The agglutination reactions of Haemophilus paraphrophilus and H. paraphrohaemolyticus, and some observations on the agglutination of H. Aphrophilus and H. haemoglobinophilus (H. canis)

Abstract

Agglutination tests were used to study the surface antigens of two recently described species of the genus Haemophilus, H. paraphrophilus and H. paraphrohaemolyticus, and their antigenic relationship to other members of the genus. The results obtained with a few strains of H. haemoglobinophilus and H. aphrophilus are also reported. The species H. paraphrophilus appears to be homogeneous; no major cross-reactions were observed. The species H. paraphrohaemolyticus contains at least three serotypes, of which two have been defined in terms of agglutination reactions. Cross-agglutinations occurred between one strain of H. paraphrohaemolyticus and strains of the other V-dependent species, H. parainfluenzae and H. parahaemolyticus. Of the X-dependent species, H. haemoglobinophilus seems to be homogeneous, and the species H. aphrophilus is not. A non-specific antibody against horse blood in the medium occurred erratically and was present in only two antisera, those raised to H. aphrophilus strain Khairat and H. haemoglobinophilus strain no. NCTC8540.