Plaque Formation by Infectious Bronchitis Virus in Chicken Embryo Kidney Cell Cultures

Abstract

SUMMARY Nine strains of avian infectious bronchitis virus, adapted and grown by serial passage in primary chicken embryo kidney (CEK) cells, produced cytopathic effects in monolayer cultures of CEK cells and formed plaques under an agar overlay medium. Plaque morphology appeared to be constant for a virus strain or clone when examined in CEK cells under defined conditions. Plaque counts were essentially the same when virus was assayed at 37 and 40 C, although mean plaque size of most strains was greater at 40 C.