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Indira Moraes Gomes Cavalcanti - One of the best experts on this subject based on the ideXlab platform.
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interactions between Streptococcus oralis actinomyces oris and candida albicans in the development of multispecies oral microbial biofilms on salivary pellicle
Molecular Oral Microbiology, 2017Co-Authors: Indira Moraes Gomes Cavalcanti, Howard F Jenkinson, Altair Antoninha Del Bel Cury, Angela H NobbsAbstract:Summary The fungus Candida albicans is carried orally and causes a range of superficial infections that may become systemic. Oral bacteria Actinomyces oris and Streptococcus oralis are abundant in early dental plaque and on oral mucosa. The aims of this study were to determine the mechanisms by which S. oralis and A. oris interact with each other and with C. albicans in biofilm development. Spatial distribution of microorganisms was visualized by confocal laser scanning microscopy of biofilms labeled by differential fluorescence or by fluorescence in situ hybridization (FISH). Actinomyces oris and S. oralis formed robust dual-species biofilms, or three-species biofilms with C. albicans. The bacterial components tended to dominate the lower levels of the biofilms while C. albicans occupied the upper levels. Non-fimbriated A. oris was compromised in biofilm formation in the absence or presence of streptococci, but was incorporated into upper biofilm layers through binding to C. albicans. Biofilm growth and hyphal filament production by C. albicans was enhanced by S. oralis. It is suggested that the interkingdom biofilms are metabolically coordinated to house all three components, and this study demonstrates that adhesive interactions between them determine spatial distribution and biofilm architecture. The physical and chemical communication processes occurring in these communities potentially augment C. albicans persistence at multiple oral cavity sites.
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interkingdom cooperation between candida albicans Streptococcus oralis and actinomyces oris modulates early biofilm development on denture material
Pathogens and Disease, 2016Co-Authors: Indira Moraes Gomes Cavalcanti, Angela H Nobbs, Antonio P Ricominifilho, Howard F Jenkinson, Altair Antoninha Del Bel CuryAbstract:Candida -associated stomatitis affects up to 60% of denture wearers, and Candida albicans remains the most commonly isolated fungal species. The oral bacteria Actinomyces oris and Streptococcus oralis are abundant in early dental plaque. The aims of this study were to determine the effects of S. oralis and A. oris on the development of C. albicans biofilms on denture material. Resin discs were coated with saliva and at early (1.5 h) or later (24 h) stages of biofilm development, cell numbers of each species were determined. Spatial distribution of microorganisms was visualized by confocal scanning laser microscopy of biofilms labelled by differential fluorescence or by fluorescence in situ hybridization (FISH). Interkingdom interactions underpinning biofilm development were also evaluated planktonically utilizing fluorescence microscopy. Synergistic interactions between all three species occurred within biofilms and planktonically. Bacterial cells coaggregated with each other and adhered singly or in coaggregates to C. albicans hyphal filaments. S. oralis appeared to enhance hyphal filament production and C. albicans biovolume was increased two-fold. Concomitantly, cell numbers of S. oralis and A. oris were enhanced by C. albicans . Thus cooperative physical and metabolic processes occurring between these three microbial species intensify pathogenic plaque communities on denture surfaces.
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Interkingdom cooperation between Candida albicans, Streptococcus oralis and Actinomyces oris modulates early biofilm development on denture material.
Pathogens and disease, 2016Co-Authors: Indira Moraes Gomes Cavalcanti, Angela H Nobbs, Howard F Jenkinson, Antônio P. Ricomini-filho, Altair Antoninha Del Bel CuryAbstract:Candida-associated stomatitis affects up to 60% of denture wearers, and Candida albicans remains the most commonly isolated fungal species. The oral bacteria Actinomyces oris and Streptococcus oralis are abundant in early dental plaque. The aims of this study were to determine the effects of S. oralis and A. oris on the development of C. albicans biofilms on denture material. Resin discs were coated with saliva and at early (1.5 h) or later (24 h) stages of biofilm development, cell numbers of each species were determined. Spatial distribution of microorganisms was visualized by confocal scanning laser microscopy of biofilms labelled by differential fluorescence or by fluorescence in situ hybridization. Interkingdom interactions underpinning biofilm development were also evaluated planktonically utilizing fluorescence microscopy. Synergistic interactions between all three species occurred within biofilms and planktonically. Bacterial cells coaggregated with each other and adhered singly or in coaggregates to C. albicans hyphal filaments. Streptococcus oralis appeared to enhance hyphal filament production and C. albicans biovolume was increased 2-fold. Concomitantly, cell numbers of S. oralis and A. oris were enhanced by C. albicans. Thus, cooperative physical and metabolic processes occurring between these three microbial species intensify pathogenic plaque communities on denture surfaces.
