title: Porphyromonas gingivalis Periodontal Infection and Its Putative Links with Alzheimer's Disease.
abstract: Periodontal disease (PD) and Alzheimer's disease (AD) are inflammatory conditions affecting the global adult population. In the pathogenesis of PD, subgingival complex bacterial biofilm induces inflammation that leads to connective tissue degradation and alveolar bone resorption around the teeth. In health, junctional epithelium seals the gingiva to the tooth enamel, thus preventing bacteria from entering the gingivae. Chronic PD involves major pathogens (Porphyromonas gingivalis, Treponema denticola, and Tannerella forsythia) which have an immune armoury that can circumvent host's immune surveillance to create and maintain an inflammatory mediator rich and toxic environment to grow and survive. The neurodegenerative condition, AD, is characterised by poor memory and specific hallmark proteins; periodontal pathogens are increasingly being linked with this dementing condition. It is therefore becoming important to understand associations of periodontitis with relevance to late-onset AD. The aim of this review is to discuss the relevance of finding the keystone periodontal pathogen P. gingivalis in AD brains and its plausible contribution to the aetiological hypothesis of this dementing condition.
authors.affiliation: Oral & Dental Sciences Research Group, School of Medicine and Dentistry, University of Central Lancashire, Preston PR1 2HE, UK.
authors.forename: Sim K
authors.initials: SK
authors.lastname: Singhrao
authors.affiliation: Oral & Dental Sciences Research Group, School of Medicine and Dentistry, University of Central Lancashire, Preston PR1 2HE, UK.
authors.forename: Alice
authors.initials: A
authors.lastname: Harding
authors.affiliation: Oral & Dental Sciences Research Group, School of Medicine and Dentistry, University of Central Lancashire, Preston PR1 2HE, UK.
authors.forename: Sophie
authors.initials: S
authors.lastname: Poole
authors.affiliation: Department of Periodontology, College of Dentistry, University of Florida, Gainesville, FL, USA.
authors.forename: Lakshmyya
authors.initials: L
authors.lastname: Kesavalu
authors.affiliation: Oral & Dental Sciences Research Group, School of Medicine and Dentistry, University of Central Lancashire, Preston PR1 2HE, UK.
authors.forename: StJohn
authors.initials: S
authors.lastname: Crean
mesh_terms: D000544:Alzheimer Disease / Q000453:epidemiology* / Q000209:etiology* / Q000276:immunology; D016866:Bacteroidaceae Infections / Q000150:complications / Q000453:epidemiology; D055113:Chronic Periodontitis / Q000150:complications* / Q000453:epidemiology* / Q000276:immunology; D005881:Gingiva / Q000276:immunology / Q000382:microbiology; D006801:Humans; D007249:Inflammation / Q000276:immunology / Q000382:microbiology; D016966:Porphyromonas gingivalis / Q000472:pathogenicity*