Molecular epidemiology and phylogenetic analysis of diverse bovine
astroviruses associated with diarrhea in cattle and water buffalo calves in
China |
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Authors: | Niyokwishimira ALFRED Huan LIU Mu Lan LI Shao Feng HONG Hai Bo TANG Zu Zhang WEI Ying CHEN Fa Kai LI Yi Zhi ZHONG Wei Jian HUANG |
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Institution: | 1)Laboratory of Animal Infectious Diseases Prevention and Molecular Immunology, Guangxi University, Daxue Road 100, Nanning, Guangxi 530004, China;2)State Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources, Guangxi University, Daxue Road 100, Nanning, Guangxi 530004, China |
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Abstract: | Astroviruses are the principal causative agents of gastroenteritis in humans and have
been associated with diarrhea in other mammals as well as birds. However, astroviral
infection of animals had been poorly studied. In the present study, 211 rectal swabs
collected from cattle and water buffalo calves with mild to severe diarrhea were tested
for bovine astrovirus (BAstV) by RT-PCR. Results: 92/211 (43.6%) samples were positive for
BAstV, 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 sequences
obtained in this study classified the Guangxi BAstVs isolates into five subgroups under
the genus of Mamastrovirus, genotype MAstV33, which
suggested that the water buffalo was a new host of this genogroup that previously included
only cattle and roe deer. Despite the origin of the host, the Guangxi BAstV isolates were
closely related to the BAstV Hong Kong isolates (B18/HK and B76-2/HK), but highly
divergent from the BAstV NeuroS1 isolate previously associated with neurologic disease in
cattle in the U.S.A. Nucleotide sequence-based characterization of the ORF1b/ORF2 junction
and corresponding overlapping regions showed distinctive properties, which may be common
to BAstVs. Our results suggested that cattle and water buffalo are prone to infection of
closely related astroviruses, which probably evolved from the same ancestor. The current
study described astroviruses in water buffalo for the first time and is thus far among the
largest epidemiological investigations of BAstV infection in cattle conducted in
China. |
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Keywords: | bovine astrovirus cattle China phylogenetic analysis water buffalo |
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