Use of gonococcal agar medium for preparation of antigen of Haemophilus paragallinarum hemagglutinin.

Some solid media for antigen preparation of Haemophilus paragallinarum (HPG) hemagglutinin (HA) were studied. When HA activities of HPG strain 221 cultivated on chicken meat infusion (CMI) and gonococcal (GC) agar media were compared, the titer of the GC agar medium appeared faster and was higher than the titer on the CMI agar medium. For both agar media, the HA titer and growth increased with the concentration of the chicken serum added. In addition, HA activity on GC agar medium showed a higher titer than activity on other media, such as brain-heart infusion, Trypticase soy, blood, and Kato's agar media. When various HPG strains were inoculated onto GC agar medium, HA titers in strains 0083 and F were equal to that in strain 221. These results confirm that the GC agar medium is useful for preparation of HA antigen of HPG.