Regine Hakenbeck - One of the best experts on this subject based on the ideXlab platform.
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highly variable Streptococcus oralis strains are common among viridans streptococci isolated from primates
mSphere, 2016Co-Authors: Dalia Denapaite, Reinhold Brückner, Martin Rieger, Sophie Kondgen, Irma Ochigava, Peter M Kappeler, Kerstin Matzrensing, Fabian H Leendertz, Regine HakenbeckAbstract:ABSTRACT Viridans streptococci were obtained from primates (great apes, rhesus monkeys, and ring-tailed lemurs) held in captivity, as well as from free-living animals (chimpanzees and lemurs) for whom contact with humans is highly restricted. Isolates represented a variety of viridans streptococci, including unknown species. Streptococcus oralis was frequently isolated from samples from great apes. Genotypic methods revealed that most of the strains clustered on separate lineages outside the main cluster of human S. oralis strains. This suggests that S. oralis is part of the commensal flora in higher primates and evolved prior to humans. Many genes described as virulence factors in Streptococcus pneumoniae were present also in other viridans streptococcal genomes. Unlike in S. pneumoniae, clustered regularly interspaced short palindromic repeat (CRISPR)–CRISPR-associated protein (Cas) gene clusters were common among viridans streptococci, and many S. oralis strains were type PI-2 (pilus islet 2) variants. S. oralis displayed a remarkable diversity of genes involved in the biosynthesis of peptidoglycan (penicillin-binding proteins and MurMN) and choline-containing teichoic acid. The small noncoding cia -dependent small RNAs (csRNAs) controlled by the response regulator CiaR might contribute to the genomic diversity, since we observed novel genomic islands between duplicated csRNAs, variably present in some isolates. All S. oralis genomes contained a β- N -acetyl-hexosaminidase gene absent in S. pneumoniae, which in contrast frequently harbors the neuraminidases NanB/C, which are absent in S. oralis. The identification of S. oralis-specific genes will help us to understand their adaptation to diverse habitats. IMPORTANCE Streptococcus pneumoniae is a rare example of a human-pathogenic bacterium among viridans streptococci, which consist of commensal symbionts, such as the close relatives Streptococcus mitis and S. oralis. We have shown that S. oralis can frequently be isolated from primates and a variety of other viridans streptococci as well. Genes and genomic islands which are known pneumococcal virulence factors are present in S. oralis and S. mitis, documenting the widespread occurrence of these compounds, which encode surface and secreted proteins. The frequent occurrence of CRISP-Cas gene clusters and a surprising variation of a set of small noncoding RNAs are factors to be considered in future research to further our understanding of mechanisms involved in the genomic diversity driven by horizontal gene transfer among viridans streptococci.
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Lipoteichoic acid of Streptococcus oralis Uo5: a novel biochemical structure comprising an unusual phosphorylcholine substitution pattern compared to Streptococcus pneumoniae.
Scientific reports, 2015Co-Authors: Nicolas Gisch, Regine Hakenbeck, Dominik Schwudke, Simone Thomsen, Nathalie Heß, Dalia DenapaiteAbstract:Members of the Mitis group of streptococci possess teichoic acids (TAs) as integral components of their cell wall that are unique among Gram-positive bacteria. Both, lipoteichoic (LTA) and wall teichoic acid, are formed by the same biosynthetic pathway, are of high complexity and contain phosphorylcholine (P-Cho) residues. These residues serve as anchors for choline-binding proteins (CBPs), some of which have been identified as virulence factors of the human pathogen Streptococcus pneumoniae. We investigated the LTA structure of its close relative Streptococcus oralis. Our analysis revealed that S. oralis Uo5 LTA has an overall architecture similar to pneumococcal LTA (pnLTA) and can be considered as a subtype of type IV LTA. Its structural complexity is even higher than that of pnLTA and its composition differs in number and type of carbohydrate moieties, inter-residue connectivities and especially the P-Cho substitution pattern. Here, we report the occurrence of a saccharide moiety substituted with two P-Cho residues, which is unique as yet in bacterial derived surface carbohydrates. Finally, we could link the observed important structural variations between S. oralis and S. pneumoniae LTA to the divergent enzymatic repertoire for their TA biosynthesis.
