scholarly journals Filifactor alocis Has Virulence Attributes That Can Enhance Its Persistence under Oxidative Stress Conditions and Mediate Invasion of Epithelial Cells by Porphyromonas gingivalis

2011 ◽  
Vol 79 (10) ◽  
pp. 3872-3886 ◽  
Author(s):  
A. Wilson Aruni ◽  
Francis Roy ◽  
H. M. Fletcher
Keyword(s):  
Oxidative Stress ◽  
Epithelial Cells ◽  
Porphyromonas Gingivalis ◽  
Virulence Factors ◽  
Clinical Isolates ◽  
Periodontal Pocket ◽  
Periodontal Pathogens ◽  
Content Type ◽  
Invasive Capacity ◽  
Filifactor Alocis

ABSTRACTFilifactor alocis, a Gram-positive anaerobic rod, is one of the most abundant bacteria identified in the periodontal pockets of periodontitis patients. There is a gap in our understanding of its pathogenicity and ability to interact with other periodontal pathogens. To evaluate the virulence potential ofF. alocisand its ability to interact withPorphyromonas gingivalisW83, several clinical isolates ofF. alociswere characterized.F. alocisshowed nongingipain protease and sialidase activities.In silicoanalysis revealed the molecular relatedness of several virulence factors fromF. alocisandP. gingivalis. In contrast toP. gingivalis,F. alociswas relatively resistant to oxidative stress and its growth was stimulated under those conditions. Biofilm formation was significantly increased in coculture. There was an increase in adherence and invasion of epithelial cells in coculture compared withP. gingivalisorF. alocismonocultures. In those epithelial cells, endocytic vesicle-mediated internalization was observed only during coculture. TheF. alocisclinical isolate had an increased invasive capacity in coculture withP. gingivaliscompared to the ATCC 35896 strain. In addition, there was variation in the proteomes of the clinical isolates compared to the ATCC 35896 strain. Hypothetical proteins and those known to be important virulence factors in other bacteria were identified. These results indicate thatF. alocishas virulence properties that may enhance its ability to survive and persist in the periodontal pocket and may play an important role in infection-induced periodontal disease.

scholarly journals Proteome Analysis of Coinfection of Epithelial Cells with Filifactor alocis and Porphyromonas gingivalis Shows Modulation of Pathogen and Host Regulatory Pathways

2014 ◽  
Vol 82 (8) ◽  
pp. 3261-3274 ◽  
Author(s):  
A. Wilson Aruni ◽  
Kangling Zhang ◽  
Yuetan Dou ◽  
Hansel Fletcher
Keyword(s):  
Epithelial Cells ◽  
Porphyromonas Gingivalis ◽  
Epigenetic Modification ◽  
Polymicrobial Infection ◽  
Host Cells ◽  
Periodontal Pocket ◽  
Membrane Microdomains ◽  
Content Type ◽  
Regulatory Pathways ◽  
Filifactor Alocis

ABSTRACTChanges in periodontal status are associated with shifts in the composition of the bacterial community in the periodontal pocket. The relative abundances of several newly recognized microbial species, includingFilifactor alocis, as-yet-unculturable organisms, and other fastidious organisms have raised questions on their impact on disease development. We have previously reported that the virulence attributes ofF. alocisare enhanced in coculture withPorphyromonas gingivalis. We have evaluated the proteome of host cells andF. alocisduring a polymicrobial infection. Coinfection of epithelial cells withF. alocisandP. gingivalisstrains showed approximately 20% to 30% more proteins than a monoinfection. UnlikeF. alocisATCC 35896, the D-62D strain expressed more proteins during coculture withP. gingivalisW83 than withP. gingivalis33277. Proteins designated microbial surface component-recognizing adhesion matrix molecules (MSCRAMMs) and cell wall anchor proteins were highly upregulated during the polymicrobial infection. Ultrastructural analysis of the epithelial cells showed formation of membrane microdomains only during coinfection. The proteome profile of epithelial cells showed proteins related to cytoskeletal organization and gene expression and epigenetic modification to be in high abundance. Modulation of proteins involved in apoptotic and cell signaling pathways was noted during coinfection. The enhanced virulence potential ofF. alocismay be related to the differential expression levels of several putative virulence factors and their effects on specific host cell pathways.

