ABSTRACT
Classi©cation. The genus Porphyromonas is classiŠed to the family of Bacteroidaceae. So far, 17 species have been described (Table 50.1). Although Porphyromonas is closely related phylogenetically to the genera Bacteroides and Prevotella, Shah and Collins suggested a new taxon after reclassiŠcation of the Bacteroides spp. B. asaccharolyticus, B. gingivalis, and B. endodontalis on the basis of their biochemical and chemical properties.1,3,6,27-29 Then 16S rRNA gene sequencing conŠrmed the independent taxon Porphyromonas. The phylogenetic differentiation of the members of the genus Porphyromonas was also evidenced by 16S rRNA gene sequence analysis and conŠrmed by DNA-DNA relatedness studies and by morphological, chemical, and biochemical criteria.30-32 The discrimination of the species P. gingivalis and P. gulae was enabled by comparing 16S-23S rRNA gene internal transcribed spacer sequences.8,21
Members of the Porphyromonas genus have been isolated from a number of mammals. The species P. asaccharolytica,1 P. bennonis,4 P. catoniae,5 P. endodontalis,1 P. gingivalis,1 P. somerae,7 and P. uenonis9 have been found worldwide in humans. Several Porphyromonas species, P. macacae,26 P. cansulci,10 P. canoris,12 P. cangingivalis,10 and P. circumdentaria,15 were isolated from animals, where they are mostly associated
with oral in³ammatory processes. These species were frequently found in humans in infected dog or cat bite wounds.33 Porphyromonas spp. are generally associated with in³ammation and purulence, but some species primarily occur in gingival and periodontal disease processes, occasionally then causing accompanying systemic in³ammative processes. P. gingivalis is closely associated with the progression of chronic periodontitis.