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Genome of Streptococcus oralis Strain Uo5
Journal of bacteriology, 2011Co-Authors: Peter Reichmann, Michael Nuhn, Dalia Denapaite, Reinhold Brückner, Bernhard Henrich, Patrick Maurer, Martin Rieger, Sven Klages, Richard Reinhard, Regine HakenbeckAbstract:Streptococcus oralis, a commensal species of the human oral cavity, belongs to the Mitis group of streptococci, which includes one of the major human pathogens as well, S. pneumoniae. We report here the first complete genome sequence of this species. S. oralis Uo5, a high-level penicillin- and multiple-antibiotic-resistant isolate from Hungary, is competent for genetic transformation under laboratory conditions. Comparative and functional genomics of Uo5 will be important in understanding the evolution of pathogenesis among Mitis streptococci and their potential to engage in interspecies gene transfer.
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mosaic pbpx genes of major clones of penicillin resistant Streptococcus pneumoniae have evolved from pbpx genes of a penicillin sensitive Streptococcus oralis
Molecular Microbiology, 1994Co-Authors: Claus Sibold, Jorgen Henrichsen, Andrea Konig, C Martin, Lynda Chalkley, Regine HakenbeckAbstract:Summary Penicillin-resistant clinical isolates of Streptococcus pneumoniae contain mosaic penicillin-binding protein (PBP) genes that encode PBPs with decreased affinity for β-lactam antibiotics. The mosaic blocks are believed to be the result of gene transfer of homologous PBP genes from related penicillin-resistant species. We have now identified a gene homologous to the pneumococcal PBP2x gene (pbpX) in a penicillin-sensitive Streptococcus oralis isolate M3 from South Africa that diverged by almost 20% from pbpX of penicillin-sensitive pneumococci, and a central sequence block of a mosaic pbpX gene of Streptococcus mitis strain NCTC 10712. In contrast, it differed by only 2-4% of the 1 to 1.5 kb mosaic block in pbpX genes of three genetically unrelated penicillin-resistant S. pneumoniae isolates, two of them representing clones of serotype 6B and 23F, which are prevalent in Spain and are also already found in other countries. With low concentrations of cefotaxime, transformants of the sensitive S. pneumoniae R6 strain could be selected containing pbpX genes from either S. mitis NCTC 10712 or S. oralis M3, demonstrating that genetic exchange can already occur between β-lactam-sensitive species. These data are in agreement with the assumption that PBPs as penicillin-resistance determinants have evolved by the accumulation of point mutations in genes of sensitive commensal species.
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mosaic pbpx genes of major clones of penicillin resistant Streptococcus pneumoniae have evolved from pbpx genes of a penicillin sensitive Streptococcus oralis
Molecular Microbiology, 1994Co-Authors: Claus Sibold, Jorgen Henrichsen, Andrea Konig, C Martin, Lynda Chalkley, Regine HakenbeckAbstract:Penicillin-resistant clinical isolates of Streptococcus pneumoniae contain mosaic penicillin-binding protein (PBP) genes that encode PBPs with decreased affinity for beta-lactam antibiotics. The mosaic blocks are believed to be the result of gene transfer of homologous PBP genes from related penicillin-resistant species. We have now identified a gene homologous to the pneumococcal PBP2x gene (pbpX) in a penicillin-sensitive Streptococcus oralis isolate M3 from South Africa that diverged by almost 20% from pbpX of penicillin-sensitive pneumococci, and a central sequence block of a mosaic pbpX gene of Streptococcus mitis strain NCTC 10712. In contrast, it differed by only 2-4% of the 1 to 1.5 kb mosaic block in pbpX genes of three genetically unrelated penicillin-resistant S. pneumoniae isolates, two of them representing clones of serotype 6B and 23F, which are prevalent in Spain and are also already found in other countries. With low concentrations of cefotaxime, transformants of the sensitive S. pneumoniae R6 strain could be selected containing pbpX genes from either S. mitis NCTC 10712 or S. oralis M3, demonstrating that genetic exchange can already occur between beta-lactam-sensitive species. These data are in agreement with the assumption that PBPs as penicillin-resistance determinants have evolved by the accumulation of point mutations in genes of sensitive commensal species.
Angela H Nobbs - One of the best experts on this subject based on the ideXlab platform.
