云南楚雄规模化猪场仔猪大肠杆菌HPI基因调查及耐药性分析

为研究规模化猪场大肠杆菌高致病性毒力岛（high pathogenicity island，HPI）基因流行特征及其耐药性，本试验从云南省楚雄州地方猪场采集粪便及肛门拭子，应用麦康凯培养基、生化鉴定管及PCR扩增对大肠杆菌进行分离鉴定，分别通过PCR反应、动物回归试验及纸片扩散法研究分离菌株的HPI基因携带情况、致病性及耐药性。结果显示，共分离获得78株大肠杆菌，分离率为83.87%，HPI基因携带率高达96.15%；24 h内，HPI阳性菌株致小鼠死亡率100%，HPI阴性菌株致小鼠死亡率75%，对照组无小鼠死亡，表明HPI基因可提高小鼠死亡率；药敏试验结果显示，分离菌株对四环素、氨苄西林、复方新诺明、卡那霉素、庆大霉素、头孢他啶及阿米卡星的耐药率分别为88.46%、84.62%、73.08%、53.85%、38.46%、19.23%和5.13%，对多黏菌素B不耐药。本试验结果可为防治大肠杆菌相关疾病提供一定的理论依据。

Investigation of HPI Gene and Drug Resistance Analysis of Piglets Escherichia coli in Large-scale Pig Farms in Chuxiong,Yunnan Province

In order to study the epidemiological characteristics and drug resistance of HPI gene of E.coli,feces and anal swabs were collected from Chuxiong local pig farms in Yunnan province.The isolation and identification of E.coli were carried out by McConkay medium,biochemical identification tube and PCR amplification.The HPI gene carrying status,pathogenicity and drug resistance of the isolates were studied by PCR reaction,animal regression test and disk diffusion method respectively.The results showed that 78 strains of E.coli were isolated,the isolation rate was 83.87%,and the carrying rate of HPI gene was 96.15%.Within 24 h,the mortality rate of HPI-positive strains was 100%,and that of HPI-negative strains was 75%.No mice died in the control group,suggesting that HPI gene could increase the mortality rate of mice.Drug susceptibility tests showed that the drug resistance rates to tetracycline,ampicillin,compound sinomenine,kanamycin,gentamicin,ceftazidime and amikacin were 88.46%,84.62%,73.08%,53.85%,38.46%,19.23% and 5.13%,respectively.Colistin B showed no drug resistance.The results showed that the epidemic situation of HPI gene in Chuxiong prefecture of Yunnan province was optimistic,and it could provide a theoretical basis for the prevention and treatment of E.coli-related diseases.