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Sample records for pathogen tannerella forsythia

  1. Pathogenic potential of Tannerella forsythia enolase.

    PubMed

    Lee, J-Y; Jung, Y-J; Jun, H-K; Choi, B-K

    2016-04-01

    Although enolases are cytosolic enzymes involved in the glycolytic pathway, they can also be secreted or expressed on the surface of a variety of eukaryotic cells and bacteria. Surface-exposed enolases of eukaryotes and bacteria can function as plasminogen receptors. Furthermore, antibodies raised against bacterial enolases can react with host enolases, suggesting molecular mimicry between bacterial and host enzymes. In this study, we analyzed an enolase of the major periodontopathogen Tannerella forsythia, which is either secreted or present on the cell surface, via matrix-assisted laser desorption ionization time-of-flight mass spectrometry and immunofluorescence, respectively. The T. forsythia enolase retained the enzymatic activity converting 2-phosphoglycerate to phosphoenolpyruvate and showed plasminogen binding and activating ability, which resulted in the degradation of fibronectin secreted from human gingival fibroblasts. In addition, it induced proinflammatory cytokine production, including interleukin-1β (IL-1β), IL-6, IL-8, and tumour necrosis factor-α (TNF-a) in the human THP-1 monocytic cell line. Taken together, our results demonstrate that T. forsythia enolase plays a role in pathogenesis in the host by plasminogen activation and proinflammatory cytokine induction, which has the potential to exaggerate inflammation in periodontitis.

  2. Glycobiology Aspects of the Periodontal Pathogen Tannerella forsythia.

    PubMed

    Posch, Gerald; Sekot, Gerhard; Friedrich, Valentin; Megson, Zoë A; Koerdt, Andrea; Messner, Paul; Schäffer, Christina

    2012-10-12

    Glycobiology is important for the periodontal pathogen Tannerella forsythia, affecting the bacterium's cellular integrity, its life-style, and virulence potential. The bacterium possesses a unique Gram-negative cell envelope with a glycosylated surface (S-) layer as outermost decoration that is proposed to be anchored via a rough lipopolysaccharide. The S-layer glycan has the structure 4‑MeO-b-ManpNAcCONH2-(1→3)-[Pse5Am7Gc-(2→4)-]-b-ManpNAcA-(1→4)-[4-MeO-a-Galp-(1→2)-]-a-Fucp-(1→4)-[-a-Xylp-(1→3)-]-b-GlcpA-(1→3)-[-b-Digp-(1→2)-]-a-Galp and is linked to distinct serine and threonine residues within the D(S/T)(A/I/L/M/T/V) amino acid motif. Also several other Tannerella proteins are modified with the S‑layer oligosaccharide, indicating the presence of a general O‑glycosylation system. Protein O‑glycosylation impacts the life-style of T. forsythia since truncated S-layer glycans present in a defined mutant favor biofilm formation. While the S‑layer has also been shown to be a virulence factor and to delay the bacterium's recognition by the innate immune system of the host, the contribution of glycosylation to modulating host immunity is currently unraveling. Recently, it was shown that Tannerella surface glycosylation has a role in restraining the Th17-mediated neutrophil infiltration in the gingival tissues. Related to its asaccharolytic physiology, T. forsythia expresses a robust enzymatic repertoire, including several glycosidases, such as sialidases, which are linked to specific growth requirements and are involved in triggering host tissue destruction. This review compiles the current knowledge on the glycobiology of T. forsythia.

  3. Sialic acid, periodontal pathogens and Tannerella forsythia: stick around and enjoy the feast!

    PubMed

    Stafford, G; Roy, S; Honma, K; Sharma, A

    2012-02-01

    Periodontal pathogens, like any other human commensal or pathogenic bacterium, must possess both the ability to acquire the necessary growth factors and the means to adhere to surfaces or reside and survive in their environmental niche. Recent evidence has suggested that sialic acid containing host molecules may provide both of these requirements in vivo for several periodontal pathogens but most notably for the red complex organism Tannerella forsythia. Several other periodontal pathogens also possess sialic acid scavenging enzymes - sialidases, which can also expose adhesive epitopes, but might also act as adhesins in their own right. In addition, recent experimental work coupled with the release of several genome sequences has revealed that periodontal bacteria have a range of sialic acid uptake and utilization systems while others may also use sialic acid as a cloaking device on their surface to mimic host and avoid immune recognition. This review will focus on these systems in a range of periodontal bacteria with a focus on Ta. forsythia.

  4. Beta-hexosaminidase activity of the oral pathogen Tannerella forsythia influences biofilm formation on glycoprotein substrates.

    PubMed

    Roy, Sumita; Phansopa, Chatchawal; Stafford, Prachi; Honma, Kiyonobu; Douglas, C W Ian; Sharma, Ashu; Stafford, Graham P

    2012-06-01

    Tannerella forsythia is an important pathogen in periodontal disease. Previously, we showed that its sialidase activity is key to utilization of sialic acid from a range of human glycoproteins for biofilm growth and initial adhesion. Removal of terminal sialic acid residues often exposes β-linked glucosamine or galactosamine, which may also be important adhesive molecules. In turn, these residues are often removed by a group of enzymes known as β-hexosaminidases. We show here that T. forsythia has the ability to cleave glucosamine and galactosamine from model substrates and that this activity can be inhibited by the hexosaminidase inhibitor PugNAc (O-(2-acetamido-2-deoxy-d-glucopyranosylidene)amino N-phenyl carbamate). We now demonstrate for the first time that β-hexosaminidase activity plays a role in biofilm growth on glycoprotein-coated surfaces because biofilm growth and initial cell adhesion are inhibited by PugNAc. In contrast, adhesion to siallo-glycoprotein-coated surfaces is unaltered by PugNAc in the absence of sialidase activity (using a sialidase-deficient mutant) or surprisingly on the clinically relevant substrates saliva or serum. These data indicate that β-hexosaminidase activity has a significant role in biofilm formation in combination with sialidase activity in the biofilm lifestyle of T. forsythia.

  5. A quantitative proteomic analysis of biofilm adaptation by the periodontal pathogen Tannerella forsythia.

    PubMed

    Pham, Trong Khoa; Roy, Sumita; Noirel, Josselin; Douglas, Ian; Wright, Phillip C; Stafford, Graham P

    2010-09-01

    Tannerella forsythia is a Gram-negative anaerobe that is one of the most prominent inhabitants of the sub-gingival plaque biofilm, which is crucial for causing periodontitis. We have used iTRAQ proteomics to identify and quantify alterations in global protein expression of T. forsythia during growth in a biofilm. This is the first proteomic study concentrating on biofilm growth in this key periodontal pathogen, and this study has identified several changes in protein expression. Moreover, we introduce a rigorous statistical method utilising peptide-level intensities of iTRAQ reporters to determine which proteins are significantly regulated. In total, 348 proteins were identified and quantified with the expression of 44 proteins being significantly altered between biofilm and planktonic cells. We identified proteins from all cell compartments, and highlighted a marked upregulation in the relative abundances of predicted outer membrane proteins in biofilm cells. These included putative transport systems and the T. forsythia S-layer proteins. These data and our finding that the butyrate production pathway is markedly downregulated in biofilms indicate possible alterations in host interaction capability. We also identified upregulation of putative oxidative stress response proteins, and showed that biofilm cells are 10 to 20 fold more resistant to oxidative stress. This may represent an important adaptation of this organism to prolonged persistence and immune evasion in the oral cavity.

  6. A novel sialic acid utilization and uptake system in the periodontal pathogen Tannerella forsythia.

    PubMed

    Roy, Sumita; Douglas, C W Ian; Stafford, Graham P

    2010-05-01

    Tannerella forsythia is a key contributor to periodontitis, but little is known of its virulence mechanisms. In this study we have investigated the role of sialic acid in biofilm growth of this periodontal pathogen. Our data show that biofilm growth of T. forsythia is stimulated by sialic acid, glycolyl sialic acid, and sialyllactose, all three of which are common sugar moieties on a range of important host glycoproteins. We have also established that growth on sialyllactose is dependent on the sialidase of T. forsythia since the sialidase inhibitor oseltamivir suppresses growth on sialyllactose. The genome of T. forsythia contains a sialic acid utilization locus, which also encodes a putative inner membrane sialic acid permease (NanT), and we have shown this is functional when it is expressed in Escherichia coli. This genomic locus also contains a putatively novel TonB-dependent outer membrane sialic acid transport system (TF0033-TF0034). In complementation studies using an Escherichia coli strain devoid of its outer membrane sialic acid transporters, the cloning and expression of the TF0033-TF0034 genes enabled an E. coli nanR nanC ompR strain to utilize sialic acid as the sole carbon and energy source. We have thus identified a novel sialic acid uptake system that couples an inner membrane permease with a TonB-dependent outer membrane transporter, and we propose to rename these novel sialic acid uptake genes nanO and nanU, respectively. Taken together, these data indicate that sialic acid is a key growth factor for this little-characterized oral pathogen and may be key to its physiology in vivo.

  7. Draft Genome Sequence of Tannerella forsythia Type Strain ATCC 43037.

    PubMed

    Friedrich, Valentin; Pabinger, Stephan; Chen, Tsute; Messner, Paul; Dewhirst, Floyd E; Schäffer, Christina

    2015-06-11

    Tannerella forsythia is an oral pathogen implicated in the development of periodontitis. Here, we report the draft genome sequence of the Tannerella forsythia strain ATCC 43037. The previously available genome of this designation (NCBI reference sequence NC_016610.1) was discovered to be derived from a different strain, FDC 92A2 (= ATCC BAA-2717).

  8. A novel matrix metalloprotease-like enzyme (karilysin) of the periodontal pathogen Tannerella forsythia ATCC 43037.

    PubMed

    Karim, Abdulkarim Y; Kulczycka, Magdalena; Kantyka, Tomasz; Dubin, Grzegorz; Jabaiah, Abeer; Daugherty, Patrick S; Thogersen, Ida B; Enghild, Jan J; Nguyen, Ky-Anh; Potempa, Jan

    2010-01-01

    Proteases of Tannerella forsythia, a pathogen associated with periodontal disease, are implicated as virulence factors. Here, we characterized a matrix metalloprotease (MMP)-like enzyme of T. forsythia referred to as karilysin. Full-length (without a signal peptide) recombinant karilysin (49.9 kDa) processed itself into the mature 18-kDa enzyme through sequential autoproteolytic cleavage at both N- and C-terminal profragments. The first cleavage at the Asn14-Tyr15 peptide bond generated the fully active enzyme (47.9 kDa) and subsequent truncations at the C-terminus did not affect proteolytic activity. Mutation of Tyr15 to Ala generated a prokarilysin variant that processed itself into the final 18-kDa form with greatly reduced kinetics. Inactive prokarilysin with the mutated catalytic Glu residue (E136A) was processed by active karilysin at the same sites as the active enzymes. Karilysin proteolytic activity and autoprocessing were inhibited by 1,10-phenanthroline and EDTA. Calcium ions were found to be important for both the activity and thermal stability of karilysin. Using CLiPS technology, the specificity of karilysin was found to be similar to that of MMPs with preference for Leu/Tyr/Met at P1' and Pro/Ala at P3. This specificity and the ability to degrade elastin, fibrinogen and fibronectin may contribute to the pathogenicity of periodontitis.

  9. Analysis of the cell surface layer ultrastructure of the oral pathogen Tannerella forsythia.

    PubMed

    Sekot, Gerhard; Posch, Gerald; Oh, Yoo Jin; Zayni, Sonja; Mayer, Harald F; Pum, Dietmar; Messner, Paul; Hinterdorfer, Peter; Schäffer, Christina

    2012-06-01

    The Gram-negative oral pathogen Tannerella forsythia is decorated with a 2D crystalline surface (S-) layer, with two different S-layer glycoprotein species being present. Prompted by the predicted virulence potential of the S-layer, this study focused on the analysis of the arrangement of the individual S-layer glycoproteins by a combination of microscopic, genetic, and biochemical analyses. The two S-layer genes are transcribed into mRNA and expressed into protein in equal amounts. The S-layer was investigated on intact bacterial cells by transmission electron microscopy, by immune fluorescence microscopy, and by atomic force microscopy. The analyses of wild-type cells revealed a distinct square S-layer lattice with an overall lattice constant of 10.1 ± 0.7 nm. In contrast, a blurred lattice with a lattice constant of 9.0 nm was found on S-layer single-mutant cells. This together with in vitro self-assembly studies using purified (glyco)protein species indicated their increased structural flexibility after self-assembly and/or impaired self-assembly capability. In conjunction with TEM analyses of thin-sectioned cells, this study demonstrates the unusual case that two S-layer glycoproteins are co-assembled into a single S-layer. Additionally, flagella and pilus-like structures were observed on T. forsythia cells, which might impact the pathogenicity of this bacterium.

  10. Characterization of an α-l-fucosidase from the periodontal pathogen Tannerella forsythia.

    PubMed

    Megson, Z A; Koerdt, A; Schuster, H; Ludwig, R; Janesch, B; Frey, A; Naylor, K; Wilson, I B H; Stafford, G P; Messner, P; Schäffer, C

    2015-01-01

    The periodontal pathogen Tannerella forsythia expresses several glycosidases which are linked to specific growth requirements and are involved in the invasion of host tissues. α-l-Fucosyl residues are exposed on various host glycoconjugates and, thus, the α-l-fucosidases predicted in the T. forsythia ATCC 43037 genome could potentially serve roles in host-pathogen interactions. We describe the molecular cloning and characterization of the putative fucosidase TfFuc1 (encoded by the bfo_2737 = Tffuc1 gene), previously reported to be present in an outer membrane preparation. In terms of sequence, this 51-kDa protein is a member of the glycosyl hydrolase family GH29. Using an artificial substrate, p-nitrophenyl-α-fucose (KM 670 μM), the enzyme was determined to have a pH optimum of 9.0 and to be competitively inhibited by fucose and deoxyfuconojirimycin. TfFuc1 was shown here to be a unique α(1,2)-fucosidase that also possesses α(1,6) specificity on small unbranched substrates. It is active on mucin after sialidase-catalyzed removal of terminal sialic acid residues and also removes fucose from blood group H. Following knock-out of the Tffuc1 gene and analyzing biofilm formation and cell invasion/adhesion of the mutant in comparison to the wild-type, it is most likely that the enzyme does not act extracellularly. Biochemically interesting as the first fucosidase in T. forsythia to be characterized, the biological role of TfFuc1 may well be in the metabolism of short oligosaccharides in the periplasm, thereby indirectly contributing to the virulence of this organism. TfFuc1 is the first glycosyl hydrolase in the GH29 family reported to be a specific α(1,2)-fucosidase.

  11. Macrophage inducible C-type lectin (Mincle) recognizes glycosylated surface (S)-layer of the periodontal pathogen Tannerella forsythia.

    PubMed

    Chinthamani, Sreedevi; Settem, Rajendra P; Honma, Kiyonobu; Kay, Jason G; Sharma, Ashu

    2017-01-01

    The oral pathogen Tannerella forsythia is implicated in the development of periodontitis, a common inflammatory disease that leads to the destruction of the gum and tooth supporting tissues, often leading to tooth loss. T. forsythia is a unique Gram-negative organism endowed with an elaborate protein O-glycosylation system that allows the bacterium to express a glycosylated surface (S)-layer comprising two high molecular weight glycoproteins modified with O-linked oligosaccharides. The T. forsythia S-layer has been implicated in the modulation of cytokine responses of antigen presenting cells, such as macrophages, that play a significant role during inflammation associated with periodontitis. The macrophage-inducible C-type lectin receptor (Mincle) is an FcRγ-coupled pathogen recognition receptor that recognizes a wide variety of sugar containing ligands from fungal and bacterial pathogens. In this study, we aimed to determine if Mincle might be involved in the recognition of T. forsythia S-layer and modulation of cytokine response of macrophages against the bacterium. Binding studies using recombinant Mincle-Fc fusion protein indicated a specific Ca2+-dependent binding of Mincle to T. forsythia S-layer. Subsequent experiments with Mincle-expressing and Mincle-knockdown macrophages revealed a role for Mincle/S-layer interaction in the induction of both pro- and anti-inflammatory cytokine secretion in macrophages stimulated with T. forsythia as well as its S-layer. Together, these studies revealed Mincle as an important macrophage receptor involved in the modulation of cytokine responses of macrophages against T. forsythia, and thus may play a critical role in orchestrating the host immune response against the bacterium.

  12. Macrophage inducible C-type lectin (Mincle) recognizes glycosylated surface (S)-layer of the periodontal pathogen Tannerella forsythia

    PubMed Central

    Chinthamani, Sreedevi; Settem, Rajendra P.; Honma, Kiyonobu; Kay, Jason G.

    2017-01-01

    The oral pathogen Tannerella forsythia is implicated in the development of periodontitis, a common inflammatory disease that leads to the destruction of the gum and tooth supporting tissues, often leading to tooth loss. T. forsythia is a unique Gram-negative organism endowed with an elaborate protein O-glycosylation system that allows the bacterium to express a glycosylated surface (S)-layer comprising two high molecular weight glycoproteins modified with O-linked oligosaccharides. The T. forsythia S-layer has been implicated in the modulation of cytokine responses of antigen presenting cells, such as macrophages, that play a significant role during inflammation associated with periodontitis. The macrophage-inducible C-type lectin receptor (Mincle) is an FcRγ-coupled pathogen recognition receptor that recognizes a wide variety of sugar containing ligands from fungal and bacterial pathogens. In this study, we aimed to determine if Mincle might be involved in the recognition of T. forsythia S-layer and modulation of cytokine response of macrophages against the bacterium. Binding studies using recombinant Mincle-Fc fusion protein indicated a specific Ca2+-dependent binding of Mincle to T. forsythia S-layer. Subsequent experiments with Mincle-expressing and Mincle-knockdown macrophages revealed a role for Mincle/S-layer interaction in the induction of both pro- and anti-inflammatory cytokine secretion in macrophages stimulated with T. forsythia as well as its S-layer. Together, these studies revealed Mincle as an important macrophage receptor involved in the modulation of cytokine responses of macrophages against T. forsythia, and thus may play a critical role in orchestrating the host immune response against the bacterium. PMID:28264048

  13. Single cell genomics of uncultured, health-associated Tannerella BU063 (Oral Taxon 286) and comparison to the closely related pathogen Tannerella forsythia.

    PubMed

    Beall, Clifford J; Campbell, Alisha G; Dayeh, Daniel M; Griffen, Ann L; Podar, Mircea; Leys, Eugene J

    2014-01-01

    The uncultivated bacterium Tannerella BU063 (oral taxon 286) is the closest relative to the periodontal pathogen Tannerella forsythia, but is not disease-associated itself. Using a single cell genomics approach, we isolated 12 individual BU063 cells by flow cytometry, and we amplified and sequenced their genomes. Comparative analyses of the assembled genomic scaffolds and their gene contents allowed us to study the diversity of this taxon within the oral community of a single human donor that provided the sample. Eight different BU063 genotypes were represented, all about 5% divergent at the nucleotide level. There were 2 pairs of cells and one group of three that were more highly identical, and may represent clonal populations. We did pooled assemblies on the nearly identical genomes to increase the assembled genomic coverage. The presence of a set of 66 "core" housekeeping genes showed that two of the single cell assemblies and the assembly derived from the three putatively identical cells were essentially complete. As expected, the genome of BU063 is more similar to Tannerella forsythia than any other known genome, although there are significant differences, including a 44% difference in gene content, changes in metabolic pathways, loss of synteny, and an 8-9% difference in GC content. Several identified virulence genes of T. forsythia are not found in BU063 including karilysin, prtH, and bspA. The absence of these genes may explain the lack of periodontal pathogenesis by this species and provides a new foundation to further understand the genome evolution and mechanisms of bacterial-host interaction in closely related oral microbes with different pathogenicity potential.

  14. Single Cell Genomics of Uncultured, Health-Associated Tannerella BU063 (Oral Taxon 286) and Comparison to the Closely Related Pathogen Tannerella forsythia

    PubMed Central

    Beall, Clifford J.; Campbell, Alisha G.; Dayeh, Daniel M.; Griffen, Ann L.; Podar, Mircea; Leys, Eugene J.

    2014-01-01

    The uncultivated bacterium Tannerella BU063 (oral taxon 286) is the closest relative to the periodontal pathogen Tannerella forsythia, but is not disease-associated itself. Using a single cell genomics approach, we isolated 12 individual BU063 cells by flow cytometry, and we amplified and sequenced their genomes. Comparative analyses of the assembled genomic scaffolds and their gene contents allowed us to study the diversity of this taxon within the oral community of a single human donor that provided the sample. Eight different BU063 genotypes were represented, all about 5% divergent at the nucleotide level. There were 2 pairs of cells and one group of three that were more highly identical, and may represent clonal populations. We did pooled assemblies on the nearly identical genomes to increase the assembled genomic coverage. The presence of a set of 66 “core” housekeeping genes showed that two of the single cell assemblies and the assembly derived from the three putatively identical cells were essentially complete. As expected, the genome of BU063 is more similar to Tannerella forsythia than any other known genome, although there are significant differences, including a 44% difference in gene content, changes in metabolic pathways, loss of synteny, and an 8–9% difference in GC content. Several identified virulence genes of T. forsythia are not found in BU063 including karilysin, prtH, and bspA. The absence of these genes may explain the lack of periodontal pathogenesis by this species and provides a new foundation to further understand the genome evolution and mechanisms of bacterial-host interaction in closely related oral microbes with different pathogenicity potential. PMID:24551246

  15. Structure and Immunogenicity of the Rough-Type Lipopolysaccharide from the Periodontal Pathogen Tannerella forsythia

    PubMed Central

    Posch, Gerald; Andrukhov, Oleh; Vinogradov, Evgeny; Lindner, Buko; Messner, Paul

    2013-01-01

    Tannerella forsythia is a Gram-negative anaerobic organism that inhabits subgingival plaque biofilms and is covered with a so far unique surface layer composed of two glycoproteins. It belongs to the so-called “red complex” of bacteria comprising species that are associated with periodontal disease. While the surface layer glycoprotein glycan structure had been elucidated recently and found to be a virulence factor, no structural data on the lipopolysaccharide (LPS) of this organism were available. In this study, the T. forsythia LPS structure was partially elucidated by a combined mass spectrometry (MS) and nuclear magnetic resonance spectroscopy (NMR) approach and initial experiments to characterize its immunostimulatory potential were performed. The T. forsythia LPS is a complex, rough-type LPS with a core region composed of one 3-deoxy-d-manno-oct-2-ulosonic acid (Kdo) residue, three mannose residues, and two glucosamine residues. MS analyses of O-deacylated LPS proved that, in addition, one phosphoethanolamine residue and most likely one galactose-phosphate residue were present, however, their positions could not be identified. Stimulation of human macrophages with T. forsythia LPS resulted in the production of the proinflammatory cytokines interleukin-1 (IL-1), IL-6, and tumor necrosis factor alpha in a dose-dependent manner. The response to T. forsythia LPS was observed only upon stimulation in the presence of fetal calf serum (FCS), whereas no cytokine production was observed in the absence of FCS. This finding suggests that the presence of certain additional cofactors is crucial for the immune response induced by T. forsythia LPS. PMID:23616409

  16. Structure and immunogenicity of the rough-type lipopolysaccharide from the periodontal pathogen Tannerella forsythia.

    PubMed

    Posch, Gerald; Andrukhov, Oleh; Vinogradov, Evgeny; Lindner, Buko; Messner, Paul; Holst, Otto; Schäffer, Christina

    2013-06-01

    Tannerella forsythia is a Gram-negative anaerobic organism that inhabits subgingival plaque biofilms and is covered with a so far unique surface layer composed of two glycoproteins. It belongs to the so-called "red complex" of bacteria comprising species that are associated with periodontal disease. While the surface layer glycoprotein glycan structure had been elucidated recently and found to be a virulence factor, no structural data on the lipopolysaccharide (LPS) of this organism were available. In this study, the T. forsythia LPS structure was partially elucidated by a combined mass spectrometry (MS) and nuclear magnetic resonance spectroscopy (NMR) approach and initial experiments to characterize its immunostimulatory potential were performed. The T. forsythia LPS is a complex, rough-type LPS with a core region composed of one 3-deoxy-d-manno-oct-2-ulosonic acid (Kdo) residue, three mannose residues, and two glucosamine residues. MS analyses of O-deacylated LPS proved that, in addition, one phosphoethanolamine residue and most likely one galactose-phosphate residue were present, however, their positions could not be identified. Stimulation of human macrophages with T. forsythia LPS resulted in the production of the proinflammatory cytokines interleukin-1 (IL-1), IL-6, and tumor necrosis factor alpha in a dose-dependent manner. The response to T. forsythia LPS was observed only upon stimulation in the presence of fetal calf serum (FCS), whereas no cytokine production was observed in the absence of FCS. This finding suggests that the presence of certain additional cofactors is crucial for the immune response induced by T. forsythia LPS.

