猪源奇异变形杆菌的分离鉴定、耐药性分析及毒力基因检测

Isolation and identification of swine-sourced Proteus mirabilis,and detection of its drug resistance and virulence genes

为确定屠宰场发病猪死亡原因,本研究对从死亡猪内脏中分离到的细菌,进行革兰染色镜检、生化鉴定和16S rRNA基因测序鉴定,并进行药敏试验、毒力基因检测及小鼠攻毒试验。结果显示,革兰染色镜检为细小或中等短杆状或丝状革兰阴性杆菌;生化试验特性分析及16S rRNA基因测序鉴定为奇异变形杆菌,命名为GZ2-2株。药敏试验结果显示,分离菌对哌拉西林、头孢呋辛、头孢他啶等11种药物敏感,对卡那霉素和米诺环素2种药物为中敏,对氨苄西林、头孢唑林、四环素等6种药物耐药;毒力基因检测结果显示,该分离菌携带rsbA、atfA、pmfA、mrpA、zapA、ureC、atfC和ucaA 8种毒力基因;小鼠攻毒试验表明,该分离菌有较强致病力。本试验成功分离到一株具有多重耐药性并携带8种毒力基因的奇异变形杆菌,为该菌感染的防治及其分子流行病学研究奠定了基础。

In order to determine the cause of death of pigs in the slaughterhouse,a bacterium was isolated from the offal of dead pigs,was subjected to test under Gram stain microscopy,biochemical identification,16 S rRNA gene sequencing,drug sensitivity test,virulence gene detection and pathogenicity test in mice.The results were that Gram staining microscopic examination showed the presence of fine or medium-short rod-shaped or filamentous Gram-negative bacilli,and that characteristics analysis by biochemical test and 16 S rRNA gene sequencing identified the isolate as Proteus mirabilis,which we named the GZ2-2 strain.The susceptibility test results showed that the isolates were resistant to six drugs,such as ampicillin,cefazolin,and tetracycline,and so on;moderately sensitive to two drugs:kanamycin and minocycline;and sensitive to 11 drugs,such as piperacillin,cefuroxime,ceftazidime,and so on.The virulence gene test results showed that the isolate carried eight virulence genes:rsbA,atfA,pmfA,mrpA,zapA,ureC,atfC and ucaA.The pathogenicity test in mice showed that the isolate had strong pathogenicity.Therefore,a strain of Proteus mirabilis(GZ2-2)with multi-drug resistance and carrying eight virulence genes was successfully isolated in this study,which laid a foundation for prevention and control of Proteus mirabilis and for molecular epidemiology research on the strain.