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 High-Resolution Taxonomic Profiling of the Subgingival Microbiome for Biomarker Discovery and Periodontitis Diagnosis

2014 ◽  
Vol 81 (3) ◽  
pp. 1047-1058 ◽  
Author(s):  
Szymon P. Szafranski ◽  
Melissa L. Wos-Oxley ◽  
Ramiro Vilchez-Vargas ◽  
Ruy Jáuregui ◽  
Iris Plumeier ◽  
...  
Keyword(s):  
High Resolution ◽  
Biomarker Discovery ◽  
Learning Algorithm ◽  
Individualized Medicine ◽  
Oral Microbiome ◽  
Rrna Gene ◽  
Periodontal Pathogens ◽  
Content Type ◽  
Linear Discriminant ◽  
Taxonomic Profiling

ABSTRACTThe oral microbiome plays a key role for caries, periodontitis, and systemic diseases. A method for rapid, high-resolution, robust taxonomic profiling of subgingival bacterial communities for early detection of periodontitis biomarkers would therefore be a useful tool for individualized medicine. Here, we used Illumina sequencing of the V1-V2 and V5-V6 hypervariable regions of the 16S rRNA gene. A sample stratification pipeline was developed in a pilot study of 19 individuals, 9 of whom had been diagnosed with chronic periodontitis. Five hundred twenty-three operational taxonomic units (OTUs) were obtained from the V1-V2 region and 432 from the V5-V6 region. Key periodontal pathogens likePorphyromonas gingivalis,Treponema denticola, andTannerella forsythiacould be identified at the species level with both primer sets. Principal coordinate analysis identified two outliers that were consistently independent of the hypervariable region and method of DNA extraction used. The linear discriminant analysis (LDA) effect size algorithm (LEfSe) identified 80 OTU-level biomarkers of periodontitis and 17 of health. Health- and periodontitis-related clusters of OTUs were identified using a connectivity analysis, and the results confirmed previous studies with several thousands of samples. A machine learning algorithm was developed which was trained on all but one sample and then predicted the diagnosis of the left-out sample (jackknife method). Using a combination of the 10 best biomarkers, 15 of 17 samples were correctly diagnosed. Training the algorithm on time-resolved community profiles might provide a highly sensitive tool to detect the onset of periodontitis.

scholarly journals Porphyromonas gingivalis: Major Periodontopathic Pathogen Overview

2014 ◽  
Vol 2014 ◽  
pp. 1-8 ◽  
Author(s):  
Jaroslav Mysak ◽  
Stepan Podzimek ◽  
Pavla Sommerova ◽  
Yelena Lyuya-Mi ◽  
Jirina Bartova ◽  
...  
Keyword(s):  
Porphyromonas Gingivalis ◽  
Anaerobic Bacterium ◽  
Bacterial Species ◽  
Host Immunity ◽  
Oral Microbiome ◽  
Treponema Denticola ◽  
High Cell ◽  
Periodontal Pathogens ◽  
Gram Negative ◽  
Cell Numbers

Porphyromonas gingivalisis a Gram-negative oral anaerobe that is involved in the pathogenesis of periodontitis and is a member of more than 500 bacterial species that live in the oral cavity. This anaerobic bacterium is a natural member of the oral microbiome, yet it can become highly destructive (termed pathobiont) and proliferate to high cell numbers in periodontal lesions: this is attributed to its arsenal of specialized virulence factors. The purpose of this review is to provide an overview of one of the main periodontal pathogens—Porphyromonas gingivalis.This bacterium, along withTreponema denticolaandTannerella forsythia, constitute the “red complex,” a prototype polybacterial pathogenic consortium in periodontitis. This review outlinesPorphyromonas gingivalisstructure, its metabolism, its ability to colonize the epithelial cells, and its influence upon the host immunity.

scholarly journals VimA-Dependent Modulation of Acetyl Coenzyme A Levels and Lipid A Biosynthesis Can Alter Virulence in Porphyromonas gingivalis

2011 ◽  
Vol 80 (2) ◽  
pp. 550-564 ◽  
Author(s):  
A. Wilson Aruni ◽  
J. Lee ◽  
D. Osbourne ◽  
Y. Dou ◽  
F. Roy ◽  
...  
Keyword(s):  
Porphyromonas Gingivalis ◽  
Genetic Background ◽  
Lipid A ◽  
Coenzyme A ◽  
Signal Sequence ◽  
Content Type ◽  
Branched Chain Amino Acid ◽  
Defective Mutant ◽  
Associated Proteins ◽  
Branched Chain

