Classification of Pasteurella species B as Pasteurella oralis sp nov.

Pasteurella species B has so far only been reported from the oral cavity of dogs, cats and a ferret. In the present study, information from 15 recent isolates from different sources, including African hedgehogs (Atelerix albiventris), banded mongoose (Mungos mungo), Moholi bushbabies (Galago moholi) and pneumonia of a cat, were compared to five strains investigated previously from bite wounds in humans inflicted by a cat and dog and from gingiva of a cat. rpoB gene sequence comparison showed that 17 isolates, including the reference strain (CCUG 19794(T)), had identical sequences, whereas two were closely related and demonstrated 97.9 and 99.6% similarity to strain CCUG 19794(T), respectively; the type strain of Pasteurella stomatis was the most closely related strain, with 92.3% similarity. This is within the mean range (76-100%) of rpoB gene sequence similarity between species of the same genus within the family Pasteurellaceae. 16S rRNA gene sequencing of four strains selected based on rpoB sequence comparison showed at least 99.7% similarity between strains of Pasteurella species B, with 96.2% similarity to the type strain of the closest related species (Pasteurella canis), indicating that Pasteurella species B should have separate species status. Separate species status was also documented when recN sequence comparisons were converted to a genome similarity of 93.7% within Pasteurella species B and 59.0% to the type strain of the closest related species (P. canis). Based on analysis of the phylogenetic and phenotypic data, and since most isolates originate from the oral cavities of a diverse group of animals, it is suggested that these bacteria be classified as Pasteurella oralis sp. nov.; the type strain is P683(T) (=CCUG 19794(T)=CCM 7950(T)=strain 23193(T)=MCCM 00102(T)), obtained from a cat. Previous reports of the type strain have shown ubiquinone-8, demethylmenaquinone-8 and menaquinone-8 as the major quinones. Polyamines in the type strain were reported as diaminopropane, putrescine, cadaverine, sym-norspermidine, spermidine and spermine in a previous investigation, and the major fatty acids of the type strain were reported to be C-16 : 0, C-16 : 1 omega 7C and C-14 : 0, with minor amounts of C-18 : 0 and C-18 : 1 omega 9c. The DNA G+C content of the type strain has been reported to be 40.0 mol%.