title: Serologic studies on porcine strains of Haemophilus parahaemolyticus (pleuropneumoniae): agglutination reactions.
abstract: Fifteen strains of Haemophilus parahaemolyticus (pleuropneumoniae) represented by 6 American isolates, 6 Swedish isolates, and 3 reference strains of Nicolet's serotype 1, 2 and 3, were used in serologic studies by agglutination and agglutinin-adsorption tests. By whole cell-agglutination tests in rabbit antiserums, 3 additional serotypes, 4, 5, and 6, were identified. All strains had strong serotype-specific agglutinating properties. Occasional weak cross reactions could be eliminated by appropriate adsorptions without effect upon type-specific reactivity. The Swedish isolates were assigned to serotypes 2, 3, 4, and 6, and the American isolates, to serotypes 4 and 5. All European isolates were distinct from 5 of the 6 American strains. An American culture isolated from a steer and another from a lamb were identical in their agglutination reactions with the porcine isolates of serotype 5. The serotyping of isolated strains is important in the epizootiologic and immunologic studies of H parahaemolyticus infections.
mesh_terms: D000327:Adsorption; D000372:Agglutination Tests; D003429:Cross Reactions; D006190:Haemophilus / Q000145:classification* / Q000276:immunology; D012703:Serotyping