Molecular epidemiology and phylogenetic analysis of diverse bovineastroviruses associated with diarrhea in cattle and water buffalo calves inChina

[摘要] References(28)Cited-By(1)Astroviruses are the principal causative agents of gastroenteritis in humans and havebeen associated with diarrhea in other mammals as well as birds. However, astroviralinfection of animals had been poorly studied. In the present study, 211 rectal swabscollected from cattle and water buffalo calves with mild to severe diarrhea were testedfor bovine astrovirus (BAstV) by RT-PCR. Results: 92/211 (43.6%) samples were positive forBAstV, at a rate of 46.10% (71/154) in cattle and 36.84% (21/57) in water buffalo.Phylogenetic analysis based on the partial and full-length of 25 ORF2 amino acid sequencesobtained in this study classified the Guangxi BAstVs isolates into five subgroups underthe genus of Mamastrovirus, genotype MAstV33, whichsuggested that the water buffalo was a new host of this genogroup that previously includedonly cattle and roe deer. Despite the origin of the host, the Guangxi BAstV isolates wereclosely related to the BAstV Hong Kong isolates (B18/HK and B76-2/HK), but highlydivergent from the BAstV NeuroS1 isolate previously associated with neurologic disease incattle in the U.S.A. Nucleotide sequence-based characterization of the ORF1b/ORF2 junctionand corresponding overlapping regions showed distinctive properties, which may be commonto BAstVs. Our results suggested that cattle and water buffalo are prone to infection ofclosely related astroviruses, which probably evolved from the same ancestor. The currentstudy described astroviruses in water buffalo for the first time and is thus far among thelargest epidemiological investigations of BAstV infection in cattle conducted inChina.

[学科分类] 兽医学

[关键词] bovine astrovirus;cattle;China;phylogenetic analysis;water buffalo