Anaerobic Gram-negative oral bacteria

Anaerobic Gram-negative oral bacteria are a diverse group of microorganisms that inhabit the subgingival dental biofilm and are primarily responsible for the development of periodontal diseases. Key species, including Porphyromonas gingivalis, Tannerella forsythia, and Treponema denticola, utilize specialized virulence factors such as gingipains and lipopolysaccharides to degrade host tissues and modulate the immune response (Socransky et al., 1998, Journal of Clinical Periodontology; Hajishengallis, 2015, Nature Reviews Immunology). These bacteria are targeted in clinical practice through mechanical debridement and the use of systemic or local antimicrobial agents like metronidazole and chlorhexidine (Slots, 2017, Periodontology 2000). The persistence of these pathogens is linked not only to localized tissue destruction but also to systemic conditions, including cardiovascular disease and diabetes, due to the chronic inflammatory state they induce (Nunn, 2003, Dental Clinics of North America). Effective therapeutic strategies focus on reducing the load of these specific anaerobes while attempting to preserve the healthy commensal oral microbiota.

Other names

Periodontal pathogensSubgingival biofilm bacteriaRed complex bacteriaBlack-pigmented anaerobesOral anaerobic microbiota

Antimicrobial agents target these bacteria through several distinct pathways: nitroimidazoles like metronidazole undergo reductive activation to form reactive intermediates that cause DNA strand breakage; beta-lactams such as amoxicillin inhibit cell wall synthesis by targeting penicillin-binding proteins; tetracyclines like doxycycline and minocycline inhibit protein synthesis by binding to the 30S ribosomal subunit; and antiseptics like chlorhexidine cause non-specific disruption of the bacterial cytoplasmic membrane (StatPearls, 2023, Periodontitis; Slots, 2017, Periodontology 2000).