Prevalence and genetic characterization of bovine coronavirus identified from diarrheic pre-weaned native Korean calves from 2019 to 2021

Eun-Mi Kim; Hyung-Chul Cho; Seung-Uk Shin; Jinho Park; Kyoung-Seong Choi

doi:10.1016/j.meegid.2022.105263

Prevalence and genetic characterization of bovine coronavirus identified from diarrheic pre-weaned native Korean calves from 2019 to 2021

Infect Genet Evol. 2022 Jun:100:105263. doi: 10.1016/j.meegid.2022.105263. Epub 2022 Mar 9.

Authors

Eun-Mi Kim¹, Hyung-Chul Cho¹, Seung-Uk Shin¹, Jinho Park², Kyoung-Seong Choi³

Affiliations

¹ Department of Animal Science and Biotechnology, College of Ecology and Environmental Science, Kyungpook National University, Sangju 37224, Republic of Korea.
² College of Veterinary Medicine, Jeonbuk National University, Iksan 54596, Republic of Korea.
³ Department of Animal Science and Biotechnology, College of Ecology and Environmental Science, Kyungpook National University, Sangju 37224, Republic of Korea. Electronic address: kschoi3@knu.ac.kr.

PMID: 35276339
DOI: 10.1016/j.meegid.2022.105263

Abstract

Bovine coronavirus (BCoV) is associated with severe diarrhea in calves, winter dysentery in adult cattle, and respiratory diseases in cattle. However, there is currently limited information regarding its molecular characterization in the Republic of Korea (KOR). Therefore, this study investigated the prevalence of BCoV in diarrheic pre-weaned calves (aged ≤60 days) and compared BCoV genome sequences identified globally. A total of 846 fecal samples were collected from calves with diarrhea across 100 beef farms in the KOR. The samples were divided into three groups based on age as follows: 1-10 days (n = 490), 11-30 days (n = 277), and 31-60 days (n = 79). BCoV infection was detected in 50 calves by real-time RT-PCR analysis. The results showed that the prevalence of BCoV was associated with calf age (P = 0.028) and was significantly higher in calves aged 31-60 days (odds ratio: 2.69, 95% confidence interval: 1.24-5.85; P = 0.012) than in those aged 1-10 days. Our findings show that BCoV is an important etiological agent of diarrhea in calves aged 31-60 days. Fifteen full genome sequences (2019-2021 variants) of the spike, hemagglutinin/esterase, and nucleocapsid were obtained from the 50 BCoV-positive samples. Phylogenetic analysis of each gene revealed that BCoVs circulating worldwide might have no boundary between enteric and respiratory tropisms, demonstrating the presence of three BCoVs groups: the classical, Asia/USA, and European. Initially, Korean BCoVs were originated from the USA, but diverged since the 1980s and rapidly evolved independently, unlike in other Asian countries. In this study, Korean BCoVs are more recent BCoVs and present relatively high nucleotide substitution rates in all genes compared with other BCoVs. Our results showed that the 2019-2021 variants undergo continuous genetic evolution and that there are genetic differences among globally distributed BCoVs.

Keywords: Bovine coronavirus; Diarrhea; Evolutionary rate; Phylogenetic analysis.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Animals
Cattle
Cattle Diseases* / epidemiology
Coronavirus Infections* / epidemiology
Coronavirus Infections* / veterinary
Coronavirus, Bovine* / genetics
Diarrhea / epidemiology
Diarrhea / veterinary
Feces
Phylogeny
Prevalence
Sequence Analysis, DNA