Virulence and Pathogenicity Properties of Aggregatibacter actinomycetemcomitans

Abstract

Aggregatibacter actinomycetemcomitans is a periodontal pathogen colonizing the oral cavity of a large proportion of the human population. It is equipped with several potent virulence factors that can cause cell death and induce or evade inflammation. Because of the large genetic diversity within the species, both harmless and highly virulent genotypes of the bacterium have emerged. The oral condition and age, as well as the geographic origin of the individual, influence the risk to be colonized by a virulent genotype of the bacterium. In the present review, the virulence and pathogenicity properties of A. actinomycetemcomitans will be addressed.

Aggregatibacter, a Low Abundance Pathobiont That Influences Biogeography, Microbial Dysbiosis, and Host Defense Capabilities in Periodontitis: The History of a Bug, and Localization of Disease

“…These findings indicate that this operon should have biological significance in long-term survival since the operon is ever-present (hence, its name the widespread colonization island) and functionally it appears to be responsible for non-specific adherence to abiotic surfaces [37]. The tad genes encode a macromolecular system responsible for biogenesis of Flp, pili that bundle to form fibrils that are related to biofilm formation, that also show an association with surface related polysaccharides [2]. Further, elegant work by Wang et al pointed to specific genes in the tad operon and their effect on extracellular matrix material such as vesicles, exopolysaccharides, and fimbriae [33].…”

“…LAgP is a phenotypically distinct clinical entity that has several unique features that show: (1) rapid-excessive bone loss relative to patient age; (2) bone loss with a molar/incisor distribution;…”

“…It was characterized as a Gram-negative, non-motile, coccobacillus that was either a facultative anaerobe or was capnophilic [10]. A. actinomycetemcomitans has been shown to possess several virulence factors, the most relevant of which are adherence factors, leukotoxin, cytolethal distending toxin, complement resistance factors, and moonlighting proteins, among other factors that account for its successful adaptation to a variety of environments [1,2]. Since there have been excellent review papers that describe these factors in detail, they do not form the basis of this review.…”

“…This review is written as an overall appraisal of a field of research that has been part of a personal journey related to a specific microorganism (Aggregatibacter actinomycetemcomitans) and its relationship to a specific form of periodontal disease (Localized Aggressive Periodontitis, LAgP). The review is not presented as a systematic review of the literature (several reviews on this topic already exist [1][2][3][4][5][6]) but rather as a critical but broad interpretation of the field of research based on studies done by members of our laboratory and others in the field. The review offers novel ways of assessing infectious diseases from the point of view of the microbe, its host, and particularly interactions between the microbe and its host.…”

Possible Involvement of Vitamin C in Periodontal Disease-Diabetes Mellitus Association

“…It is related to many other chronic diseases, such as cardiovascular disease, inflammatory bowel disease, rheumatoid arthritis, respiratory tract infection and Alzheimer's disease, displaying a particular interest in the relationship between oral and systemic health [3][4][5]. PD is caused by specific oral microorganisms, such as Porphyromonas gingivalis, Treponema denticola, Tannerella forsythia and Aggregatibacter actinomycetemcomitans [6][7][8], inducing loss of periodontal ligament and alveolar bone, also representing the primary cause of tooth loss [9]. Periodontal impairment is influenced by many risk factors, including alcohol, stress, smoking, heredity, DM and endocrinological changes (pregnancy or menopause); thus, maintaining periodontal health becomes a real challenge [10].…”