Taxonomy and identification of periodontopathogenic bacteria and related species.

The tumultuous evolution of oral and periodontal microbiology has focussed the attention of many researchers on the necessity to clarify the taxonomic position and identification criteria of putative periodontopathogens, in order to elucidate the role played by each species in the pathogenesis of periodontal disease. Many of the most important periodontopathogens recently underwent a radical reclassification process that may create some confusion and certainly deserves an accurate analysis aimed at focussing the actual situation of these bacteria. The taxonomic evolution and identification criteria of species of the genera Bacteroides, Prevotella, Porphyromonas and Actinobacillus is here analyzed in detail to clarify this recent evolutive taxonomic process, and to explain the importance of molecular studies for both taxonomic and identification purposes in this field.