Phylogenetic analysis of Porphyromonas species isolated from the oral cavity of Australian marsupials
Deirdre Mikkelsen,1,2 Gabriel J. Milinovich,3 Paul C. Burrell,4 Sharnan C. Huynh,1 Lyndall M. Pettett,1 Linda L. Blackall,5 Darren J. Trott3 and Philip S. Bird1*
1Oral Biology and Pathology, School of Dentistry, Faculty of Health Sciences, The University of Queensland, St Lucia, 4072, Queensland, Australia.
2Centre for Nutrition and Food Sciences The University of Queensland, St Lucia, 4072, Queensland, Australia.
3School of Veterinary Sciences, Faculty of Natural Resources, Agriculture and Veterinary Science, The University of Queensland, St Lucia, 4072, Queensland, Australia.
4Department of Natural Resources and Water, 59 Adelaide Street, Brisbane 4000, Queensland, Australia.
5Australian Institute of Marine Science (AIMS), Cape Ferguson, 4810, Queensland, Australia.
Porphyromonas species are frequently isolated from the oral cavity and are associated with periodontal disease in both animals and humans. Black, pigmented Porphyromonas spp. isolated from the gingival margins of selected wild and captive Australian marsupials with varying degrees of periodontal disease (brushtail possums, koalas and macropods) were compared phylogenetically to Porphyromonas strains from non-marsupials (bear, wolf, coyote, cats and dogs) and Porphyromonas gingivalis strains from humans using 16S rRNA gene sequence analysis. The results of the phylogenetic analysis identiﬁed three distinct groups of strains. A monophyletic P. gingivalis group (Group 1) contained only strains isolated from humans and a Porphyromonas gulae group (Group 2) was divided into three distinct subclades, each containing both marsupial and nonmarsupial strains. Group 3, which contained only marsupial strains, including all six strains isolated from captive koalas, was genetically distinct from P. gulae and may constitute a new Porphyromonas species.