ABSTRACTThePorphyromonas gingivalisVimA protein has multifunctional properties that can modulate several of its major virulence factors. To further characterize VimA,P. gingivalisFLL406 carrying an additionalvimAgene and avimA-defective mutant in a differentP. gingivalisgenetic background were evaluated. ThevimA-defective mutant (FLL451) in theP. gingivalisATCC 33277 genetic background showed a phenotype similar to that of thevimA-defective mutant (FLL92) in theP. gingivalisW83 genetic background. In contrast to the wild type, gingipain activity was increased inP. gingivalisFLL406, avimAchimeric strain.P. gingivalisFLL451 had a five times higher biofilm-forming capacity than the parent strain. HeLa cells incubated withP. gingivalisFLL92 showed a decrease in invasion, in contrast toP. gingivalisFLL451 and FLL406, which showed increases of 30 and 40%, respectively. VimA mediated coenzyme A (CoA) transfer to isoleucine and reduced branched-chain amino acid metabolism. The lipid A content and associated proteins were altered in thevimA-defective mutants. The VimA chimera interacted with several proteins which were found to have an LXXTG motif, similar to the sorting motif of Gram-positive organisms. All the proteins had an N-terminal signal sequence with a putative sorting signal of L(P/T/S)X(T/N/D)G and two unique signatures of EXGXTX and HISXXGXG, in addition to a polar tail. Taken together, these observations further confirm the multifunctional role of VimA in modulating virulence possibly through its involvement in acetyl-CoA transfer and lipid A synthesis and possibly by protein sorting.

scholarly journals The Periodontal Pathogen Porphyromonas gingivalis Induces Expression of Transposases and Cell Death of Streptococcus mitis in a Biofilm Model

2014 ◽  
Vol 82 (8) ◽  
pp. 3374-3382 ◽  
Author(s):  
Ana E. Duran-Pinedo ◽  
Vinesha D. Baker ◽  
Jorge Frias-Lopez
Keyword(s):  
Cell Death ◽  
Microbial Community ◽  
Porphyromonas Gingivalis ◽  
Bacterial Species ◽  
The United States ◽  
Oral Microbiome ◽  
Microbial Pathogens ◽  
Periodontal Pathogen ◽  
Streptococcus Mitis ◽  
Content Type

ABSTRACTOral microbial communities are extremely complex biofilms with high numbers of bacterial species interacting with each other (and the host) to maintain homeostasis of the system. Disturbance in the oral microbiome homeostasis can lead to either caries or periodontitis, two of the most common human diseases. Periodontitis is a polymicrobial disease caused by the coordinated action of a complex microbial community, which results in inflammation of tissues that support the teeth. It is the most common cause of tooth loss among adults in the United States, and recent studies have suggested that it may increase the risk for systemic conditions such as cardiovascular diseases. In a recent series of papers, Hajishengallis and coworkers proposed the idea of the “keystone-pathogen” where low-abundance microbial pathogens (Porphyromonas gingivalis) can orchestrate inflammatory disease by turning a benign microbial community into a dysbiotic one. The exact mechanisms by which these pathogens reorganize the healthy oral microbiome are still unknown. In the present manuscript, we present results demonstrating thatP. gingivalisinducesS. mitisdeath and DNA fragmentation in anin vitrobiofilm system. Moreover, we report here the induction of expression of multiple transposases in aStreptococcus mitisbiofilm when the periodontopathogenP. gingivalisis present. Based on these results, we hypothesize thatP. gingivalisinducesS. mitiscell death by an unknown mechanism, shaping the oral microbiome to its advantage.

scholarly journals Porphyromonas gingivalis Exacerbates Ligature-Induced, RANKL-Dependent Alveolar Bone Resorption via Differential Regulation of Toll-Like Receptor 2 (TLR2) and TLR4

2014 ◽  
Vol 82 (10) ◽  
pp. 4127-4134 ◽  
Author(s):  
Jiang Lin ◽  
Liangjia Bi ◽  
Xiaoqian Yu ◽  
Toshihisa Kawai ◽  
Martin A. Taubman ◽  
...  
Keyword(s):  
Bone Resorption ◽  
Porphyromonas Gingivalis ◽  
Alveolar Bone ◽  
Differential Regulation ◽  
Periodontal Pathogens ◽  
Rankl Expression ◽  
Necrosis Factor Alpha ◽  
Tlr4 Signaling ◽  
Content Type ◽  
Tnf Α

