牦牛腹泻源大肠杆菌O抗原血清型鉴定与HPI相关基因检测

Identification of yak-diarrhea-derived Escherichia coli O serotype and detection of HPI-related genes

为了研究牦牛腹泻源大肠杆菌的O抗原血清型及强毒力岛(HPI)相关基因的携带情况,试验对采自西藏山南地区某牦牛养殖场的80份腹泻牦牛肛拭子样本进行细菌的分离与鉴定,并对分离的大肠杆菌菌株进行F17毒力因子检测、O抗原血清型鉴定及HPI相关基因irp3、irp5、irp2、ybtA、fyuA、irp8、ans_-tRNA_-intB检测。结果表明:从80份肛拭子样本共分离到28株大肠杆菌。在28株分离菌株中,有5株菌株携带F17毒力因子,共有17种O抗原血清型。其中O158检出率最高,为50.00%(14/28);O125、O119、O146检出率较高,分别为39.28%(11/28)、39.28%(11/28)、35.71%(10/28);而O127、O18检出率最低,均为14.29%(4/28)。HPI相关基因irp3、irp5、irp2、ybtA、fyuA、irp8、ans_-tRNA_-intB的阳性率分别为35.71%(10/28)、28.57%(8/28)、32.14%(9/28)、32.14%(9/28)、28.57%(8/28)、28.57%(8/28)和28.57%(8/28)。说明分离到的牦牛腹泻源大肠杆菌优势血清型为O158,且存在携带HPI相关基因的情况。

In order to study yak-diarrhea-derived Escherichia coli O antigen serotype and the carriage of high-pathogenitility island(HPI)-related genes,in the experiment,bacterial isolation and identification on 80 anal swab samples of diarrheic yaks taken from a yak farm in Shannan area,Tibet city.The isolated E.coli strains were also tested for F17 virulence factor O serotype identification and HPI-related genes irp3,irp5,irp2,ybtA,fyuA,irp8,ans-tRNA-intB.The results showed that a total of 28 suspected E.coli strains were isolated from 80 anal swab samples.Among the 28 isolates,five strains carried F17 virulence factor,with a total of 17 O antigen serotypes.Among them,O158 had the highest detection rate of 50.00%(14/28);O125,O119,and O146 had high detection rates of 39.28%(11/28),39.28%(11/28),and 35.71%(10/28),respectively;while the number of strains of O127 and O18 had the lowest detection rate,both of which were 14.29%(4/28).The positive rates of HPI-related genes irp3,irp5,irp2,ybtA,fyuA,irp8,ans-tRNA-intB were 35.71%(10/28),28.57%(8/28),32.14%(9/28),32.14%(9/28),28.57%(8/28),28.57%(8/28)and 28.57%(8/28),respectively.The results indicated that the dominant serotype of isolated yak-diarrhea-derived E.coli was O158 and there was HPI related genes were carried.