» Articles » PMID: 38338032

Characterization and Spike Gene Analysis of a Candidate Attenuated Live Bovine Coronavirus Vaccine

Overview
Journal Animals (Basel)
Date 2024 Feb 10
PMID 38338032
Authors
Affiliations
Soon will be listed here.
Abstract

The bovine coronavirus (BCoV) KBR-1 strain, obtained from calf diarrhea samples collected in 2017, belongs to group GIIa. To attenuate this strain, it was subcultured continuously (up to 79 times) in HRT-18 cells, followed by 80-120 passages in MDBK cells. The KBR-1-p120 strain harvested from MDBK cells at passage 120 harbored 13 amino acid mutations in the spike gene. Additionally, the KBR-1-p120 strain showed a high viral titer and cytopathogenic effects in MDBK cells. Seven-day-old calves (negative for BCoV antigen and antibodies) that did not consume colostrum were orally inoculated with the attenuated candidate strain (KBR-1-p120), or with KBR-1 passaged 10 times (KBR-1-p10) in HRT-18 cells. Calves inoculated with KBR-1-p10 had a low diarrhea score, and BCoV RNA was detected at 3-7 days post-inoculation (DPI). The virus was also present in the duodenum, jejunum, and ileum at autopsy; however, calves inoculated with KBR-1-p120 had low levels of BCoV RNA in feces at 4-6 DPI, and no diarrhea. In addition, an extremely small amount of BCoV RNA was present in the jejunum and ileum at autopsy. The small intestines of calves inoculated with KBR-1-p120 were emulsified and used to infect calves two more times, but pathogenicity was not recovered. Therefore, the KBR-1-p120 strain has potential as a live vaccine candidate.

References
1.
Cho Y, Kim W, Liu S, Kinyon J, Yoon K . Development of a panel of multiplex real-time polymerase chain reaction assays for simultaneous detection of major agents causing calf diarrhea in feces. J Vet Diagn Invest. 2010; 22(4):509-17. DOI: 10.1177/104063871002200403. View

2.
Decaro N, Elia G, Campolo M, Desario C, Mari V, Radogna A . Detection of bovine coronavirus using a TaqMan-based real-time RT-PCR assay. J Virol Methods. 2008; 151(2):167-171. PMC: 7112840. DOI: 10.1016/j.jviromet.2008.05.016. View

3.
Shin J, Choe S, Park G, Song S, Kim K, An B . Isolation and Genetic Characterization of a Bovine Coronavirus KBR-1 Strain from Calf Feces in South Korea. Viruses. 2022; 14(11). PMC: 9695762. DOI: 10.3390/v14112376. View

4.
Brandao P, Gregori F, Richtzenhain L, Rosales C, Villarreal L, Jerez J . Molecular analysis of Brazilian strains of bovine coronavirus (BCoV) reveals a deletion within the hypervariable region of the S1 subunit of the spike glycoprotein also found in human coronavirus OC43. Arch Virol. 2006; 151(9):1735-48. PMC: 7086848. DOI: 10.1007/s00705-006-0752-9. View

5.
Yu J, Qiao S, Guo R, Wang X . Cryo-EM structures of HKU2 and SADS-CoV spike glycoproteins provide insights into coronavirus evolution. Nat Commun. 2020; 11(1):3070. PMC: 7300015. DOI: 10.1038/s41467-020-16876-4. View