  17. Identification and characterization of a chymotrypsin-like serine protease from periodontal pathogen, Tannerella forsythia.

    PubMed

    Hockensmith, K; Dillard, K; Sanders, B; Harville, B A

    2016-11-01

    Tannerella forsythia is a bacteria associated with severe periodontal disease. This study reports identification and characterization of a membrane-associated serine protease from T. forsythia. The protease was isolated from T. forsythia membrane fractions and shown to cleave both gelatin and type I collagen. The protease was able to cleave both substrates over a wide range of pH values, however optimal cleavage occurred at pH 7.5 for gelatin and 8.0 for type I collagen. The protease was also shown to cleave both gelatin and type I collagen at the average reported temperature for the gingival sulcus however it showed a lack of thermal stability with a complete loss of activity by 60 °C. When treated with protease inhibitors the enzyme's activity could only be completely inhibited by serine protease inhibitors antipain and phenylmethanesulfonyl fluoride (PMSF). Further characterization of the protease utilized serine protease synthetic peptides. The protease cleaved N-succinyl-Ala-Ala-Pro-Phe p-nitroanilide but not Nα-benzoyl-dl-arginine p-nitroanilide (BAPNA) or N-methoxysuccinyl-Ala-Ala-Pro-Val p-nitroanilide indicating that the protease is a chymotrypsin-like serine protease. Since type I collagen is a major component in the gingival tissues and periodontal ligament, identification and characterization of this enzyme provides important information regarding the role of T. forsythia in periodontal disease.

  18. Inositol-phosphodihydroceramides in the periodontal pathogen Tannerella forsythia: Structural analysis and incorporation of exogenous myo-inositol

    PubMed Central

    Megson, Zoë Anne; Pittenauer, Ernst; Duda, Katarzyna Anna; Engel, Regina; Ortmayr, Karin; Koellensperger, Gunda; Mach, Lukas; Allmaier, Günter; Holst, Otto; Messner, Paul; Schäffer, Christina

    2015-01-01

    Background Unique phosphodihydroceramides containing phosphoethanolamine and glycerol have been previously described in Porphyromonas gingivalis. Importantly, they were shown to possess pro-inflammatory properties. Other common human bacteria were screened for the presence of these lipids, and they were found, amongst others, in the oral pathogen Tannerella forsythia. To date, no detailed study into the lipids of this organism has been performed. Methods Lipids were extracted, separated and purified by HPTLC, and analyzed using GC-MS, ESI–MS and NMR. Of special interest was how T. forsythia acquires the metabolic precursors for the lipids studied here. This was assayed by radioactive and stable isotope incorporation using carbon-14 and deuterium labeled myo-inositol, added to the growth medium. Results T. forsythia synthesizes two phosphodihydroceramides (Tf GL1, Tf GL2) which are constituted by phospho-myo-inositol linked to either a 17-, 18-, or 19-carbon sphinganine, N-linked to either a branched 17:0(3-OH) or a linear 16:0(3-OH) fatty acid which, in Tf GL2, is, in turn, ester-substituted with a branched 15:0 fatty acid. T. forsythia lacks the enzymatic machinery required for myo-inositol synthesis but was found to internalize inositol from the medium for the synthesis of both Tf GL1 and Tf GL2. Conclusion The study describes two novel glycolipids in T. forsythia which could be essential in this organism. Their synthesis could be reliant on an external source of myo-inositol. General significance The effects of these unique lipids on the immune system and their role in bacterial virulence could be relevant in the search for new drug targets. PMID:26277409

  19. [Pathogenic potential of Porphyromonas gingivalis, Treponema denticola and Tannerella forsythia, the red bacterial complex associated with periodontitis].

    PubMed

    Bodet, C; Chandad, F; Grenier, D

    2007-01-01

    Periodontitis are mixed bacterial infections leading to destruction of tooth-supporting tissues, including periodontal ligament and alveolar bone. Among over 500 bacterial species living in the oral cavity, a bacterial complex named "red complex" and made of Porphyromonas gingivalis, Treponema denticola and Tannerella forsythia has been strongly related to advanced periodontal lesions. While periodontopathogenic bacteria are the primary etiologic factor of periodontitis, tissue destruction essentially results from the host immune response to the bacterial challenge. Members of the red complex are Gram negative anaerobic bacteria expressing numerous virulence factors allowing bacteria to colonize the subgingival sites, to disturb the host defense system, to invade and destroy periodontal tissue as well as to promote the immunodestructive host response. This article reviews current knowledge of the pathogenic mechanisms of bacteria of the red complex leading to tissue and alveolar bone destruction observed during periodontitis.

  20. Reducing the bioactivity of Tannerella forsythia lipopolysaccharide by Porphyromonas gingivalis.

    PubMed

    Kim, Young-Jae; Lee, Sung-Hoon

    2014-08-01

    Tannerella forsythia is considered a pathogen of periodontitis and forms a biofilm with multi-species bacteria in oral cavity. Lipopolysaccharide is a powerful immunostimulator and induces inflammation and shock. The purpose of this study was to investigate the characteristics of T. forsythia LPS in its co-cultivation with Fusobacterium nucleatum or Porphyromonas gingivalis. T. forsythia was co-cultured in the presence and absence of F. nucleatum and P. gingivalis and then T. forsythia LPS was extracted. The extracts were analyzed by SDS-PAGE and NF-κB reporter CHO cell lines. THP-1 cells were treated with the LPS and evaluated induction of cytokine expression by real-time RT-PCR and ELISA. For analysis of the bioactivity of T. forsythia LPS, the binding assay on LPS-binding protein (LBP) and CD14 was processed. The extracts did not contaminate other molecules except LPS and showed TLR4 agonists. Co-cultured T. forsythia LPS with P. gingivalis exhibited a lower level of induction of TNF-α, IL-1β, and IL-6 expression than single- or co-cultured T. forsythia LPS with F. nucleatum in the conditions of human serum. However, the three T. forsythia LPS did not show difference of cytokine induction in the serum free conditions. Co-cultured T. forsythia LPS with P. gingivalis exhibited a lower affinity to LBP and CD14 as binding site of O-antigen and attached at a lower level to THP-1 cells compared to single- or co-cultured T. forsythia LPS with F. nucleatum. The virulence of T. forsythia LPS was decreased by co-culturing with P. gingivalis and their affinity to LBP and CD14 was reduced, which may due to modification of O-antigen chain by P. gingivalis.

  1. Isolation and identification of a cytopathic activity in Tannerella forsythia.

    PubMed

    Nakajima, Takuma; Tomi, Naoko; Fukuyo, Yayoi; Ishikura, Hiroaki; Ohno, Yuka; Arvind, Ramanathan; Arai, Takao; Ishikawa, Isao; Arakawa, Shinichi

    2006-12-08

    Interactions between pathogens and host induce human disorders including periodontitis, disintegration of the tooth supporting tissues. Tannerella forsythia has been linked to the periodontitis and several cytopathic reagents have been found in the bacterium; however, its contribution to the disease remains unclear. Biochemical approach to explore the cytopathic effect revealed two distinct activities in T. forsythia (ATCC 43037) extract; one detaches adherent cells from substratum and another arrests cells at G2. An executor of former activity, forsythia detaching factor (FDF) was identified; its genomic sequence and peptidase activity revealed that FDF is a substantial form of putative PrtH; prtH gene was hypothetically identified directly from a DNA fragment of the bacterium and its native product has never been shown. Since FDF was found in the bacterial culture supernatant, its activity implies a contribution to the disintegration of tissues although the mechanism how FDF disturbs cellular anchors remains elusive.

  2. A pathogenic trace of Tannerella forsythia - shedding of soluble fully active tumor necrosis factor α from the macrophage surface by karilysin.

    PubMed

    Bryzek, D; Ksiazek, M; Bielecka, E; Karim, A Y; Potempa, B; Staniec, D; Koziel, J; Potempa, J

    2014-12-01

    Tannerella forsythia is implicated as a pathogen causing chronic and aggressive periodontitis. However, its virulence factors, including numerous putative proteases, are mostly uncharacterized. Karilysin is a newly described matrix metalloprotease-like enzyme of T. forsythia. Since pathogen-derived proteases may affect the host defense system via modulation of the cytokine network, the aim of this study was to determine the influence of karilysin on tumor necrosis factor-α (TNF-α). The results showed that karilysin cleaved the membrane form of TNF-α on the surface of macrophages, and that this led to an increased concentration of soluble TNF-α in the conditioned medium. Importantly, despite partial degradation of soluble TNF-α by karilysin, the released cytokine retained its biological activity, inducing apoptosis and stimulating autocrine pathway of pro-inflammatory gene expression. Notably, the observed effect required proteolytic activity by karilysin, since a catalytically inactive mutant of the enzyme did not affect TNF-α secretion. The shedding was independent of the activity of ADAM17, a major endogenous TNF-α converting enzyme. Karilysin-dependent TNF-α release from the cell surface is likely to occur in vivo because human plasma, the main constituent of gingival crevicular fluid, only slightly affected the sheddase activity of karilysin. Taken together, these results indicate that karilysin modulates the host immune response through regulation of TNF-α secretion, and should therefore be considered as a new virulence factor of T. forsythia.

  3. Dentilisin involvement in coaggregation between Treponema denticola and Tannerella forsythia.

    PubMed

    Sano, Yumiko; Okamoto-Shibayama, Kazuko; Tanaka, Kimiko; Ito, Rieko; Shintani, Seikou; Yakushiji, Masashi; Ishihara, Kazuyuki

    2014-12-01

    Periodontitis arises from a biofilm consisting of gram-negative anaerobic rods and spirochetes. Porphyromonas gingivalis, Treponema denticola, and Tannerella forsythia, termed the Red complex, have been co-isolated with high frequency from chronic periodontitis lesions, and these microorganisms are thought to be major pathogens of the disease. Coaggregation is an important strategy in the colonization of dental plaque biofilm by these bacteria. In the present study, we investigated the coaggregation of T. denticola strains with T. forsythia ATCC 43037 by use of visual grading or spectrophotometry. T. denticola ATCC 35405 coaggregated with T. forsythia, reaching a plateau at approximately 60 min. This coaggregation was inhibited by heat treatment of T. denticola ATCC 35405, but not of T. forsythia. Disaccharides such as sucrose, maltose, and lactose inhibited coaggregation by approximately 50%. The coaggregation reaction varied among T. denticola strains. There was somewhat less coaggregation between T. denticola ATCC 33520 and T. forsythia than between T. denticola ATCC 35405 and T. forsythia, although this difference was not statistically significant; T. denticola ATCC 33521 showed a trace level of coaggregation with T. forsythia. The magnitude of coaggregation among the three T. denticola strains was proportional to their dentilisin activities. Inactivation of dentilisin abolished coaggregation activity, but inactivation of the major outer sheath protein did not. In addition, phenylmethylsulfonyl fluoride did not affect coaggregation. These results indicate that dentilisin is involved indirectly in the coaggregation between T. denticola and T. forsythia, because its proteolytic activity is not required, possibly via ligand maturation.

  4. Role of sialidase in glycoprotein utilization by Tannerella forsythia.

    PubMed

    Roy, Sumita; Honma, Kiyonobu; Douglas, C W Ian; Sharma, Ashu; Stafford, Graham P

    2011-11-01

    The major bacterial pathogens associated with periodontitis include Tannerella forsythia. We previously discovered that sialic acid stimulates biofilm growth of T. forsythia, and that sialidase activity is key to utilization of sialoconjugate sugars and is involved in host-pathogen interactions in vitro. The aim of this work was to assess the influence of the NanH sialidase on initial biofilm adhesion and growth in experiments where the only source of sialic acid was sialoglycoproteins or human oral secretions. After showing that T. forsythia can utilize sialoglycoproteins for biofilm growth, we showed that growth and initial adhesion with sialylated mucin and fetuin were inhibited two- to threefold by the sialidase inhibitor oseltamivir. A similar reduction (three- to fourfold) was observed with a nanH mutant compared with the wild-type. Importantly, these data were replicated using clinically relevant serum and saliva samples as substrates. In addition, the ability of the nanH mutant to form biofilms on glycoprotein-coated surfaces could be restored by the addition of purified NanH, which we show is able to cleave sialic acid from the model glycoprotein fetuin and, much less efficiently, 9-O-acetylated bovine submaxillary mucin. These data show for the first time that glycoprotein-associated sialic acid is likely to be a key in vivo nutrient source for T. forsythia when growing in a biofilm, and suggest that sialidase inhibitors might be useful adjuncts in periodontal therapy.

  5. Role of sialidase in glycoprotein utilization by Tannerella forsythia

    PubMed Central

    Roy, Sumita; Honma, Kiyonobu; Douglas, C. W. Ian; Sharma, Ashu

    2011-01-01

    The major bacterial pathogens associated with periodontitis include Tannerella forsythia. We previously discovered that sialic acid stimulates biofilm growth of T. forsythia, and that sialidase activity is key to utilization of sialoconjugate sugars and is involved in host–pathogen interactions in vitro. The aim of this work was to assess the influence of the NanH sialidase on initial biofilm adhesion and growth in experiments where the only source of sialic acid was sialoglycoproteins or human oral secretions. After showing that T. forsythia can utilize sialoglycoproteins for biofilm growth, we showed that growth and initial adhesion with sialylated mucin and fetuin were inhibited two- to threefold by the sialidase inhibitor oseltamivir. A similar reduction (three- to fourfold) was observed with a nanH mutant compared with the wild-type. Importantly, these data were replicated using clinically relevant serum and saliva samples as substrates. In addition, the ability of the nanH mutant to form biofilms on glycoprotein-coated surfaces could be restored by the addition of purified NanH, which we show is able to cleave sialic acid from the model glycoprotein fetuin and, much less efficiently, 9-O-acetylated bovine submaxillary mucin. These data show for the first time that glycoprotein-associated sialic acid is likely to be a key in vivo nutrient source for T. forsythia when growing in a biofilm, and suggest that sialidase inhibitors might be useful adjuncts in periodontal therapy. PMID:21885482

  6. A simple mutagenesis using natural competence in Tannerella forsythia.

    PubMed

    Nishikawa, Kiyoshi; Tanaka, Yoshinobu

    2013-09-01

    We report the discovery of natural competence in Tannerella forsythia and its application to targeted chromosomal mutagenesis. Keeping T. forsythia in a biofilm throughout the procedure allowed efficient DNA uptake and allelic replacement. This simple method is cost-effective and reproducible compared with the conventional protocols using broth culture and electroporation.

  7. Tannerella forsythia GroEL induces inflammatory bone resorption and synergizes with interleukin-17.

    PubMed

    Jung, Y-J; Choi, Y-J; An, S-J; Lee, H-R; Jun, H-K; Choi, B-K

    2016-08-03

    Tannerella forsythia is a major periodontal pathogen, and T. forsythia GroEL is a molecular chaperone homologous to human heat-shock protein 60. Interleukin-17 (IL-17) has been implicated in the pathogenesis of periodontitis and several systemic diseases. This study investigated the potential of T. forsythia GroEL to induce inflammatory bone resorption and examined the cooperative effect of IL-17 and T. forsythia GroEL on inflammatory responses. Human gingival fibroblasts (HGFs) and periodontal ligament (PDL) fibroblasts were stimulated with T. forsythia GroEL and/or IL-17. Gene expression of IL-6, IL-8, and cyclooxygenase-2 (COX-2) and concentrations of IL-6, IL-8, and prostaglandin E2 (PGE2 ) were measured by real-time reverse transcription polymerase chain reaction and enzyme-linked immunosorbent assays, respectively. After stimulation of MG63 cells with T. forsythia GroEL and/or IL-17, gene expression of osteoprotegerin (OPG) was examined. After subcutaneous injection of T. forsythia GroEL and/or IL-17 above the calvaria of BALB/c mice, calvarial bone resorption was assessed by micro-computed tomography and histological examination. Tannerella forsythia GroEL induced IL-6 and IL-8 production in HGFs and PDL cells, and IL-17 further promoted IL-6 and IL-8 production. Both T. forsythia GroEL and IL-17 synergistically increased PGE2 production and inhibited OPG gene expression. Calvarial bone resorption was induced by T. forsythia GroEL injection, and simultaneous injection of T. forsythia GroEL and IL-17 further increased bone resorption. These results suggest that T. forsythia GroEL is a novel virulence factor that can contribute to inflammatory bone resorption caused by T. forsythia and synergizes with IL-17 to exacerbate inflammation and bone resorption.

  8. Characterization of a sialate-O-acetylesterase (NanS) from the oral pathogen Tannerella forsythia that enhances sialic acid release by NanH, its cognate sialidase.

    PubMed

    Phansopa, Chatchawal; Kozak, Radoslaw P; Liew, Li Phing; Frey, Andrew M; Farmilo, Thomas; Parker, Jennifer L; Kelly, David J; Emery, Robert J; Thomson, Rebecca I; Royle, Louise; Gardner, Richard A; Spencer, Daniel I R; Stafford, Graham P

    2015-12-01

    Tannerella forsythia, a Gram-negative member of the Bacteroidetes has evolved to harvest and utilize sialic acid. The most common sialic acid in humans is a mono-N-acetylated version termed Neu5Ac (5-N-acetyl-neuraminic acid). Many bacteria are known to access sialic acid using sialidase enzymes. However, in humans a high proportion of sialic acid contains a second acetyl group attached via an O-group, i.e. chiefly O-acetylated Neu5,9Ac2 or Neu5,4Ac2. This diacetylated sialic acid is not cleaved efficiently by many sialidases and in order to access diacetylated sialic acid, some organisms produce sialate-O-acetylesterases that catalyse the removal of the second acetyl group. In the present study, we performed bioinformatic and biochemical characterization of a putative sialate-O-acetylesterase from T. forsythia (NanS), which contains two putative SGNH-hydrolase domains related to sialate-O-acetylesterases from a range of organisms. Purification of recombinant NanS revealed an esterase that has activity against Neu5,9Ac2 and its glycolyl form Neu5Gc,9Ac. Importantly, the enzyme did not remove acetyl groups positioned at the 4-O position (Neu5,4Ac2). In addition NanS can act upon complex N-glycans released from a glycoprotein [erythropoietin (EPO)], bovine submaxillary mucin and oral epithelial cell-bound glycans. When incubated with its cognate sialidase, NanS increased sialic acid release from mucin and oral epithelial cell surfaces, implying that this esterase improves sialic acid harvesting for this pathogen and potentially other members of the oral microbiome. In summary, we have characterized a novel sialate-O-acetylesterase that contributes to the sialobiology of this important human pathogen and has potential applications in the analysis of sialic acid diacetylation of biologics in the pharmaceutical industry.

  9. Draft Genome Sequence of Tannerella forsythia Clinical Isolate 9610

    PubMed Central

    Hanson-Drury, Sesha; Liu, Quanhui; Vo, Anh T.; Kim, Michelle; Watling, Michael; Bumgarner, Roger S.

    2017-01-01

    ABSTRACT We present here the draft genome sequence of Tannerella forsythia 9610, a clinical isolate obtained from a periodontitis patient. The genome is composed of 79 scaffolds with 82 contigs, for a length of 3,201,941 bp and a G+C of 47.3%. PMID:28336586

  10. Outer membrane proteome and antigens of Tannerella forsythia.

    PubMed

    Veith, Paul D; O'Brien-Simpson, Neil M; Tan, Yan; Djatmiko, Deasy C; Dashper, Stuart G; Reynolds, Eric C

    2009-09-01

    Tannerella forsythia is a Gram-negative, anaerobic, fusiform bacterium implicated as a periodontal pathogen. With use of 2D PAGE, SDS PAGE, and LC-MALDI-TOF/TOF MS, 221 proteins of T. forsythia outer membrane preparations were identified, of which 197 were predicted to be localized to the cell envelope. Fifty-six proteins were reproducibly mapped by 2D PAGE and included several highly abundant proteins in the MW range 140-250 kDa that exhibited C-terminal sequence similarity to the CTD family of Porphyromonas gingivalis. Two-dimensional Western blot analyses revealed that these CTD family proteins together with several other outer membrane proteins were antigenic. The CTD family proteins exhibited a higher than expected MW, and were strongly reactive with the fluorescent glycoprotein stain, ProQ Emerald. This group included BspA and surface layer proteins A and B. TonB-dependent receptors (TDRs) (46) were identified together with 28 putative lipoproteins whose genes are immediately downstream of a TDR gene. The major OmpA-like protein was found to be TF1331. Uniquely, it was found to exist as a homodimer held together by up to three disulfide bridges as demonstrated by MS/MS of a tryptic peptide derived from unreduced TF1331.

  11. A pseudaminic acid or a legionaminic acid derivative transferase is strain-specifically implicated in the general protein O-glycosylation system of the periodontal pathogen Tannerella forsythia.

    PubMed

    Tomek, Markus B; Janesch, Bettina; Maresch, Daniel; Windwarder, Markus; Altmann, Friedrich; Messner, Paul; Schäffer, Christina

    2017-03-16

    The occurrence of nonulosonic acids in bacteria is wide-spread and linked to pathogenicity. However, the knowledge of cognate nonulosonic acid transferases is scarce. In the periodontopathogen Tannerella forsythia, several proposed virulence factors carry strain-specifically either a pseudaminic or a legionaminic acid derivative as terminal sugar on an otherwise structurally identical, protein-bound oligosaccharide. This study aims to shed light on the transfer of either nonulosonic acid derivative on a proximal N-acetylmannosaminuronic acid residue within the O-glycan structure, exemplified with the bacterium's abundant S-layer glycoproteins. Bioinformatic analyses provided the candidate genes Tanf_01245 (strain ATCC 43037) and TFUB4_00887 (strain UB4), encoding a putative pseudaminic and a legionaminic acid derivative transferase, respectively. These transferases have identical C-termini and contain motifs typical of glycosyltransferases (DXD) and bacterial sialyltransferases (D/E-D/E-G and HP). They share homology to type B glycosyltransferases and TagB, an enzyme catalyzing glycerol transfer to an N-acetylmannosamine residue in teichoic acid biosynthesis. Analysis of a cellular pool of nucleotide-activated sugars confirmed the presence of the CMP-activated nonulosonic acid derivatives, which are most likely serving as substrates for the corresponding transferase. Single gene knock-out mutants targeted at either transferase were analyzed for S-layer O-glycan composition by ESI-MS, confirming the loss of the nonulosonic acid derivative. Cross-complementation of the mutants with the nonnative nonulosonic acid transferase was not successful indicating high stringency of the enzymes. This study identified plausible candidates for a pseudaminic and a legionaminic acid derivative transferase; these may serve as valuable tools for engineering of novel sialoglycoconjugates.

  12. Polymerase chain reaction of Porphyromonas gingivalis, Treponema denticola, and Tannerella forsythia in primary endodontic infections.

    PubMed

    Gomes, Brenda P F A; Montagner, Francisco; Jacinto, Rogério Castilho; Zaia, Alexandre A; Ferraz, Caio Cezar Randi; Souza-Filho, Francisco J

    2007-09-01

    The aim of this study was to investigate the correlation between endodontic clinical signs and symptoms and the presence of Porphyromonas gingivalis, Treponema denticola, and Tannerella forsythia or their association by nested polymerase chain reaction assay. Microbial samples were taken from 50 cases with necrotic pulp tissues in primary infections. DNA was extracted from the samples, which were analyzed for the presence of three endodontic pathogens by using species-specific primers. P gingivalis, T denticola, and T forsythia were detected in 46%, 38%, and 22% of the symptomatic cases, respectively. The bacterial complex composed by T forsythia, P gingivalis, and T denticola was found in 14% of the cases with spontaneous pain, tenderness to percussion, swelling, and pain on palpation. The high prevalence of P gingivalis, T denticola, and T forsythia in the samples examined suggests that these bacteria are related to the etiology of symptomatic periradicular diseases.

