Comparative Sensitivities of Embryonating Chicken's Eggs and Primary Chicken Embryo Kidney and Liver Cell Cultures to Infectious Bronchitis Virus

Abstract

The embryonating chicken''s egg was 12-40 times as sensitive to infectious bronchitis virus as chicken embryo kidney (CEK) cells and about 500-100 times as sensitive as chicken embryo liver (CELi) cells. Plaque counts in both CEK and CELi cells followed a linear relationship with virus concentration, indicating that one virus particle initiates a plaque. Tissue culture ID63 titers in kidney and liver cultures were equivalent to homologous PFU titers, showing that all cell-culture-infecting virus was also plaque-forming virus. There were no differences in adsorption of virus to both cell types. One-step growth curves in liver cells show that the eclipse phase was longer and virus production and release was much slower than in kidney cells. The differences in plaque-forming ability of the virus in CEK and CELi cells could not be altered by adaptation of the virus to cell cultures or by selection for virus with increased plaquing efficiency.