Investigation of bovine coronavirus strain CV-315 cultural properties

Abstract

The purpose of this study was to investigate the features of cultivation of bovine coronavirus strain CV-315 isolated in Ukraine from a calf with coronavirus infection and to select optimal methods of virus cultivation to obtain viral material with the highest possible titers of infectious activity in order to develop manufacturing technology of means of immunoprophylaxis and specific diagnostics. During the study, the influence of a number of factors on the accumulation of strain CV-315 was studied: the presence and concentration of trypsin in the nutrient medium, the effect of fetal bovine serum, the degree of cell culture monolayer during virus infection, also the virus dose, temperature and the term of cultivation. According to the results, it was established that bovine coronavirus strain CV-315 has the highest infectious activity when cultured for 72 hours before the manifestation of CPE of 70–80%, without the addition of trypsin and fetal bovine serum content of 2% at 37±0.5°C. It was also found that the optimal infective dose is 0.1–0.01 viral particles per cell for infection of the fully formed monolayer of MDBK cell culture. The obtained results will be used in the development of veterinary vaccines against bovine coronavirus.