为46.9%、44.1%、28.6%和23.9%;经耐药基因检测,blaCTX-M-9G基因检出率为17.4%（37/213）,在blaCTX-M-9G阳性菌中还检测出qnrA（5.4%）、qnrB（37.8%）、qnrS（73.0%）、oqxA（70.3%）、oqxB（75.7%）及qepA（18.9%）等PMQR耐药基因,其中83.8%含有三种以上耐药基因,以携带blaCTX-M-9G＋qnr S＋oqx A＋oqx B基因型最为流行,检出率为32.4%。闽西地区猪源大肠杆菌对β-内酰胺类药物表现出一定的耐药性,blaCTX-M-9G耐药基因携带率较高,并且耐药基因blaCTX-M-9G阳性菌中PMQR基因的携带率较高。

The aim of this research was to master the prevalence of antimicrobial resistance forβ-lactam drugs and blaCTX-M-9 Gresistance gene in Escherichia coli isolated from pig origin in the west of Fujian,and provide guidance for the rational use of antibiotics in the locality.A total of 213 isolates collected from anus swab of diarrhea piglet were tested for antimicrobial susceptibility to β-lactam drugs by agar dilution method,and screened for resistance gene by PCR.It was found high resistance to ampicillin,amoxicillin/clavulanic acid,ceftiofur and cefotaxime,with resistance rates of 46.9%,44.1%,28.6% and 23.9%,respectively.17.4%（37/213） isolates were positive for blaCTX-M-9 Gresistance gene,among those positive strains,they also were detected the PMQR genes,such as qnr A（5.4%）,qnr B（37.8%）,qnr S（73.0%）,oqx A（70.3%）,oqx B（75.7%） and qep A（18.9%）,and 83.8% isolates contained more than three kinds of resistance genes.The mostest prevalence genotypes was blaCTX-M-9 G＋qnr S＋oqx A＋oqx B resistance genes,and its detection rate was 32.4%.Escherichia coli showed a certain resistance toβ-lactam drugs in Western Fujian,and the resistance rate of blaCTX-M-9 Gresistance genes was quite high.A high rates of the PMQR genes were found among blaCTX-M-9 Gpositive strains.