云南蛋鸡源肠炎沙门氏菌的分离鉴定及生物学特性

Isolation,identification and characterization of Salmonella enteritis from Yunnan laying hens

【背景】肠炎沙门氏菌(Salmonella enteritidis)是一种重要的人畜共患病原菌,禽类的肉制品及蛋类是其重要的传播途径。【目的】确诊云南某蛋鸡场疑似沙门氏菌感染病原情况。【方法】无菌采集发病蛋鸡肝脏组织进行细菌分离培养鉴定,对获得的菌株进行耐药性分析、致病性实验及毒力基因的检测。【结果】鉴定该分离菌为肠炎沙门氏菌,其抗原结构式为:O抗原1(+)、9(+)、12(+),H抗原gm(+)、[1,7](+),将其命名为SSYN001株。药敏实验表明,该菌株对青霉素、复方新诺明、强力霉素和四环素4种药物耐药,对阿莫西林、氨苄西林、庆大霉素、妥布霉素和头孢他啶等8种抗菌药物敏感;耐药基因检测发现,该菌株含有四环素类耐药基因tetA;动物致病性试验显示,该菌对雏鸡、产蛋鸡及小鼠的致死率分别为40%、80%和100%;该菌检测出spvB、spiA、pagC、msgA、invA、sipB、prgH、spaN、tolC、iroN、sitC、lpfC、sifA、sopB和orgA这15种毒力基因。【结论】对云南蛋鸡源肠炎沙门氏菌的致病性和菌株提供了新的生物学信息数据,对食源性人畜共患沙门氏菌的检测具有重要的公共卫生学意义。

[Background]Salmonella enteritis is an important zoonotic pathogenic bacterium that is transmitted essentially by poultry meat products and eggs.[Objective]In order to confirm pathogen information in a breeder farm where the poultry was suspected to be infected by Salmonella in Yunnan province.[Methods]We collected liver tissues from infected chicken in sterile environment to isolate and culture bacteria,then performed drug sensitive test and pathogenicity test,as well as identification of virulence genes for obtained strain.[Results]The isolated bacterium was identified to be Salmonella enteritidis and named SSYN001.Its antigen structural formula consists of the O antigen 1(+),9(+),12(+),H antigen gm(+)and[1,7](+).Drug resistance assay suggests that this strain was resistant to penicillin,bactrim,doxycycline and tetracycline,but sensitive to 8 antibiotics,include amoxicillin,ampicillin,gentamicin,tobramycin and ceftazidime.By detecting its resistance gene,we found that the strain contains tetA,a tetracycline resistance gene.The pathogenicity test shows the lethality of this strain for chicks,layer chicken and mice was 40%,80%and 100%,respectively;eventually,we found this bacterium has 15 virulence genes consisted of spvB,spiA,pagC,msgA,invA,sipB,prgH,spaN,tolC,iroN,sitC,lpfC,sifA,sopB and orgA.[Conclusion]The present study provides new data of the pathogenicity of laying hen’s Salmonella enteritidis in Yunnan province,with implication for public health on detection of foodborne zoonotic Salmonella.