Genetic relatedness of Haemophilus somnus to select genera of bacteria

The degree of DNA homology from Haemophilus somnus and DNA from select members of the genera Haemophilus, Actinobacillus, Pasteurella, Escherichia, and Micrococcus was determined. Hybridization tests indicated that H somnus DNA has a 46%, 58%, and 43% homology with the DNA from H influenzae, H parainfluenzae, and A lignieresii, respectively. These percentages of homology values indicate that H somnus was moderately related to 2 members of the genus Haemophilus and 1 member of the genus Actinobacillus. Haemophilus somnus DNA did not show any hybridization with DNA from the genera of Escherichia, Micrococcus, or Pasteurella.