Propagation of bovine coronavirus on Vero cell line: electron microscopic studies

The in vitro adaptation of enteric coronaviruses is difficult. In our Laboratories, the multiplication of the COI bovine strain (F15 origin), on Vero cells is commonly practised. Since other laboratory tests (hemagglutination inhibition, cytopathic effect and immunofluorescence) are not totally reliable, electron microscopic studies present definite advantages in the interpretation of viral synthesis, as demonstrated at the 11th passage in our study. We were able to observe the following: --that the rate of infected and productive cells was important; --that the stages of viral morphogenesis were well established; --that the viral synthesis was prolific and regular and could be witnessed by important intracytoplasmic storage. The results of this study prove that the choice of our cell system is very satisfactory.