Notes: Branhamaceae fam. nov., a Proposed Family To Accommodate the Genera Branhamella and Moraxella

Abstract

The genera assigned to the family Neisseriaceae in 1984 (K. Bøvre, p. 288-290, in N. R. Krieg and J. G. Holt, ed., Bergey’s Manual of Systematic Bacteriology, vol. 1) are now recognized as members of two different groups (the beta and gamma groups) of the class Proteobacteria. DNA base composition data, findings from DNA-mediated transformation to streptomycin resistance, DNA-DNA hybridization, and DNA-rRNA hybridization, and results from electrophoresis of soluble proteins have revealed differences that mandate separation from Neisseria of the three species of “false neisseriae” (Neisseria caviae, Neisseria ovis, and Neisseria cuniculi), and also of the genera Branhamella, Moraxella, and Acinetobacter. Since these organisms must be excluded from the Neisseriaceae, the new family Branhamaceae is proposed to accommodate the genera Branhamella (including the false neisseriae) and Moraxella. This arrangement acknowledges the phylogenetic relationships of these organisms and resolves controversies concerning (i) the recommendation that the genus Moraxella should be divided into the subgenus Moraxella (for rod-shaped organisms) and the subgenus Branhamella (for cocci) and (ii) the taxonomic placement of the false neisseriae. The present evidence does not favor inclusion of the genus Acinetobacter in the family Branhamaceae. The following species are included at this time in the type genus, Branhamella: Branhamella catarrhalis (the type species), Branhamella caviae, Branhamella ovis, and Branhamella cuniculi. The species allocated at this time to the genus Moraxella are Moraxella lacunata (the type species) Moraxella bovis, Moraxella nonliquefaciens, Moraxella osloensis, Moraxella phenylpyruvica, and Moraxella atlantae.