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interactions between Streptococcus oralis actinomyces oris and candida albicans in the development of multispecies oral microbial biofilms on salivary pellicle
Molecular Oral Microbiology, 2017Co-Authors: Indira Moraes Gomes Cavalcanti, Howard F Jenkinson, Altair Antoninha Del Bel Cury, Angela H NobbsAbstract:Summary The fungus Candida albicans is carried orally and causes a range of superficial infections that may become systemic. Oral bacteria Actinomyces oris and Streptococcus oralis are abundant in early dental plaque and on oral mucosa. The aims of this study were to determine the mechanisms by which S. oralis and A. oris interact with each other and with C. albicans in biofilm development. Spatial distribution of microorganisms was visualized by confocal laser scanning microscopy of biofilms labeled by differential fluorescence or by fluorescence in situ hybridization (FISH). Actinomyces oris and S. oralis formed robust dual-species biofilms, or three-species biofilms with C. albicans. The bacterial components tended to dominate the lower levels of the biofilms while C. albicans occupied the upper levels. Non-fimbriated A. oris was compromised in biofilm formation in the absence or presence of streptococci, but was incorporated into upper biofilm layers through binding to C. albicans. Biofilm growth and hyphal filament production by C. albicans was enhanced by S. oralis. It is suggested that the interkingdom biofilms are metabolically coordinated to house all three components, and this study demonstrates that adhesive interactions between them determine spatial distribution and biofilm architecture. The physical and chemical communication processes occurring in these communities potentially augment C. albicans persistence at multiple oral cavity sites.
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interkingdom cooperation between candida albicans Streptococcus oralis and actinomyces oris modulates early biofilm development on denture material
Pathogens and Disease, 2016Co-Authors: Indira Moraes Gomes Cavalcanti, Angela H Nobbs, Antonio P Ricominifilho, Howard F Jenkinson, Altair Antoninha Del Bel CuryAbstract:Candida -associated stomatitis affects up to 60% of denture wearers, and Candida albicans remains the most commonly isolated fungal species. The oral bacteria Actinomyces oris and Streptococcus oralis are abundant in early dental plaque. The aims of this study were to determine the effects of S. oralis and A. oris on the development of C. albicans biofilms on denture material. Resin discs were coated with saliva and at early (1.5 h) or later (24 h) stages of biofilm development, cell numbers of each species were determined. Spatial distribution of microorganisms was visualized by confocal scanning laser microscopy of biofilms labelled by differential fluorescence or by fluorescence in situ hybridization (FISH). Interkingdom interactions underpinning biofilm development were also evaluated planktonically utilizing fluorescence microscopy. Synergistic interactions between all three species occurred within biofilms and planktonically. Bacterial cells coaggregated with each other and adhered singly or in coaggregates to C. albicans hyphal filaments. S. oralis appeared to enhance hyphal filament production and C. albicans biovolume was increased two-fold. Concomitantly, cell numbers of S. oralis and A. oris were enhanced by C. albicans . Thus cooperative physical and metabolic processes occurring between these three microbial species intensify pathogenic plaque communities on denture surfaces.
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Interkingdom cooperation between Candida albicans, Streptococcus oralis and Actinomyces oris modulates early biofilm development on denture material.
Pathogens and disease, 2016Co-Authors: Indira Moraes Gomes Cavalcanti, Angela H Nobbs, Howard F Jenkinson, Antônio P. Ricomini-filho, Altair Antoninha Del Bel CuryAbstract:Candida-associated stomatitis affects up to 60% of denture wearers, and Candida albicans remains the most commonly isolated fungal species. The oral bacteria Actinomyces oris and Streptococcus oralis are abundant in early dental plaque. The aims of this study were to determine the effects of S. oralis and A. oris on the development of C. albicans biofilms on denture material. Resin discs were coated with saliva and at early (1.5 h) or later (24 h) stages of biofilm development, cell numbers of each species were determined. Spatial distribution of microorganisms was visualized by confocal scanning laser microscopy of biofilms labelled by differential fluorescence or by fluorescence in situ hybridization. Interkingdom interactions underpinning biofilm development were also evaluated planktonically utilizing fluorescence microscopy. Synergistic interactions between all three species occurred within biofilms and planktonically. Bacterial cells coaggregated with each other and adhered singly or in coaggregates to C. albicans hyphal filaments. Streptococcus oralis appeared to enhance hyphal filament production and C. albicans biovolume was increased 2-fold. Concomitantly, cell numbers of S. oralis and A. oris were enhanced by C. albicans. Thus, cooperative physical and metabolic processes occurring between these three microbial species intensify pathogenic plaque communities on denture surfaces.
David Beighton - One of the best experts on this subject based on the ideXlab platform.
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Population structure of Streptococcus oralis.