  13. Gingipain-dependent augmentation by Porphyromonas gingivalis of phagocytosis of Tannerella forsythia.

    PubMed

    Jung, Y-J; Jun, H-K; Choi, B-K

    2016-12-01

    In the pathogenesis of periodontitis, Porphyromonas gingivalis plays a role as a keystone pathogen that manipulates host immune responses leading to dysbiotic oral microbial communities. Arg-gingipains (RgpA and RgpB) and Lys-gingipain (Kgp) are responsible for the majority of bacterial proteolytic activity and play essential roles in bacterial virulence. Therefore, gingipains are often considered as therapeutic targets. This study investigated the role of gingipains in the modulation by P. gingivalis of phagocytosis of Tannerella forsythia by macrophages. Phagocytosis of T. forsythia was significantly enhanced by coinfection with P. gingivalis in a multiplicity of infection-dependent and gingipain-dependent manner. Mutation of either Kgp or Rgp in the coinfecting P. gingivalis resulted in attenuated enhancement of T. forsythia phagocytosis. Inhibition of coaggregation between the two bacterial species reduced phagocytosis of T. forsythia in mixed infection, and this coaggregation was dependent on gingipains. Inhibition of gingipain protease activities in coinfecting P. gingivalis abated the coaggregation and the enhancement of T. forsythia phagocytosis. However, the direct effect of protease activities of gingipains on T. forsythia seemed to be minimal. Although most of the phagocytosed T. forsythia were cleared in infected macrophages, more T. forsythia remained in cells coinfected with gingipain-expressing P. gingivalis than in cells coinfected with the gingipain-null mutant or infected only with T. forsythia at 24 and 48 h post-infection. Collectively, these results suggest that P. gingivalis, mainly via its gingipains, alters the clearance of T. forsythia, and provide some insights into the role of P. gingivalis as a keystone pathogen.

  14. KLIKK proteases of Tannerella forsythia: putative virulence factors with a unique domain structure.

    PubMed

    Ksiazek, Miroslaw; Mizgalska, Danuta; Eick, Sigrum; Thøgersen, Ida B; Enghild, Jan J; Potempa, Jan

    2015-01-01

    Comparative genomics of virulent Tannerella forsythia ATCC 43037 and a close health-associated relative, Tannerella BU063, revealed, in the latter, the absence of an entire array of genes encoding putative secretory proteases that possess a nearly identical C-terminal domain (CTD) that ends with a -Lys-Leu-Ile-Lys-Lys motif. This observation suggests that these proteins, referred to as KLIKK proteases, may function as virulence factors. Re-sequencing of the loci of the KLIKK proteases found only six genes grouped in two clusters. All six genes were expressed by T. forsythia in routine culture conditions, although at different levels. More importantly, a transcript of each gene was detected in gingival crevicular fluid (GCF) from periodontitis sites infected with T. forsythia indicating that the proteases are expressed in vivo. In each protein, a protease domain was flanked by a unique N-terminal profragment and a C-terminal extension ending with the CTD. Partially purified recombinant proteases showed variable levels of proteolytic activity in zymography gels and toward protein substrates, including collagen, gelatin, elastin, and casein. Taken together, these results indicate that the pathogenic strain of T. forsythia secretes active proteases capable of degrading an array of host proteins, which likely represents an important pathogenic feature of this bacterium.

  15. TLR2 signaling and Th2 responses drive Tannerella forsythia-induced periodontal bone loss.

    PubMed

    Myneni, Srinivas R; Settem, Rajendra P; Connell, Terry D; Keegan, Achsah D; Gaffen, Sarah L; Sharma, Ashu

    2011-07-01

    Periodontal disease (PD) is a chronic inflammation of the tooth-supporting soft tissue and alveolar bone due to infection by a select group of gram-negative microbes, which leads to tooth loss if untreated. Because mice deficient in CD4(+) cells are resistant to infection-induced alveolar bone loss, Th cells have been implicated in bone-destructive processes during PD. However, the extent to which different Th cell subtypes play roles in pathogenesis or host protection remains to be defined and is likely to vary depending on the dominant microorganism involved. By far, Porphyromonas gingivalis is the best-studied periodontal microbe in PD. Although the gram-negative anaerobe Tannerella forsythia is also a vital contributor to periodontal bone loss, almost nothing is known about immune responses to this organism. Previous studies from our laboratory revealed that T. forsythia induces periodontal bone loss in mice and that this bone loss depends on the bacterially expressed BspA protein. In this study, we showed that T. forsythia activates murine APCs primarily through TLR2-dependent signaling via BspA. Furthermore, T. forsythia infection causes a pronounced Th2 bias, evidenced by T cell expression of IL-5, but not IFN-γ or IL-17, in draining lymph nodes. Consistently, deficiencies in TLR2 or STAT6 result in resistance to T. forsythia-induced alveolar bone loss. Thus, TLR2 signaling and Th2 cells play pathogenic roles in T. forsythia-induced alveolar bone destruction.

  16. Identification of Tannerella forsythia antigens specifically expressed in patients with periodontal disease.

    PubMed

    Yoo, Ji Yeon; Kim, Hyeong Chan; Zhu, Weidong; Kim, Seon-Mi; Sabet, Mojgan; Handfield, Martin; Hillman, Jeffrey; Progulske-Fox, Ann; Lee, Seok-Woo

    2007-10-01

    Molecular pathogenesis of Tannerella forsythia, a putative periodontal pathogen, has not yet been adequately elucidated due to limited information on its virulence factors. Here, identification of in vivo expressed antigens of T. forsythia is reported using in vivo-induced antigen technology (IVIAT). Among 13 000 recombinant clones screened, 16 positive clones were identified that reacted reproducibly with sera obtained from patients with periodontal disease. DNA sequences from 12 of these in vivo-induced genes were determined. IVIAT-identified protein antigens of T. forsythia include: BspA, a well-defined virulence factor of T. forsythia; enzymes involved in housekeeping functions (tRNA synthetases, glycine hydroxymethyltransferase, and glucoside glucohydrolase); enzymes implicated in tissue destruction (dipeptidyl peptidase IV); a DNA mismatch repair protein; and putative outer membrane proteins of unknown function. The in vivo gene expression of these IVIAT-identified antigens was confirmed by a quantitative real-time PCR analysis. This is, to the best of the authors' knowledge, the first report using IVIAT in T. forsythia. It is anticipated that detailed analysis of the in vivo-induced genes identified by IVIAT in this study will lead to a better understanding of the molecular mechanisms mediating periodontal infection by T. forsythia.

  17. Outer membrane vesicles of Tannerella forsythia: biogenesis, composition, and virulence.

    PubMed

    Friedrich, V; Gruber, C; Nimeth, I; Pabinger, S; Sekot, G; Posch, G; Altmann, F; Messner, P; Andrukhov, O; Schäffer, C

    2015-12-01

    Tannerella forsythia is the only 'red-complex' bacterium covered by an S-layer, which has been shown to affect virulence. Here, outer membrane vesicles (OMVs) enriched with putative glycoproteins are described as a new addition to the virulence repertoire of T. forsythia. Investigations of this bacterium are hampered by its fastidious growth requirements and the recently discovered mismatch of the available genome sequence (92A2 = ATCC BAA-2717) and the widely used T. forsythia strain (ATCC 43037). T. forsythia was grown anaerobically in serum-free medium and biogenesis of OMVs was analyzed by electron and atomic force microscopy. This revealed OMVs with a mean diameter of ~100 nm budding off from the outer membrane while retaining the S-layer. An LC-ESI-TOF/TOF proteomic analysis of OMVs from three independent biological replicates identified 175 proteins. Of these, 14 exhibited a C-terminal outer membrane translocation signal that directs them to the cell/vesicle surface, 61 and 53 were localized to the outer membrane and periplasm, respectively, 22 were predicted to be extracellular, and 39 to originate from the cytoplasm. Eighty proteins contained the Bacteroidales O-glycosylation motif, 18 of which were confirmed as glycoproteins. Release of pro-inflammatory mediators from the human monocytic cell line U937 and periodontal ligament fibroblasts upon stimulation with OMVs followed a concentration-dependent increase that was more pronounced in the presence of soluble CD14 in conditioned media. The inflammatory response was significantly higher than that caused by whole T. forsythia cells. Our study represents the first characterization of T. forsythia OMVs, their proteomic composition and immunogenic potential. © 2015 The Authors Molecular Oral Microbiology Published by John Wiley & Sons Ltd.

  18. Chronic oral infection with major periodontal bacteria Tannerella forsythia modulates systemic atherosclerosis risk factors and inflammatory markers

    PubMed Central

    Chukkapalli, Sasanka S.; Rivera-Kweh, Mercedes F.; Velsko, Irina M.; Chen, Hao; Zheng, Donghang; Bhattacharyya, Indraneel; Gangula, Pandu R.; Lucas, Alexandra R.; Kesavalu, Lakshmyya

    2015-01-01

    Tannerella forsythia is a Gram-negative anaerobic organism that inhabits the subgingival cavity and initiates connective tissue destruction and alveolar bone resorption in periodontal disease (PD). PD is a chronic immunoinflammatory disease and has been linked to several systemic diseases including atherosclerosis. This study evaluated the effects of a chronic oral infection with T. forsythia ATCC 43037 on the induction of PD, inflammatory markers and atherosclerosis risk factors in hyperlipidemic ApoEnull mice. Mice were orally infected for 12 and 24 weeks prior to euthanasia. Bacterial colonization of the oral cavity and bacteremia was confirmed via isolation of genomic DNA from oral plaque and tissues. Oral infection elicited significantly elevated levels of serum IgG and IgM antibodies and alveolar bone resorption compared to control mice. Tannerella forsythia-infected mice had increased serum amyloid A, and significantly reduced serum nitric oxide when compared to controls. Tannerella forsythia chronic infection also significantly increased serum lipoproteins suggesting altered cholesterol metabolism and potential for aortic inflammation. Despite enhanced acute phase reactants and altered lipid profiles, T. forsythia infection was associated with decreased aortic plaque. This study investigates the potential of a known periodontal bacterial pathogen found in atherosclerotic plaque in humans to accelerate atherosclerosis in hyperlipdemic mice. PMID:25663343

  19. Chronic oral infection with major periodontal bacteria Tannerella forsythia modulates systemic atherosclerosis risk factors and inflammatory markers.

    PubMed

    Chukkapalli, Sasanka S; Rivera-Kweh, Mercedes F; Velsko, Irina M; Chen, Hao; Zheng, Donghang; Bhattacharyya, Indraneel; Gangula, Pandu R; Lucas, Alexandra R; Kesavalu, Lakshmyya

    2015-04-01

    Tannerella forsythia is a Gram-negative anaerobic organism that inhabits the subgingival cavity and initiates connective tissue destruction and alveolar bone resorption in periodontal disease (PD). PD is a chronic immunoinflammatory disease and has been linked to several systemic diseases including atherosclerosis. This study evaluated the effects of a chronic oral infection with T. forsythia ATCC 43037 on the induction of PD, inflammatory markers and atherosclerosis risk factors in hyperlipidemic ApoE(null) mice. Mice were orally infected for 12 and 24 weeks prior to euthanasia. Bacterial colonization of the oral cavity and bacteremia was confirmed via isolation of genomic DNA from oral plaque and tissues. Oral infection elicited significantly elevated levels of serum IgG and IgM antibodies and alveolar bone resorption compared to control mice. Tannerella forsythia-infected mice had increased serum amyloid A, and significantly reduced serum nitric oxide when compared to controls. Tannerella forsythia chronic infection also significantly increased serum lipoproteins suggesting altered cholesterol metabolism and potential for aortic inflammation. Despite enhanced acute phase reactants and altered lipid profiles, T. forsythia infection was associated with decreased aortic plaque. This study investigates the potential of a known periodontal bacterial pathogen found in atherosclerotic plaque in humans to accelerate atherosclerosis in hyperlipdemic mice.

  20. Fusobacterium nucleatum and Tannerella forsythia induce synergistic alveolar bone loss in a mouse periodontitis model.

    PubMed

    Settem, Rajendra P; El-Hassan, Ahmed Taher; Honma, Kiyonobu; Stafford, Graham P; Sharma, Ashu

    2012-07-01

    Tannerella forsythia is strongly associated with chronic periodontitis, an inflammatory disease of the tooth-supporting tissues, leading to tooth loss. Fusobacterium nucleatum, an opportunistic pathogen, is thought to promote dental plaque formation by serving as a bridge bacterium between early- and late-colonizing species of the oral cavity. Previous studies have shown that F. nucleatum species synergize with T. forsythia during biofilm formation and pathogenesis. In the present study, we showed that coinfection of F. nucleatum and T. forsythia is more potent than infection with either species alone in inducing NF-κB activity and proinflammatory cytokine secretion in monocytic cells and primary murine macrophages. Moreover, in a murine model of periodontitis, mixed infection with the two species induces synergistic alveolar bone loss, characterized by bone loss which is greater than the additive alveolar bone losses induced by each species alone. Further, in comparison to the single-species infection, mixed infection caused significantly increased inflammatory cell infiltration in the gingivae and osteoclastic activity in the jaw bones. These data show that F. nucleatum subspecies and T. forsythia synergistically stimulate the host immune response and induce alveolar bone loss in a murine experimental periodontitis model.

  1. An orthologue of Bacteroides fragilis NanH is the principal sialidase in Tannerella forsythia.

    PubMed

    Thompson, Hayley; Homer, Karen A; Rao, Susmitha; Booth, Veronica; Hosie, Arthur H F

    2009-06-01

    Sialidase activity is a putative virulence factor of the anaerobic periodontal pathogen Tannerella forsythia, but it is uncertain which genes encode this activity. Characterization of a putative sialidase, SiaHI, by others, indicated that this protein alone may not be responsible for all of the sialidase activity. We describe a second sialidase in T. forsythia (TF0035), an orthologue of Bacteroides fragilis NanH, and its expression in Escherichia coli. Sialidase activity of the expressed NanH was confirmed by using 2'-(4-methylumbelliferyl)-alpha-D-N-acetylneuraminic acid as a substrate. Biochemical characterization of the recombinant T. forsythia NanH indicated that it was active over a broad pH range, with optimum activity at pH 5.5. This enzyme has high affinity for 2'-(4-methylumbelliferyl)-alpha-D-N-acetylneuraminic acid (K(m) of 32.9 +/- 10.3 microM) and rapidly releases 4-methylumbelliferone (V(max) of 170.8 +/- 11.8 nmol of 4-methylumbelliferone min(-1) mg of protein(-1)). E. coli lysates containing recombinant T. forsythia NanH cleave sialic acid from a range of substrates, with a preference for alpha2-3 glycosidic linkages. The genes adjacent to nanH encode proteins apparently involved in the metabolism of sialic acid, indicating that the NanH sialidase is likely to be involved in nutrient acquisition.

  2. Tannerella forsythia and the HLA-DQB1 allele are associated with susceptibility to periodontal disease in Japanese adolescents.

    PubMed

    Shimomura-Kuroki, Junko; Yamashita, Kie; Shimooka, Shohachi

    2009-01-01

    Periodontal disease is a multiple factor disease caused by genetic factors, environmental factors, and periodontal bacteria (periodontal pathogens). The present study aimed to elucidate the risk factors for periodontal disease in Japanese adolescents. Subjects (11-16 years old) were classified into three groups: localized aggressive periodontitis (LAP), periodontal attachment loss (PAL), and periodontally healthy (PH) groups. Genomic DNA isolated from the buccal mucosa was used for single-nucleotide polymorphism analyses of the candidate genes (interleukin-1alpha-889; interleukin-1alpha +4845; interleukin-1beta +3954; an immunoglobulin G Fc gamma receptor, FcgammaRIIa-R/H131; and a human leukocyte antigen class II allele, HLA-DQB1) of aggressive periodontitis. Subgingival plaque samples obtained from the same subjects were used for 16S rRNAbased polymerase chain reaction analysis of five important periodontal pathogens (Aggregatibacter actinomycetemcomitans, Porphyromonas gingivalis, Prevotella intermedia, Treponema denticola, and Tannerella forsythia). Tannerella forsythia was detected in the deepest periodontal pockets in all subjects in the LAP and PAL groups. The prevalence of an atypical BamHI restriction site in HLA-DQB1 of the LAP group was significantly higher than that in the PH and PAL groups. Furthermore, all subjects who had the atypical BamHI restriction site in HLA-DQB1 had T. forsythia infection. These results suggested that T. forsythia is associated with periodontal disease in Japanese adolescents and also suggested that HLA-DQB1 is related to LAP and is associated with T. forsythia infection.

  3. A metalloproteinase mirolysin of Tannerella forsythia inhibits all pathways of the complement system

    PubMed Central

    Jusko, Monika; Potempa, Jan; Mizgalska, Danuta; Bielecka, Ewa; Ksiazek, Miroslaw; Riesbeck, Kristian; Garred, Peter; Eick, Sigrun; Blom, Anna M.

    2015-01-01

    Recent reports focusing on virulence factors of periodontal pathogens implicated proteinases as major determinants of remarkable pathogenicity of these species, with special emphasis on their capacity to modulate complement activity. In particular, bacteria-mediated cleavage of C5 and subsequent release of C5a seems to be an important phenomenon in the manipulation of the local inflammatory response in periodontitis. Here we present mirolysin, a novel metalloproteinase secreted by Tannerella forsythia, a well-recognized pathogen strongly associated with periodontitis. Mirolysin exhibited a strong effect on all complement pathways. It inhibited the classical and lectin complement pathways due to efficient degradation of mannose-binding lectin, ficolin-2, ficolin-3 and C4, while inhibition of the alternative pathway was caused by degradation of C5. This specificity toward complement largely resembled the activity of a previously characterized metalloproteinase of T. forsythia, karilysin. Interestingly, mirolysin released the biologically active C5a peptide in human plasma and induced migration of neutrophils. Importantly, we demonstrated that combination of mirolysin with karilysin, as well as a cysteine proteinase of another periodontal pathogen, Prevotella intermedia, resulted in a strong synergistic effect on complement. Furthermore, mutant strains of T. forsythia, devoid of either mirolysin or karilysin, showed diminished survival in human serum, providing further evidence for the synergistic inactivation of complement by these metalloproteinases. Taken together, our findings on interactions of mirolysin with complement significantly add to the understanding of immune evasion strategies of T. forsythia, and expand the knowledge on molecular mechanisms driving pathogenic events in the infected periodontium. PMID:26209620

  4. A Metalloproteinase Mirolysin of Tannerella forsythia Inhibits All Pathways of the Complement System.

    PubMed

    Jusko, Monika; Potempa, Jan; Mizgalska, Danuta; Bielecka, Ewa; Ksiazek, Miroslaw; Riesbeck, Kristian; Garred, Peter; Eick, Sigrun; Blom, Anna M

    2015-09-01

    Recent reports focusing on virulence factors of periodontal pathogens implicated proteinases as major determinants of remarkable pathogenicity of these species, with special emphasis on their capacity to modulate complement activity. In particular, bacteria-mediated cleavage of C5 and subsequent release of C5a seems to be an important phenomenon in the manipulation of the local inflammatory response in periodontitis. In this study, we present mirolysin, a novel metalloproteinase secreted by Tannerella forsythia, a well-recognized pathogen strongly associated with periodontitis. Mirolysin exhibited a strong effect on all complement pathways. It inhibited the classical and lectin complement pathways due to efficient degradation of mannose-binding lectin, ficolin-2, ficolin-3, and C4, whereas inhibition of the alternative pathway was caused by degradation of C5. This specificity toward complement largely resembled the activity of a previously characterized metalloproteinase of T. forsythia, karilysin. Interestingly, mirolysin released the biologically active C5a peptide in human plasma and induced migration of neutrophils. Importantly, we demonstrated that combination of mirolysin with karilysin, as well as a cysteine proteinase of another periodontal pathogen, Prevotella intermedia, resulted in a strong synergistic effect on complement. Furthermore, mutant strains of T. forsythia, devoid of either mirolysin or karilysin, showed diminished survival in human serum, providing further evidence for the synergistic inactivation of complement by these metalloproteinases. Taken together, our findings on interactions of mirolysin with complement significantly add to the understanding of immune evasion strategies of T. forsythia and expand the knowledge on molecular mechanisms driving pathogenic events in the infected periodontium.

  5. Molecular analysis of Filifactor alocis, Tannerella forsythia, and treponema denticola associated with primary endodontic infections and failed endodontic treatment.

    PubMed

    Gomes, Brenda P F A; Jacinto, Rogério C; Pinheiro, Ericka T; Sousa, Ezilmara L R; Zaia, Alexandre A; Ferraz, Caio C R; Souza-Filho, Francisco J

    2006-10-01

    The aim of this study was to investigate the presence of strict anaerobes such as Filifactor alocis, Tannerella forsythia, and Treponema denticola in primary and secondary root-infected canals with periapical lesions by molecular analysis and the association of these species with specific endodontic signs and symptoms. Microbial samples were taken from 100 root canals, 50 with necrotic pulp tissues (NPT, primary infection), and 50 with failed endodontic treatment (FET, secondary infection). DNA was extracted from the samples, which were analyzed for the presence of three endodontic pathogens using species-specific primers and PCR. F. alocis were isolated from 23 canals with NPT and 12 canals with FET; T. forsythia from 12 canals with NPT and three canals with FET; T. denticola from 19 canals with NPT and 12 canals with TEP. Suggested associations were found between primary infection and the presence of F. alocis and T. forsythia (both p < 0.05). In particular, associations were found between: pain and F. alocis; swelling and F. alocis; tenderness to percussion and T. forsythia; mobility and T. forsythia and T. denticola; wet canals and F. alocis, T. forsythia, and T. denticola; purulent exsudate and F. alocis, T. forsythia and T. denticola; abscess and F. alocis, T. forsythia, and T. denticola (all p < 0.05). The findings of this study indicated that F. alocis, T. forsythia, and T. denticola seem to be associated with endodontic signs and symptoms. Additionally, F. alocis and T. forsythia were detected more frequently in teeth with necrotic pulp than in teeth with failing endodontic treatment.

  6. Mirolase, a novel subtilisin-like serine protease from the periodontopathogen Tannerella forsythia

    PubMed Central

    Ksiazek, Miroslaw; Karim, Abdulkarim Y.; Bryzek, Danuta; Enghild, Jan J.; Thøgersen, Ida B.; Koziel, Joanna; Potempa, Jan

    2015-01-01

    The genome of Tannerella forsythia, an etiologic factor of chronic periodontitis, contains several genes encoding putative proteases. Here, we characterized a subtilisin-like serine protease of T. forsythia referred to as mirolase. Recombinant full-length latent promirolase (85 kDa, without its signal peptide) processed itself through sequential autoproteolytic cleavages into a mature enzyme of 40 kDa. Mirolase latency was driven by the N-terminal prodomain (NTP). In stark contrast to almost all known subtilases, the cleaved NTP remained non-covalently associated with mirolase, inhibiting its proteolytic, but not amidolytic, activity. Full activity was observed only after the NTP was gradually, and fully, degraded. Both activity and processing was absolutely dependent on calcium ions, which were also essential for enzyme stability. As a consequence, both serine protease inhibitors and calcium ions chelators inhibited mirolase activity. Activity assays using an array of chromogenic substrates revealed that mirolase specificity is driven not only by the substrate-binding subsite S1, but also by other subsites. Taken together mirolase is a calcium-dependent serine protease of the S8 family with the unique mechanism of activation that may contribute to T. forsythia pathogenicity by degradation of fibrinogen, hemoglobin and the antimicrobial peptide LL-37. PMID:25391881

  7. Lack of a surface layer in Tannerella forsythia mutants deficient in the type IX secretion system

    PubMed Central

    Narita, Yuka; Sato, Keiko; Yukitake, Hideharu; Shoji, Mikio; Nakane, Daisuke; Nagano, Keiji; Yoshimura, Fuminobu; Naito, Mariko

    2014-01-01

    Tannerella forsythia, a Gram-negative anaerobic bacterium, is an important pathogen in periodontal disease. This bacterium possesses genes encoding all known components of the type IX secretion system (T9SS). T. forsythia mutants deficient in genes orthologous to the T9SS-encoding genes porK, porT and sov were constructed. All porK, porT and sov single mutants lacked the surface layer (S-layer) and expressed less-glycosylated versions of the S-layer glycoproteins TfsA and TfsB. In addition, these mutants exhibited decreased haemagglutination and increased biofilm formation. Comparison of the proteins secreted by the porK and WT strains revealed that the secretion of several proteins containing C-terminal domain (CTD)-like sequences is dependent on the porK gene. These results indicate that the T9SS is functional in T. forsythia and contributes to the translocation of CTD proteins to the cell surface or into the extracellular milieu. PMID:25023245

  8. Lack of a surface layer in Tannerella forsythia mutants deficient in the type IX secretion system.

    PubMed

    Narita, Yuka; Sato, Keiko; Yukitake, Hideharu; Shoji, Mikio; Nakane, Daisuke; Nagano, Keiji; Yoshimura, Fuminobu; Naito, Mariko; Nakayama, Koji

    2014-10-01

    Tannerella forsythia, a Gram-negative anaerobic bacterium, is an important pathogen in periodontal disease. This bacterium possesses genes encoding all known components of the type IX secretion system (T9SS). T. forsythia mutants deficient in genes orthologous to the T9SS-encoding genes porK, porT and sov were constructed. All porK, porT and sov single mutants lacked the surface layer (S-layer) and expressed less-glycosylated versions of the S-layer glycoproteins TfsA and TfsB. In addition, these mutants exhibited decreased haemagglutination and increased biofilm formation. Comparison of the proteins secreted by the porK and WT strains revealed that the secretion of several proteins containing C-terminal domain (CTD)-like sequences is dependent on the porK gene. These results indicate that the T9SS is functional in T. forsythia and contributes to the translocation of CTD proteins to the cell surface or into the extracellular milieu.

