Production and properties of hemagglutinin of Haemophilus gallinarum.

Production of hemagglutinin (HA) of Haemophilus gallinarum was compared in some media, and its properties were studied. HA was produced in Kato's media, brain heart infusion (BHI) broth containing beta-diphosphopyridine nucleotide, and chicken meat infusion (CMI) broth. The HA in CMI broth different according to the concentration of the chicken serum; no HA titer was found in 0.5% or more chicken serum, but HA was activated by storage in a refrigerator. Cells of H. gallinarum cultured for a long time had markedly decreased HA titer. A weak HA was produced in blood and Kato's agars, but no titer appeared in CMI and BHI agars. HA of H. gallinarum was heat-labile and inactivated by formalin, ethanol, methanol, and ethyl acetate. On the other hand, HA was resistant to chloroform, acetone, and some enzymes. Moreover, the HA titer of cell cultured in CMI broth was enhanced by hyaluronidase. H. gallinarum in Kato's and BHI broths were pleomorphic rods with or without a capsule, but were capsulated ovoid cells in CMI broth, according to electron microscopy.