Propionibacterium australiense sp. nov. Derived from Granulomatous Bovine Lesions*

Abstract

Granulomatous lesions from bovines were examined using standard histological methods from geographically separated herds in Queensland, Australia. Bacteria recovered from a number of these lesions were studied by the by the staff of Queensland Department of Primary Industries, Oonoonba Veterinary Laboratory, using standard microbiological methods. The bacteria appeared to be phenotypically similar to each other and like members of the genus Propionibacterium but could not be assigned to any currently named species. Actinomyces species, a cause of granulomatous lesions in cattle, were ruled out based on polyphasic testing and negative results for direct fluorescent antibody. Phenotypic studies indicated that strains were fermentative. Chemotaxonomic analyses revealed mesodiaminopimelic acids in the cell walls, a majority of the cellular fatty acids were of the branched-chain type and products of fermentation included major propionic acid. Comparative 16s rRNA gene sequencing demonstrated that the bacteria were genealogically highly related to each other and constituted a new subline within the genus Propionibacterium, displaying >3% divergence from other named species of that genus. The novel taxon could be distinguished from other validly described Propionibacterium species and so it is proposed that these strains represent a new species, Propionibacterium australiense sp. nov. Health Canada's National Microbiology Laboratory (NML) identifier numbers 98A072 (type strain) and 98A078 have been deposited as ATCC BAA-264 T, CCUG 46075 T, and ATCC BAA-263, CCUG 46174, respectively. Genbank accession number for the 16s rRNA gene sequence for 98A072 is AF225962.