  9. Mirolase, a novel subtilisin-like serine protease from the periodontopathogen Tannerella forsythia.

    PubMed

    Ksiazek, Miroslaw; Karim, Abdulkarim Y; Bryzek, Danuta; Enghild, Jan J; Thøgersen, Ida B; Koziel, Joanna; Potempa, Jan

    2015-03-01

    The genome of Tannerella forsythia, an etiological factor of chronic periodontitis, contains several genes encoding putative proteases. Here, we characterized a subtilisin-like serine protease of T. forsythia referred to as mirolase. Recombinant full-length latent promirolase [85 kDa, without its signal peptide (SP)] processed itself through sequential autoproteolytic cleavages into a mature enzyme of 40 kDa. Mirolase latency was driven by the N-terminal prodomain (NTP). In stark contrast to almost all known subtilases, the cleaved NTP remained non-covalently associated with mirolase, inhibiting its proteolytic, but not amidolytic, activity. Full activity was observed only after the NTP was gradually, and fully, degraded. Both activity and processing was absolutely dependent on calcium ions, which were also essential for enzyme stability. As a consequence, both serine protease inhibitors and calcium ions chelators inhibited mirolase activity. Activity assays using an array of chromogenic substrates revealed that mirolase specificity is driven not only by the substrate-binding subsite S1, but also by other subsites. Taken together, mirolase is a calcium-dependent serine protease of the S8 family with the unique mechanism of activation that may contribute to T. forsythia pathogenicity by degradation of fibrinogen, hemoglobin, and the antimicrobial peptide LL-37.

  10. Prevalence of Aggregatibacter actinomycetemcomitans, Porphyromonas gingivalis and Tannerella forsythia in Japanese patients with generalized chronic and aggressive periodontitis.

    PubMed

    Tomita, Sachiyo; Komiya-Ito, Akiyo; Imamura, Kentaro; Kita, Daichi; Ota, Koki; Takayama, Saori; Makino-Oi, Asako; Kinumatsu, Takashi; Ota, Mikio; Saito, Atsushi

    2013-01-01

    This study aimed to investigate the prevalence and levels of major periodontal pathogens, Aggregatibacter actinomycetemcomitans, Porphyromonas gingivalis and Tannerella forsythia in subgingival plaque samples of a group of Japanese patients with aggressive periodontitis (AgP) and chronic periodontitis (CP). A total of 40 patients with clinical diagnosis of AgP or CP and 10 periodontally healthy volunteers were subjected to clinical and microbiological analysis. Subgingival plaque samples were analyzed for A. actinomycetemcomitans, P. gingivalis and T. forsythia with a real-time polymerase chain reaction (PCR) technique. The prevalence of P. gingivalis and T. forsythia was relatively high in patients with periodontitis: over 60% of AgP or CP patients harbored these pathogens whereas they were not detected in the subgingival plaque samples from periodontally healthy individuals. P. gingivalis and T. forsythia were relatively frequently detected together in AgP and CP patients. No significant differences in the prevalence or level of the 3 pathogens were found between periodontitis groups. The proportion of T. forsythia was approximately 4-fold higher in CP group than in AgP group (P = 0.02). In periodontitis patients, a significant positive correlation was found between periodontal parameters (probing depth and clinical attachment level) and the numbers of total bacteria, P. gingivalis and T. forsythia. No distinct pattern of the subgingival profile of these pathogens was discerned between the two disease entities, except for the difference in the proportion of T. forsythia. The red complex bacteria, P. gingivalis and T. forsythia were highly prevalent in this population of Japanese AgP and CP patients, collaborating their roles in periodontitis.

  11. Prediction of a caspase-like fold in Tannerella forsythia virulence factor PrtH.

    PubMed

    Pei, Jimin; Grishin, Nick V

    2009-05-01

    Tannerella forsythia is a bacterial pathogen involved in periodontal disease. A cysteine protease PrtH has been characterized in this bacterium as a virulence factor. PrtH has the activity of detaching adherent cells from substratum, and the level of PrtH is associated with periodontal attachment loss. No reports exist on the structure, active site, and catalytic mechanism of PrtH. Using comparative sequence and structural analyses, we have identified homologs of PrtH in a number of bacterial and archaeal species. PrtH was found to be remotely related to caspases and other proteases with a caspase-like fold, such as gingipains from another periodontal pathogen Porphyromonas gingivalis. Our results offer structural and mechanistic insights into PrtH and its homologs, and help classification of this protease family.

  12. The OxyR homologue in Tannerella forsythia regulates expression of oxidative stress responses and biofilm formation.

    PubMed

    Honma, Kiyonobu; Mishima, Elina; Inagaki, Satoru; Sharma, Ashu

    2009-06-01

    Tannerella forsythia is an anaerobic periodontal pathogen that encounters constant oxidative stress in the human oral cavity due to exposure to air and reactive oxidative species from coexisting dental plaque bacteria as well as leukocytes. In this study, we sought to characterize a T. forsythia ORF with close similarity to bacterial oxidative stress response sensor protein OxyR. To analyse the role of this OxyR homologue, a gene deletion mutant was constructed and characterized. Aerotolerance, survival after hydrogen peroxide challenge and transcription levels of known bacterial antioxidant genes were then determined. Since an association between oxidative stress and biofilm formation has been observed in bacterial systems, we also investigated the role of the OxyR protein in biofilm development by T. forsythia. Our results showed that aerotolerance, sensitivity to peroxide challenge and the expression of oxidative stress response genes were significantly reduced in the mutant as compared with the wild-type strain. Moreover, the results of biofilm analyses showed that, as compared with the wild-type strain, the oxyR mutant showed significantly less autoaggregation and a reduced ability to form mixed biofilms with Fusobacterium nucleatum. In conclusion, a gene annotated in the T. forsythia genome as an oxyR homologue was characterized. Our studies showed that the oxyR homologue in T. forsythia constitutively activates antioxidant genes involved in resistance to peroxides as well as oxygen stress (aerotolerance). In addition, the oxyR deletion attenuates biofilm formation in T. forsythia.

  13. Characterization and scope of S-layer protein O-glycosylation in Tannerella forsythia.

    PubMed

    Posch, Gerald; Pabst, Martin; Brecker, Lothar; Altmann, Friedrich; Messner, Paul; Schäffer, Christina

    2011-11-04

    Cell surface glycosylation is an important element in defining the life of pathogenic bacteria. Tannerella forsythia is a Gram-negative, anaerobic periodontal pathogen inhabiting the subgingival plaque biofilms. It is completely covered by a two-dimensional crystalline surface layer (S-layer) composed of two glycoproteins. Although the S-layer has previously been shown to delay the bacterium's recognition by the innate immune system, we characterize here the S-layer protein O-glycosylation as a potential virulence factor. The T. forsythia S-layer glycan was elucidated by a combination of electrospray ionization-tandem mass spectrometry and nuclear magnetic resonance spectroscopy as an oligosaccharide with the structure 4-Me-β-ManpNAcCONH(2)-(1→3)-[Pse5Am7Gc-(2→4)-]-β-ManpNAcA-(1→4)-[4-Me-α-Galp-(1→2)-]-α-Fucp-(1→4)-[-α-Xylp-(1→3)-]-β-GlcpA-(1→3)-[-β-Digp-(1→2)-]-α-Galp, which is O-glycosidically linked to distinct serine and threonine residues within the three-amino acid motif (D)(S/T)(A/I/L/M/T/V) on either S-layer protein. This S-layer glycan obviously impacts the life style of T. forsythia because increased biofilm formation of an UDP-N-acetylmannosaminuronic acid dehydrogenase mutant can be correlated with the presence of truncated S-layer glycans. We found that several other proteins of T. forsythia are modified with that specific oligosaccharide. Proteomics identified two of them as being among previously classified antigenic outer membrane proteins that are up-regulated under biofilm conditions, in addition to two predicted antigenic lipoproteins. Theoretical analysis of the S-layer O-glycosylation of T. forsythia indicates the involvement of a 6.8-kb gene locus that is conserved among different bacteria from the Bacteroidetes phylum. Together, these findings reveal the presence of a protein O-glycosylation system in T. forsythia that is essential for creating a rich glycoproteome pinpointing a possible relevance for the virulence of

  14. Tannerella forsythia infection-induced calvarial bone and soft tissue transcriptional profiles.

    PubMed

    Bakthavatchalu, V; Meka, A; Sathishkumar, S; Lopez, M C; Bhattacharyya, I; Boyce, B F; Mans, J J; Lamont, R J; Baker, H V; Ebersole, J L; Kesavalu, L

    2010-10-01

    Tannerella forsythia is associated with subgingival biofilms in adult periodontitis, although the molecular mechanisms contributing to chronic inflammation and loss of periodontal bone remain unclear. We examined changes in the host transcriptional profiles during a T. forsythia infection using a murine calvarial model of inflammation and bone resorption. Tannerella forsythia was injected into the subcutaneous soft tissue over calvariae of BALB/c mice for 3 days, after which the soft tissues and calvarial bones were excised. RNA was isolated and Murine GeneChip (Affymetrix, Santa Clara, CA) array analysis of transcript profiles showed that 3226 genes were differentially expressed in the infected soft tissues (P < 0.05) and 2586 genes were differentially transcribed in calvarial bones after infection. Quantitative real-time reverse transcription-polymerase chain reaction analysis of transcription levels of selected genes corresponded well with the microarray results. Biological pathways significantly impacted by T. forsythia infection in calvarial bone and soft tissue included leukocyte transendothelial migration, cell adhesion molecules (immune system), extracellular matrix-receptor interaction, adherens junction, and antigen processing and presentation. Histologic examination revealed intense inflammation and increased osteoclasts in calvariae compared with controls. In conclusion, localized T. forsythia infection differentially induces transcription of a broad array of host genes, and the profiles differ between inflamed soft tissues and calvarial bone.

  15. A metalloproteinase karilysin present in the majority of Tannerella forsythia isolates inhibits all pathways of the complement system.

    PubMed

    Jusko, Monika; Potempa, Jan; Karim, Abdulkarim Y; Ksiazek, Miroslaw; Riesbeck, Kristian; Garred, Peter; Eick, Sigrun; Blom, Anna M

    2012-03-01

    Tannerella forsythia is a poorly studied pathogen despite being one of the main causes of periodontitis, which is an inflammatory disease of the supporting structures of the teeth. We found that despite being recognized by all complement pathways, T. forsythia is resistant to killing by human complement, which is present at up to 70% of serum concentration in gingival crevicular fluid. Incubation of human serum with karilysin, a metalloproteinase of T. forsythia, resulted in a decrease in bactericidal activity of the serum. T. forsythia strains expressing karilysin at higher levels were more resistant than low-expressing strains. Furthermore, the low-expressing strain was significantly more opsonized with activated complement factor 3 and membrane attack complex from serum compared with the other strains. The high-expressing strain was more resistant to killing in human blood. The protective effect of karilysin against serum bactericidal activity was attributable to its ability to inhibit complement at several stages. The classical and lectin complement pathways were inhibited because of the efficient degradation of mannose-binding lectin, ficolin-2, ficolin-3, and C4 by karilysin, whereas inhibition of the terminal pathway was caused by degradation of C5. Interestingly, karilysin was able to release biologically active C5a peptide in human plasma and induce migration of neutrophils. Importantly, we detected the karilysin gene in >90% of gingival crevicular fluid samples containing T. forsythia obtained from patients with periodontitis. Taken together, the newly characterized karilysin appears to be an important virulence factor of T. forsythia and might have several important implications for immune evasion.

  16. Identification of a Novel N-Acetylmuramic Acid Transporter in Tannerella forsythia.

    PubMed

    Ruscitto, Angela; Hottmann, Isabel; Stafford, Graham P; Schäffer, Christina; Mayer, Christoph; Sharma, Ashu

    2016-11-15

    Tannerella forsythia is a Gram-negative periodontal pathogen lacking the ability to undergo de novo synthesis of amino sugars N-acetylmuramic acid (MurNAc) and N-acetylglucosamine (GlcNAc) that form the disaccharide repeating unit of the peptidoglycan backbone. T. forsythia relies on the uptake of these sugars from the environment, which is so far unexplored. Here, we identified a novel transporter system of T. forsythia involved in the uptake of MurNAc across the inner membrane and characterized a homolog of the Escherichia coli MurQ etherase involved in the conversion of MurNAc-6-phosphate (MurNAc-6-P) to GlcNAc-6-P. The genes encoding these components were identified on a three-gene cluster spanning Tanf_08375 to Tanf_08385 located downstream from a putative peptidoglycan recycling locus. We show that the three genes, Tanf_08375, Tanf_08380, and Tanf_08385, encoding a MurNAc transporter, a putative sugar kinase, and a MurQ etherase, respectively, are transcriptionally linked. Complementation of the Tanf_08375 and Tanf_08380 genes together in trans, but not individually, rescued the inability of an E. coli mutant deficient in the phosphotransferase (PTS) system-dependent MurNAc transporter MurP as well as that of a double mutant deficient in MurP and components of the PTS system to grow on MurNAc. In addition, complementation with this two-gene construct in E. coli caused depletion of MurNAc in the medium, further confirming this observation. Our results show that the products of Tanf_08375 and Tanf_08380 constitute a novel non-PTS MurNAc transporter system that seems to be widespread among bacteria of the Bacteroidetes phylum. To the best of our knowledge, this is the first identification of a PTS-independent MurNAc transporter in bacteria. In this study, we report the identification of a novel transporter for peptidoglycan amino sugar N-acetylmuramic acid (MurNAc) in the periodontal pathogen T. forsythia It has been known since the late 1980s that T. forsythia

  17. Sialic acid transporter NanT participates in Tannerella forsythia biofilm formation and survival on epithelial cells.

    PubMed

    Honma, Kiyonobu; Ruscitto, Angela; Frey, Andrew M; Stafford, Graham P; Sharma, Ashu

    2016-05-01

    Tannerella forsythia is a periodontal pathogen implicated in periodontitis. This gram-negative pathogen depends on exogenous peptidoglycan amino sugar N-acetylmuramic acid (NAM) for growth. In the biofilm state the bacterium can utilize sialic acid (Neu5Ac) instead of NAM to sustain its growth. Thus, the sialic acid utilization system of the bacterium plays a critical role in the growth and survival of the organism in the absence of NAM. We sought the function of a T. forsythia gene annotated as nanT coding for an inner-membrane sugar transporter located on a sialic acid utilization genetic cluster. To determine the function of this putative sialic acid transporter, an isogenic nanT-deletion mutant generated by allelic replacement strategy was evaluated for biofilm formation on NAM or Neu5Ac, and survival on KB epithelial cells. Moreover, since T. forsythia forms synergistic biofilms with Fusobacterium nucleatum, co-biofilm formation activity in mixed culture and sialic acid uptake in culture were also assessed. The data showed that the nanT-inactivated mutant of T. forsythia was attenuated in its ability to uptake sialic acid. The mutant formed weaker biofilms compared to the wild-type strain in the presence of sialic acid and as co-biofilms with F. nucleatum. Moreover, compared to the wild-type T. forsythia nanT-inactivated mutant showed reduced survival when incubated on KB epithelial cells. Taken together, the data presented here demonstrate that NanT-mediated sialic transportation is essential for sialic acid utilization during biofilm growth and survival of the organism on epithelial cells and implies sialic acid might be key for its survival both in subgingival biofilms and during infection of human epithelial cells in vivo.

  18. Porphyromonas gingivalis vesicles enhance attachment, and the leucine-rich repeat BspA protein is required for invasion of epithelial cells by "Tannerella forsythia".

    PubMed

    Inagaki, Satoru; Onishi, Shinsuke; Kuramitsu, Howard K; Sharma, Ashu

    2006-09-01

    The human oral cavity harbors more than 500 species of bacteria. Periodontitis, a bacterially induced inflammatory disease that leads to tooth loss, is believed to result from infection by a select group of gram-negative periodontopathogens that includes Porphyromonas gingivalis, Treponema denticola, and "Tannerella forsythia" (opinion on name change from Tannerella forsythensis pending; formerly Bacteroides forsythus). Epithelial cell invasion by periodontopathogens is considered to be an important virulence mechanism for evasion of the host defense responses. Further, the epithelial cells with invading bacteria also serve as reservoirs important in recurrent infections. The present study was therefore undertaken to address the epithelial cell adherence and invasion properties of T. forsythia and the role of the cell surface-associated protein BspA in these processes. Further, we were interested in determining if P. gingivalis, one of the pathogens frequently found associated in disease, or its outer membrane vesicles (OMVs) could modulate the epithelial cell adherence and invasion abilities of T. forsythia. Here we show that epithelial cell attachment and invasion by T. forsythia are dependent on the BspA protein. In addition, P. gingivalis or its OMVs enhance the attachment and invasion of T. forsythia to epithelial cells. Thus, interactions between these two bacteria may play important roles in virulence by promoting host cell attachment and invasion.

  19. Mirolysin, a LysargiNase from Tannerella forsythia, proteolytically inactivates the human cathelicidin, LL-37.

    PubMed

    Koneru, Lahari; Ksiazek, Miroslaw; Waligorska, Irena; Straczek, Anna; Lukasik, Magdalena; Madej, Mariusz; Thøgersen, Ida B; Enghild, Jan J; Potempa, Jan

    2016-12-20

    Tannerella forsythia is a periodontal pathogen expressing six secretory proteolytic enzymes with a unique multidomain structure referred to as KLIKK proteases. Two of these proteases, karilysin and mirolysin, were previously shown to protect the bacterium against complement-mediated bactericidal activity. The latter metalloprotease, however, was not characterized at the protein level. Therefore, we purified recombinant mirolysin and subjected it to detailed biochemical characterization. Mirolysin was obtained as a 66 kDa zymogen, which autoproteolytically processed itself into a 31 kDa active form via truncations at both the N- and C-termini. Further autodegradation was prevented by calcium. Substrate specificity was determined by the S1' subsite of the substrate-binding pocket, which shows strong preference for Arg and Lys at the carbonyl side of a scissile peptide bond (P1' residue). The protease cleaved an array of host proteins, including human fibronectin, fibrinogen, complement proteins C3, C4, and C5, and the antimicrobial peptide, LL-37. Degradation of LL-37 abolished not only the bactericidal activity of the peptide, but also its ability to bind lipopolysaccharide (LPS), thus quenching the endotoxin proinflammatory activity. Taken together, these results indicate that, through cleavage of LL-37 and complement proteins, mirolysin might be involved in evasion of the host immune response.

  20. Identification and characterization of the genes encoding a unique surface (S-) layer of Tannerella forsythia.

    PubMed

    Lee, Seok-Woo; Sabet, Mojgan; Um, Heung-Sik; Yang, Jun; Kim, Hyeong C; Zhu, Weidong

    2006-04-12

    A newly emerged periodontopathic pathogen Tannerella forsythia (formerly Bacteroides forsythus), a Gram-negative, filament-shaped, strict anaerobic, non-pigmented oral bacterium, possesses a surface (S-) layer. In our previous studies, the S-layer has been isolated, and shown to mediate hemagglutination, adhesion/invasion of epithelial cell, and murine subcutaneous abscess formation. In the present study, biochemical and molecular genetic characterization of the S-layer are reported. Amino acid sequencing and mass spectrometry indicated that the S-layer is composed of two different proteins, termed 200 and 210 kDa proteins. It was also shown that these proteins are glycosylated. The genes encoding the core proteins of these glycoproteins, designated as tfsA and tfsB, have been identified in silico, cloned, and their sequences have been determined. The tfsA (3.5 kb) and tfsB (4.1 kb) genes are located in tandem, and encode for 135 and 152 kDa proteins, respectively. An apparent discrepancy in molecular weights, 135 vs. 200 kDa and 152 vs. 210 kDa, is accounted for carbohydrate residues attached to the core proteins. Amino acid sequence comparison exhibited a 24% similarity between the 200 and 210 kDa proteins. Further sequence analyses showed that TfsA and TfsB possess putative signal peptide sequences with cleavage sites at alanine residues, and transmembrane domains on the C-terminal region. Northern blot and RT-PCR analyses confirmed an operon structure of tfsAB, suggesting co-regulation of these genes in producing the S-layer. Putative promoter sequences and transcription termination sequences for this operon have also been identified. Comparison with database indicates that the S-layer of T. forsythia has a unique structure exhibiting no homology to other known S-layers of prokaryotic organisms. The present study shows that the T. forsythia S-layer is very unique, since it appears to be composed of two large glycoproteins, and it does not reveal any homology to

  1. Behavior of two Tannerella forsythia strains and cell surface mutants in multispecies oral biofilms.

    PubMed

    Bloch, Susanne; Thurnheer, Thomas; Murakami, Yukitaka; Belibasakis, Georgios N; Schäffer, Christina

    2017-04-05

    As a member of subgingival multispecies biofilms, Tannerella forsythia is commonly associated with periodontitis. The bacterium has a characteristic cell surface (S-) layer modified with a unique O-glycan. Both the S-layer and the O-glycan were analyzed in this study for their role in biofilm formation by employing an in vitro multispecies biofilm model mimicking the situation in the oral cavity. Different T. forsythia strains and mutants with characterized defects in cell surface composition were incorporated into the model, together with nine species of select oral bacteria. The influence of the T. forsythia S-layer and attached glycan on the bacterial composition of the biofilms was analyzed quantitatively using colony forming unit counts and quantitative real-time PCR, as well as qualitatively by fluorescence in situ hybridization and confocal laser scanning microscopy. This revealed that changes of the T. forsythia cell surface did not affect the quantitative composition of the multispecies consortium, with the exception of Campylobacter rectus cell numbers. The localization of T. forsythia within the bacterial agglomeration varied depending on changes in the S-layer glycan, and this also affected its aggregation with Porphyromonas gingivalis. This suggests a selective role for the glycosylated T. forsythia S-layer in the positioning of this species within the biofilm, its co-localization with P. gingivalis, and the prevalence of C. rectus. These findings might translate into a potential role of T. forsythia cell surface structures in the virulence of this species when interacting with host tissues and immune system, from within or beyond the biofilm. This article is protected by copyright. All rights reserved.

  2. DNA from Porphyromonas gingivalis and Tannerella forsythia induce cytokine production in human monocytic cell lines.

    PubMed

    Sahingur, S E; Xia, X-J; Alamgir, S; Honma, K; Sharma, A; Schenkein, H A

    2010-04-01

    Toll-like receptor 9 (TLR9) expression is increased in periodontally diseased tissues compared with healthy sites indicating a possible role of TLR9 and its ligand, bacterial DNA (bDNA), in periodontal disease pathology. Here, we determine the immunostimulatory effects of periodontal bDNA in human monocytic cells (THP-1). THP-1 cells were stimulated with DNA of two putative periodontal pathogens: Porphyromonas gingivalis and Tannerella forsythia. The role of TLR9 in periodontal bDNA-initiated cytokine production was determined either by blocking TLR9 signaling in THP-1 cells with chloroquine or by measuring IL-8 production and nuclear factor-kappaB (NF-kappaB) activation in HEK293 cells stably transfected with human TLR9. Cytokine production (IL-1beta, IL-6, and TNF-alpha) was increased significantly in bDNA-stimulated cells compared with controls. Chloroquine treatment of THP-1 cells decreased cytokine production, suggesting that TLR9-mediated signaling pathways are operant in the recognition of DNA from periodontal pathogens. Compared with native HEK293 cells, TLR9-transfected cells demonstrated significantly increased IL-8 production (P < 0.001) and NF-kappaB activation in response to bDNA, further confirming the role of TLR9 in periodontal bDNA recognition. The results of PCR arrays demonstrated upregulation of proinflammatory cytokine and NF-kappaB genes in response to periodontal bDNA in THP-1 cells, suggesting that cytokine induction is through NF-kappaB activation. Hence, immune responses triggered by periodontal bacterial nucleic acids may contribute to periodontal disease pathology by inducing proinflammatory cytokine production through the TLR9 signaling pathway.