Microbiology, 2009Co-Authors: Keith A. Jolley, Martin C. J. Maiden, S C Gilbert, D T Clark, William G. Wade, David BeightonAbstract:Streptococcus oralis is a member of the normal human oral microbiota, capable of opportunistic pathogenicity; like related oral streptococci, it exhibits appreciable phenotypic and genetic variation. A multilocus sequence typing (MLST) scheme for S. oralis was developed and the resultant data analysed to examine the population structure of the species. Analysis of 113 isolates, confirmed as belonging to the S. oralis/mitis group by 16S rRNA gene sequencing, characterized the population as highly diverse and undergoing inter- and intra-species recombination with a probable clonal complex structure. ClonalFrame analysis of these S. oralis isolates along with examples of Streptococcus pneumoniae, Streptococcus mitis and Streptococcus pseudopneumoniae grouped the named species into distinct, coherent populations and did not support the clustering of S. pseudopneumoniae with S. mitis as reported previously using distance-based methods. Analysis of the individual loci suggested that this discrepancy was due to the possible hybrid nature of S. pseudopneumoniae. The data are available on the public MLST website (http://pubmlst.org/soralis/).
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effect of the environment on genotypic diversity of actinomyces naeslundii and Streptococcus oralis in the oral biofilm
Applied and Environmental Microbiology, 2003Co-Authors: James S Paddick, S C Gilbert, D T Clark, Sharmin Alam, Susan Brailsford, E A M Kidd, Zoe J Killick, David BeightonAbstract:Dental plaque bacteria colonize the hard tissues of the oral cavity by ecological succession (4, 29, 30). Early colonizers of the dentition, including Actinomyces naeslundii and Streptococcus oralis, facilitate further bacterial colonization (16, 29) and maintain biofilm integrity (23), protecting the host against colonization by extraoral pathogens (36). S. oralis is an oral commensal organism and is a member of the mitis group of viridans streptococci (41). A. naeslundii is a gram-positive pleomorphic rod which forms a significant component of commensal oral microfloras (7). A. naeslundii strains are assigned to two genospecies (1 and 2) on the basis of DNA homology (19) and may be identified by using genospecies-specific antisera (28). The ability of bacteria to survive and persist in a given environment will depend, in part, on their inherent genetic plasticity, which determines their ability to respond to fluctuating local environmental conditions or stresses (13). The presence of active carious lesions indicates that the oral cavity is subject to local stresses, including the intake of fermentable carbohydrates and the production of organic acids, resulting in enamel demineralization and carious lesion formation. It has been suggested that acid stress associated with carious lesion formation will result in the reduction of genotypic diversity as strains best suited to survival are selected (5). However, this hypothesis has not been tested in relation to the ecology of the oral biofilm. Previous studies have shown that oral bacteria, including streptococci (15, 17, 20-22, 24-26, 27, 32, 33) and A. naeslundii (6, 31), are genotypically heterogeneous. Repetitive extragenic palindromic PCR (REP-PCR) (37, 38) is suitable for genotyping oral bacteria, and this method has been used previously to study the epidemiology and relatedness of S. oralis strains in dental plaque (1, 2) and Actinomyces gerencseriae and Actinomyces israelii isolated from root caries lesions (8). In this study REP-PCR was used to investigate the genetic diversity of S. oralis and A. naeslundii populations isolated from sound anterior approximal tooth sites of caries-free and caries-active subjects. These strains were studied to test the hypothesis that the genetic diversity of individual species exhibits increased homogeneity and reduced diversity in environments subjected to increased stress.
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Effect of Acidic pH on Expression of Surface-Associated Proteins of Streptococcus oralis
Applied and environmental microbiology, 2003Co-Authors: J C Wilkins, David Beighton, Karen A. HomerAbstract:Streptococcus oralis, a member of the mitis group of oral streptococci, is implicated in the pathogenesis of infective endocarditis and is the predominant aciduric non-mutans-group Streptococcus in dental plaque. We undertook to identify the most abundant surface-associated proteins of S. oralis and to investigate changes in protein expression when the organism was grown under acidic culture conditions. Surface-associated proteins were extracted from cells grown in batch culture, separated by two-dimensional gel electrophoresis, excised, digested with trypsin, and analyzed by matrix-assisted laser desorption ionization-time of flight mass spectrometry and liquid chromatography-tandem mass spectrometry. Putative functions were assigned by homology to a translated genomic database of Streptococcus pneumoniae. A total of 27 proteins were identified; these included a lipoprotein, a ribosome recycling factor, and the glycolytic enzymes phosphoglycerate kinase, fructose bisphosphate aldolase, glyceraldehyde-3-phosphate dehydrogenase, and enolase. The most abundant protein, phosphocarrier protein HPr, was present as three isoforms. Neither lactate dehydrogenase nor pyruvate oxidase, dominant intracellular proteins, were present among the proteins on the gels, demonstrating that proteins in the surface-associated pool did not arise as a result of cell lysis. Eleven of the proteins identified were differentially expressed when cells were grown at pH 5.2 versus pH 7.0, and these included superoxide dismutase, a homologue of dipeptidase V from Lactococcus lactis, and the protein translation elongation factors G, Tu, and Ts. This study has extended the range of streptococcal proteins known to be expressed at the cell surface. Further investigations are required to ascertain their functions at this extracellular location and determine how their expression is influenced by other environmental conditions.
