Characterization of haemagglutinin from Bordetella bronchiseptica

In comparison with haemagglutinin (HA)-active strains of Bordetella bronchiseptica, the HA-deficient strains lacked a 150 kDa protein band on SDS-polyacrylamide gel electrophoresis (SDS-PAGE). Adsorption of partially purified HA with bovine erythrocytes showed the loss of the 150 kDa band in the supernatant. This 150 kDa protein was purified by high-performance liquid chromatography using gel filtration columns. Electron microscopic examination revealed that the purified HA possessed a fine filamentous structure with dimensions of ≈ 2 × 150 nm, which was considered to represent the filamentous haemagglutinin of B. bronchiseptica. Both the cell-free antigen obtained from the culture supernatant of phase-I strain of the bacteria and the bovine erythrocytes, which combined with crude HA showed an excellent protective activity of the challenge by virulent strain of B. bronchiseptica in mice.