scholarly journals Pathogenicity of the highly leukotoxic JP2 clone of Aggregatibacter actinomycetemcomitans and its geographic dissemination and role in aggressive periodontitis

2014 ◽  
Vol 6 (1) ◽  
pp. 23980 ◽  
Author(s):  
Dorte Haubek ◽  
Anders Johansson
Keyword(s):  
Aggregatibacter Actinomycetemcomitans ◽  
Aggressive Periodontitis

scholarly journals Genome Sequence of Aggregatibacter actinomycetemcomitans Serotype c Strain D11S-1

2009 ◽  
Vol 191 (23) ◽  
pp. 7378-7379 ◽  
Author(s):  
Casey Chen ◽  
Weerayuth Kittichotirat ◽  
Yan Si ◽  
Roger Bumgarner
Keyword(s):  
Genome Sequence ◽  
Complete Genome Sequence ◽  
Complete Genome ◽  
Aggregatibacter Actinomycetemcomitans ◽  
Aggressive Periodontitis ◽  
Etiological Agent ◽  
Subgingival Plaque

ABSTRACT Aggregatibacter actinomycetemcomitans is a major etiological agent of periodontitis. Here we report the complete genome sequence of serotype c strain D11S-1, which was recovered from the subgingival plaque of a patient diagnosed with generalized aggressive periodontitis.

scholarly journals Aggregatibacter actinomycetemcomitans Leukotoxin Is Delivered to Host Cells in an LFA-1-Indepdendent Manner When Associated with Outer Membrane Vesicles

Toxins ◽  
2018 ◽  
Vol 10 (10) ◽  
pp. 414 ◽  
Author(s):  
Justin Nice ◽  
Nataliya Balashova ◽  
Scott Kachlany ◽  
Evan Koufos ◽  
Eric Krueger ◽  
...  
Keyword(s):  
Outer Membrane ◽  
Membrane Vesicles ◽  
Aggregatibacter Actinomycetemcomitans ◽  
Aggressive Periodontitis ◽  
Outer Membrane Vesicles ◽  
Host Cells ◽  
Type I ◽  
Outer Membranes ◽  
Independent Mechanism ◽  
Bacterial Outer Membrane

The Gram-negative bacterium, Aggregatibacter actinomycetemcomitans, has been associated with localized aggressive periodontitis (LAP). In particular, highly leukotoxic strains of A. actinomycetemcomitans have been more closely associated with this disease, suggesting that LtxA is a key virulence factor for A. actinomycetemcomitans. LtxA is secreted across both the inner and outer membranes via the Type I secretion system, but has also been found to be enriched within outer membrane vesicles (OMVs), derived from the bacterial outer membrane. We have characterized the association of LtxA with OMVs produced by the highly leukotoxic strain, JP2, and investigated the interaction of these OMVs with host cells to understand how LtxA is delivered to host cells in this OMV-associated form. Our results demonstrated that a significant fraction of the secreted LtxA exists in an OMV-associated form. Furthermore, we have discovered that in this OMV-associated form, the toxin is trafficked to host cells by a cholesterol- and receptor-independent mechanism in contrast to the mechanism by which free LtxA is delivered. Because OMV-associated toxin is trafficked to host cells in an entirely different manner than free toxin, this study highlights the importance of studying both free and OMV-associated forms of LtxA to understand A. actinomycetemcomitans virulence.

scholarly journals Aggregatibacter actinomycetemcomitans: The virulence factors and relation to persistence biofilm formation

Biomedicine ◽  
2021 ◽  
Vol 40 (4) ◽  
pp. 429-435
Author(s):  
Syakir Syahiran ◽  
Wan Rohani Wan Taib ◽  
Norzawani Jaffar
Keyword(s):  
Oral Cavity ◽  
Virulence Factors ◽  
Tooth Loss ◽  
Periodontal Diseases ◽  
Aggregatibacter Actinomycetemcomitans ◽  
Aggressive Periodontitis ◽  
Essential Factor ◽  
Abiotic Surfaces ◽  
Functional Biology ◽  
Systemic Infections

Periodontitis is an infectious and inflammatory condition that is associated with subgingival biofilms in tooth-supporting tissues. Among the several hundred isolated organisms in the oral cavity, one of the most isolated bacteria from infected periodontal pockets are Aggregatibacter actinomycetemcomitans. It is a Gram-negative, facultative anaerobic bacillus that causes juvenile (localized aggressive periodontitis) and adolescent periodontal diseases. The development of biofilms is an essential factor in pathogenesis for A. actinomycetemcomitans. The early attachment of A. actinomycetemcomitans to abiotic surfaces relies on its protein-like fimbriae. This organism's ability to form tenacious biofilms can determine its survival and progression. A. actinomycetemcomitans, a pathogen not solely in periodontal but also involve in some systemic infections. This species has several virulence factors and genes that contribute to its oral cavity survival and, worst of all, cause bone resorption and tooth loss. Genetic diversity between the different A. actinomycetemcomitans isolates are great, and their ability to express and release virulence factors varies. In this review article, we discuss about the potential virulence factors and candidates genes for A. actinomycetemcomitans and their roles within periodontal disease by revealing their functional biology in facilitating attachment to oral surfaces, hindering protection of the host and causing inflammation and degradation of tissue.

scholarly journals Aggregatibacter actinomycetemcomitans colonization and persistence in a primate model

2019 ◽  
Vol 116 (44) ◽  
pp. 22307-22313 ◽  
Author(s):  
Senthil Kumar Velusamy ◽  
Vandana Sampathkumar ◽  
Narayanan Ramasubbu ◽  
Bruce J. Paster ◽  
Daniel H. Fine
Keyword(s):  
Aggregatibacter Actinomycetemcomitans ◽  
Aggressive Periodontitis ◽  
Microbial Interactions ◽  
Primate Model ◽  
Monkey Model ◽  
Oral Environment ◽  
Indigenous Microbiota ◽  
Weighted Network Analysis

Aggregatibacter actinomycetemcomitans is associated with aggressive periodontitis resulting in premature tooth loss in adolescents. Tooth adherence and biofilm persistence are prerequisites for survival in the oral domain. Here, using a rhesus monkey model, 16S rRNA sequencing, and weighted network analysis, we assessed colonization of A. actinomycetemcomitans variants and ascertained microbial interactions in biofilm communities. Variants in A. actinomycetemcomitans leukotoxin (ltx) were created, labeled, inoculated, and compared with their progenitor strain for in vivo colonization. Samples of tooth-related plaque were assessed for colonization at baseline and after debridement and inoculation of labeled strains. Null, minimal, and hyper-Ltx–producing strains were created and assessed for hydroxyapatite binding and biofilm formation in vitro. Ltx-hyperproducing strains colonized with greater prevalence and at higher levels than wild type or ltx mutants (P = 0.05). Indigenous and inoculated A. actinomycetemcomitans strains that attached were associated with lactate-producing species (i.e., Leptotrichia, Abiotrophia, and Streptoccocci). A. actinomycetemcomitans was found at 0.13% of the total flora at baseline and at 0.05% 4 wk after inoculation. In vivo data were supported by in vitro results. We conclude that hyper-Ltx production affords these strains with an attachment advantage providing a foothold for competition with members of the indigenous microbiota. Increased attachment can be linked to ltx gene expression and up-regulation of adherence-associated genes. Growth of attached A. actinomycetemcomitans in vivo was enhanced by lactate availability due to consorting species. These associations provide A. actinomycetemcomitans with the constituents required for its colonization and survival in the complex and competitive oral environment.

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