Phenotypic differentiation of Pasteurella sensu stricto and the Actinobacillus group.

The current classification of recognized actinobacilli and pasteurellas does not allow differentiation of the two genera by their phenotypic features. Recent investigations of their genetic relationships have shown that several species hitherto assigned to the genus Pasteurella are more closely related to the actinobacilli. Moreover, some recently described taxa were located by DNA-DNA hybridization in one or the other of the two genera. On the basis of the genetic system, improved identification keys have been devised which separate the taxonomic groups on the genus and species levels according to an appropriate set of biochemical characteristics.