  3. Role of a Tannerella forsythia exopolysaccharide synthesis operon in biofilm development.

    PubMed

    Honma, Kiyonobu; Inagaki, Satoru; Okuda, Katsuji; Kuramitsu, Howard K; Sharma, Ashu

    2007-04-01

    Tannerella forsythia is a Gram-negative oral anaerobe implicated in the development of periodontitis, a chronic inflammatory disease induced by bacterial infections which leads to tooth loss if untreated. Since biofilms formed by periodontal bacteria are considered important in disease progression and pose difficulties in treatment, we sought to investigate the underlying mechanisms of T. forsythia biofilm formation. This was carried out by screening random insertion mutants of T. forsythia for alterations in biofilm development. This approach lead to the identification of an operon involved in exopolysaccharide (EPS) synthesis. An isogenic mutant of one of the genes, wecC, contained within the operon was constructed. The isogenic wecC mutant showed increased ability to form biofilms as compared to the parent strain. The wecC mutant also formed aggregated microcolonies and showed increased cell-surface associated hydrophobicity as compared to the parent strain. Moreover, biochemical characterization of the wecC mutant indicated that glycosylation of surface glycoproteins was reduced. Therefore, our results suggest that the wecC operon is associated with glycosylation of surface-glycoprotein expression and likely plays an inhibitory role in T. forsythia biofilm formation.

  4. OmpA-like protein influences cell shape and adhesive activity of Tannerella forsythia.

    PubMed

    Abe, T; Murakami, Y; Nagano, K; Hasegawa, Y; Moriguchi, K; Ohno, N; Shimozato, K; Yoshimura, F

    2011-12-01

    Tannerella forsythia, a gram-negative fusiform rod, is implicated in several types of oral anaerobic infections. Most gram-negative bacteria have OmpA-like proteins that are homologous to the OmpA protein in Escherichia coli. We identified an OmpA-like protein in T. forsythia encoded by the tf1331 gene as one of the major proteins by mass spectrometric analysis. Two-dimensional, diagonal electrophoresis showed that the OmpA-like protein formed a dimeric or trimeric structure via intermolecular disulfide bonds. A biotin labeling experiment revealed that a portion of the protein was exposed on the cell surface, even though T. forsythia possesses an S-layer at the outermost cell surface. Using a tf1331-deletion mutant, we showed that the OmpA-like protein affected cell morphology. The length of the mutant cell was reduced almost by half. Cell swelling was observed in more than 40% of the mutant cells. Moreover, the mutant exhibited decreased adhesion to fibronectin, retarded autoaggregation, and reduced cell surface hydrophobicity. These results suggest that the OmpA-like protein in T. forsythia plays an important role in cellular integrity and adhesive function.

  5. The structure of the catalytic domain of Tannerella forsythia karilysin reveals it is a bacterial xenolog of animal matrix metalloproteinases

    PubMed Central

    Cerdà-Costa, Núria; Guevara, Tibisay; Karim, Abdulkarim Y.; Ksiazek, Miroslaw; Nguyen, Ky-Anh; Arolas, Joan L.; Potempa, Jan; Gomis-Rüth, F. Xavier

    2010-01-01

    Metallopeptidases (MPs) are among virulence factors secreted by pathogenic bacteria at the site of infection. One such pathogen is Tannerella forsythia, a member of the microbial consortium that causes peridontitis, arguably the most prevalent infective chronic inflammatory disease known to mankind. The only reported MP secreted by T. forsythia is karilysin, a 52-kDa multidomain protein comprising a central 18-kDa catalytic domain (CD), termed Kly18, flanked by domains unrelated to any known protein. We analyzed the 3D structure of Kly18 in the absence and presence of Mg2+ or Ca2+, which are required for function and stability, and found that it evidences most of the structural features characteristic of the CDs of mammalian matrix metalloproteinases (MMPs). Unexpectedly, a peptide was bound to the active-site cleft of Kly18 mimicking a left-behind cleavage product, which revealed that the specificity pocket accommodates bulky hydrophobic side chains of substrates as in mammalian MMPs. In addition, Kly18 displayed a unique Mg2+ or Ca2+ binding site and two flexible segments that could play a role in substrate binding. Phylogenetic and sequence similarity studies revealed that Kly18 is evolutionarily much closer to winged-insect and mammalian MMPs than to potential bacterial counterparts found by genomic sequencing projects. Therefore, we conclude that this first structurally-characterized non-mammalian MMP is a xenolog co-opted through horizontal gene transfer during the intimate coexistence between T. forsythia and humans or other animals, in a very rare case of gene shuffling from eukaryotes to prokaryotes. Subsequently, this protein would have evolved in a bacterial environment to give rise to full-length karilysin that is furnished with unique flanking domains that do not conform to the general multidomain architecture of animal MMPs. PMID:21166898

  6. The structure of the catalytic domain of Tannerella forsythia karilysin reveals it is a bacterial xenologue of animal matrix metalloproteinases.

    PubMed

    Cerdà-Costa, Núria; Guevara, Tibisay; Karim, Abdulkarim Y; Ksiazek, Miroslaw; Nguyen, Ky-Anh; Arolas, Joan L; Potempa, Jan; Gomis-Rüth, F Xavier

    2011-01-01

    Metallopeptidases (MPs) are among virulence factors secreted by pathogenic bacteria at the site of infection. One such pathogen is Tannerella forsythia, a member of the microbial consortium that causes peridontitis, arguably the most prevalent infective chronic inflammatory disease known to mankind. The only reported MP secreted by T. forsythia is karilysin, a 52 kDa multidomain protein comprising a central 18 kDa catalytic domain (CD), termed Kly18, flanked by domains unrelated to any known protein. We analysed the 3D structure of Kly18 in the absence and presence of Mg(2+) or Ca(2+) , which are required for function and stability, and found that it evidences most of the structural features characteristic of the CDs of mammalian matrix metalloproteinases (MMPs). Unexpectedly, a peptide was bound to the active-site cleft of Kly18 mimicking a left-behind cleavage product, which revealed that the specificity pocket accommodates bulky hydrophobic side-chains of substrates as in mammalian MMPs. In addition, Kly18 displayed a unique Mg(2+) or Ca(2+) binding site and two flexible segments that could play a role in substrate binding. Phylogenetic and sequence similarity studies revealed that Kly18 is evolutionarily much closer to winged-insect and mammalian MMPs than to potential bacterial counterparts found by genomic sequencing projects. Therefore, we conclude that this first structurally characterized non-mammalian MMP is a xenologue co-opted through horizontal gene transfer during the intimate coexistence between T. forsythia and humans or other animals, in a very rare case of gene shuffling from eukaryotes to prokaryotes. Subsequently, this protein would have evolved in a bacterial environment to give rise to full-length karilysin that is furnished with unique flanking domains that do not conform to the general multidomain architecture of animal MMPs.

  7. The surface layer of Tannerella forsythia contributes to serum resistance and oral bacterial coaggregation.

    PubMed

    Shimotahira, Naohiro; Oogai, Yuichi; Kawada-Matsuo, Miki; Yamada, Sakuo; Fukutsuji, Kenji; Nagano, Keiji; Yoshimura, Fuminobu; Noguchi, Kazuyuki; Komatsuzawa, Hitoshi

    2013-04-01

    Tannerella forsythia is an anaerobic, Gram-negative bacterium involved in the so-called "red complex," which is associated with severe and chronic periodontitis. The surface layer (S-layer) of T. forsythia is composed of cell surface glycoproteins, such as TfsA and TfsB, and is known to play a role in adhesion/invasion and suppression of proinflammatory cytokine expression. Here we investigated the association of this S-layer with serum resistance and coaggregation with other oral bacteria. The growth of the S-layer-deficient mutant in a bacterial medium containing more than 20% non-heat-inactivated calf serum (CS) or more than 40% non-heat-inactivated human serum was significantly suppressed relative to that of the wild type (WT). Next, we used confocal microscopy to perform quantitative analysis on the effect of serum. The survival ratio of the mutant exposed to 100% non-heat-inactivated CS (76% survival) was significantly lower than that of the WT (97% survival). Furthermore, significant C3b deposition was observed in the mutant but not in the WT. In a coaggregation assay, the mutant showed reduced coaggregation with Streptococcus sanguinis, Streptococcus salivarius, and Porphyromonas gingivalis but strong coaggregation with Fusobacterium nucleatum. These results indicated that the S-layer of T. forsythia plays multiple roles in virulence and may be associated with periodontitis.

  8. The Surface Layer of Tannerella forsythia Contributes to Serum Resistance and Oral Bacterial Coaggregation

    PubMed Central

    Shimotahira, Naohiro; Oogai, Yuichi; Kawada-Matsuo, Miki; Yamada, Sakuo; Fukutsuji, Kenji; Nagano, Keiji; Yoshimura, Fuminobu; Noguchi, Kazuyuki

    2013-01-01

    Tannerella forsythia is an anaerobic, Gram-negative bacterium involved in the so-called “red complex,” which is associated with severe and chronic periodontitis. The surface layer (S-layer) of T. forsythia is composed of cell surface glycoproteins, such as TfsA and TfsB, and is known to play a role in adhesion/invasion and suppression of proinflammatory cytokine expression. Here we investigated the association of this S-layer with serum resistance and coaggregation with other oral bacteria. The growth of the S-layer-deficient mutant in a bacterial medium containing more than 20% non-heat-inactivated calf serum (CS) or more than 40% non-heat-inactivated human serum was significantly suppressed relative to that of the wild type (WT). Next, we used confocal microscopy to perform quantitative analysis on the effect of serum. The survival ratio of the mutant exposed to 100% non-heat-inactivated CS (76% survival) was significantly lower than that of the WT (97% survival). Furthermore, significant C3b deposition was observed in the mutant but not in the WT. In a coaggregation assay, the mutant showed reduced coaggregation with Streptococcus sanguinis, Streptococcus salivarius, and Porphyromonas gingivalis but strong coaggregation with Fusobacterium nucleatum. These results indicated that the S-layer of T. forsythia plays multiple roles in virulence and may be associated with periodontitis. PMID:23357386

  9. Contact-dependent regulation of a Tannerella forsythia virulence factor, BspA, in biofilms.

    PubMed

    Inagaki, Satoru; Kuramitsu, Howard K; Sharma, Ashu

    2005-08-15

    Tannerella forsythia is one of the periodontal organisms implicated in the development of periodontal diseases. The surface associated and secreted protein, BspA (encoded by the bspA gene), of this bacterium is an important virulence factor. The present study was carried out to examine the regulation of the bspA gene during biofilm growth and contact stimuli encountered in interbacterial interactions. The expression levels of the bspA transcript were determined by real-time RT-PCR approach. The levels of bspA transcript were found to be significantly reduced as a result of contact stimulus and in biofilm cells relative to planktonic cells. The results of our study suggest that the likely downregulation of the BspA protein in biofilms and following contact may have implications in pathogenesis as a plausible mechanism of evasion of host immune responses.

  10. Proteolytic inactivation of LL-37 by karilysin, a novel virulence mechanism of Tannerella forsythia.

    PubMed

    Koziel, Joanna; Karim, Aabdulkarim Y; Przybyszewska, Kornelia; Ksiazek, Miroslaw; Rapala-Kozik, Maria; Nguyen, Ky-Anh; Potempa, Jan

    2010-01-01

    Tannerella forsythia is a gram-negative bacterium strongly associated with the development and/or progression of periodontal disease. Here, we have shown that a newly characterized matrix metalloprotease-like enzyme, referred to as karilysin, efficiently cleaved the antimicrobial peptide LL-37, significantly reducing its bactericidal activity. This may contribute to the resistance of T. forsythia to the antibacterial activity of LL-37, since their vitality was found not to be affected by LL-37 at concentrations up to 2.2 muM. Furthermore, proteolysis of LL-37 by karilysin not only abolished its ability to bind lipopolysaccharide (LPS) to quench endotoxin-induced proinflammatory activity, but LL-37 cleavage also caused the release of active endotoxin from the LPS/LL-37 complex. Proteolytic inactivation of LL-37 bactericidal activity by karilysin may protect LL-37-sensitive species in the subgingival plaque and maintain the local inflammatory reaction driven by LPS from gram-negative bacteria. Consequently, the karilysin protease may directly contribute to periodontal tissue damage and the development and/or progression of chronic periodontitis.

  11. Tannerella forsythia strains display different cell-surface nonulosonic acids: biosynthetic pathway characterization and first insight into biological implications

    PubMed Central

    Windwarder, Markus; Maresch, Daniel; Braun, Matthias L.; Megson, Zoë A.; Vinogradov, Evgeny; Goneau, Marie-France; Sharma, Ashu; Altmann, Friedrich; Messner, Paul; Schoenhofen, Ian C.; Schäffer, Christina

    2017-01-01

    Tannerella forsythia is an anaerobic, Gram-negative periodontal pathogen. A unique O-linked oligosaccharide decorates the bacterium’s cell surface proteins and was shown to modulate the host immune response. In our study, we investigated the biosynthesis of the nonulosonic acid (NulO) present at the terminal position of this glycan. A bioinformatic analysis of T. forsythia genomes revealed a gene locus for the synthesis of pseudaminic acid (Pse) in the type strain ATCC 43037 while strains FDC 92A2 and UB4 possess a locus for the synthesis of legionaminic acid (Leg) instead. In contrast to the NulO in ATCC 43037, which has been previously identified as a Pse derivative (5-N-acetimidoyl-7-N-glyceroyl-3,5,7,9-tetradeoxy-l-glycero-l-manno-NulO), glycan analysis of strain UB4 performed in this study indicated a 350-Da, possibly N-glycolyl Leg (3,5,7,9-tetradeoxy-d-glycero-d-galacto-NulO) derivative with unknown C5,7 N-acyl moieties. We have expressed, purified and characterized enzymes of both NulO pathways to confirm these genes’ functions. Using capillary electrophoresis (CE), CE–mass spectrometry and NMR spectroscopy, our studies revealed that Pse biosynthesis in ATCC 43037 essentially follows the UDP-sugar route described in Helicobacter pylori, while the pathway in strain FDC 92A2 corresponds to Leg biosynthesis in Campylobacter jejuni involving GDP-sugar intermediates. To demonstrate that the NulO biosynthesis enzymes are functional in vivo, we created knockout mutants resulting in glycans lacking the respective NulO. Compared to the wild-type strains, the mutants exhibited significantly reduced biofilm formation on mucin-coated surfaces, suggestive of their involvement in host-pathogen interactions or host survival. This study contributes to understanding possible biological roles of bacterial NulOs. PMID:27986835

  12. Tannerella forsythia strains display different cell-surface nonulosonic acids: biosynthetic pathway characterization and first insight into biological implications.

    PubMed

    Friedrich, Valentin; Janesch, Bettina; Windwarder, Markus; Maresch, Daniel; Braun, Matthias L; Megson, Zoë A; Vinogradov, Evgeny; Goneau, Marie-France; Sharma, Ashu; Altmann, Friedrich; Messner, Paul; Schoenhofen, Ian C; Schäffer, Christina

    2016-12-16

    Tannerella forsythia is an anaerobic, Gram-negative periodontal pathogen. A unique O-linked oligosaccharide decorates the bacterium's cell surface proteins and was shown to modulate the host immune response. In our study, we investigated the biosynthesis of the nonulosonic acid (NulO) present at the terminal position of this glycan. A bioinformatic analysis of T. forsythia genomes revealed a gene locus for the synthesis of pseudaminic acid (Pse) in the type strain ATCC 43037 while strains FDC 92A2 and UB4 possess a locus for the synthesis of legionaminic acid (Leg) instead. In contrast to the NulO in ATCC 43037, which has been previously identified as a Pse derivative (5-N-acetimidoyl-7-N-glyceroyl-3,5,7,9-tetradeoxy-l-glycero-l-manno-NulO), glycan analysis of strain UB4 performed in this study indicated a 350-Da, possibly N-glycolyl Leg (3,5,7,9-tetradeoxy-d-glycero-d-galacto-NulO) derivative with unknown C5,7 N-acyl moieties. We have expressed, purified and characterized enzymes of both NulO pathways to confirm these genes' functions. Using capillary electrophoresis (CE), CE-mass spectrometry and NMR spectroscopy, our studies revealed that Pse biosynthesis in ATCC 43037 essentially follows the UDP-sugar route described in Helicobacter pylori, while the pathway in strain FDC 92A2 corresponds to Leg biosynthesis in Campylobacter jejuni involving GDP-sugar intermediates. To demonstrate that the NulO biosynthesis enzymes are functional in vivo, we created knockout mutants resulting in glycans lacking the respective NulO. Compared to the wild-type strains, the mutants exhibited significantly reduced biofilm formation on mucin-coated surfaces, suggestive of their involvement in host-pathogen interactions or host survival. This study contributes to understanding possible biological roles of bacterial NulOs.

  13. Identification of OmpA-Like Protein of Tannerella forsythia as an O-Linked Glycoprotein and Its Binding Capability to Lectins

    PubMed Central

    Horie, Toshi; Inomata, Megumi; Into, Takeshi; Hasegawa, Yoshiaki; Kitai, Noriyuki; Yoshimura, Fuminobu; Murakami, Yukitaka

    2016-01-01

    Bacterial glycoproteins are associated with physiological and pathogenic functions of bacteria. It remains unclear whether bacterial glycoproteins can bind to specific classes of lectins expressed on host cells. Tannerella forsythia is a gram-negative oral anaerobe that contributes to the development of periodontitis. In this study, we aimed to find lectin-binding glycoproteins in T. forsythia. We performed affinity chromatography of wheat germ agglutinin, which binds to N-acetylglucosamine (GlcNAc) and sialic acid (Sia), and identified OmpA-like protein as the glycoprotein that has the highest affinity. Mass spectrometry revealed that OmpA-like protein contains O-type N-acetylhexosamine and hexose. Fluorometry quantitatively showed that OmpA-like protein contains Sia. OmpA-like protein was found to bind to lectins including E-selectin, P-selectin, L-selectin, Siglec-5, Siglec-9, Siglec-10, and DC-SIGN. The binding of OmpA-like protein to these lectins, except for the Siglecs, depends on the presence of calcium. N-acetylneuraminic acid (NeuAc), which is the most abundant Sia, inhibited the binding of OmpA-like protein to all of these lectins, whereas GlcNAc and mannose only inhibited the binding to DC-SIGN. We further found that T. forsythia adhered to human oral epithelial cells, which express E-selectin and P-selectin, and that this adhesion was inhibited by addition of NeuAc. Moreover, adhesion of an OmpA-like protein-deficient T. forsythia strain to the cells was reduced compared to that of the wild-type strain. Our findings indicate that OmpA-like protein of T. forsythia contains O-linked sugar chains that can mediate interactions with specific lectins. This interaction is suggested to facilitate adhesion of T. forsythia to the surface of host cells. PMID:27711121

  14. Identification of OmpA-Like Protein of Tannerella forsythia as an O-Linked Glycoprotein and Its Binding Capability to Lectins.

    PubMed

    Horie, Toshi; Inomata, Megumi; Into, Takeshi; Hasegawa, Yoshiaki; Kitai, Noriyuki; Yoshimura, Fuminobu; Murakami, Yukitaka

    2016-01-01

    Bacterial glycoproteins are associated with physiological and pathogenic functions of bacteria. It remains unclear whether bacterial glycoproteins can bind to specific classes of lectins expressed on host cells. Tannerella forsythia is a gram-negative oral anaerobe that contributes to the development of periodontitis. In this study, we aimed to find lectin-binding glycoproteins in T. forsythia. We performed affinity chromatography of wheat germ agglutinin, which binds to N-acetylglucosamine (GlcNAc) and sialic acid (Sia), and identified OmpA-like protein as the glycoprotein that has the highest affinity. Mass spectrometry revealed that OmpA-like protein contains O-type N-acetylhexosamine and hexose. Fluorometry quantitatively showed that OmpA-like protein contains Sia. OmpA-like protein was found to bind to lectins including E-selectin, P-selectin, L-selectin, Siglec-5, Siglec-9, Siglec-10, and DC-SIGN. The binding of OmpA-like protein to these lectins, except for the Siglecs, depends on the presence of calcium. N-acetylneuraminic acid (NeuAc), which is the most abundant Sia, inhibited the binding of OmpA-like protein to all of these lectins, whereas GlcNAc and mannose only inhibited the binding to DC-SIGN. We further found that T. forsythia adhered to human oral epithelial cells, which express E-selectin and P-selectin, and that this adhesion was inhibited by addition of NeuAc. Moreover, adhesion of an OmpA-like protein-deficient T. forsythia strain to the cells was reduced compared to that of the wild-type strain. Our findings indicate that OmpA-like protein of T. forsythia contains O-linked sugar chains that can mediate interactions with specific lectins. This interaction is suggested to facilitate adhesion of T. forsythia to the surface of host cells.

  15. Disease severity associated with presence in subgingival plaque of Porphyromonas gingivalis, Aggregatibacter actinomycetemcomitans, and Tannerella forsythia, singly or in combination, as detected by nested multiplex PCR.

    PubMed

    Ready, D; D'Aiuto, F; Spratt, D A; Suvan, J; Tonetti, M S; Wilson, M

    2008-10-01

    This study used a nested multiplex PCR method to detect three periodontal pathogens in subgingival plaque collected before treatment and at 2 and 6 months posttreatment from 107 patients with severe, generalized periodontitis. The proportions of the patients who harbored these bacteria before periodontal treatment were as follows: Tannerella forsythia, 81%; Porphyromonas gingivalis, 78%; and Aggregatibacter (formerly Actinobacillus) actinomycetemcomitans, 47%. At 2 months posttreatment there was a significant reduction in the numbers of patients harboring P. gingivalis (46%; P < 0.001) or T. forsythia (63%; P = 0.043) but not A. actinomycetemcomitans (50%) compared to pretreatment data. At 6 months posttreatment, significantly fewer patients harbored P. gingivalis (43%; P < 0.001); A. actinomycetemcomitans, (31%; P = 0.025), or T. forsythia (63%; P = 0.030). Interestingly, at baseline and at 2 months posttherapy, subjects who harbored only a single pathogen had a greater level of periodontal disease than subjects who harbored two, or all three, of these periodontal pathogens. These data suggest that a reduction in the number of species present may be associated with an increase in the severity of periodontal diseases.

  16. The S-layer proteins of Tannerella forsythia are secreted via a type IX secretion system that is decoupled from protein O-glycosylation

    PubMed Central

    Tomek, Markus B.; Neumann, Laura; Nimeth, Irene; Koerdt, Andrea; Andesner, Philipp; Messner, Paul; Mach, Lukas; Potempa, Jan S.; Schäffer, Christina

    2014-01-01

    SUMMARY Conserved C-terminal domains (CTD) have been shown to act as a signal for the translocation of certain proteins across the outer membrane of Bacteroidetes via a type IX secretion system (T9SS). The genome sequence of the periodontal pathogen Tannerella forsythia predicts the presence of the components for a T9SS in conjunction with a suite of CTD proteins. T. forsythia is covered with a 2-dimensional crystalline surface (S-) layer composed of the glycosylated CTD proteins TfsA and TfsB. To investigate if T9SS is functional in T. forsythia, T9SS-deficient mutants were generated by targeting either TF0955 (putative C-terminal signal peptidase) or TF2327 (PorK ortholog), and the mutants were analyzed with respect to secretion, assembly and glycosylation of the S-layer proteins as well as to proteolytic processing of the CTD and biofilm formation. In either mutant, TfsA and TfsB were incapable of translocation, as evidenced by the absence of the S-layer in transmission electron microscopy of ultrathin-sectioned bacterial cells. Despite entrapped within the periplasm, mass spectrometry analysis revealed that the S-layer proteins were modified with the complete, mature glycan found on the secreted proteins, indicating that protein translocation and glycosylation are two independent processes. Further, the T9SS mutants showed a denser biofilm with less voids compared to the wild-type. This study demonstrates the functionality of T9SS and the requirement of CTD for the outer membrane passage of extracellular proteins in T. forsythia, exemplified with the two S-layer proteins. In addition, T9SS protein translocation is decoupled from O-glycan attachment in T. forsythia. PMID:24943676

  17. The S-layer proteins of Tannerella forsythia are secreted via a type IX secretion system that is decoupled from protein O-glycosylation.

    PubMed

    Tomek, M B; Neumann, L; Nimeth, I; Koerdt, A; Andesner, P; Messner, P; Mach, L; Potempa, J S; Schäffer, C

    2014-12-01

    Conserved C-terminal domains (CTD) have been shown to act as a signal for the translocation of certain proteins across the outer membrane of Bacteroidetes via a type IX secretion system (T9SS). The genome sequence of the periodontal pathogen Tannerella forsythia predicts the presence of the components for a T9SS in conjunction with a suite of CTD proteins. T. forsythia is covered with a two-dimensional crystalline surface (S-) layer composed of the glycosylated CTD proteins TfsA and TfsB. To investigate, if T9SS is functional in T. forsythia, T9SS-deficient mutants were generated by targeting either TF0955 (putative C-terminal signal peptidase) or TF2327 (PorK ortholog), and the mutants were analyzed with respect to secretion, assembly and glycosylation of the S-layer proteins as well as proteolytic processing of the CTD and biofilm formation. In either mutant, TfsA and TfsB were incapable of translocation, as evidenced by the absence of the S-layer in transmission electron microscopy of ultrathin-sectioned bacterial cells. Despite being entrapped within the periplasm, mass spectrometry analysis revealed that the S-layer proteins were modified with the complete, mature glycan found on the secreted proteins, indicating that protein translocation and glycosylation are two independent processes. Further, the T9SS mutants showed a denser biofilm with fewer voids compared with the wild-type. This study demonstrates the functionality of T9SS and the requirement of CTD for the outer membrane passage of extracellular proteins in T. forsythia, exemplified by the two S-layer proteins. In addition, T9SS protein translocation is decoupled from O-glycan attachment in T. forsythia.

