Genomic characterization of a new bovine picornavirus (boosepivirus) in diarrheal cattle and detection in different states of the United States, 2019

The Boosepivirus is a newly proposed genus in the family Picornaviridae in 2020. Bovine boosepiviruses (BooV) were initially identified in diarrheal cattle through deep sequencing in Japan in 2009. These diarrheal cases were either BooV alone positive or coinfection with other viruses, suggesting that BooV is an enteric pathogen. In 2019, through metagenomic sequencing, a US BooV strain IL41203-19 was identified in the fecal sample of a 10-day old calf with diarrhea and characterized in the present study. Genomic characterization revealed that IL41203-19 share the highest identities with the Japan BooV strain (Bo-12-7/2009/JPN) at both the complete nucleotide and amino acid levels, belonging to Boosepivirus B species in the genus Boosepivirus. Further real-time RT-PCR testing of 84 clinical samples from the diarrheal testing panel showed that five were positive for BooV and were all coinfected with one to four other enteric pathogens. Our data provided further evidence that BooV might contribute to cattle diarrhea observed in different states. Future studies on epidemiology and pathogenesis of bovine BooV are warranted.