Bordetella bronchialis sp nov., Bordetella flabilis sp nov and Bordetella sputigena sp nov., isolated from human respiratory specimens, and reclassification of Achromobacter sediminum Zhang et al. 2014 as Verticia sediminum gen. nov., comb. nov.

Abstract

The phenotypic and genotypic characteristics of four Bordetella hinzii-like strains from human respiratory specimens and representing nrdA gene sequence based genogroups 3, 14 and 15 were examined. In a 16S rRNA gene sequence based phylogenetic tree, the four strains consistently formed a single coherent lineage but their assignment to the genus Bordetella was equivocal. The respiratory quinone, polar lipid and fatty acid profiles generally conformed to those of species of the genus Bordetella and were characterized by the presence of ubiquinone 8, of phosphatidylethanolamine, phosphatidylglycerol, diphosphatidylglycerol and several aminolipids, and of high percentages of C-16 : 0, cyclo-C-17 : 0 and summed feature 2, as major chemotaxonomic marker molecules, respectively. The DNA G+C content was about 66 mol%, which corresponded with that of the high-percentage DNA G+C content genera of the family Alcaligenaceae including the genus Bordetella. DNA DNA hybridiiation experiments revealed the presence of three distinct genomospecies and thus confirmed phenotypic differences as revealed by means of extensive biochemical characterization. We therefore propose to formally classify Bordetella genogroups 3, 14 and 15 as Bordetella bronchialis sp. nov. (type strain LMG 28640(T)=AU3182(T)=CCUG 56828(T)), Bordetella sputigena sp. nov. (type strain LMG 28641(T)=CCUG 56478(T)) and Bordetella flabilis sp. nov. (type strain LMG 28642(T)=AU10664(T)=CCUG 56827(T)). In addition, we propose to reclassify Achromobacter sediminum into the novel genus Verticia, as Verticia sediminum, gen. nov., comb. nov., on the basis of its unique phylogenetic position, its marine origin and its distinctive phenotypic, fatty acid and polar lipid profile.