ABSTRACTToll-like receptors (TLRs) play a key role in the innate immune responses to periodontal pathogens in periodontal disease. The present study was performed to determine the roles of TLR2 and TLR4 signaling in alveolar bone resorption, using aPorphyromonas gingivalis-associated ligature-induced periodontitis model in mice. Wild-type (WT), Tlr2−/−, and Tlr4−/−mice (8 to 10 weeks old) in the C57/BL6 background were used. Silk ligatures were applied to the maxillary second molars in the presence or absence of liveP. gingivalisinfection. Ligatures were removed from the second molars on day 14, and mice were kept for another 2 weeks before sacrifice for final analysis (day 28). On day 14, there were no differences in alveolar bone resorption and gingival RANKL expression between mice treated with ligation plusP. gingivalisinfection and mice treated with ligation alone. Gingival interleukin-1β (IL-1β) and tumor necrosis factor alpha (TNF-α) expression was increased, whereas IL-10 expression was decreased in WT and Tlr2−/−mice but not in Tlr4−/−mice. On day 28, WT and Tlr4−/−mice treated with ligation plusP. gingivalisinfection showed significantly increased bone loss and gingival RANKL expression compared to those treated with ligation alone, whereas such an increase was diminished in Tlr2−/−mice. Gingival TNF-α upregulation and IL-10 downregulation were observed only in WT and Tlr4−/−mice, not in Tlr2−/−mice. In all mice, bone resorption induced by ligation plusP. gingivalisinfection was antagonized by local anti-RANKL antibody administration. This study suggests thatP. gingivalisexacerbates ligature-induced, RANKL-dependent periodontal bone resorption via differential regulation of TLR2 and TLR4 signaling.

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 Novel Aggregation Properties of Candida albicans Secreted Aspartyl Proteinase Sap6 Mediate Virulence in Oral Candidiasis

2015 ◽  
Vol 83 (7) ◽  
pp. 2614-2626 ◽  
Author(s):  
Rohitashw Kumar ◽  
Darpan Saraswat ◽  
Swetha Tati ◽  
Mira Edgerton
Keyword(s):  
Candida Albicans ◽  
Epithelial Cells ◽  
Oral Candidiasis ◽  
Oral Microbiome ◽  
Proteinase Activity ◽  
Adhesion Properties ◽  
Content Type ◽  
Oral Epithelial Cells ◽  
Oral Epithelial ◽  
Cell Cell

Candida albicans, a commensal fungus of the oral microbiome, causes oral candidiasis in humans with localized or systemic immune deficiencies. Secreted aspartic proteinases (Saps) are a family of 10 related proteases and are virulence factors due to their proteolytic activity, as well as their roles in adherence and colonization of host tissues. We found that mice infected sublingually withC. albicanscells overexpressing Sap6 (SAP6OE and a Δsap8strain) had thicker fungal plaques and more severe oral infection, while infection with the Δsap6strain was attenuated. These hypervirulent strains had highly aggregative colony structurein vitroand higher secreted proteinase activity; however, the levels of proteinase activity ofC. albicansSaps did not uniformly match their abilities to damage cultured oral epithelial cells (SCC-15 cells). Hyphal induction in cells overexpressing Sap6 (SAP6OE and Δsap8cells) resulted in formation of large cell-cell aggregates. These aggregates could be produced in germinated wild-type cells by addition of native or heat-inactivated Sap6. Sap6 bound only to germinated cells and increasedC. albicansadhesion to oral epithelial cells. The adhesion properties of Sap6 were lost upon deletion of its integrin-binding motif (RGD) and could be inhibited by addition of RGD peptide or anti-integrin antibodies. Thus, Sap6 (but not Sap5) has an alternative novel function in cell-cell aggregation, independent of its proteinase activity, to promote infection and virulence in oral candidiasis.

scholarly journals Use of Proteins Identified through a Functional Genomic Screen To Develop a Protein Subunit Vaccine That Provides Significant Protection against Virulent Streptococcus suis in Pigs

2017 ◽  
Vol 86 (3) ◽  
Author(s):  
Susan L. Brockmeier ◽  
Crystal L. Loving ◽  
Tracy L. Nicholson ◽  
Jinhong Wang ◽  
Sarah E. Peters ◽  
...  
Keyword(s):  
Immune Response ◽  
Vaccine Trial ◽  
Streptococcus Suis ◽  
Protein Subunit ◽  
Content Type ◽  
Degree Of Protection ◽  
Wide Range ◽  
Associated Proteins ◽  
Clinical Protection ◽  
Cellular Immune

ABSTRACT Streptococcus suis is a bacterium that is commonly carried in the respiratory tract and that is also one of the most important invasive pathogens of swine, commonly causing meningitis, arthritis, and septicemia. Due to the existence of many serotypes and a wide range of immune evasion capabilities, efficacious vaccines are not readily available. The selection of S. suis protein candidates for inclusion in a vaccine was accomplished by identifying fitness genes through a functional genomics screen and selecting conserved predicted surface-associated proteins. Five candidate proteins were selected for evaluation in a vaccine trial and administered both intranasally and intramuscularly with one of two different adjuvant formulations. Clinical protection was evaluated by subsequent intranasal challenge with virulent S. suis . While subunit vaccination with the S. suis proteins induced IgG antibodies to each individual protein and a cellular immune response to the pool of proteins and provided substantial protection from challenge with virulent S. suis , the immune response elicited and the degree of protection were dependent on the parenteral adjuvant given. Subunit vaccination induced IgG reactive against different S. suis serotypes, indicating a potential for cross protection.