scholarly journals 8-Oxo-7,8-Dihydroguanine Is Removed by a Nucleotide Excision Repair-Like Mechanism in Porphyromonas gingivalis W83

2004 ◽  
Vol 186 (22) ◽  
pp. 7697-7703 ◽  
Author(s):  
N. A. Johnson ◽  
R. McKenzie ◽  
L. McLean ◽  
L. C. Sowers ◽  
H. M. Fletcher
Keyword(s):  
Oxidative Stress ◽  
Nucleotide Excision Repair ◽  
Porphyromonas Gingivalis ◽  
Excision Repair ◽  
Periodontal Pocket ◽  
Periodontal Pathogens ◽  
Chromosomal Dna ◽  
Inflammatory Microenvironment ◽  
Cell Extracts ◽  
Nucleotide Excision

ABSTRACT A consequence of oxidative stress is DNA damage. The survival of Porphyromonas gingivalis in the inflammatory microenvironment of the periodontal pocket requires an ability to overcome oxidative stress caused by reactive oxygen species (ROS). 8-Oxo-7,8-dihydroguanine (8-oxoG) is typical of oxidative damage induced by ROS. There is no information on the presence of 8-oxoG in P. gingivalis under oxidative stress conditions or on a putative mechanism for its repair. High-pressure liquid chromatography with electrochemical detection analysis of chromosomal DNA revealed higher levels of 8-oxoG in P. gingivalis FLL92, a nonpigmented isogenic mutant, than in the wild-type strain. 8-OxoG repair activity was also increased in cell extracts from P. gingivalis FLL92 compared to those from the parent strain. Enzymatic removal of 8-oxoG was catalyzed by a nucleotide excision repair (NER)-like mechanism rather than the base excision repair (BER) observed in Escherichia coli. In addition, in comparison with other anaerobic periodontal pathogens, the removal of 8-oxoG was unique to P. gingivalis. Taken together, the increased 8-oxoG levels in P. gingivalis FLL92 could further support a role for the hemin layer as a unique mechanism in oxidative stress resistance in this organism. In addition, this is the first observation of an NER-like mechanism as the major mechanism for removal of 8-oxoG in P. gingivalis.

scholarly journals In Situ Anabolic Activity of Periodontal Pathogens Porphyromonas gingivalis and Filifactor alocis in Chronic Periodontitis

2016 ◽  
Vol 6 (1) ◽  
Author(s):  
Ralee Spooner ◽  
Kris M. Weigel ◽  
Peter L. Harrison ◽  
KyuLim Lee ◽  
Gerard A. Cangelosi ◽  
...  
Keyword(s):  
Porphyromonas Gingivalis ◽  
Chronic Periodontitis ◽  
Periodontal Pathogens ◽  
Anabolic Activity ◽  
Filifactor Alocis

scholarly journals Staphylococcus epidermidis MSCRAMM SesJ Is Encoded in Composite Islands

mBio ◽  
2020 ◽  
Vol 11 (1) ◽  
Author(s):  
Srishtee Arora ◽  
Xiqi Li ◽  
Andrew Hillhouse ◽  
Kranti Konganti ◽  
Sara V. Little ◽  
...  
Keyword(s):  
Cell Wall ◽  
Antibiotic Resistance ◽  
Virulence Factors ◽  
Staphylococcus Epidermidis ◽  
Core Genome ◽  
Clinical Isolates ◽  
Modification System ◽  
Content Type ◽  
Genes Encoding ◽  
Staphylococcal Cassette Chromosome

