Filifactor alocis Has Virulence Attributes That Can Enhance Its Persistence under Oxidative Stress Conditions and Mediate Invasion of Epithelial Cells by Porphyromonas gingivalis

Abstract

Filifactor alocis, a Gram-positive anaerobic rod, is one of the most abundant bacteria identified in the periodontal pockets of periodontitis patients. There is a gap in our understanding of its pathogenicity and ability to interact with other periodontal pathogens. To evaluate the virulence potential of F. alocis and its ability to interact with Porphyromonas gingivalis W83, several clinical isolates of F. alocis were characterized. F. alocis showed nongingipain protease and sialidase activities. In silico analysis revealed the molecular relatedness of several virulence factors from F. alocis and P. gingivalis. In contrast to P. gingivalis, F. alocis was relatively resistant to oxidative stress and its growth was stimulated under those conditions. Biofilm formation was significantly increased in coculture. There was an increase in adherence and invasion of epithelial cells in coculture compared with P. gingivalis or F. alocis monocultures. In those epithelial cells, endocytic vesiclemediated internalization was observed only during coculture. The F. alocis clinical isolate had an increased invasive capacity in coculture with P. gingivalis compared to the ATCC 35896 strain. In addition, there was variation in the proteomes of the clinical isolates compared to the ATCC 35896 strain. Hypothetical proteins and those known to be important virulence factors in other bacteria were identified. These results indicate that F. alocis has virulence properties that may enhance its ability to survive and persist in the periodontal pocket and may play an important role in infection-induced periodontal disease.

Dysbiosis and Alterations in Predicted Functions of the Subgingival Microbiome in Chronic Periodontitis

“…Filifactor alocis is a fastidious, Gram-positive anaerobic rod found to be highly prevalent and abundant in patients with generalized aggressive periodontitis and chronic periodontitis (49). This organism encodes several virulence factors, which may play a role in the pathogenesis of periodontal disease by enabling the organism to persist in periodontal pockets (50). Members of the phylum Synergistetes, a newly recognized phylum of Gram-negative anaerobic bacteria, were recently implicated in periodontal disease (51).…”

Phylogenetic and functional gene structure shifts of the oral microbiomes in periodontitis patients

“…Research is warranted on this type of microorganisms as they may play an important role in development of periodontitis. As a matter of fact, Filifactor alocis, a fastidious, Grampositive, obligate anaerobic rod, has been proven to harbor characteristics in common with established periodontal pathogens and has the potential to contribute to periodontal tissue destruction (Aruni et al, 2011;Moffatt et al, 2011).…”

Treponema denticola chymotrypsin-like proteinase (CTLP) integrates spirochaetes within oral microbial communities

“…Investigations of bacterial species detected in subgingival plaque from subjects affected by periodontitis have consistently revealed the presence of bacteria such as Treponema denticola, Porphyromonas gingivalis, Tannerella forsythia, Fusobacterium nucleatum, Prevotella intermedia and Parvimonas micra (Ali et al, 1994;Socransky et al, 1998;Mayanagi et al, 2004). More recent studies have indicated that bacteria such as Filifactor alocis (Aruni et al, 2011;Moffatt et al, 2011) may also be associated with the development of periodontal disease. In vitro models of infection suggest that synergistic interactions between these periodontal bacteria can be related to severity of disease (Kesavalu et al, 2007;Bakthavatchalu et al, 2011;Orth et al, 2011).…”