  18. Tannerella forsythia invasion in oral epithelial cells requires phosphoinositide 3-kinase activation and clathrin-mediated endocytosis.

    PubMed

    Mishima, Elina; Sharma, Ashu

    2011-08-01

    Tannerella forsythia, a Gram-negative anaerobe implicated in periodontitis, has been detected within human buccal epithelial cells and shown to invade oral epithelial cells in vitro. We have previously shown that this bacterium triggers host tyrosine kinase-dependent phosphorylation and actin-dependent cytoskeleton reorganization for invasion. On the bacterial side, the leucine-rich repeat cell-surface BspA protein is important for entry. The present study was undertaken to identify host signalling molecules during T. forsythia entry into human oral and cervical epithelial cells. Specifically, the roles of phosphatidylinositol 3-kinase (PI3K), Rho-family GTPases, cholesterol-rich membrane microdomains and the endocytic protein clathrin were investigated. For this purpose, cell lines were pretreated with chemical inhibitors or small interfering RNAs (siRNAs) that target PI3Ks, Rho GTPases, clathrin and cholesterol (a critical component of 'lipid rafts'), and the resulting effects on T. forsythia uptake were determined. Our studies revealed that T. forsythia entry is dependent on host PI3K signalling, and that purified BspA protein causes activation of this lipid kinase. Bacterial entry also requires the cooperation of host Rac1 GTPase. Finally, our findings indicate an important role for clathrin and cholesterol-rich lipid microdomains in the internalization process.

  19. Role of Tannerella forsythia NanH sialidase in epithelial cell attachment.

    PubMed

    Honma, Kiyonobu; Mishima, Elina; Sharma, Ashu

    2011-01-01

    Tannerella forsythia is a Gram-negative oral anaerobe which contributes to the development of periodontitis, an inflammatory disease of the tooth-supporting tissues leading to tooth loss. The mechanisms by which this bacterium colonizes the oral cavity are poorly understood. The bacterium has been shown to express two distinct sialidases, namely, SiaHI and NanH, with the latter being the major sialidase. Bacterial sialidases can play roles in pathogenesis by cleaving sialic acids on host glycoproteins, destroying their integrity, and/or unmasking hidden epitopes on host surfaces for colonization. In the present study, we investigated the roles of the SiaHI and NanH sialidases by generating and characterizing specific deletion mutants. Our results showed that the NanH deficiency resulted in a total loss of sialidase activity associated with the outer-membrane and secreted fractions. On the other hand, the SiaHI deficiency resulted in only a slight reduction in the total sialidase activity, with no significant differences in the levels of sialidase activity in the outer membrane or secreted fractions compared to that in the wild-type strain. The results demonstrated that NanH is both surface localized and secreted. The NanH-deficient mutant but not the SiaHI-deficient mutant was significantly attenuated in epithelial cell binding and invasion abilities compared to the wild-type strain. Moreover, the NanH-deficient mutant alone was impaired in cleaving surface sialic acids on epithelial cells. Thus, our study suggests that NanH sialidase might play roles in bacterial colonization by exposing sialic acid-hidden epitopes on epithelial cells.

  20. Draft Genome Sequences of Three Clinical Isolates of Tannerella forsythia Isolated from Subgingival Plaque from Periodontitis Patients in the United States.

    PubMed

    Stafford, Graham P; Chaudhuri, Roy R; Haraszthy, Violet; Friedrich, Valentin; Schäffer, Christina; Ruscitto, Angela; Honma, Kiyonobu; Sharma, Ashu

    2016-12-01

    We report the genome sequences of three clinical isolates of Tannerella forsythia from the subgingival plaque of periodontitis patients attending clinics at the School of Dental Medicine, University at Buffalo. The availability of these genome sequences will aid the understanding of the pathogenesis of periodontitis.

  1. Draft Genome Sequences of Three Clinical Isolates of Tannerella forsythia Isolated from Subgingival Plaque from Periodontitis Patients in the United States

    PubMed Central

    Stafford, Graham P.; Chaudhuri, Roy R.; Haraszthy, Violet; Friedrich, Valentin; Schäffer, Christina; Ruscitto, Angela; Honma, Kiyonobu

    2016-01-01

    We report the genome sequences of three clinical isolates of Tannerella forsythia from the subgingival plaque of periodontitis patients attending clinics at the School of Dental Medicine, University at Buffalo. The availability of these genome sequences will aid the understanding of the pathogenesis of periodontitis. PMID:27908987

  2. A hybrid two-component system of Tannerella forsythia affects autoaggregation and post-translational modification of surface proteins.

    PubMed

    Niwa, Daisuke; Nishikawa, Kiyoshi; Nakamura, Hiroshi

    2011-05-01

    Tannerella forsythia is a Gram-negative oral anaerobe closely associated with both periodontal and periapical diseases. The ORF TF0022 of strain ATCC 43037 encodes a hybrid two-component system consisting of an N-terminal histidine kinase and a C-terminal response regulator. Disruption of the TF0022 locus enhanced autoaggregation of the broth-cultured cells. Comparative proteome analyses revealed that two S-layer proteins in the TF0022 mutant exhibited decreased apparent masses by denaturing gel electrophoresis, suggesting a deficiency in post-translational modification. Furthermore, the mutant decreased the production of a glycosyltransferase encoded by TF1061 that is located in a putative glycosylation-related gene cluster. Quantitative real-time PCR revealed reduced transcription of TF1061 and the associated genes in the TF0022 mutant. These results indicate that TF0022 upregulates the expression of the glycosylation-related genes and suggest modulation of the autoaggregation of T. forsythia cells by a possible post-translational modification of cell-surface components.

  3. Miropin, a novel bacterial serpin from the periodontopathogen Tannerella forsythia, inhibits a broad range of proteases by using different peptide bonds within the reactive center loop.

    PubMed

    Ksiazek, Miroslaw; Mizgalska, Danuta; Enghild, Jan J; Scavenius, Carsten; Thogersen, Ida B; Potempa, Jan

    2015-01-02

    All prokaryotic genes encoding putative serpins identified to date are found in environmental and commensal microorganisms, and only very few prokaryotic serpins have been investigated from a mechanistic standpoint. Herein, we characterized a novel serpin (miropin) from the human pathogen Tannerella forsythia, a bacterium implicated in initiation and progression of human periodontitis. In contrast to other serpins, miropin efficiently inhibited a broad range of proteases (neutrophil and pancreatic elastases, cathepsin G, subtilisin, and trypsin) with a stoichiometry of inhibition of around 3 and second-order association rate constants that ranged from 2.7 × 10(4) (cathepsin G) to 7.1 × 10(5) m(-1)s(-1) (subtilisin). Inhibition was associated with the formation of complexes that were stable during SDS-PAGE. The unusually broad specificity of miropin for target proteases is achieved through different active sites within the reactive center loop upstream of the P1-P1' site, which was predicted from an alignment of the primary structure of miropin with those of well studied human and prokaryotic serpins. Thus, miropin is unique among inhibitory serpins, and it has apparently evolved the ability to inhibit a multitude of proteases at the expense of a high stoichiometry of inhibition and a low association rate constant. These characteristics suggest that miropin arose as an adaptation to the highly proteolytic environment of subgingival plaque, which is exposed continually to an array of host proteases in the inflammatory exudate. In such an environment, miropin may function as an important virulence factor by protecting bacterium from the destructive activity of neutrophil serine proteases. Alternatively, it may act as a housekeeping protein that regulates the activity of endogenous T. forsythia serine proteases.

  4. Toll-like receptor 2-mediated interleukin-8 expression in gingival epithelial cells by the Tannerella forsythia leucine-rich repeat protein BspA.

    PubMed

    Onishi, Shinsuke; Honma, Kiyonobu; Liang, Shuang; Stathopoulou, Panagiota; Kinane, Denis; Hajishengallis, George; Sharma, Ashu

    2008-01-01

    Tannerella forsythia is a gram-negative anaerobe strongly associated with chronic human periodontitis. This bacterium expresses a cell surface-associated and secreted protein, designated BspA, which has been recognized as an important virulence factor. The BspA protein belongs to the leucine-rich repeat (LRR) and bacterial immunoglobulin-like protein families. BspA is, moreover, a multifunctional protein which interacts with a variety of host cells, including monocytes which appear to respond to BspA through Toll-like receptor (TLR) signaling. Since gingival epithelium forms a barrier against periodontal pathogens, this study was undertaken to determine if gingival epithelial cells respond to BspA challenge and if TLRs play any role in BspA recognition. This study was also directed towards identifying the BspA domains responsible for cellular activation. We provide direct evidence for BspA binding to TLR2 and demonstrate that the release of the chemokine interleukin-8 from human gingival epithelial cells by BspA is TLR2 dependent. Furthermore, the LRR domain of BspA is involved in activation of TLR2, while TLR1 serves as a signaling partner. Thus, our findings suggest that BspA is an important modulator of host innate immune responses through activation of TLR2 in cooperation with TLR1.

  5. Human dental stem cells suppress PMN activity after infection with the periodontopathogens Prevotella intermedia and Tannerella forsythia.

    PubMed

    Hieke, Cathleen; Kriebel, Katja; Engelmann, Robby; Müller-Hilke, Brigitte; Lang, Hermann; Kreikemeyer, Bernd

    2016-12-15

    Periodontitis is characterized by inflammation associated with the colonization of different oral pathogens. We here aimed to investigate how bacteria and host cells shape their environment in order to limit inflammation and tissue damage in the presence of the pathogen. Human dental follicle stem cells (hDFSCs) were co-cultured with gram-negative P. intermedia and T. forsythia and were quantified for adherence and internalization as well as migration and interleukin secretion. To delineate hDFSC-specific effects, gingival epithelial cells (Ca9-22) were used as controls. Direct effects of hDFSCs on neutrophils (PMN) after interaction with bacteria were analyzed via chemotactic attraction, phagocytic activity and NET formation. We show that P. intermedia and T. forsythia adhere to and internalize into hDFSCs. This infection decreased the migratory capacity of the hDFSCs by 50%, did not disturb hDFSC differentiation potential and provoked an increase in IL-6 and IL-8 secretion while leaving IL-10 levels unaltered. These environmental modulations correlated with reduced PMN chemotaxis, phagocytic activity and NET formation. Our results suggest that P. intermedia and T. forsythia infected hDFSCs maintain their stem cell functionality, reduce PMN-induced tissue and bone degradation via suppression of PMN-activity, and at the same time allow for the survival of the oral pathogens.

  6. Human dental stem cells suppress PMN activity after infection with the periodontopathogens Prevotella intermedia and Tannerella forsythia

    PubMed Central

    Hieke, Cathleen; Kriebel, Katja; Engelmann, Robby; Müller-Hilke, Brigitte; Lang, Hermann; Kreikemeyer, Bernd

    2016-01-01

    Periodontitis is characterized by inflammation associated with the colonization of different oral pathogens. We here aimed to investigate how bacteria and host cells shape their environment in order to limit inflammation and tissue damage in the presence of the pathogen. Human dental follicle stem cells (hDFSCs) were co-cultured with gram-negative P. intermedia and T. forsythia and were quantified for adherence and internalization as well as migration and interleukin secretion. To delineate hDFSC-specific effects, gingival epithelial cells (Ca9-22) were used as controls. Direct effects of hDFSCs on neutrophils (PMN) after interaction with bacteria were analyzed via chemotactic attraction, phagocytic activity and NET formation. We show that P. intermedia and T. forsythia adhere to and internalize into hDFSCs. This infection decreased the migratory capacity of the hDFSCs by 50%, did not disturb hDFSC differentiation potential and provoked an increase in IL-6 and IL-8 secretion while leaving IL-10 levels unaltered. These environmental modulations correlated with reduced PMN chemotaxis, phagocytic activity and NET formation. Our results suggest that P. intermedia and T. forsythia infected hDFSCs maintain their stem cell functionality, reduce PMN-induced tissue and bone degradation via suppression of PMN-activity, and at the same time allow for the survival of the oral pathogens. PMID:27974831

  7. Subchronic Infection of Porphyromonas gingivalis and Tannerella forsythia Stimulates an Immune Response but Not Arthritis in Experimental Murine Model.

    PubMed

    Hernández-Aguas, Jorday; Montiel-Hernández, José Luis; De La Garza-Ramos, Myriam A; Ruiz-Ramos, Rosa Velia; Escamilla García, Erandi; Guzmán-García, Mario Alberto; Ayón-Haro, Esperanza Raquel; Garza-Elizondo, Mario Alberto

    2017-01-01

    Studies have proposed that Porphyromonas gingivalis (Pg) and Tannerella forsythia (Tf) promote a nonspecific inflammatory response that could produce systemic disease. Oral inoculation of Pg and Tf on the immune and arthritis response was evaluated in BALB/C mice divided into four groups: (1) sham; (2) food contaminated with Pg/Tf; (3) complete Freund's adjuvant (CFA) + Pg/Tf; and (4) CFA alone. CFA was administered subcutaneously on days 1 and 14. The arthritis response was monitored for 21 days after day 14 of CFA administration. IL-1β and IL-6 were determined in serum. T cell activation was evaluated by CD25 in salivary lymph nodes or mouse spleen. Pad inflammation appeared by day 19 in the CFA group, but animals with bacteria inoculation presented a delay. A significant increase in IL-6 was found in Groups 3 and 4, but not with respect to IL-1β. We observed an increase in CD25 in cells derived from cervical nodes and in animals with bacteria inoculation and CFA. A local immune response was observed in mice inoculated with Pg and Tf (T cell activation); a systemic response was observed with CFA. Since pad inflammation was delayed by bacterial inoculation this suggests that local T cell activation could decrease pad inflammation.

  8. Subchronic Infection of Porphyromonas gingivalis and Tannerella forsythia Stimulates an Immune Response but Not Arthritis in Experimental Murine Model

    PubMed Central

    Hernández-Aguas, Jorday; Montiel-Hernández, José Luis; Ruiz-Ramos, Rosa Velia; Escamilla García, Erandi; Guzmán-García, Mario Alberto; Ayón-Haro, Esperanza Raquel; Garza-Elizondo, Mario Alberto

    2017-01-01

    Studies have proposed that Porphyromonas gingivalis (Pg) and Tannerella forsythia (Tf) promote a nonspecific inflammatory response that could produce systemic disease. Oral inoculation of Pg and Tf on the immune and arthritis response was evaluated in BALB/C mice divided into four groups: (1) sham; (2) food contaminated with Pg/Tf; (3) complete Freund's adjuvant (CFA) + Pg/Tf; and (4) CFA alone. CFA was administered subcutaneously on days 1 and 14. The arthritis response was monitored for 21 days after day 14 of CFA administration. IL-1β and IL-6 were determined in serum. T cell activation was evaluated by CD25 in salivary lymph nodes or mouse spleen. Pad inflammation appeared by day 19 in the CFA group, but animals with bacteria inoculation presented a delay. A significant increase in IL-6 was found in Groups 3 and 4, but not with respect to IL-1β. We observed an increase in CD25 in cells derived from cervical nodes and in animals with bacteria inoculation and CFA. A local immune response was observed in mice inoculated with Pg and Tf (T cell activation); a systemic response was observed with CFA. Since pad inflammation was delayed by bacterial inoculation this suggests that local T cell activation could decrease pad inflammation. PMID:28676826

  9. Antimicrobial Effect of Lactobacillus reuteri on Cariogenic Bacteria Streptococcus gordonii, Streptococcus mutans, and Periodontal Diseases Actinomyces naeslundii and Tannerella forsythia.

    PubMed

    Baca-Castañón, Magda Lorena; De la Garza-Ramos, Myriam Angélica; Alcázar-Pizaña, Andrea Guadalupe; Grondin, Yohann; Coronado-Mendoza, Anahí; Sánchez-Najera, Rosa Isela; Cárdenas-Estrada, Eloy; Medina-De la Garza, Carlos Eduardo; Escamilla-García, Erandi

    2015-03-01

    Lactic acid bacteria (LAB) are well known for their beneficial effects on human health in the intestine and immune system; however, there are few studies on the impact they can generate in oral health. The aim of this study was to test and compare in vitro antimicrobial activity of L. reuteri on pathogenic bacteria involved in the formation of dental caries: S. mutans, S. gordonii, and periodontal disease: A. naeslundii and T. forsythia. Also, we determined the growth kinetics of each bacterium involved in this study. Before determining the antimicrobial action of L. reuteri on cariogenic bacteria and periodontal disease, the behavior and cell development time of each pathogenic bacterium were studied. Once the conditions for good cell growth of each of selected pathogens were established according to their metabolic requirements, maximum exponential growth was determined, this being the reference point for analyzing the development or inhibition by LAB using the Kirby Bauer method. Chlorhexidine 0.12% was positive control. L. reuteri was shown to have an inhibitory effect against S. mutans, followed by T. forsythia and S. gordonii, and a less significant effect against A. naeslundii. Regarding the effect shown by L. reuteri on the two major pathogens, we consider its potential use as a possible functional food in the prevention or treatment of oral diseases.

  10. Energy dispersive spectroscopy-scanning transmission electron microscope observations of free radical production in human polymorphonuclear leukocytes phagocytosing non-opsonized Tannerella forsythia.

    PubMed

    Moriguchi, Keiichi; Hasegawa, Yoshiaki; Higuchi, Naoya; Murakami, Yukitaka; Yoshimura, Fuminobu; Nakata, Kazuhiko; Honda, Masaki

    2017-06-01

    We investigated the association between human polymorphonuclear leukocytes (PMNs) and non-opsonized Tannerella forsythia ATCC 43037 displaying a serum-resistant surface layer (S-layer). When PMNs were mixed with T. forsythia in suspension, the cells phagocytosed T. forsythia cells. Nitro blue tetrazolium (NBT) reduction, indicative of O2- production, was observed by light microscopy; cerium (Ce) perhydroxide deposition, indicative of H2 O2 production, was observed by electron microscopy. We examined the relationship between high-molecular-weight proteins of the S-layer and Ce reaction (for T. forsythia phagocytosis) using electron microscopic immunolabeling. Immunogold particles were localized within the PMNs and on cell surfaces, labelling at the same Ce-reacted sites where the S-layer was present. We then used energy dispersive spectroscopy (EDS)-scanning transmission electron microscope (STEM) to perform Ce and nitrogen (N) (for S-layer immunocytochemistry) elemental analysis on the phagocytosed cells. That is, the elemental mapping and analysis of N by EDS appeared to reflect the presence of the same moieties detected by the 3,3'-diaminobenzidine-tetrahydrochloride (DAB) reaction with horseradish peroxidase (HRP)-conjugated secondary antibodies, instead of immunogold labeling. We focused on the use of EDS-STEM to visualize the presence of N resulting from the DAB reaction. In a parallel set of experiments, we used EDS-STEM to perform Ce and gold (Au; from immunogold labeling of the S-layer) elemental analysis on the same phagocytosing cells. © 2016 Wiley Periodicals, Inc.

  11. Structure of the catalytic domain of the Tannerella forsythia matrix metallopeptidase karilysin in complex with a tetrapeptidic inhibitor

    PubMed Central

    Guevara, Tibisay; Ksiazek, Miroslaw; Skottrup, Peter Durand; Cerdà-Costa, Núria; Trillo-Muyo, Sergio; de Diego, Iñaki; Riise, Erik; Potempa, Jan; Gomis-Rüth, F. Xavier

    2013-01-01

    Karilysin is the only metallopeptidase identified as a virulence factor in the odontopathogen Tannerella forsythia owing to its deleterious effect on the host immune response during bacterial infection. The very close structural and sequence-based similarity of its catalytic domain (Kly18) to matrix metallo­proteinases suggests that karilysin was acquired by horizontal gene transfer from an animal host. Previous studies by phage display identified peptides with the consensus sequence XWFPXXXGGG (single-letter amino-acid codes; X represents any residue) as karilysin inhibitors with low-micromolar binding affinities. Subsequent refinement revealed that inhibition comparable to that of longer peptides could be achieved using the tetrapeptide SWFP. To analyze its binding, the high-resolution crystal structure of the complex between Kly18 and SWFP was determined and it was found that the peptide binds to the primed side of the active-site cleft in a substrate-like manner. The catalytic zinc ion is clamped by the α-amino group and the carbonyl O atom of the serine, thus distantly mimicking the general manner of binding of hydroxamate inhibitors to metallopeptidases and contributing, together with three zinc-binding histidines from the protein scaffold, to an octahedral-minus-one metal-coordination sphere. The tryptophan side chain penetrates the deep partially water-filled specificity pocket of Kly18. Together with previous serendipitous product complexes of Kly18, the present results provide the structural determinants of inhibition of karilysin and open the field for the design of novel inhibitory strategies aimed at the treatment of human periodontal disease based on a peptidic hit molecule. PMID:23695557

  12. Structure of the catalytic domain of the Tannerella forsythia matrix metallopeptidase karilysin in complex with a tetrapeptidic inhibitor.

    PubMed

    Guevara, Tibisay; Ksiazek, Miroslaw; Skottrup, Peter Durand; Cerdà-Costa, Núria; Trillo-Muyo, Sergio; de Diego, Iñaki; Riise, Erik; Potempa, Jan; Gomis-Rüth, F Xavier

    2013-05-01

    Karilysin is the only metallopeptidase identified as a virulence factor in the odontopathogen Tannerella forsythia owing to its deleterious effect on the host immune response during bacterial infection. The very close structural and sequence-based similarity of its catalytic domain (Kly18) to matrix metalloproteinases suggests that karilysin was acquired by horizontal gene transfer from an animal host. Previous studies by phage display identified peptides with the consensus sequence XWFPXXXGGG (single-letter amino-acid codes; X represents any residue) as karilysin inhibitors with low-micromolar binding affinities. Subsequent refinement revealed that inhibition comparable to that of longer peptides could be achieved using the tetrapeptide SWFP. To analyze its binding, the high-resolution crystal structure of the complex between Kly18 and SWFP was determined and it was found that the peptide binds to the primed side of the active-site cleft in a substrate-like manner. The catalytic zinc ion is clamped by the α-amino group and the carbonyl O atom of the serine, thus distantly mimicking the general manner of binding of hydroxamate inhibitors to metallopeptidases and contributing, together with three zinc-binding histidines from the protein scaffold, to an octahedral-minus-one metal-coordination sphere. The tryptophan side chain penetrates the deep partially water-filled specificity pocket of Kly18. Together with previous serendipitous product complexes of Kly18, the present results provide the structural determinants of inhibition of karilysin and open the field for the design of novel inhibitory strategies aimed at the treatment of human periodontal disease based on a peptidic hit molecule.

  13. Levels of Serum Immunoglobulin G Specific to Bacterial Surface Protein A of Tannerella forsythia are Related to Periodontal Status

    PubMed Central

    Hall, Lindsay M.; Dunford, Robert G.; Genco, Robert J.; Sharma, Ashu

    2015-01-01

    Background Tannerella forsythia (Tf) is a Gram-negative anaerobe implicated in the development of periodontal disease. Bacterial surface protein A (BspA) is a surface-expressed and -secreted protein that is recognized as an important virulence factor of Tf. This study was undertaken to determine whether Tf BspA induces an antibody response in periodontal disease. We hypothesized that serum immunoglobulin (Ig)G antibody levels against BspA correlate with the disease of patients. Methods Sera were obtained from 100 patients with cardiac disorders and periodontal disease and 73 patients who experienced myocardial infarction but were periodontally healthy. Sera samples were assayed for anti-BspA antibody (total IgG and IgG subtypes) by enzyme-linked immunosorbent assay (ELISA). Antibody levels were measured in ELISA units by using an arbitrary patient as a standard. Results A negative correlation was found with BspA-specific total IgG antibody titers and the severity of disease measured as the clinical attachment level (CAL) when healthy and diseased groups were analyzed separately (healthy group: [−0.23, correlation value] Student’s t value [73 degrees of freedom] = 1.99; P = 0.05; diseased group: [−0.21] t [100 degrees of freedom] = 2.12; P = 0.03]). However, there was a positive correlation ([0.18 correlation value] Student’s t value [173 degrees of freedom] = 2.39; P = 0.017) when healthy and diseased groups were combined. A strong positive correlation ([0.338 correlation value] Student’s t value [173 degrees of freedom] = 4.69; P <0.0001) between the BspA-specific IgG titers and periodontal probing depth was observed when healthy and disease groups were combined. Conclusions Data demonstrated that antibodies to Tf BspA were elicited in patients with periodontal disease, and antibody levels were associated with the disease severity. Furthermore, data suggested that anti-BspA IgG might have a protective function in periodontal disease by minimizing the

  14. Inflammatory responses of a macrophage/epithelial cell co-culture model to mono and mixed infections with Porphyromonas gingivalis, Treponema denticola, and Tannerella forsythia.

