Crossed immunoelectrophoresis applied to representative strains from 11 different Pasteurella species under taxonomic...

Crossed immunoelectrophoresis evaluated on a numerical basis revealed a close antigenic relationship between species of the genus Pasteurella. By cluster analysis, 4 groups on similarity levels between 87% and 72% S could be separated which were connected by a minimum level of 69.5% S. One subgroup included all biovars or subspecies consisting of strains with mucoid growth. Another feature governing the antigenic relationship seemed to be the host range of Pasteurella species. Despite a considerable number of cross-reacting antigens, representative strains of the genera Haemophilus and Actinobacillus were clearly separated from Pasteurella. Similarly, "Pasteurella" haemolytica and Taxon 16 strains tested did not belong to this genus. An Escherichia coli strain showed a higher number of cross-reacting antigens, confirming known antigenic relationship among Gram-negative bacterial species.