Identification of a new bovine picornavirus (Boosepivirus) in the Republic of Korea.

Despite advancements in herd management, feeding, and pharmaceutical interventions, neonatal calf diarrhea (NCD) remains a major global health concern. Bacteria, viruses, and parasites are the major contributors to NCD. Although several pathogens have been identified in the Republic of Korea (ROK), the etiological agents of numerous NCD cases have not been identified. To identify, for the first time, the prevalence and impact of Boosepivirus (BooV) on calf diarrhea in the ROK. Here, the unknown cause of calf diarrhea was determined using metagenomics We then explored the prevalence of certain pathogens, including BooV, that cause NCD. Seventy diarrheal fecal samples from Hanwoo (Bos taurus coreanae) calves were analyzed using reverse transcriptase and quantitative real-time polymerase chain reaction for pathogen detection and BooV isolate sequencing. The complete genome of BooV was detected from unknown causes of calf diarrhea. And also, BooV was the most frequently detected pathogen (35.7%) among 8 pathogens in 70 diarrheic feces from Hanwoo calves. Co-infection analyses indicated that most BooV-positive samples were solely infected with BooV, indicating its significance in NCD in the ROK. All isolates were classified as BooV B in phylogenetic analysis. This is the first study to determine the prevalence and molecular characteristics of BooV in calf diarrhea in the ROK, highlighting the potential importance of BooV as a causative agent of calf diarrhea and highlighting the need for further research on its epidemiology and pathogenicity.

Chae JB ，Shin SU ，Kim S ，Chae H ，Kim WG ，Chae JS ，Song H ，Kang JW ... -  《-》

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.

Wang L ，Lim A ，Fredrickson R 《-》

Identification of boosepivirus B in U.S. calves.

Bovine enteric disease has a complex etiology that can include viral, bacterial, and parasitic pathogens and is a significant source of losses due to morbidity and mortality. Boosepivirus was identified in calves with enteric disease with unclear etiology in Japan in 2009 and has not been reported elsewhere. Metagenomic sequencing and PCR here identified boosepivirus in bovine enteric disease diagnostic submissions from six states in the USA with 98% sequence identity to members of the species Boosepivirus B. In all cases, boosepivirus was identified as a coinfection with the established pathogens bovine coronavirus, bovine rotavirus, and cryptosporidia. Further research is needed to determine the clinical significance of boosepivirus infection.

Hause BM ，Nelson E ，Christopher-Hennings J 《-》

Identification and complete genome analysis of a novel bovine picornavirus in Japan.

We identified novel viruses in feces from cattle with diarrhea collected in 2009 in Hokkaido Prefecture, Japan, by using a metagenomics approach and determined the (near) complete sequences of the virus. Sequence analyses revealed that they had a standard picornavirus genome organization, i.e. 5' untranslated region (UTR) - L- P1 (VP4- VP3- VP2- VP1) - P2 (2A- 2B- 2C) - P3 (3A- 3B- 3C-3D) - 3'UTR- poly(A). They are closely related to other unclassified Chinese picornaviruses; bat picornaviruses group 1-3, feline picornavirus, and canine picornavirus, sharing 45.4-51.4% (P1), 38.0-44.9% (P2), and 49.6-53.3% (P3) amino acid identities, respectively. The phylogenetic analyses and detailed genome characterization showed that they, together with the unclassified Chinese picornaviruses, grouped as a cluster for the P1, 2C, 3CD and VP1 coding regions. These viruses had conserved features (e.g. predicted protein cleavage sites, presence of a leader protein, 2A, 2C, 3C, and 3D functional domains), suggesting they have a common ancestor. Reverse-transcription-PCR assays, using specific primers designed from the 5'UTR sequence of these viruses, showed that 23.0% (20/87) of fecal samples from cattle with diarrhea were positive, indicating the prevalence of these picornavirus in the Japanese cattle population in Hokkaido Prefecture. However, further studies are needed to investigate the pathogenic potential and etiological role of these viruses in cattle.

Nagai M ，Omatsu T ，Aoki H ，Kaku Y ，Belsham GJ ，Haga K ，Naoi Y ，Sano K ，Umetsu M ，Shiokawa M ，Tsuchiaka S ，Furuya T ，Okazaki S ，Katayama Y ，Oba M ，Shirai J ，Katayama K ，Mizutani T ... -  《-》

Molecular surveillance of viral pathogens associated with diarrhea in pre-weaned Korean native calves.

Ryu JH ，Shin SU ，Choi KS 《-》