Production of monoclonal antibodies to the Bordetella avium 41-kilodalton surface protein and characterization of the hemagglutinin.

Production of monoclonal antibodies (MAbs) to Bordetella avium surface proteins led to further characterization of the hemagglutinin. Proteins obtained by homogenization of whole-cell B. avium were used to immunize mice for the production of monoclonal antibodies. Immunoprecipitation and Western blot techniques were used to determine the specificity of three MAbs, which all recognized the B. avium 41-kilodalton (kd) surface protein. In addition, all of the MAbs inhibited hemagglutination (HA) of guinea pig erythrocytes by B. avium. The 41-kd protein recognized by the MAbs was observed by the indirect immunofluorescence test and sodium dodecyl sulfate-polyacrylamide gel electrophoresis to bind to guinea pig erythrocytes. When HA-positive isolates of B. avium were treated with periodic acid, which cleaves carbohydrates from proteins, the isolates became HA-negative. Likewise, treatment of HA-positive B. avium isolates with proteinase K, which would also remove carbohydrates associated with proteins on the surface of the bacterium, inhibited HA. Considering these data, we suggest that the B. avium hemagglutinin is a carbohydrate closely associated with the 41-kd surface protein.