Three clusters of bovine kobuvirus isolated in Korea, 2008–2010

Abstract

Fecal samples (n = 107) were collected from cattle with ascertained or suspected diarrheal disease on Korean farms during 2008-2010. Of these, 37 samples tested positive for bovine kobuvirus. The 37 positive samples came from 32 cattle that exhibited diarrhea and five cattle that were non-diarrhetic. The majority of the virus-positive feces samples were from calves under 1 month of age (n = 25). Nine of the 37 cattle infected with bovine kobuvirus were confirmed to have a co-infection with other viruses including bovine rotavirus (n = 3), bovine coronavirus (n = 1), bovine viral diarrhea virus (n = 1), and both bovine coronavirus and bovine viral diarrhea virus (n = 4). A neighbor-joining tree grouped 36 of the Korean kobuvirus strains (with the exception of the KB8 strain) into three clusters (G1, G3, and G4), while strains derived from Thailand and Japan (except the U1 strain) were included in the G2 cluster. The results indicated that Korean bovine kobuvirus has diverse lineages regardless of disease status and species.

Bovine Kobuvirus in Calves with Diarrhea, United States

“…Among 3 BKV-positive calves with diarrhea, 2 were <1 month of age and 1 was ≈5 months of age. Previous studies reported high prevalence of BKV infection in young calves with diarrhea; 20.9% (38/182) in calves <2 months of age in Brazil and 26.7% (23/86) in calves <1 month of age in South Korea (5,9). Our study further supports the hypothesis that BKV causes neonatal diarrhea in calves.…”

“…Leyi (1). Since then, BKV has been reported in Thailand, Hungary, the Netherlands, Korea, Italy, Brazil, China, and Egypt (2)(3)(4)(5)(6)(7)(8)(9). However, circulation of BKV in North America remains unclear.…”

Molecular detection and genomic characteristics of bovine kobuvirus from dairy calves in China

“…The cDNA was synthesized using the instructions (TaKaRa Bio Inc.) and then stored at −20°C. BKoV was detected by an RT-PCR assay targeting a 631 bp fragment of the 3D gene according to previous report (Jeoung et al, 2011). To screen for the presence of co-infections with bovine rotavirus (BRV), bovine coronavirus (BCoV), and bovine viral diarrhea virus (BVDV), all the BKoVpositive diarrheic samples were subjected to specific RT-PCR assays for these viruses (Guo et al, 2019;Zheng et al, 2014).…”

Molecular detection of kobuviruses in European roe deer (Capreolus capreolus) in Italy

“…Based on the inspection of the tree and according to the pairwise homology and distance analyses, the strains 50R/IT, 51R/IT, 61R/IT and 71R/IT segregated with the CKVs (bootstrap value, 99 %) within the novel proposed species Aichivirus D [9]. All of the BKV-like sequences obtained in this study clustered along with the prototype strain U1 and the BKVs previously detected either in diarrhoeic or asymptomatic calves [2,3,5,12,17].…”

“…Upon sequence analysis of 3D fragments, nine strains (92B/IT, 67R/IT, 70R/IT, 45R/IT, 43R/IT, 37R/IT, 35R/IT, 95R/IT, 106R/IT) shared 93.7-99.4 % nt sequence identity with each other and displayed the closest relatedness (91.2-97.4 % nt sequence identity) to the prototype BKV strain U1 [17] and to several BKV-like sequences identified in cattle in Korea and in the Netherlands [2,5,6,12], while they were more distantly related (89.3-91.0 %) to strains previously detected in Italy [3]. For one strain, sample 50R/ IT, the highest sequence identity was found to the newly described CKVs [8,9].…”