Detection and seroprevalence of infectious bronchitis virus strains

ABSTRACT This study was conducted to investigate the incidence of infectious bronchitis virus (IBV) in com-mercial broiler and layer flocks in Pakistan. Serum sam-ples from 16 layers and 9 broiler flocks were screened against M-41, D-274, D-1466, and 4-91 strain antigens using hemagglutination inhibition assay. Overall, 88 % of the flocks were seropositive for M-41 antibodies, whereas 40, 52, and 8 % of the flocks were positive for D-274, D-1466, and 4-91 IBV strains, respectively. The M-41 antigen was also detected in lungs and tracheal tissues of the clinically positive infectious bronchitis cases. Phospholi-pase C treatment of the lung and tracheal tissue homoge