Contribution of Adhesion Proteins to Aggregatibacter actinomycetemcomitans Biofilm Formation

2021 ◽  
Author(s):  
David R. Danforth ◽  
Marcella Melloni ◽  
Jake Tristano ◽  
Keith P. Mintz
Keyword(s):  
Biofilm Formation ◽  
Aggregatibacter Actinomycetemcomitans ◽  
Adhesion Proteins

scholarly journals AI-2 of Aggregatibacter actinomycetemcomitans inhibits Candida albicans biofilm formation

2014 ◽  
Vol 4 ◽  
Author(s):  
Endang W. Bachtiar ◽  
Boy M. Bachtiar ◽  
Lucja M. Jarosz ◽  
Lisa R. Amir ◽  
Hari Sunarto ◽  
...  
Keyword(s):  
Candida Albicans ◽  
Biofilm Formation ◽  
Aggregatibacter Actinomycetemcomitans

Author response for "Lactobacilli Postbiotics reduce biofilm formation and alter transcription of virulence genes of Aggregatibacter actinomycetemcomitans"

2020 ◽  
Author(s):  
Karin Hitomi Ishikawa ◽  
Manuela Rocha Bueno ◽  
Dione Kawamoto ◽  
Maria Regina Lorenzetti Simionato ◽  
Marcia Pinto Alves Mayer
Keyword(s):  
Biofilm Formation ◽  
Virulence Genes ◽  
Aggregatibacter Actinomycetemcomitans ◽  
Author Response

scholarly journals Transcriptional and Translational Analysis of Biofilm Determinants of Aggregatibacter actinomycetemcomitans in Response to Environmental Perturbation

2009 ◽  
Vol 77 (7) ◽  
pp. 2896-2907 ◽  
Author(s):  
Jayaleka J. Amarasinghe ◽  
Frank A. Scannapieco ◽  
Elaine M. Haase
Keyword(s):  
Biofilm Formation ◽  
Aggregatibacter Actinomycetemcomitans ◽  
Iron Limitation ◽  
Anaerobic Conditions ◽  
Aerobic Conditions ◽  
Environmental Perturbation ◽  
Full Strength ◽  
Half Strength ◽  
Strength Medium ◽  
Cells Cultured

ABSTRACT Fimbriae, lipopolysaccharide (LPS), and extracellular polymeric substance (EPS) all contribute to biofilm formation by the periodontopathogen Aggregatibacter actinomycetemcomitans. To understand how individual biofilm determinants respond to changing environmental conditions, the transcription of genes responsible for fimbria, LPS, and EPS production, as well as the translation of these components, was determined in rough (Rv) and isogenic smooth (Sv) variants of A. actinomycetemcomitans cultured in half-strength and full-strength culture medium under anaerobic or aerobic conditions, and in iron-supplemented and iron-chelated medium. The transcription of tadV (fimbrial assembly), pgaC (extracellular polysaccharide synthesis), and orf8 or rmlB (lipopolysaccharide synthesis) was measured by real-time PCR. The amounts of fimbriae, LPS, and EPS were also estimated from stained sodium dodecyl sulfate-polyacrylamide gels and verified by Western blotting and enzyme-linked immunoadsorbent assay using specific antibodies. Each gene was significantly upregulated in the Rv compared to in the Sv. The transcription of fimbrial, LPS, and EPS genes in the Rv was increased approximately twofold in cells cultured in full-strength medium under anaerobic conditions compared to that in cells cultured under aerobic conditions. Under anaerobic conditions, the transcription of fimbrial and EPS enzymes was elevated in both Rv and Sv cells cultured in half-strength medium, compared to that in full-strength medium. Iron chelation also increased the transcription and translation of all biofilm determinants compared to their expression with iron supplementation, yet the quantity of biofilm was not significantly changed by any environmental perturbation except iron limitation. Thus, anaerobic conditions, nutrient stress, and iron limitation each upregulate known biofilm determinants of A. actinomycetemcomitans to contribute to biofilm formation.

scholarly journals LL-37 Opsonizes and Inhibits Biofilm Formation of Aggregatibacter actinomycetemcomitans at Subbactericidal Concentrations

2013 ◽  
Vol 81 (10) ◽  
pp. 3577-3585 ◽  
Author(s):  
Asaf Sol ◽  
Ofir Ginesin ◽  
Stella Chaushu ◽  
Laila Karra ◽  
Shunit Coppenhagen-Glazer ◽  
...  
Keyword(s):  
Host Defense ◽  
Biofilm Formation ◽  
Aggregatibacter Actinomycetemcomitans ◽  
Bactericidal Effect ◽  
Raw 264.7 Cells ◽  
Gingival Tissue ◽  
Host Defense Peptides ◽  
Content Type ◽  
Major Mechanism ◽  
Defense Peptides

