Serological Comparisons of Strains of Infectious Bronchitis Virus Using Plaque-Purified Isolants

Abstract

SUMMARY Nineteen isolants of infectious bronchitis virus (IBV), including most of the recently reported new isolants, were adapted to chick kidney cell cultures. After plaque purification and the preparation of antiserums against purified strains, antigen interrelatedness was evaluated with cross-neutralization tests by the plaque-reduction technique. The results indicated that there are 7 serotypes current in the United States and that the Australian T strain is distinct from each of these. Antigenic variants occurred within some of these serotypes.