和田地区鹅源致病性大肠杆菌的血清群、致病性与耐药性研究

Serogroup,Pathogenicity and Drug Resistance of Pathogenic Escherichia coli from Geese in Hotan Area

为了查明新疆和田地区鹅场发生的以腹泻为主要症状,以肝周炎和心包炎为主要病理变化的疾病是否由大肠杆菌引发,本研究无菌采集23份病死鹅内脏样本,采用常规细菌分离鉴定、PCR方法进行大肠杆菌鉴定,对分离菌的O血清群、致病性及耐药情况进行分析。结果显示,共分离到23株大肠杆菌,血清群包括O18(21.74%)、O78(13.04%)、O2(8.70%)和O1(4.35%),12株(52.17%)血清群未明。主要携带的毒力基因包括irp2(95.65%)、iucD(73.91%)、fyuA(17.39%)和astA(8.70%),分离株对小鼠具有致病性。23株大肠杆菌对四环素的耐药率为100%,氯霉素、环丙沙星、氨苄西林、左氧氟沙星、哌拉西林、复方新诺明、链霉素和头孢噻肟的耐药率在60.87%~95.65%,对多黏菌素B均敏感。共检测出12种耐药基因,tetA、tetG、cml 1、bla_(TEM)、sul1、aac、bla_(CTX-M-1)的检出率在43.48%以上,bla SHV、bla_(CTX-M-9)、tetE、aadA1的检出率在4.35%~30.43%,未检到bla CTX-M-2。本研究确定和田地区鹅场腹泻、肝周炎和心包炎为大肠杆菌感染所致,血清型较为复杂,耐药性严重。

In order to find out whether the diseases characterized bydiarrhea,pericarditis and pericarditis were caused by Escherichia coli on goose farms in Hotan,Xinjiang,23 visceral samples were collected from dead geese for E.coli isolation.The bacterial isolates were identified using PCR and analyzed for their O serogroup,pathogenicity and drug resistance.The results showed that a total of 23 E.coli strains were isolated and their serogroups were determined as O18(21.74%),O78(13.04%),O2(8.70%)and O1(4.35%).The serogroups of 12 strains(52.17%)was unknown.The main virulence genes include irp2(95.65%),iucD(73.91%),fyuA(17.39%)and astA(8.70%),which were all pathogenic to mice.The drug resistance rates of these 23 strains were found 100%to tetracycline and 60.87%-95.65%to chloramphenicol,ciprofloxacin,ampicillin,levofloxacin,piperacillin,compound sulfamethoxazole,streptomycin and cefotaxime.A total of 12 drug resistance genes were detected,among which tetA,tetG,cml1,bla_(TEM),sul1,aac and bla_(CTX-M-1) accounted for more than 43.48%,bla SHV,bla_(CTX-M-9),tetE and aadA1 for 4.35%-30.43%.The bla_(CTX-M-2) gene was not detected.This study confirmed that diarrhea,perihepatic inflammation and pericarditis on goose farms in Hotan area were caused by E.coli infection.In addition,these of E.coli strains possessed complicated serotypes and severe drug resistance.