Isolation and identification of NAD‐independent bacteria from chickens with symptoms of infectious coryza

Abstract

Since 1990, NAD-independent bacteria have been isolated in South Africa from poultry showing respiratory manifestations similar to infectious coryza. A total of 126 isolates was examined biochemically and serologically, using polyclonal as well as monoclonal antibodies. Forty isolates were identified as Ornithobacterium rhinotra-cheale, some of which agglutinated glutaraldehyde-fixed red blood cells. Furthermore, fourteen Pasteurella avium isolates, five P. volantium and three Pasteurella species A were isolated for the first time. The remaining 64 isolates were biochemically identified as NAD-independent H. paragallinarum. Of these, 37 were Page serovar A, while no Page serovar B isolates were found. The remaining 25 isolates were typed as Page serovar C. Two different haemagglutination inhibition reaction patterns were found among the Page serovar C isolates, i.e. isolates which reacted with a 1 in 100 dilution of the Page serovar C antiserum, and another larger group which did not react with this dilution of the serum, but did react with rabbit raised antiserum prepared against other Kume serogroup C isolates. This is the first recorded isolation of Page serovar C NAD-independent H. paragallinarum.