Association between Prevotella intermedia and Prevotella nigrescens with Porphyromonas gingivalis: modulating the interaction with gingival epithelial cells

Abstract

Genus Prevotella consists of anaerobic Gram-negative bacilli with black pigmented colonies in blood agar plates. In the oral cavity, Prevotella intermedia and Prevotella nigrescens, the most frequently isolated species were associated with periodontitis, and also with acute necrotizing ulcerative gingivitis, gingivitis of pregnancy, and endodontic infections. Besides the oral cavity, an important role has been attributed to P. intermedia and P. nigrescens in the pathogenesis of cardiovascular disease by their frequent isolation from atherosclerotic plaques. Although P. intermedia and P. nigrescens have a close biochemical and phylogenetic relationship, the pattern of biofilm formation beside the interaction with epithelial and endothelial cells may be a decisive factor in the virulence of these species. Results from previous investigations suggest that the intra-specific variation may interfere with the ability of P. intermedia and P. nigrescens recognition of surface molecules of bacterial or host cells by modulating the biofilm formation as well the colonization of the host surfaces, not only quantitatively, but also qualitatively. Moreover, the association with other oral pathogens such as Porphyromonas gingivalis might influence the invasive process possibly leading to more or less harmful consequences to the host than each species separately. Since knowledge of the effects of associations of P. intermedia and P.nigrescens in the oral cavity remains incomplete, the objectives of this study are to verify the effects of the association of strains of P. intermedia and P. nigrescens with P. gingivalis in modulating the interaction with gingival epithelial cells (adhesion, invasion, and persistence). (AU)