Aspects of the taxonomy of bordetella and related organisms.

Two hundred and one strains of Gram-negative bacteria representing the genera of the family Brucellaceae, together with species of Neisseria, Achromobacter, Acinetobacter, Alcaligenes and Agrobacterium have been subjected to a taxonomic examination, A numerical taxononic analysis has separated the strains into fifteen clusters, Two of the clusters consisted of composite groups each containing two genera which could not be clearly separated on the tests carried out. The homogeneity of the clusters was substantiated by results obtained on selected strains when examined for GO base ratios (by thermal denaturation) and similarity of protein patterns (examined by poly-acrylamide gel electropheresis). The family Brucellaceae Breed, Murray and Smith 1957 contains a heterogeneous collection of genera which have little in common apart from often requiring special media for growth and in being potentially pathogenic. The results of this study suggest that the Brucellaceae should be sub-divided into two families, 1) Pasteurellaceae Pribram 1933 or Fam. nov. This would contain the genera Haemophilus, Pasteurella and Actinobacillus. The close similarity between Pasteurella and Actinobacillus is recognised and it is suggested that further work on these two genera may reveal that they can be combined in a single genus. 2) Brucellaceae Breed, Murray and Smith 1957 emend. This family would contain only three genera, Brucella, Bordetella and Alcaligenes. Difficulties were found in separating oxidase-positive, motile Alcaligenes species from Bordetella bronchiseptica, although there is little evidence for separating B. bronchiseptica from the other species of Bordetella. Further work may suggest combining Alcaligenes and Bordetella. Oxidase-negative, non-motile Alcaligenes species should not be included in the genus Alcaligenes. Results from this study indicate that they should be transferred to the species Acinetobacter lwoffii. Definitions for the families Pasteurellaceae and Brucellaceae are proposed.