Biochemical properties of catalase-positive avian haemophili.

The biochemical properties of 39 strains of Haemophilus avium from chickens were determined. All the strains produced acid from fructose, galactose, glucose and mannose but not from lactose. Variable reactions were found for arabinose, maltose, mannitol, sorbitol, trehalose and xylose. No strains showed urease activity or produced indole, while beta-galactosidase and/or ornithine decarboxylase activity was present in some strains. This variability allowed the recognition of 15 biochemical biovars including some not previously recognized in H. avium. Only 25 (64%) of the H. avium strains could be assigned to the three species (Pasteurella avium, P. volantium and Pasteurella species A) recently proposed to replace H. avium.