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Altered Protein Expression of Streptococcus oralis Cultured at Low pH Revealed by Two-Dimensional Gel Electrophoresis
Applied and environmental microbiology, 2001Co-Authors: J C Wilkins, Karen A. Homer, David BeightonAbstract:Streptococcus oralis is the predominant aciduric nonmutans Streptococcus isolated from the human dentition, but the role of this organism in the initiation and progression of dental caries has yet to be established. To identify proteins that are differentially expressed by S. oralis growing under conditions of low pH, soluble cellular proteins extracted from bacteria grown in batch culture at pH 5.2 or 7.0 were analyzed by two-dimensional (2-D) gel electrophoresis. Thirty-nine proteins had altered expression at low pH; these were excised, digested with trypsin using an in-gel protocol, and further analyzed by peptide mass fingerprinting using matrix-assisted laser desorption ionization mass spectrometry. The resulting fingerprints were compared with the genomic database for Streptococcus pneumoniae, an organism that is phylogenetically closely related to S. oralis, and putative functions for the majority of these proteins were determined on the basis of functional homology. Twenty-eight proteins were up-regulated following growth at pH 5.2; these included enzymes of the glycolytic pathway (glyceraldehyde-3-phosphate dehydrogenase and lactate dehydrogenase), the polypeptide chains comprising ATP synthase, and proteins that are considered to play a role in the general stress response of bacteria, including the 60-kDa chaperone, Hsp33, and superoxide dismutase, and three distinct ABC transporters. These data identify, for the first time, gene products that may be important in the survival and proliferation of nonmutans aciduric S. oralis under conditions of low pH that are likely to be encountered by this organism in vivo.
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Genotypic Heterogeneity of Streptococcus oralis and Distinct Aciduric Subpopulations in Human Dental Plaque
Applied and environmental microbiology, 2000Co-Authors: Sharmin Alam, Susan Brailsford, S Adams, C Allison, Evelyn C. Sheehy, L. Zoitopoulos, Edwina Kidd, David BeightonAbstract:Received 3 April 2000/Accepted 31 May 2000 The genotypic heterogeneity of Streptococcus oralis isolated from the oral cavity was investigated using repetitive extragenic palindromic PCR. Unrelated subjects harbored unique genotypes, with numerous genotypes being isolated from an individual. S. oralis is the predominant aciduric bacterium isolated from noncarious tooth sites. Genotypic comparison of the aciduric populations isolated at pH 5.2 with those isolated from mitis-salivarius agar (MSA) (pH 7.0) indicated that the aciduric populations were genotypically distinct in the majority of subjects (x 2 5 13.09; P 5 0.0031). Neither the aciduric nor the MSA-isolated strains were stable, with no strains isolated at baseline being isolated 4 or 12 weeks later in the majority of subjects. The basis of this instability is unknown but is similar to that reported for Streptococcus mitis. Examination of S. oralis strains isolated from cohabiting couples demonstrated that in three of five couples, genotypically identical strains were isolated from both partners and this was confirmed by using Salmonella enteritidis repetitive element PCR and enterobacterial PCR typing. These data provide further evidence of the physiological and genotypic heterogeneity of non-mutans streptococci. The demonstration of distinct aciduric populations of S. oralis implies that the role of these and other non-mutans streptococci in the caries process requires reevaluation. The initiation of dental caries is associated with the ability of dental plaque to produce acid from ingested foods on a cariesprone tooth surface. At caries-prone sites, smooth tooth surfaces, interproximal sites, pits and fissures where plaque accumulates (1, 3, 10), and certainly within carious lesions, the local pH is acidic, and the bacteria present in these sites must be aciduric, exhibiting an ability to replicate in the prevailing or transient acidic environment. Dental plaque contains many species of acidogenic and aciduric microorganisms. The acidogenic bacteria most closely associated with the dental caries