Falsochrobactrum ovis gen. nov., sp. nov., isolated from a sheep

Abstract

A Gram-stain-negative, rod-shaped, oxidase-positive, non-spore-forming, non-motile bacterium (B1315(T)) was isolated from the placenta of a sheep with abortion. On the basis of 16S rRNA gene sequence analyses the strain was assigned to the Brucella-Ochrobactrum-Paenochrobactrum-Pseudochrobactrum group with 94.5-94.8 %, 94.3-96.1 %, 95.0-95.1 %, and 95.9-96.1 % sequence similarities to type strains of species of the four genera, respectively. Phylogenetic trees indicated a close relationship to the type strains of Ochrobactrum gallinifaecis and Ochrobactrum oryzae (95.9 and 96.1 % sequence similarity, respectively). Chemotaxonomic data confirmed the allocation of strain B1315(T) to the family Brucellaceae (quinone system: ubiquinone Q-10 and major fatty acids: C18 : 1ω7c and C19 : 0 cyclo ω8c). The polar lipid profile contained the major lipids diphosphatidylglycerol, phosphatidylmonomethylethanolamine, phosphatidylethanolamine, phosphatidylglycerol, phosphatidylcholine and the unidentified but unique phospholipid PL7. The polyamine pattern of strain B1315(T) contained the major polyamines spermidine and putrescine. On the basis of the 16S rRNA gene and recA sequence phylogeny and chemotaxonomic data strain B1315(T) was clearly different from the genera Brucella, Ochrobactrum, Paenochrobactrum and Pseudochrobactrum. On the basis of these data we propose the novel genus Falsochrobactrum gen. nov. with the type species Falsochrobactrum ovis sp. nov. with the type strain B1315(T) ( = CCM 8460(T) = LMG 27356(T.)) The taxonomic allocation of O. gallinifaecis, which grouped inconsistently together with strain B1315(T) on the basis of 16S rRNA gene sequence data, but shows the chemotaxonomic features of the genus Ochrobactrum, remains to be clarified.