Disc Electrophoresis of Acid-Phenol-Soluble Proteins for Identification of the “Haemophilus somnus” Group

Summary Comparison of the acid-phenol-soluble structural proteins of “ Haemophilus somnus ” with those of related species showed that this organism was closely related to “ Histophilus ovis ”, and shared some proteins with “ Actinobacillus seminis ”. A distant relationship with Actinobacillus lignieresii was also apparent. In contrast, there was little resemblance to the other Haemophilus species tested with the exception of “ Haemophilus ovis ” which showed many similarities. “ H. somnus ” produced protein migration patterns quite distinct from those of “ H. equigenitalis ” which was also unrelated to any of the other species tested. This method is recommended as an aid to the identification of “ H. somnus ”.