process are mutans streptococci (Streptococcus mutans and Streptococcus sobrinus), lactobacilli, and perhaps Actinomyces spp. There has been considerable discussion as to the role of other bacteria, in particular the role of the non-mutans streptococci (NMS), in the initiation and progression of dental caries. In an attempt to obtain understanding of the potential pathogenic role of these, van Houte and colleagues studied the acidogenicity of NMS isolated from sound and carious tooth sites (29, 35, 36). In these studies, the NMS were heterogeneous with respect to acidogenicity. Thus, from infected dentine within carious lesions and from plaque on sound surfaces in the mouths of caries-active subjects, NMS which were more acidogenic than NMS were isolated from sound tooth surfaces in caries-free subjects. The clonality of these strains has not been reported nor was the aciduricity of the isolates investigated. However, this was the first detailed and focused report of heterogeneity amongst individual NMS species of a determinant expected to be a significant feature of any microorganism involved in the initiation of dental caries. The acidogenic NMS were also more numerous than mutans streptococci, and it was proposed that these organisms may play a significant role in the caries process. The aciduricity of bacteria isolated from the dental plaque biofilm has been investigated in a number of studies with a variety of in vitro techniques, primarily by determining the ability of isolates to metabolize carbohydrates and survive at acidic pH levels (11, 12, 15, 18, 23, 31, 32). These studies have demonstrated that lactobacilli and mutans streptococci are the most aciduric dental plaque bacteria, while NMS and Actinomyces spp. are less aciduric. However, the strains tested in those experiments were all isolated from conventional selective and nonselective culture media, which may have influenced the phenotypes of the strains isolated and subsequently examined. The predominant aciduric component of dental plaque has not been extensively investigated. In a preliminary report, we indicated that the predominant aciduric bacteria isolated from dental plaque taken from noncarious surfaces were NMS, with Streptococcus oralis, Streptococcus parasanguinis, and Streptococcus intermedius being the most frequently isolated (8). In this paper, we extend these observations and report the genotypic characterization of aciduric S. oralis strains from saliva and interproximal dental plaque samples. Representatives of the aciduric isolates from each subject were genotyped by using repetitive extragenic palindromic PCR (REP-PCR [2]) and were compared to those isolated from conventional culture media (pH 7.0). The stability of the S. oralis populations was assessed over periods of up to 12 weeks, and the transmissibility of strains was determined by comparing the S. oralis genotypes in the plaque flora of cohabiting couples.
Kazuhiko Maeda - One of the best experts on this subject based on the ideXlab platform.
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Proteomic and transcriptional analysis of interaction between oral microbiota Porphyromonas gingivalis and Streptococcus oralis.
Journal of proteome research, 2014Co-Authors: Kazuhiko Maeda, Hideki Nagata, Miki Ojima, Atsuo AmanoAbstract:Porphyromonas gingivalis, a major periodontal pathogen, forms biofilm with other oral bacteria such as streptococci. Here, by using shotgun proteomics, we examined the molecular basis of mixed-biofilm formation by P. gingivalis with Streptococcus oralis. We identified a total of 593 bacterial proteins in the biofilm. Compared to the expression profile in the P. gingivalis monobiofilm, the expression of three proteins was induced and that of 31 proteins was suppressed in the mixed biofilm. Additionally, the expression of two S. oralis proteins was increased, while that of two proteins was decreased in the mixed biofilm, as compared to its monotypic profile. mRNA expression analysis of selected genes using a quantitative reverse transcription polymerase chain reaction confirmed the proteomics data, which included overexpression of P. gingivalis FimA and S. oralis glyceraldehyde-3-phosphate dehydrogenase in association with the biofilm. The results also indicated that S. oralis regulates the transcriptional ...