ABSTRACT Staphylococcus epidermidis is a leading cause of nosocomial infections in patients with a compromised immune system and/or an implanted medical device. Seventy to 90% of S. epidermidis clinical isolates are methicillin resistant and carry the mecA gene, present in a mobile genetic element (MGE) called the staphylococcal cassette chromosome mec (SCCmec) element. Along with the presence of antibiotic and heavy metal resistance genes, MGEs can also contain genes encoding secreted or cell wall-anchored virulence factors. In our earlier studies of S. epidermidis clinical isolates, we discovered S. epidermidis surface protein J (SesJ), a prototype of a recently discovered subfamily of the microbial surface component recognizing adhesive matrix molecule (MSCRAMM) group. MSCRAMMs are major virulence factors of pathogenic Gram-positive bacteria. Here, we report that the sesJ gene is always accompanied by two glycosyltransferase genes, gtfA and gtfB, and is present in two MGEs, called the arginine catabolic mobile element (ACME) and the staphylococcal cassette chromosome (SCC) element. The presence of the sesJ gene was associated with the left-hand direct repeat DR_B or DR_E. When inserted via DR_E, the sesJ gene was encoded in the SCC element. When inserted via DR_B, the sesJ gene was accompanied by the genes for the type 1 restriction modification system and was encoded in the ACME. Additionally, the SCC element and ACME carry different isoforms of the SesJ protein. To date, the genes encoding MSCRAMMs have been seen to be located in the bacterial core genome. Here, we report the presence of an MSCRAMM in an MGE in S. epidermidis clinical isolates. IMPORTANCE S. epidermidis is an opportunistic bacterium that has established itself as a successful nosocomial pathogen. The modern era of novel therapeutics and medical devices has extended the longevity of human life, but at the same time, we also witness the evolution of pathogens to adapt to newly available niches in the host. Increasing antibiotic resistance among pathogens provides an example of such pathogen adaptation. With limited opportunities to modify the core genome, most of the adaptation occurs by acquiring new genes, such as virulence factors and antibiotic resistance determinants present in MGEs. In this study, we describe that the sesJ gene, encoding a recently discovered cell wall-anchored protein in S. epidermidis, is present in both ACME and the SCC element. The presence of virulence factors in MGEs can influence the virulence potential of a specific strain. Therefore, it is critical to study the virulence factors found in MGEs in emerging pathogenic bacteria or strains to understand the mechanisms used by these bacteria to cause infections.

scholarly journals MicroRNAs Regulate Cytokine Responses in Gingival Epithelial Cells

2016 ◽  
Vol 84 (12) ◽  
pp. 3282-3289 ◽  
Author(s):  
Steven C. Y. Chen ◽  
Christos Constantinides ◽  
Moritz Kebschull ◽  
Panos N. Papapanou
Keyword(s):  
Epithelial Cells ◽  
Enzyme Linked Immunosorbent Assay ◽  
Periodontal Pathogens ◽  
Loss Of Function ◽  
Microbial Infection ◽  
Western Blot Assay ◽  
Content Type ◽  
Protein Levels ◽  
Gingival Epithelial Cells ◽  
Protease Deficient

