牦牛德尔卑沙门氏菌的分离、鉴定及致病性研究

为调查四川省阿坝州红原县牦牛腹泻病因，本课题组从红原县4所养殖场采集牦牛腹泻粪便16份，并对分离株进行多位点序列分型、血清型鉴定、耐药性试验及小鼠致病性试验.结果表明：16份样品共计分离出16株沙门氏菌，均为德尔卑沙门氏菌ST71型，100%菌株对四环素、氨苄西林、氯霉素和头孢噻呋多重耐药；选取腹泻较严重牦牛粪样沙门氏菌分离株（编号15XLR）进行致病性试验，得出分离株15XLR的半致死剂量为1.2×107 CFU，病理切片结果显示小鼠后脾脏、肠道损伤严重.本研究对红原县牦牛腹泻病因进行了调查研究，并证实德尔卑沙门氏菌除感染猪鸡外,其能够入侵牦牛机体，提示牦牛腹泻疾病的防控应注重沙门氏菌的感染以及在牦牛群体中的传播.

Isolation, identification and pathogenicity experiment of Salmonella enterica Serovar Derby from yaks (Poephagus grunniens) with diarrhea in Tibetan Qiang Autonomous Prefecture of Ngawa, China

In order to investigate the pathogen of yaks diarrhea, 16 feces were collected from 4 farms in Hongyuan, Tibetan Qiang Autonomous Prefecture of Ngawa, China. Multilocus sequence typing, serotyping, antimicrobial resistance and pathogenicity experiment were carried out. A total of 16 Salmonella were selected, all strains were Salmonella Derby ST71 and multi-resistant to tetracycline, ampicillin, chloramphenicol and ceftiofur. Salmonella isolated from bloody stool (No. 15XLR) was selected for pathogenicity experiment and the result showed that the half lethal dose of 15XLR was 1.2 × 107 CFU, which can cause severe damage to spleen and intestine according to HE slice. This study investigated the causes of diarrhea in yaks in Hongyuan County, and confirmed that Salmonella Derby can invade yaks except pigs and chickens, suggesting that the prevention and control of diarrhea in yaks should pay attention to infected and the spread of Salmonella in yak population.