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identification and characterization of porphyromonas gingivalis client proteins that bind to Streptococcus oralis glyceraldehyde 3 phosphate dehydrogenase
Infection and Immunity, 2013Co-Authors: Kazuhiko Maeda, Hideki Nagata, Masae Kuboniwa, Miki Ojima, Naoto Minamino, Tsukasa Osaki, Atsuo AmanoAbstract:Coaggregation of Porphyromonas gingivalis and oral streptococci is thought to play an important role in P. gingivalis colonization. Previously, we reported that P. gingivalis major fimbriae interacted with Streptococcus oralis glyceraldehyde-3-phosphate dehydrogenase (GAPDH), and that amino acid residues 166 to 183 of GAPDH exhibited strong binding activity toward P. gingivalis fimbriae (H. Nagata, M. Iwasaki, K. Maeda, M. Kuboniwa, E. Hashino, M. Toe, N. Minamino, H. Kuwahara, and S. Shizukuishi, Infect. Immun. 77:5130–5138, 2009). The present study aimed to identify and characterize P. gingivalis components other than fimbriae that interact with S. oralis GAPDH. A pulldown assay was performed to detect potential interactions between P. gingivalis client proteins and S. oralis recombinant GAPDH with amino acid residues 166 to 183 deleted by site-directed mutagenesis. Seven proteins, namely, tonB-dependent receptor protein (RagA4), arginine-specific proteinase B, 4-hydroxybutyryl-coenzyme A dehydratase (AbfD), lysine-specific proteinase, GAPDH, NAD-dependent glutamate dehydrogenase (GDH), and malate dehydrogenase (MDH), were identified by two-dimensional gel electrophoresis followed by proteomic analysis using tandem mass spectrometry. Interactions between these client proteins and S. oralis GAPDH were analyzed with a biomolecular interaction analysis system. S. oralis GAPDH showed high affinity for five of the seven client proteins (RagA4, AbfD, GAPDH, GDH, and MDH). Interactions between P. gingivalis and S. oralis were measured by a turbidimetric method and fluorescence microscopy. RagA4, AbfD, and GDH enhanced coaggregation, whereas GAPDH and MDH inhibited coaggregation. Furthermore, the expression of luxS in P. gingivalis was upregulated by RagA4, AbfD, and GDH but was downregulated by MDH. These results indicate that the five P. gingivalis client proteins function as regulators in P. gingivalis biofilm formation with oral streptococci.
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Identification of the Binding Domain of Streptococcus oralis Glyceraldehyde-3-Phosphate Dehydrogenase for Porphyromonas gingivalis Major Fimbriae
Infection and immunity, 2009Co-Authors: Hideki Nagata, Kazuhiko Maeda, Masae Kuboniwa, Mio Iwasaki, Ei Hashino, Masahiro Toe, Naoto Minamino, Hiromiki Kuwahara, Satoshi ShizukuishiAbstract:Porphyromonas gingivalis forms communities with antecedent oral biofilm constituent streptococci. P. gingivalis major fimbriae bind to glyceraldehyde-3-phosphate dehydrogenase (GAPDH) present on the streptococcal surface, and this interaction plays an important role in P. gingivalis colonization. This study identified the binding domain of Streptococcus oralis GAPDH for P. gingivalis fimbriae. S. oralis recombinant GAPDH (rGAPDH) was digested with lysyl endopeptidase. Cleaved fragments of rGAPDH were applied to a reverse-phase high-pressure liquid chromatograph equipped with a C18 column. Each peak was collected; the binding activity toward P. gingivalis recombinant fimbrillin (rFimA) was analyzed with a biomolecular interaction analysis system. The fragment displaying the strongest binding activity was further digested with various proteinases, after which the binding activity of each fragment was measured. The amino acid sequence of each fragment was determined by direct sequencing, mass spectrometric analysis, and amino acid analysis. Amino acid residues 166 to 183 of S. oralis GAPDH exhibited the strongest binding activity toward rFimA; confocal laser scanning microscopy revealed that the synthetic peptide corresponding to amino acid residues 166 to 183 of S. oralis GAPDH (pep166-183, DNFGVVEGLMTTIHAYTG) inhibits S. oralis-P. gingivalis biofilm formation in a dose-dependent manner. Moreover, pep166-183 inhibited interbacterial biofilm formation by several oral streptococci and P. gingivalis strains with different types of FimA. These results indicate that the binding domain of S. oralis GAPDH for P. gingivalis fimbriae exists within the region encompassing amino acid residues 166 to 183 of GAPDH and that pep166-183 may be a potent inhibitor of P. gingivalis colonization in the oral cavity.
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Characterization of binding of Streptococcus oralis glyceraldehyde-3-phosphate dehydrogenase to Porphyromonas gingivalis major fimbriae.
Infection and immunity, 2004Co-Authors: Kazuhiko Maeda, Hideki Nagata, Masae Kuboniwa, Kosuke Kataoka, Nobuko Nishida, Muneo Tanaka, Satoshi ShizukuishiAbstract:Binding of Streptococcus oralis glyceraldehyde-3-phosphate dehydrogenase (GAPDH) to Porphyromonas gingivalis fimbriae was characterized via a biomolecular interaction analysis system. The interaction was specific, and the association constant value was 4.34 x 10(7) M(-1), suggesting that S. oralis GAPDH functions as a dominant receptor for P. gingivalis and contributes to P. gingivalis colonization.