MicroRNAs (miRNAs) have been established as key regulators of various biological processes with possible involvement in the pathobiology of periodontal disease. Expanding our earlier observations of substantial differential expression of specific miRNAs between clinically healthy and periodontitis-affected gingival tissues, we used miRNA inhibitors (sponges) in loss-of-function experiments to investigate the involvement of specific miRNAs in the response of pocket epithelium-derived, telomerase-immortalized human gingival keratinocytes (TIGKs) to microbial infection. We constructed stable knockdown (KD) cell lines for five epithelium-expressed miRNAs (miR-126, miR-141, miR-155, miR-210, and miR-1246) and assessed their response to infection with periodontal pathogens using microarray analysis, quantitative PCR (qPCR), enzyme-linked immunosorbent assay (ELISA), and Western blot assay. miR-126 KD cells showed lower expression of interleukin 8 (IL-8) and CXCL1, both on the mRNA and protein levels, than did controls upon stimulation by heat-killed wild-typePorphyromonas gingivalis, liveP. gingivalisprotease-deficient mutant KDP128, and liveAggregatibacter actinomycetemcomitans. In contrast, infection of miR-155 KD and miR-210 KD cells with the same organisms resulted in higher IL-8 and CXCL1 mRNA and protein expression. These effects appeared to be regulated by NF-κB, as suggested by altered transcription and/or phosphorylation status of components of the NF-κB system. Reduced neutrophil-like HL-60 cell chemotactic activity was observed in response to infection of miR-126 KD cells, indicating that miR-126 plays an important role in immune responses. Our findings indicate that specific miRNAs regulate the expression of inflammatory cytokines in human gingival epithelial cells in response to microbial infection.

scholarly journals Efficacy and Safety of Liposomal Clarithromycin and Its Effect on Pseudomonas aeruginosa Virulence Factors

2013 ◽  
Vol 57 (6) ◽  
pp. 2694-2704 ◽  
Author(s):  
Mai Alhajlan ◽  
Moayad Alhariri ◽  
Abdelwahab Omri
Keyword(s):  
Cystic Fibrosis ◽  
Pseudomonas Aeruginosa ◽  
Virulence Factors ◽  
Biological Fluid ◽  
Free Drug ◽  
Clinical Isolates ◽  
Epithelial Cell Line ◽  
Efficacy And Safety ◽  
Surface Charges ◽  
Content Type

ABSTRACTWe investigated the efficacy and safety of liposomal clarithromycin formulations with different surface charges against clinical isolates ofPseudomonas aeruginosafrom the lungs of cystic fibrosis (CF) patients. The liposomal clarithromycin formulations were prepared by the dehydration-rehydration method, and their sizes were measured using the dynamic-light-scattering technique. Encapsulation efficiency was determined by microbiological assay, and the stabilities of the formulations in biological fluid were evaluated for a period of 48 h. The MICs and minimum bactericidal concentrations (MBCs) of free and liposomal formulations were determined withP. aeruginosastrains isolated from CF patients. Liposomal clarithromycin activity against biofilm-formingP. aeruginosawas compared to that of free antibiotic using the Calgary Biofilm Device (CBD). The effects of subinhibitory concentrations of free and liposomal clarithromycin on bacterial virulence factors and motility on agar were investigated on clinical isolates ofP. aeruginosa. The cytotoxicities of the liposome preparations and free drug were evaluated on a pulmonary epithelial cell line (A549). The average diameter of the formulations was >222 nm, with encapsulation efficiencies ranging from 5.7% to 30.4%. The liposomes retained more than 70% of their drug content during the 48-h time period. The highly resistant strains ofP. aeruginosabecame susceptible to liposome-encapsulated clarithromycin (MIC, 256 mg/liter versus 8 mg/liter;P< 0.001). Liposomal clarithromycin reduced the bacterial growth within the biofilm by 3 to 4 log units (P< 0.001), significantly attenuated virulence factor production, and reduced bacterial twitching, swarming, and swimming motilities. The clarithromycin-entrapped liposomes were less cytotoxic than the free drug (P< 0.001). These data indicate that our novel formulations could be a useful strategy to enhance the efficacy of clarithromycin against resistantP. aeruginosastrains that commonly affect individuals with cystic fibrosis.

scholarly journals Interleukin-8 and Intercellular Adhesion Molecule 1 Regulation in Oral Epithelial Cells by Selected Periodontal Bacteria: Multiple Effects of Porphyromonas gingivalis via Antagonistic Mechanisms