    PubMed

    Bodet, Charles; Chandad, Fatiha; Grenier, Daniel

    2006-01-01

    Accumulated evidence points to Porphyromonas gingivalis, Treponema denticola, and Tannerella forsythia as three major etiologic agents of chronic periodontitis. Epithelial cells and macrophages play a major role in the host response to periodontopathogens, and the secretion of inflammatory mediators and matrix metalloproteinases (MMPs) by these host cells is believed to contribute to periodontal tissue destruction. The aim of this study was to investigate the inflammatory response of a macrophage/epithelial cell co-culture model following mono or mixed infections with the above three periodontopathogens. An in vitro co-culture model composed of epithelial-like transformed cells (HeLa cell line) and macrophage-like cells (phorbol myristic acid-differentiated U937 monocytic cell line) was challenged with whole cells or lipopolysaccharides (LPS) of P. gingivalis, T. denticola, and T. forsythia, individually and in combination. Following stimulation, the production of interleukin-1 beta (IL-1beta), IL-6, IL-8, tumor necrosis factor alpha (TNF-alpha), regulated on activation normal T cell expressed and secreted (RANTES), prostaglandin E2 (PGE2), and MMP-9 were quantified by enzyme-linked immunoassays. We observed that mono or mixed infections of the co-culture model induced the secretion of IL-1beta, IL-6, IL-8, PGE2, and MMP-9. P. gingivalis and T. forsythia induced an increase in RANTES secretion, whereas T. denticola alone or in combination resulted in a significant decrease in RANTES levels. All LPS challenges induced an increase in chemokine, MMP-9, and PGE2 production. No synergistic effect on the production of cytokines, chemokines, PGE2, and MMP-9 was observed for any of the bacterial or LPS mixtures tested. This study supports the view that P. gingivalis, T. denticola, and T. forsythia may induce high levels of pro-inflammatory mediators and MMP-9 in periodontal lesions, thus contributing to the progression of periodontitis.

  15. A Phage Display Selected 7-mer Peptide Inhibitor of the Tannerella forsythia Metalloprotease-Like Enzyme Karilysin can be Truncated to Ser-Trp-Phe-Pro

    PubMed Central

    Skottrup, Peter Durand; Sørensen, Grete; Ksiazek, Miroslaw; Potempa, Jan; Riise, Erik

    2012-01-01

    Tannerella forsythia is a gram-negative bacteria, which is strongly associated with the development of periodontal disease. Karilysin is a newly identified metalloprotease-like enzyme, that is secreted from T. forsythia. Karilysin modulates the host immune response and is therefore considered a likely drug target. In this study peptides were selected towards the catalytic domain from Karilysin (Kly18) by phage display. The peptides were linear with low micromolar binding affinities. The two best binders (peptide14 and peptide15), shared the consensus sequence XWFPXXXGGG. A peptide15 fusion with Maltose Binding protein (MBP) was produced with peptide15 fused to the N-terminus of MBP. The peptide15-MBP was expressed in E. coli and the purified fusion-protein was used to verify Kly18 specific binding. Chemically synthesised peptide15 (SWFPLRSGGG) could inhibit the enzymatic activity of both Kly18 and intact Karilysin (Kly48). Furthermore, peptide15 could slow down the autoprocessing of intact Kly48 to Kly18. The WFP motif was important for inhibition and a truncation study further demonstrated that the N-terminal serine was also essential for Kly18 inhibition. The SWFP peptide had a Ki value in the low micromolar range, which was similar to the intact peptide15. In conclusion SWFP is the first reported inhibitor of Karilysin and can be used as a valuable tool in structure-function studies of Karilysin. PMID:23119051

  16. A phage display selected 7-mer peptide inhibitor of the Tannerella forsythia metalloprotease-like enzyme Karilysin can be truncated to Ser-Trp-Phe-Pro.

    PubMed

    Skottrup, Peter Durand; Sørensen, Grete; Ksiazek, Miroslaw; Potempa, Jan; Riise, Erik

    2012-01-01

    Tannerella forsythia is a gram-negative bacteria, which is strongly associated with the development of periodontal disease. Karilysin is a newly identified metalloprotease-like enzyme, that is secreted from T. forsythia. Karilysin modulates the host immune response and is therefore considered a likely drug target. In this study peptides were selected towards the catalytic domain from Karilysin (Kly18) by phage display. The peptides were linear with low micromolar binding affinities. The two best binders (peptide14 and peptide15), shared the consensus sequence XWFPXXXGGG. A peptide15 fusion with Maltose Binding protein (MBP) was produced with peptide15 fused to the N-terminus of MBP. The peptide15-MBP was expressed in E. coli and the purified fusion-protein was used to verify Kly18 specific binding. Chemically synthesised peptide15 (SWFPLRSGGG) could inhibit the enzymatic activity of both Kly18 and intact Karilysin (Kly48). Furthermore, peptide15 could slow down the autoprocessing of intact Kly48 to Kly18. The WFP motif was important for inhibition and a truncation study further demonstrated that the N-terminal serine was also essential for Kly18 inhibition. The SWFP peptide had a Ki value in the low micromolar range, which was similar to the intact peptide15. In conclusion SWFP is the first reported inhibitor of Karilysin and can be used as a valuable tool in structure-function studies of Karilysin.

  17. Tannerella forsythia Outer Membrane Vesicles Are Enriched with Substrates of the Type IX Secretion System and TonB-Dependent Receptors.

    PubMed

    Veith, Paul D; Chen, Yu-Yen; Chen, Dina; O'Brien-Simpson, Neil M; Cecil, Jessica D; Holden, James A; Lenzo, Jason C; Reynolds, Eric C

    2015-12-04

    Tannerella forsythia, a Gram-negative oral bacterium closely associated with chronic periodontitis, naturally produces outer membrane vesicles (OMVs). In this study, OMVs were purified by gradient centrifugation, and the proteome was investigated together with cellular fractions using LC-MS/MS analyses of SDS-PAGE fractions, resulting in the identification of 872 proteins including 297 OMV proteins. Comparison of the OMV proteome with the subcellular proteomes led to the localization of 173 proteins to the vesicle membrane and 61 proteins to the vesicle lumen, while 27 substrates of the type IX secretion system were assigned to the vesicle surface. These substrates were generally enriched in OMVs; however, the stoichiometry of the S-layer proteins, TfsA and TfsB, was significantly altered, potentially to accommodate the higher curvature required of the S-layer around OMVs. A vast number of TonB-dependent receptors related to SusC, together with their associated SusD-like lipoproteins, were identified, and these were also relatively enriched in OMVs. In contrast, other lipoproteins were significantly depleted from the OMVs. This study identified the highest number of membrane-associated OMV proteins to date in any bacterium and conclusively demonstrates cargo sorting of particular classes of proteins, which may have significant impact on the virulence of OMVs.

  18. Characterizing the S-layer structure and anti-S-layer antibody recognition on intact Tannerella forsythia cells by scanning probe microscopy and small angle X-ray scattering.

    PubMed

    Oh, Yoo Jin; Sekot, Gerhard; Duman, Memed; Chtcheglova, Lilia; Messner, Paul; Peterlik, Herwig; Schäffer, Christina; Hinterdorfer, Peter

    2013-11-01

    Tannerella forsythia is among the most potent triggers of periodontal diseases, and approaches to understand underlying mechanisms are currently intensively pursued. A ~22-nm-thick, 2D crystalline surface (S-) layer that completely covers Tannerella forsythia cells is crucially involved in the bacterium-host cross-talk. The S-layer is composed of two intercalating glycoproteins (TfsA-GP, TfsB-GP) that are aligned into a periodic lattice. To characterize this unique S-layer structure at the nanometer scale directly on intact T. forsythia cells, three complementary methods, i.e., small-angle X-ray scattering (SAXS), atomic force microscopy (AFM), and single-molecular force spectroscopy (SMFS), were applied. SAXS served as a difference method using signals from wild-type and S-layer-deficient cells for data evaluation, revealing two possible models for the assembly of the glycoproteins. Direct high-resolution imaging of the outer surface of T. forsythia wild-type cells by AFM revealed a p4 structure with a lattice constant of ~9.0 nm. In contrast, on mutant cells, no periodic lattice could be visualized. Additionally, SMFS was used to probe specific interaction forces between an anti-TfsA antibody coupled to the AFM tip and the S-layer as present on T. forsythia wild-type and mutant cells, displaying TfsA-GP alone. Unbinding forces between the antibody and wild-type cells were greater than with mutant cells. This indicated that the TfsA-GP is not so strongly attached to the mutant cell surface when the co-assembling TfsB-GP is missing. Altogether, the data gained from SAXS, AFM, and SMFS confirm the current model of the S-layer architecture with two intercalating S-layer glycoproteins and TfsA-GP being mainly outwardly oriented.

  19. An Orthologue of Bacteroides fragilis NanH Is the Principal Sialidase in Tannerella forsythia▿

    PubMed Central

    Thompson, Hayley; Homer, Karen A.; Rao, Susmitha; Booth, Veronica; Hosie, Arthur H. F.

    2009-01-01

    Sialidase activity is a putative virulence factor of the anaerobic periodontal pathogen Tannerella forsythia, but it is uncertain which genes encode this activity. Characterization of a putative sialidase, SiaHI, by others, indicated that this protein alone may not be responsible for all of the sialidase activity. We describe a second sialidase in T. forsythia (TF0035), an orthologue of Bacteroides fragilis NanH, and its expression in Escherichia coli. Sialidase activity of the expressed NanH was confirmed by using 2′-(4-methylumbelliferyl)-α-d-N-acetylneuraminic acid as a substrate. Biochemical characterization of the recombinant T. forsythia NanH indicated that it was active over a broad pH range, with optimum activity at pH 5.5. This enzyme has high affinity for 2′-(4-methylumbelliferyl)-α-d-N-acetylneuraminic acid (Km of 32.9 ± 10.3 μM) and rapidly releases 4-methylumbelliferone (Vmax of 170.8 ± 11.8 nmol of 4-methylumbelliferone min−1 mg of protein−1). E. coli lysates containing recombinant T. forsythia NanH cleave sialic acid from a range of substrates, with a preference for α2-3 glycosidic linkages. The genes adjacent to nanH encode proteins apparently involved in the metabolism of sialic acid, indicating that the NanH sialidase is likely to be involved in nutrient acquisition. PMID:19304852

  20. Comparison of periodontal pathogens between cats and their owners.

    PubMed

    Booij-Vrieling, H E; van der Reijden, W A; Houwers, D J; de Wit, W E A J; Bosch-Tijhof, C J; Penning, L C; van Winkelhoff, A J; Hazewinkel, H A W

    2010-07-29

    The periodontal pathogens Porphyromonas gingivalis and Tannerella forsythia are strongly associated with periodontal disease and are highly prevalent in humans with periodontitis. Porphyromonas and Tannerella spp. have also been isolated from the oral cavity of cats. The oral microflora in animals was compared with those in humans in earlier studies, but no studies are available on the comparison of the oral microflora from pets and their respective owners. The aim of this study was to determine the presence of these bacteria in the oral microflora of cats and their owners, since animal to human transmission, or vice versa, of oral pathogens could have public health implications. This study investigated the prevalence of Porphyromonas gulae, P. gingivalis, and T. forsythia in the oral microflora of cats and their owners, using culture and polymerase chain reaction (PCR). All Porphyromonas isolates from cats (n=64) were catalase positive, whereas the Porphyromonas isolates from owners (n=7) were catalase negative, suggesting that the isolates from cats were P. gulae whereas those from the owners were P. gingivalis. T. forsythia was recovered from both cats (n=63) and owners (n=31); the proportion of T. forsythia relative to the total CFU was higher in cats with periodontitis than in cats without periodontal disease. Genotyping of T. forsythia isolates (n=54) in six cat/owner couples showed that in one cat/owner couple the T. forsythia isolates (n=6) were identical. These T. forsythia isolates were all catalase positive, which led us to hypothesize that transmission from cats to owners had occurred and that cats may be a reservoir of T. forsythia.

  1. Antibacterial Activity of Fructus forsythia Essential Oil and the Application of EO-Loaded Nanoparticles to Food-Borne Pathogens

    PubMed Central

    Guo, Na; Gai, Qing-Yan; Jiao, Jiao; Wang, Wei; Zu, Yuan-Gang; Fu, Yu-Jie

    2016-01-01

    Fructus forsythia essential oil (FEO) with excellent antibacterial activity was rarely reported. The objective of the present study was to investigate the antibacterial activity and the antibacterial mechanism of FEO against two food-borne pathogenic bacteria, Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus) in vitro. When treated FEO, the zones of inhibition (ZOI) of E. coli (20.5 ± 0.25 mm) and S. aureus (24.3 ± 0.21 mm) were much larger than control (p < 0.05). The minimum inhibitory concentrations (MICs) of FEO were 3.13 mg/mL and 1.56 mg/mL for E. coli and S. aureus, respectively. The antibacterial mechanism of FEO against E. coil was due to the changes in permeability and integrity of cell membrane leading to the leakage of nucleic acids and proteins. With the superior antibacterial activity of FEO, the nano-encapsulation method has been applied in FEO. When compared to FEO and blank chitosan nanoparticles, FEO-loaded nanoparticles (chitosan to FEO of 1:1) can effectively inhibit the growth of E. coil above 90% at room temperature. It is necessary to consider that FEO and FEO-loaded nanoparticles will become promising antibacterial additives for food preservative, cosmetic, and pharmaceutical applications. PMID:28231167

  2. Identification of Microbial Pathogens in Periodontal disease and Diabetic patients of South Indian Population

    PubMed Central

    Chiranjeevi, Tikka; Prasad, Osuru Hari; Prasad, Uppu Venkateswara; Kumar, Avula Kishor; Chakravarthi, Veeraraghavulu Praveen; Rao, Paramala Balaji; Sarma, Potuguchi Venkata Gurunadha Krishna; Reddy, Nagi reddy Raveendra; Bhaskar, Matcha

    2014-01-01

    Periodontitis have been referred to as the sixth complication of diabetes found in high prevalence among diabetic patients than among healthy controls. The aim of the present study was to examine the periodontal disease status among collected dental plaque samples. Chromosomal DNA was isolated and amplified by universal primers. The DNA was sequenced for bacterial confirmation and phylogenetic analysis performed for the evolutionary relationship with other known pathogens. No amplification products were observed in groups labeled non periodontal and non Diabetes (NP&ND) and non Periodontal and Diabetes (NP&D). But in the case of Periodontal and non Diabetes (P&ND) groups 22 amplified products were observed. In case of Periodontal and Diabetes (P&D), 32 amplified products were positive for microbes. Among the four microbial groups, Treponemadenticola, and Tannerella forsythia were found to be prevalent in P&D. The phylogenetic analysis of 16s rRNA of Treponemadenticola showed the relationship with other Treponema oral pathogen species and with the Spirochaetazuelaera. Tannerella forsythia shows its evolutionary relationship only with four oral pathogens (Macellibacteroidesfermentans, Porphyromadaceae bacterium, Parabacteroidesmeredae and Bacillus fosythus). Prevotellaintermedia also showed its evolutionary relationship only with Prevotella Spcs while Fusobacterium revealed close evolutionary relationship only with Porpiromonasgingivalis. PMID:24966528

  3. Pathogens and host immunity in the ancient human oral cavity

    PubMed Central

    Warinner, Christina; Matias Rodrigues, João F.; Vyas, Rounak; Trachsel, Christian; Shved, Natallia; Grossmann, Jonas; Radini, Anita; Hancock, Y.; Tito, Raul Y.; Fiddyment, Sarah; Speller, Camilla; Hendy, Jessica; Charlton, Sophy; Luder, Hans Ulrich; Salazar-García, Domingo C.; Eppler, Elisabeth; Seiler, Roger; Hansen, Lars; Samaniego Castruita, José Alfredo; Barkow-Oesterreicher, Simon; Teoh, Kai Yik; Kelstrup, Christian; Olsen, Jesper V.; Nanni, Paolo; Kawai, Toshihisa; Willerslev, Eske; von Mering, Christian; Lewis, Cecil M.; Collins, Matthew J.; Gilbert, M. Thomas P.; Rühli, Frank; Cappellini, Enrico

    2014-01-01

    Calcified dental plaque (dental calculus) preserves for millennia and entraps biomolecules from all domains of life and viruses. We report the first high-resolution taxonomic and protein functional characterization of the ancient oral microbiome and demonstrate that the oral cavity has long served as a reservoir for bacteria implicated in both local and systemic disease. We characterize: (i) the ancient oral microbiome in a diseased state, (ii) 40 opportunistic pathogens, (iii) the first evidence of ancient human-associated putative antibiotic resistance genes, (iv) a genome reconstruction of the periodontal pathogen Tannerella forsythia, (v) 239 bacterial and 43 human proteins, allowing confirmation of a long-term association between host immune factors, “red-complex” pathogens, and periodontal disease, and (vi) DNA sequences matching dietary sources. Directly datable and nearly ubiquitous, dental calculus permits the simultaneous investigation of pathogen activity, host immunity, and diet, thereby extending the direct investigation of common diseases into the human evolutionary past. PMID:24562188

  4. Pathogens and host immunity in the ancient human oral cavity.

    PubMed

    Warinner, Christina; Rodrigues, João F Matias; Vyas, Rounak; Trachsel, Christian; Shved, Natallia; Grossmann, Jonas; Radini, Anita; Hancock, Y; Tito, Raul Y; Fiddyment, Sarah; Speller, Camilla; Hendy, Jessica; Charlton, Sophy; Luder, Hans Ulrich; Salazar-García, Domingo C; Eppler, Elisabeth; Seiler, Roger; Hansen, Lars H; Castruita, José Alfredo Samaniego; Barkow-Oesterreicher, Simon; Teoh, Kai Yik; Kelstrup, Christian D; Olsen, Jesper V; Nanni, Paolo; Kawai, Toshihisa; Willerslev, Eske; von Mering, Christian; Lewis, Cecil M; Collins, Matthew J; Gilbert, M Thomas P; Rühli, Frank; Cappellini, Enrico

    2014-04-01

    Calcified dental plaque (dental calculus) preserves for millennia and entraps biomolecules from all domains of life and viruses. We report the first, to our knowledge, high-resolution taxonomic and protein functional characterization of the ancient oral microbiome and demonstrate that the oral cavity has long served as a reservoir for bacteria implicated in both local and systemic disease. We characterize (i) the ancient oral microbiome in a diseased state, (ii) 40 opportunistic pathogens, (iii) ancient human-associated putative antibiotic resistance genes, (iv) a genome reconstruction of the periodontal pathogen Tannerella forsythia, (v) 239 bacterial and 43 human proteins, allowing confirmation of a long-term association between host immune factors, 'red complex' pathogens and periodontal disease, and (vi) DNA sequences matching dietary sources. Directly datable and nearly ubiquitous, dental calculus permits the simultaneous investigation of pathogen activity, host immunity and diet, thereby extending direct investigation of common diseases into the human evolutionary past.

  5. Rheumatoid arthritis is an autoimmune disease caused by periodontal pathogens.

    PubMed

    Ogrendik, Mesut

    2013-01-01

    A statistically significant association between periodontal disease (PD) and systemic diseases has been identified. Rheumatoid arthritis (RA), which is a chronic inflammatory joint disease, exhibits similar characteristics and pathogenesis to PD. The association between RA and PD has been investigated, and numerous publications on this subject exist. Approximately 20 bacterial species have been identified as periodontal pathogens, and these organisms are linked to various types of PD. The most analyzed species of periodontopathic bacteria are Porphyromonas gingivalis, Prevotella intermedia, Tannerella forsythia, and Aggregatibacter actinomycetemcomitans. Antibodies and DNA from these oral pathogens have been isolated from the sera and synovial fluids of RA patients. This rapid communication describes the role of periodontal pathogens in the etiopathogenesis of RA.

  6. Porphyromonas gingivalis: Major Periodontopathic Pathogen Overview

    PubMed Central

    Mysak, Jaroslav; Podzimek, Stepan; Sommerova, Pavla; Lyuya-Mi, Yelena; Bartova, Jirina; Janatova, Tatjana; Prochazkova, Jarmila; Duskova, Jana

    2014-01-01

    Porphyromonas gingivalis is 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 with Treponema denticola and Tannerella forsythia, constitute the “red complex,” a prototype polybacterial pathogenic consortium in periodontitis. This review outlines Porphyromonas gingivalis structure, its metabolism, its ability to colonize the epithelial cells, and its influence upon the host immunity. PMID:24741603

  7. First Cultivation of Health-Associated Tannerella sp. HOT-286 (BU063).

    PubMed

    Vartoukian, S R; Moazzez, R V; Paster, B J; Dewhirst, F E; Wade, W G

    2016-10-01

    Despite significant advances in recent years in culture-independent molecular microbiology methods, the detailed study of individual bacterial species still relies on having pure cultures in the laboratory. Yet, more than a third of the approximately 700 bacterial taxa found in the human oral cavity are as yet uncultivated in vitro. One such taxon, Tannerella sp. HOT-286 (phylotype BU063), is the focus of much interest since it is associated with periodontal health, while Tannerella forsythia, its closest phylogenetic neighbor, is strongly associated with periodontal disease. HOT-286, however, has remained uncultivated despite the efforts of several research groups, spanning over a decade. The aim of this study was to cultivate Tannerella sp. HOT-286. A heavily diluted sample of subgingival plaque was inoculated onto culture plates supplemented with siderophores (pyoverdines-Fe complex or desferricoprogen) or a neat plaque suspension. After 8 d of anaerobic incubation, microcolonies and colonies showing satellitism were passaged onto fresh culture plates cross-streaked with potential helper strains or onto cellulose-acetate membranes placed over lawn cultures of helper strains. Subcultured colonies were identified by 16S rRNA gene sequencing, and purity was confirmed by sequencing 20 clones per library prepared from a single colony. Three colonies of interest (derived from pyoverdines- and plaque-supplemented plates) were identified as Tannerella sp. HOT-286. The isolates were found to be incapable of independent growth, requiring helpers such as Propionibacterium acnes and Prevotella intermedia for stimulation, with best growth on membranes over "helper" lawns. A representative isolate was subjected to phenotypic characterization and found to produce a range of glycosidic and proteolytic enzymes. Further comparison of this novel "periodontal health-associated" taxon with T. forsythia will be valuable in investigating virulence factors of the latter and possible

  8. Putative periodontal pathogens in the subgingival plaque of Sudanese subjects with aggressive periodontitis.

    PubMed

    Hashim, N T; Linden, G J; Winning, L; Ibrahim, M E; Gismalla, B G; Lundy, F T; El Karim, I A

    2017-09-01

    There has been limited study of the bacterial species associated with aggressive periodontitis (AgP) in high-risk populations in Africa. The aim of this study was to investigate and quantify the presence of four putative periodontal pathogens in the subgingival plaque of Sudanese subjects with AgP. A secondary aim was to investigate the effect of varying the detection threshold on the reported prevalence of the bacterial species investigated. Subgingival plaque samples were collected from AgP cases (n=73) and healthy controls (n=71). Bacterial DNA was extracted and analyzed by quantitative polymerase chain reaction for the detection and quantification of four putative periodontal pathogens: Porphyromonas gingivalis, Aggregatibacter actinomycetemcomitans, Treponema denticola and Tannerella forsythia. At the lowest detection threshold (>10(1) cells), P. gingivalis (p<0.0001) was more prevalent in AgP cases than controls. T. forsythia and T. denticola had a high prevalence (>70%) in AgP cases at all detection levels. While T. forsythia was significantly more frequently identified in AgP than in controls at all detection thresholds, this was only the case for T. denticola at the intermediate threshold (>10(2) cells). A. actinomycetemcomitans was identified less frequently than the other bacterial species with no difference in its prevalence between AgP cases and controls. The prevalence of the putative periodontal pathogens investigated varied considerably in Sudanese subjects with AgP and in periodontally healthy controls depending on the detection thresholds applied. T. forsythia was identified as having the strongest association with AgP. Copyright © 2017 Elsevier Ltd. All rights reserved.

  9. Differential Responses of Pattern Recognition Receptors to Outer Membrane Vesicles of Three Periodontal Pathogens

    PubMed Central

    Lenzo, Jason C.; Holden, James A.; Chen, Yu-Yen; Singleton, William; Gause, Katelyn T.; Yan, Yan; Caruso, Frank; Reynolds, Eric C.