scholarly journals The impact of fixed orthodontic appliances on oral microbiome dynamics in Japanese patients

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Isamu Kado ◽  
Junzo Hisatsune ◽  
Keiko Tsuruda ◽  
Kotaro Tanimoto ◽  
Motoyuki Sugai
Keyword(s):  
Relative Abundance ◽  
Japanese Patients ◽  
Oral Microbiome ◽  
Orthodontic Appliances ◽  
Periodontal Pathogens ◽  
Supragingival Plaque ◽  
Fixed Orthodontic Appliances ◽  
Microbial Dna ◽  
The Impact ◽  
Level Analysis

AbstractFixed orthodontic appliances are common and effective tools to treat malocclusion. Adverse effects of these appliances, such as dental caries and periodontitis, may be associated with alteration of the microbiome. This study investigated the impact of these appliances on the dynamics of the oral microbiome. Seventy-one patients were selected. Supragingival plaque samples were collected before placement (T0) and six months after placement (T1). Saliva samples were collected at T0 and T1, and then when appliance removal (T2). Microbial DNA was analyzed by 16S rRNA meta-sequencing. The diversity analysis indicated dynamic changes in the structure of the oral microbiome. Taxonomic analysis at phylum level showed a significant increase in Bacteroidetes and Saccharibacteria (formally TM7) and decrease in Proteobacteria and Actinobacteria over time, in both plaque and saliva. Genus level analysis of relative abundance indicated a significant increase in anaerobic and facultative anaerobes in both plaque and saliva. Fixed orthodontic appliances induced measurable changes in the oral microbiome. This was characterized by an increase in relative abundance of obligate anaerobes, including periodontal pathogens. It can be concluded that this dysbiosis induced by fixed orthodontic appliances is likely to represent a transitional stage in the shift in microbiome from healthy to periodontitis.

scholarly journals Characterization of RarA, a Novel AraC Family Multidrug Resistance Regulator in Klebsiella pneumoniae

2012 ◽  
Vol 56 (8) ◽  
pp. 4450-4458 ◽  
Author(s):  
Mark Veleba ◽  
Paul G. Higgins ◽  
Gerardo Gonzalez ◽  
Harald Seifert ◽  
Thamarai Schneiders
Keyword(s):  
Multidrug Resistance ◽  
Klebsiella Pneumoniae ◽  
Efflux Pump ◽  
Content Type ◽  
Resistance Phenotype ◽  
Serratia Proteamaculans ◽  
Virulence Potential ◽  
Article Type ◽  
Acrab Efflux Pump

ABSTRACTTranscriptional regulators, such as SoxS, RamA, MarA, and Rob, which upregulate the AcrAB efflux pump, have been shown to be associated with multidrug resistance in clinically relevant Gram-negative bacteria. In addition to the multidrug resistance phenotype, these regulators have also been shown to play a role in the cellular metabolism and possibly the virulence potential of microbial cells. As such, the increased expression of these proteins is likely to cause pleiotropic phenotypes.Klebsiella pneumoniaeis a major nosocomial pathogen which can express the SoxS, MarA, Rob, and RamA proteins, and the accompanying paper shows that the increased transcription oframAis associated with tigecycline resistance (M. Veleba and T. Schneiders, Antimicrob. Agents Chemother. 56:4466–4467, 2012). Bioinformatic analyses of the availableKlebsiellagenome sequences show that an additional AraC-type regulator is encoded chromosomally. In this work, we characterize this novel AraC-type regulator, hereby called RarA (Regulator of antibiotic resistance A), which is encoded inK. pneumoniae,Enterobactersp. 638,Serratia proteamaculans568, andEnterobacter cloacae. We show that the overexpression ofrarAresults in a multidrug resistance phenotype which requires a functional AcrAB efflux pump but is independent of the other AraC regulators. Quantitative real-time PCR experiments show thatrarA(MGH 78578 KPN_02968) and its neighboring efflux pump operonoqxAB(KPN_02969_02970) are consistently upregulated in clinical isolates collected from various geographical locations (Chile, Turkey, and Germany). Our results suggest thatrarAoverexpression upregulates theoqxABefflux pump. Additionally, it appears thatoqxR, encoding a GntR-type regulator adjacent to theoqxABoperon, is able to downregulate the expression of theoqxABefflux pump, where OqxR complementation resulted in reductions to olaquindox MICs.

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