of Embryo- and Organ-Culture Adapted Beaudette Strain of Infectious Bronchitis Virus in Embryonated Chicken Eggs

SUMMARY Three Beaudette strains of infectious bronchitis virus (IBV) [two chicken-embryo trachea-culture-adapted (Ei7CET1o and E71CEK10CET30) and one embryo-adapted (E72)] were propagated in 10-day-old embryonated chicken eggs (CE) to investigate growth and lethality patterns. The E72 and E71CEK10CET30 viruses were similar in growth pattern as to logarithmic phase and maximum virus production, but 95% of the CE mortality with E72 virus occurred between 20 and 32 hours whereas with E71CEK1oCET3o 60% mortality occurred between 36 and 84 hours. The yield of the E71CETo1 virus was minimum, with little lethality.