Isolation of 'variant' strains of infectious bronchitis virus from vaccinated chickens in Great Britain.

摘要

In 1996, 3 of 17 isolates of infectious bronchitis virus (IBV) from commercial birds with respiratory disease and egg production problems showed no relationship to the M41, 793/B or M41/793/B (recombinant) serotypes when examined by haemagglutination inhibition and virus neutralization tests. Comparison with European and North American reference strains showed a close serological relationship with the Dutch 'variant' strain D1466, a member of the D212 serogroup. Haemagglutinating antigen, preparedfrom one (42/96) of the 3 isolates, which all came from IBV vaccinated birds, was used to test over 300 serum samples from IBV vaccinated laying flocks with histories of egg production and quality problems in various locations in Great Britain. In over 85% of cases, significant levels of antibody to 42/96 were detected.