ABSTRACTHost defense peptides are immediate responders of the innate immunity that express antimicrobial, immunoregulatory, and wound-healing activities. Neutrophils are a major source for oral host defense peptides, and phagocytosis by neutrophils is a major mechanism for bacterial clearance in the gingival tissue. Dysfunction of or reduction in the numbers of neutrophils or deficiency in the LL-37 host defense peptide was each previously linked with proliferation of oralAggregatibacter actinomycetemcomitanswhich resulted in an aggressive periodontal disease. Surprisingly,A. actinomycetemcomitansshows resistance to high concentrations of LL-37. In this study, we demonstrated that submicrocidal concentrations of LL-37 inhibit biofilm formation byA. actinomycetemcomitansand act as opsonins and agglutinins that greatly enhance its clearance by neutrophils and macrophages. Improved uptake ofA. actinomycetemcomitansby neutrophils was mediated by their opsonization with LL-37. Enhanced phagocytosis and killing ofA. actinomycetemcomitansby murine macrophage-like RAW 264.7 cells were dependent on their preagglutination by LL-37. AlthoughA. actinomycetemcomitansis resistant to the bactericidal effect of LL-37, our results offer a rationale for the epidemiological association between LL-37 deficiency and the expansion of oralA. actinomycetemcomitansand indicate a possible therapeutic use of cationic peptides for host defense.

scholarly journals Influence of Aae Autotransporter Protein on Adhesion and Biofilm Formation by Aggregatibacter actinomycetemcomitans

2016 ◽  
Vol 27 (3) ◽  
pp. 255-260 ◽  
Author(s):  
Ana Carla Robatto Nunes ◽  
Priscila Larcher Longo ◽  
Marcia Pinto Alves Mayer
Keyword(s):  
Epithelial Cells ◽  
Bacterial Adhesion ◽  
Parental Strain ◽  
Biofilm Formation ◽  
Aggregatibacter Actinomycetemcomitans ◽  
Salivary Proteins ◽  
Null Mutant ◽  
Hydrophobic Properties ◽  
Multiple Functions

Abstract The periodontopathogen Aggregatibacter actinomycetemcomitans colonizes oral cavity by binding to and invading epithelial cells as well as by participating in biofilms formed on hard surfaces. Aae, an autotransporter protein, is implicated in bacterial adhesion to epithelial cells. Due to the multiple functions of bacterial autotransporter proteins, this study aimed to evaluate the role of aae in A. actinomycetemcomitans ability to adhere to both saliva-coated hydroxyapatite (SHA) and biofilm. An aae null mutant was constructed. Its hydrophobic properties as well as its ability to adhere to epithelial cells, SHA and to form biofilm were evaluated and compared with the parental strain, A. actinomycetemcomitans VT1169. The aae null mutant showed reduced hydrophobicity, as well as decreased binding to SHA and biofilm formation compared to the parental strain. These data suggest that aae mediates A. actinomycetemcomitans adhesion to epithelial cells and may be involved in biofilm formation and interaction with adsorbed salivary proteins.

Lactobacilli Postbiotics reduce biofilm formation and alter transcription of virulence genes of Aggregatibacter actinomycetemcomitans

2020 ◽  
Author(s):  
Karin Hitomi Ishikawa ◽  
Manuela Rocha Bueno ◽  
Dione Kawamoto ◽  
Maria Regina Lorenzetti Simionato ◽  
Marcia Pinto Alves Mayer
Keyword(s):  
Biofilm Formation ◽  
Virulence Genes ◽  
Aggregatibacter Actinomycetemcomitans

scholarly journals Transcriptional Regulation of the tad Locus in Aggregatibacter actinomycetemcomitans: a Termination Cascade

2008 ◽  
Vol 190 (11) ◽  
pp. 3859-3868 ◽  
Author(s):  
Karin E. Kram ◽  
Galadriel A. Hovel-Miner ◽  
Mladen Tomich ◽  
David H. Figurski
Keyword(s):  
Bacterial Adhesion ◽  
Biofilm Formation ◽  
Aggregatibacter Actinomycetemcomitans ◽  
Northern Hybridization ◽  
Reporter Plasmid ◽  
Complete Understanding ◽  
Transcriptional Termination ◽  
Pilus Biogenesis ◽  
Pilin Gene ◽  
And Behavior

ABSTRACT The tad (tight adherence) locus of Aggregatibacter actinomycetemcomitans includes genes for the biogenesis of Flp pili, which are necessary for bacterial adhesion to surfaces, biofilm formation, and pathogenesis. Although studies have elucidated the functions of some of the Tad proteins, little is known about the regulation of the tad locus in A. actinomycetemcomitans. A promoter upstream of the tad locus was previously identified and shown to function in Escherichia coli. Using a specially constructed reporter plasmid, we show here that this promoter (tadp) functions in A. actinomycetemcomitans. To study expression of the pilin gene (flp-1) relative to that of tad secretion complex genes, we used Northern hybridization analysis and a lacZ reporter assay. We identified three terminators, two of which (T1 and T2) can explain flp-1 mRNA abundance, while the third (T3) is at the end of the locus. T1 and T3 have the appearance and behavior of intrinsic terminators, while T2 has a different structure and is inhibited by bicyclomycin, indicating that T2 is probably Rho dependent. To help achieve the appropriate stoichiometry of the Tad proteins, we show that a transcriptional-termination cascade is important to the proper expression of the tad genes. These data indicate a previously unreported mechanism of regulation in A. actinomycetemcomitans and lead to a more complete understanding of its Flp pilus biogenesis.

Sign in / Sign up

Export Citation Format

Share Document