2001 ◽  
Vol 69 (3) ◽  
pp. 1364-1372 ◽  
Author(s):  
George T.-J. Huang ◽  
Daniel Kim ◽  
Jonathan K.-H. Lee ◽  
Howard K. Kuramitsu ◽  
Susan Kinder Haake
Keyword(s):  
Epithelial Cells ◽  
Porphyromonas Gingivalis ◽  
Adhesion Molecule ◽  
Intercellular Adhesion ◽  
Interleukin 8 ◽  
Intercellular Adhesion Molecule ◽  
Mrna Levels ◽  
Periodontal Pathogens ◽  
Intercellular Adhesion Molecule 1 ◽  
Gingival Epithelial Cells

ABSTRACT Interaction of bacteria with mucosal surfaces can modulate the production of proinflammatory cytokines and adhesion molecules produced by epithelial cells. Previously, we showed that expression of interleukin-8 (IL-8) and intercellular adhesion molecule 1 (ICAM-1) by gingival epithelial cells increases following interaction with several putative periodontal pathogens. In contrast, expression of IL-8 and ICAM-1 is reduced after Porphyromonas gingivalis ATCC 33277 challenge. In the present study, we investigated the mechanisms that govern the regulation of these two molecules in bacterially infected gingival epithelial cells. Experimental approaches included bacterial stimulation of gingival epithelial cells by either a brief challenge (1.5 to 2 h) or a continuous coculture throughout the incubation period. The kinetics of IL-8 and ICAM-1 expression following brief challenge were such that (i) secretion of IL-8 by gingival epithelial cells reached its peak 2 h following Fusobacterium nucleatum infection whereas it rapidly decreased within 2 h after P. gingivalis infection and remained decreased up to 30 h and (ii) IL-8 and ICAM-1 mRNA levels were up-regulated rapidly 2 to 4 h postinfection and then decreased to basal levels 8 to 20 h after infection with either Actinobacillus actinomycetemcomitans, F. nucleatum, or P. gingivalis. Attenuation of IL-8 secretion was facilitated by adherent P. gingivalis strains. The IL-8 secreted from epithelial cells after F. nucleatum stimulation could be down-regulated by subsequent infection with P. gingivalisor its culture supernatant. Although these results suggested that IL-8 attenuation at the protein level might be associated with P. gingivalis proteases, the Arg- and Lys-gingipain proteases did not appear to be solely responsible for IL-8 attenuation. In addition, while P. gingivalis up-regulated IL-8 mRNA expression, this effect was overridden when the bacteria were continuously cocultured with the epithelial cells. The IL-8 mRNA levels in epithelial cells following sequential challenge with P. gingivalis andF. nucleatum and vice versa were approximately identical and were lower than those following F. nucleatum challenge alone and higher than control levels or those following P. gingivalis challenge alone. Thus, together with the protease effect, P. gingivalis possesses a powerful strategy to ensure the down-regulation of IL-8 and ICAM-1.

scholarly journals Role of the Filifactor alocis Hypothetical Protein FA519 in Oxidative Stress Resistance

2021 ◽  
Author(s):  
Ezinne Aja ◽  
Arunima Mishra ◽  
Yuetan Dou ◽  
Hansel M. Fletcher
Keyword(s):  
Oxidative Stress ◽  
Periodontal Disease ◽  
Stress Resistance ◽  
Hypothetical Protein ◽  
Content Type ◽  
Genetic Tools ◽  
Oxidative Stress Resistance ◽  
Filifactor Alocis ◽  
Diagnostic Indicator

Filifactor alocis is an emerging member of the periodontal community and is now proposed to be a diagnostic indicator of periodontal disease. However, due to the lack of genetic tools available to study this organism, not much is known about its virulence attributes.

scholarly journals Virulence of the Pathogen Porphyromonas gingivalis Is Controlled by the CRISPR-Cas Protein Cas3

mSystems ◽  
2020 ◽  
Vol 5 (5) ◽  
Author(s):  
Jose Solbiati ◽  
Ana Duran-Pinedo ◽  
Fernanda Godoy Rocha ◽  
Frank C. Gibson ◽  
Jorge Frias-Lopez
Keyword(s):  
Chronic Inflammation ◽  
Porphyromonas Gingivalis ◽  
Clinical Findings ◽  
Bacterial Virulence ◽  
Oral Microbiome ◽  
Periodontal Pathogens ◽  
Content Type ◽  
Virulence Potential ◽  
Associated Proteins ◽  
Polymicrobial Disease

Porphyromonas gingivalis is a key pathogen of periodontitis, a polymicrobial disease characterized by a chronic inflammation that destroys the tissues supporting the teeth. Thus, understanding the virulence potential of P. gingivalis is essential to maintaining a healthy oral microbiome. In nonoral organisms, CRISPR-Cas systems have been shown to modulate a variety of microbial processes, including protection from exogenous nucleic acids, and, more recently, have been implicated in bacterial virulence. Previously, our clinical findings identified activation of the CRISPR-Cas system in patient samples at the transition to disease; however, the mechanism of contribution to disease remained unknown. The importance of the present study resides in that it is becoming increasingly clear that CRISPR-associated proteins have broader functions than initially thought and that those functions now include their role in the virulence of periodontal pathogens. Studying a P. gingivalis cas3 mutant, we demonstrate that at least one of the CRISPR-Cas systems is involved in the regulation of virulence during infection.

scholarly journals Periodontal Pathogens Invade Gingiva and Aortic Adventitia and Elicit Inflammasome Activation in αvβ6 Integrin-Deficient Mice

2015 ◽  
Vol 83 (12) ◽  
pp. 4582-4593 ◽  
Author(s):  
Irina M. Velsko ◽  
Sasanka S. Chukkapalli ◽  
Mercedes F. Rivera-Kweh ◽  
Donghang Zheng ◽  
Ikramuddin Aukhil ◽  
...  
Keyword(s):  
Atherosclerotic Plaque ◽  
Inflammatory Responses ◽  
Periodontal Diseases ◽  
Periodontal Pocket ◽  
Bacterial Invasion ◽  
Inflammasome Activation ◽  
Periodontal Pathogens ◽  
Content Type ◽  
Amyloid A ◽  
Significant Difference

The American Heart Association supports an association between periodontal diseases and atherosclerosis but not a causal association. This study explores the use of the integrin β6−/−mouse model to study the causality. We investigated the ability of a polymicrobial consortium ofPorphyromonas gingivalis,Treponema denticola,Tannerella forsythia, andFusobacterium nucleatumto colonize the periodontium and induce local and systemic inflammatory responses. Polymicrobially infectedItgβ6−/−mice demonstrate greater susceptibility to gingival colonization/infection, with severe gingival inflammation, apical migration of the junctional epithelium, periodontal pocket formation, alveolar bone resorption, osteoclast activation, bacterial invasion of the gingiva, a greater propensity for the bacteria to disseminate hematogenously, and a strong splenic T cell cytokine response. Levels of atherosclerosis risk factors, including serum nitric oxide, oxidized low-density lipoprotein, serum amyloid A, and lipid peroxidation, were significantly altered by polybacterial infection, demonstrating an enhanced potential for atherosclerotic plaque progression. Aortic gene expression revealed significant alterations in specific Toll-like receptor (TLR) and nucleotide-binding domain- and leucine-rich-repeat-containing receptor (NLR) pathway genes in response to periodontal bacterial infection. Histomorphometry of the aorta demonstrated larger atherosclerotic plaques inItgβ6−/−mice than in wild-type (WT) mice but no significant difference in atherosclerotic plaque size between mice with polybacterial infection and mice with sham infection. Fluorescencein situhybridization demonstrated active invasion of the aortic adventitial layer byP. gingivalis. Our observations suggest that polybacterial infection elicits distinct aortic TLR and inflammasome signaling and significantly increases local aortic oxidative stress. These results are the first to demonstrate the mechanism of the host aortic inflammatory response induced by polymicrobial infection with well-characterized periodontal pathogens.

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