    2016-01-01

    Highly purified outer membrane vesicles (OMVs) of the periodontal pathogens, Porphyromonas gingivalis, Treponema denticola and Tannerella forsythia were produced using tangential flow ultrafiltration, ultracentrifugation and Optiprep density gradient separation. Cryo-TEM and light scattering showed OMVs to be single lipid-bilayers with modal diameters of 75 to 158 nm. Enumeration of OMVs by nanoparticle flow-cytometry at the same stage of late exponential culture indicated that P. gingivalis was the most prolific OMV producer. P. gingivalis OMVs induced strong TLR2 and TLR4-specific responses and moderate responses in TLR7, TLR8, TLR9, NOD1 and NOD2 expressing-HEK-Blue cells. Responses to T. forsythia OMVs were less than those of P. gingivalis and T. denticola OMVs induced only weak responses. Compositional analyses of OMVs from the three pathogens demonstrated differences in protein, fatty acids, lipopolysaccharide, peptidoglycan fragments and nucleic acids. Periodontal pathogen OMVs induced differential pattern recognition receptor responses that have implications for their role in chronic periodontitis. PMID:27035339

  10. Differential Responses of Pattern Recognition Receptors to Outer Membrane Vesicles of Three Periodontal Pathogens.

    PubMed

    Cecil, Jessica D; O'Brien-Simpson, Neil M; Lenzo, Jason C; Holden, James A; Chen, Yu-Yen; Singleton, William; Gause, Katelyn T; Yan, Yan; Caruso, Frank; Reynolds, Eric C

    2016-01-01

    Highly purified outer membrane vesicles (OMVs) of the periodontal pathogens, Porphyromonas gingivalis, Treponema denticola and Tannerella forsythia were produced using tangential flow ultrafiltration, ultracentrifugation and Optiprep density gradient separation. Cryo-TEM and light scattering showed OMVs to be single lipid-bilayers with modal diameters of 75 to 158 nm. Enumeration of OMVs by nanoparticle flow-cytometry at the same stage of late exponential culture indicated that P. gingivalis was the most prolific OMV producer. P. gingivalis OMVs induced strong TLR2 and TLR4-specific responses and moderate responses in TLR7, TLR8, TLR9, NOD1 and NOD2 expressing-HEK-Blue cells. Responses to T. forsythia OMVs were less than those of P. gingivalis and T. denticola OMVs induced only weak responses. Compositional analyses of OMVs from the three pathogens demonstrated differences in protein, fatty acids, lipopolysaccharide, peptidoglycan fragments and nucleic acids. Periodontal pathogen OMVs induced differential pattern recognition receptor responses that have implications for their role in chronic periodontitis.

  11. Chronic Periodontal Disease, Periodontal Pathogen Colonization, and an Increased Risk of Precancerous Gastric Lesions.

    PubMed

    Sun, Jinghua; Zhou, Min; Salazar, Christian R; Hays, Rosemary; Bedi, Sukhleen; Chen, Yu; Li, Yihong

    2017-07-03

    The present study assessed the association between periodontal pathogen colonization and the potential risk of developing precancerous lesions of gastric cancer (PLGC) in a clinical setting. The present study included 35 newly diagnosed patients with PLGC and 70 age-matched individuals without PLGC. A full-mouth intra-oral examination was performed to assess the periodontal conditions. Stimulated whole saliva and pooled plaque samples were collected to evaluate colonization by Porphyromonas gingivalis, Treponema denticola, Tannerella forsythia and Actinobacillus actinomycetemcomitans and to characterize the oral microbial diversity in the saliva and dental plaque. Compared with the control group, the patients with PLGC experienced a higher prevalence of bleeding on probing (BOP; 31.5% vs. 22.4%, P < 0.05), higher levels of T. denticola (P < 0.01) and A. actinomycetemcomitans (P <0.01), and less bacterial diversity in their saliva (P < 0.01). The final multivariate logistic regression model comprising all key socio-demographic characteristics, oral health behavioral factors and periodontal assessments revealed that elevated colonization with periodontal pathogens, specifically T. forsythia, T. denticola, and A. actinomycetemcomitans, decreased bacterial diversity in the dental plaque, and not flossing teeth regularly were significant predictors of an increased risk of PLGC (P = 0.022). The findings of the present study provide new evidence suggesting that periodontal pathogen burdens and bacterial diversity in the oral cavity are important factors contributing to a potential increased risk of developing precancerous gastric lesions.

  12. Quantitative Analysis of Periodontal Pathogens Using Real-Time Polymerase Chain Reaction (PCR).

    PubMed

    Marin, Mª José; Figuero, Elena; Herrera, David; Sanz, Mariano

    2017-01-01

    The quantitative polymerase chain reaction (qPCR) is a variant of PCR aimed to detect and quantify a targeted DNA molecule through the addition of probes labeled with fluorescent molecules that emit fluorescence within each amplification cycle, what results in fluorescence values proportional to the amount of accumulated PCR product. This chapter presents the detailed procedures for quantification of different periodontal pathogens (Porphyromonas gingivalis, Aggregatibacter actinomycetemcomitans, Tannerella forsythia, Campylobacter rectus, and Fusobacterium spp.) using qPCR. It also includes the description of the most frequent problems encountered and how to solve them. In addition, a detailed protocol for multiplex qPCR to detect and quantify P. gingivalis and A. actinomycetemcomitans is included.

  13. Quantitative PCR analysis of salivary pathogen burden in periodontitis

    PubMed Central

    Salminen, Aino; Kopra, K. A. Elisa; Hyvärinen, Kati; Paju, Susanna; Mäntylä, Päivi; Buhlin, Kåre; Nieminen, Markku S.; Sinisalo, Juha; Pussinen, Pirkko J.

    2015-01-01

    Our aim was to investigate the value of salivary concentrations of four major periodontal pathogens and their combination in diagnostics of periodontitis. The Parogene study included 462 dentate subjects (mean age 62.9 ± 9.2 years) with coronary artery disease (CAD) diagnosis who underwent an extensive clinical and radiographic oral examination. Salivary levels of four major periodontal bacteria were measured by quantitative real-time PCR (qPCR). Median salivary concentrations of Porphyromonas gingivalis, Tannerella forsythia, and Prevotella intermedia, as well as the sum of the concentrations of the four bacteria, were higher in subjects with moderate to severe periodontitis compared to subjects with no to mild periodontitis. Median salivary Aggregatibacter actinomycetemcomitans concentrations did not differ significantly between the subjects with no to mild periodontitis and subjects with moderate to severe periodontitis. In logistic regression analysis adjusted for age, gender, diabetes, and the number of teeth and implants, high salivary concentrations of P. gingivalis, T. forsythia, and P. intermedia were significantly associated with moderate to severe periodontitis. When looking at different clinical and radiographic parameters of periodontitis, high concentrations of P. gingivalis and T. forsythia were significantly associated with the number of 4–5 mm periodontal pockets, ≥6 mm pockets, and alveolar bone loss (ABL). High level of T. forsythia was associated also with bleeding on probing (BOP). The combination of the four bacteria, i.e., the bacterial burden index, was associated with moderate to severe periodontitis with an odds ratio (OR) of 2.40 (95% CI 1.39–4.13). When A. actinomycetemcomitans was excluded from the combination of the bacteria, the OR was improved to 2.61 (95% CI 1.51–4.52). The highest OR 3.59 (95% CI 1.94–6.63) was achieved when P. intermedia was further excluded from the combination and only the levels of P. gingivalis and

  14. Quantitative PCR analysis of salivary pathogen burden in periodontitis.

    PubMed

    Salminen, Aino; Kopra, K A Elisa; Hyvärinen, Kati; Paju, Susanna; Mäntylä, Päivi; Buhlin, Kåre; Nieminen, Markku S; Sinisalo, Juha; Pussinen, Pirkko J

    2015-01-01

    Our aim was to investigate the value of salivary concentrations of four major periodontal pathogens and their combination in diagnostics of periodontitis. The Parogene study included 462 dentate subjects (mean age 62.9 ± 9.2 years) with coronary artery disease (CAD) diagnosis who underwent an extensive clinical and radiographic oral examination. Salivary levels of four major periodontal bacteria were measured by quantitative real-time PCR (qPCR). Median salivary concentrations of Porphyromonas gingivalis, Tannerella forsythia, and Prevotella intermedia, as well as the sum of the concentrations of the four bacteria, were higher in subjects with moderate to severe periodontitis compared to subjects with no to mild periodontitis. Median salivary Aggregatibacter actinomycetemcomitans concentrations did not differ significantly between the subjects with no to mild periodontitis and subjects with moderate to severe periodontitis. In logistic regression analysis adjusted for age, gender, diabetes, and the number of teeth and implants, high salivary concentrations of P. gingivalis, T. forsythia, and P. intermedia were significantly associated with moderate to severe periodontitis. When looking at different clinical and radiographic parameters of periodontitis, high concentrations of P. gingivalis and T. forsythia were significantly associated with the number of 4-5 mm periodontal pockets, ≥6 mm pockets, and alveolar bone loss (ABL). High level of T. forsythia was associated also with bleeding on probing (BOP). The combination of the four bacteria, i.e., the bacterial burden index, was associated with moderate to severe periodontitis with an odds ratio (OR) of 2.40 (95% CI 1.39-4.13). When A. actinomycetemcomitans was excluded from the combination of the bacteria, the OR was improved to 2.61 (95% CI 1.51-4.52). The highest OR 3.59 (95% CI 1.94-6.63) was achieved when P. intermedia was further excluded from the combination and only the levels of P. gingivalis and T

  15. Periodontal pathogen levels in adolescents before, during, and after fixed orthodontic appliance therapy.

    PubMed

    Thornberg, Michelle J; Riolo, Christopher S; Bayirli, Burcu; Riolo, Michael L; Van Tubergen, Elizabeth A; Kulbersh, Richard

    2009-01-01

    This purpose of this study was to document and investigate changes in periodontal pathogen levels before, during, and after orthodontic treatment in adolescents. DNA gene probe analysis was used to quantify the levels of 8 periodontal pathogens before, during, and after treatment with fixed orthodontic appliances in 190 concurrently treated adolescent orthodontic patients. The 8 pathogens examined were Actinobacillus actinomycetemcomitans (AA), Porphyromonas gingivalis (PG), Prevotella intermedia (PI), Tannerella forsythia (TF), Eikenella corrodens (EC), Fusobacterium nucleatum (FN), Treponema denticola (TD), and Campylobacter rectus (CR). Chi-square tests were used to determine whether the percentages of subjects with high counts significantly changed over time. Logistic regression analyses were also performed to derive the relative risk of higher counts of pathogenic bacteria with fixed appliances at the various time intervals studied. For 6 (PI, TF, EC, FN, TD, CR) of the 8 pathogens, the percentages of subjects with high pathogen counts increased significantly after 6 months of fixed appliance treatment, but these returned to pretreatment levels by 12 months of orthodontic treatment. No pathogen level was significantly higher after 12 months of orthodontic treatment, and orthodontic treatment was found to be significantly protective for half of the pathogens (EC, FN, TD, CR) posttreatment. Orthodontic treatment with fixed appliances does not increase the risk of high levels of these periodontal pathogens.

  16. Alendronate augments interleukin-1{beta} release from macrophages infected with periodontal pathogenic bacteria through activation of caspase-1

    SciTech Connect

    Deng Xue; Tamai, Riyoko; Endo, Yasuo; Kiyoura, Yusuke

    2009-02-15

    Nitrogen-containing bisphosphonates (NBPs) are anti-bone-resorptive drugs with inflammatory side effects that include osteomyelitis and osteonecrosis of the jaw. Oral bacteria have been considered to be a trigger for these NBP-associated jaw bone diseases. The present study examined the effects of alendronate (a typical NBP) and clodronate (a non-NBP) on the production of proinflammatory cytokines by macrophages infected with Porphyromonas gingivalis and Tannerella forsythia, which are important pathogens of periodontal diseases. Pretreatment with alendronate augmented IL-1{beta}, but not TNF{alpha}, production by macrophages infected with P. gingivalis or T. forsythia. This augmentation of IL-1{beta} production was inhibited by clodronate. Furthermore, caspase-1, a promoter of IL-1{beta} production, was activated by treatment with alendronate, and caspase-1 inhibitor reduced the production of IL-1{beta} induced by alendronate and P. gingivalis. These results suggest that NBPs augment periodontal pathogenic bacteria-induced IL-1{beta} release via caspase-1 activation, and this phenomenon may contribute to the development of NBP-associated inflammatory side effects including jaw osteomyelitis. Co-treatment with clodronate may prevent and/or reduce these inflammatory effects induced by NBPs.

  17. Quinoid glycosides from Forsythia suspensa.

    PubMed

    Li, Chang; Dai, Yi; Zhang, Shu-Xiang; Duan, Ying-Hui; Liu, Ming-Li; Chen, Liu-Yuan; Yao, Xin-Sheng

    2014-08-01

    Phytochemical investigation on Forsythia suspensa (Thunb.) Vahl afforded 10 compounds, including quinoid glycosides, lignan glycosides, phenylethanoid glycoside and allylbenzene glycoside together with 13 known ones. Their structures were established based on extensive spectroscopic data analyses, including IR, UV, HRESIMS, 1D NMR and 2D NMR. Absolute configurations were determined by ECD calculation method and chemical degradation. In addition, all compounds were evaluated for their antiviral activity against influenza A (H1N1) virus and several were further evaluated against respiratory syncytial virus (RSV) in vitro. Among them, two previously known compounds showed significant activities against RSV with EC50 values of 3.43 and 6.72 μM.

  18. Evaluation of periodontal pathogens in amniotic fluid and the role of periodontal disease in pre-term birth and low birth weight.

    PubMed

    Ercan, Esra; Eratalay, Kenan; Deren, Ozgur; Gur, Deniz; Ozyuncu, Ozgur; Altun, Belgin; Kanli, Ceyda; Ozdemir, Pınar; Akincibay, Hakan

    2013-01-01

    Pre-term birth and/or low birth weight (PTLBW) is a serious problem in developing countries. The absence of known risk factors in ≈ 50% of PTLBW cases has resulted in a continued search for other causes. The aim of this study was to examine the effect of periodontitis on pregnancy outcomes. Samples were taken from 50 pregnant women who underwent amniocentesis. Polymerase chain reaction was performed on amniotic fluid samples obtained during amniocentesis and on subgingival plaque samples to determine the presence of Porphyromonas gingivalis, Aggregatibacter actinomycetemcomitans, Treponema denticola, Tannerella forsythia, Fusobacterium nucleatum, Prevotella intermedia, Campylobacter rectus and Eikenella corrodens. Plaque index, gingival index, bleeding on probing, probing depth and clinical attachment level were evaluated. Medical records were obtained after birth. Social and demographic variables were similar among the Gingivitis (G), Localized Periodontitis (LP) and Generalized Periodontitis (GP) groups. Four subjects gave birth to PTLBW neonates. Campylobacter rectus, T. forsythia, P. gingivalis and F. nucleatum were detected in the amniotic fluid and subgingival plaque samples of three patients who gave birth to PTLBW neonates. The amniotic fluid sample from the fourth patient was not positive for any of the tested pathogens. These findings suggest that the transmission of some periodontal pathogens from the oral cavity of the mother may cause adverse pregnancy outcomes. The results contribute to an understanding of the association between periodontal disease and PTLBW, but further studies are required to better clarify the possible relationship.

  19. Anaerobic culture to detect periodontal and caries pathogens

    PubMed Central

    Tanner, Anne C. R.

    2014-01-01

    Background Anaerobic culture has been critical in our understanding of the oral microbiotas. Highlight Studies in advanced periodontitis in the 1970’s revealed microbial complexes that associated with different clinical presentations. Taxonomy studies identified species newly-observed in periodontitis as Aggregatibacter (Actinobacillus) actinomycetemcomitans, Campylobacter (Wolinella) rectus and other Campylobacter species, and Tannerella (Bacteroides) forsythia. Anaerobic culture of initial periodontitis showed overlap in the microbiota with gingivitis, and added Selenomonas noxia and Filifactor alocis as putative periodontal pathogens. Porphyromonas gingivalis and T. forsythia were found to be associated with initial periodontitis in adults. The dominant microbiota of dental caries differs from that of periodontitis. The major cariogenic species are acidogenic and acid tolerant species particularly Streptococcus mutans, and Lactobacillus and Bifidobacterium species. Anaerobic culture of severe early childhood caries revealed a widely diverse microbiota, comparable to that observed using cloning and sequencing. The PCR-based cloning approach, however, underestimated Actinobacteria compared with culture. Only a subset of the caries-associated microbiota was acid tolerant, with different segments of the microbiota cultured on blood agar compared to a low pH acid agar. While the major caries-associated species was S. mutans, a new species, Scardovia wiggsiae, was significantly associated with early childhood caries. Higher counts of S. wiggsiae were also observed in initial white spot carious lesions in adolescents. Conclusion In periodontitis and dental caries, anaerobic culture studies of advanced disease provided a comprehensive analysis of the microbiota of these infections. Anaerobic culture highlighted the limitation of PCR with standard primers that underestimate detection of Actinobacteria. PMID:25678835

  20. Periodontal Pathogens in the Etiology of Pancreatic Cancer.

    PubMed

    Öğrendik, Mesut

    2017-03-01

    Pancreatic cancer is the fourth leading cause of cancer-related deaths worldwide. Chronic pancreatitis is frequently observed in patients with pancreatic cancer, and a significant relationship between orodigestive cancer-related deaths and chronic periodontitis has been detected. Porphyromonas gingivalis, Tannerella forsythia, and Treponema denticola, collectively called the Red complex, are the major pathogens responsible for chronic periodontitis and secrete peptidylarginine deiminase. Anti-P. gingivalis antibodies titers are higher in pancreatic cancer patients than in healthy subjects. This review examines the association between oral bacteria and the etiology of pancreatic cancer. High rates of tumor suppressor gene p53 mutations, particularly p53 arginine mutations, were detected in pancreatic cancer patients. K-ras arginine mutations were detected in patients with pancreatic cancer. Oral bacteria peptidylarginine deiminases might lead to the p53 and K-ras point mutations by degrading arginine. Oral bacteria are likely to be responsible for the development of pancreatic cancer. If this hypothesis is true, it may reveal the real cause of pancreatic cancer, which is a fatal disease.

  1. Periodontal Pathogens and Risk of Incident Cancer in Postmenopausal Females: The Buffalo OsteoPerio Study

    PubMed Central

    Mai, Xiaodan; Genco, Robert J.; LaMonte, Michael J.; Hovey, Kathleen M.; Freudenheim, Jo L.; Andrews, Christopher A.; Wactawski-Wende, Jean

    2016-01-01

    Background Extraoral translocation of oral bacteria may contribute to associations between periodontal disease and cancer. The associations among the presence of three orange-complex periodontal pathogens (Fusobacterium nucleatum, Prevotella intermedia, and Campylobacter rectus), two red-complex periodontal pathogens (Porphyromonas gingivalis and Tannerella forsythia), and cancer risk were investigated. Methods A total of 1,252 postmenopausal females enrolled in the Buffalo Osteoporosis and Periodontal Disease Study were followed prospectively. Baseline subgingival plaque samples were assessed for the presence of periodontal pathogens using indirect immunofluorescence. Incident cancer cases were adjudicated by staff physicians via review of medical records. Cox proportional hazards regression was used to calculate hazard ratios (HRs) and 95% confidence intervals (CIs) for the associations of periodontal pathogens with total cancer and site-specific cancer risk in unadjusted and multivariable-adjusted models. Results Neither the presence of individual pathogens nor the presence of any red-complex pathogens was associated with total cancer or site-specific cancers. Borderline associations were seen among the presence of any orange-complex pathogens (F. nucleatum, P. intermedia, and C. rectus), total cancer risk (HR = 1.35, 95% CI = 1.00 to 1.84), and lung cancer risk (HR = 3.02, 95% CI = 0.98 to 9.29). Conclusions No associations were found between the presence of individual subgingival pathogens and cancer risk. However, there were suggestions of borderline positive associations of the presence of any orange-complex pathogens with total cancer and lung cancer risk. The study is limited by the small number of cancer cases and the assessment of only five oral bacteria. Additional research is needed to understand the possi ble role of periodontal disease in carcinogenesis. PMID:26513268

  2. Influence of glycemic control on the levels of subgingival periodontal pathogens in patients with generalized chronic periodontitis and type 2 diabetes

    PubMed Central

    MIRANDA, Tamires Szeremeske; FERES, Magda; RETAMAL-VALDÉS, Belén; PEREZ-CHAPARRO, Paula Juliana; MACIEL, Suellen Silva; DUARTE, Poliana Mendes

    2017-01-01

    Abstract Objective This study evaluated the influence of glycemic control on the levels and frequency of subgingival periodontal pathogens in patients with type 2 diabetes mellitus (DM) and generalized chronic periodontitis (ChP). Material and Methods Fifty-six patients with generalized ChP and type 2 DM were assigned according to the levels of glycated hemoglobin (HbA1c) into one of the following groups: HbA1c<8% (n=28) or HbA1c≥8% (n=28). Three subgingival biofilm samples from sites with probing depth (PD)<5 mm and three samples from sites with PD≥5 mm were analyzed by quantitative Polymerase Chain Reaction (PCR) for the presence and levels of Porphyromonas gingivalis, Tannerella forsythia, Treponema denticola, Eubacterium nodatum, Parvimona micra, Fusobacterium nucleatum ssp. and Prevotella intermedia. Results The mean counts of F. nucleatum ssp. were statistically significantly higher in the sites with PD≥5 mm of the HbA1c≥8% group (p<0.05). Frequencies of detection of T. forsythia, E. nodatum, P. micra and F. nucleatum ssp. were all higher in the sites with PD≥5 mm of the patients with HbA1c≥8%, compared with those of patients with HbA1c<8% (p<0.05). Frequency of detection of P. intermedia was higher in the sites with PD<5 mm of the patients with HbA1c≥8% than those of the patients with HbA1c<8% (p<0.05). Conclusions Poor glycemic control, as indicated by HbA1c≥8%, is associated with increased levels and frequencies of periodontal pathogens in the subgingival biofilm of subjects with type 2 DM and ChP. PMID:28198980

  3. Quantitative Molecular Detection of 19 Major Pathogens in the Interdental Biofilm of Periodontally Healthy Young Adults

    PubMed Central

    Carrouel, Florence; Viennot, Stéphane; Santamaria, Julie; Veber, Philippe; Bourgeois, Denis

    2016-01-01

    In oral health, the interdental spaces are a real ecological niche for which the body has few or no alternative defenses and where the traditional daily methods for control by disrupting biofilm are not adequate. The interdental spaces are the source of many hypotheses regarding their potential associations with and/or causes of cardiovascular disease, diabetes, chronic kidney disease, degenerative disease, and depression. This PCR study is the first to describe the interdental microbiota in healthy adults aged 18–35 years-old with reference to the Socransky complexes. The complexes tended to reflect microbial succession events in developing dental biofilms. Early colonizers included members of the yellow, green, and purple complexes. The orange complex bacteria generally appear after the early colonizers and include many putative periodontal pathogens, such as Fusobacterium nucleatum. The red complex (Porphyromonas gingivalis, Tannerella forsythia, and Treponema denticola) was considered the climax community and is on the list of putative periodontal pathogens. The 19 major periodontal pathogens tested were expressed at various levels. F. nucleatum was the most abundant species, and the least abundant were Actinomyces viscosus, P. gingivalis, and Aggregatibacter actinomycetemcomitans. The genome counts for Eikenella corrodens, Campylobacter concisus, Campylobacter rectus, T. denticola, and Tannerella forsythensis increased significantly with subject age. The study highlights the observation that bacteria from the yellow complex (Streptococcus spp., S. mitis), the green complex (E. corrodens, Campylobacter gracilis, Capnocytophaga ochracea, Capnocytophaga sputigena, A. actinomycetemcomitans), the purple complex (Veillonella parvula, Actinomyces odontolyticus) and the blue complex (A. viscosus) are correlated. Concerning the orange complex, F. nucleatum is the most abundant species in interdental biofilm. The red complex, which is recognized as the most important

  4. Frequency of periodontal pathogens and Helicobacter pylori in the mouths and stomachs of obese individuals submitted to bariatric surgery: a cross-sectional study.

    PubMed

    Pataro, André Luiz; Cortelli, Sheila Cavalca; Abreu, Mauro Henrique Nogueira Guimarães; Cortelli, José Roberto; Franco, Gilson Cesar Nobre; Aquino, Davi Romeiro; Cota, Luis Otavio Miranda; Costa, Fernando Oliveira

    2016-01-01

    This cross-sectional study compared the frequency of oral periodontopathogens and H. pylori in the mouths and stomachs of obese individuals with or without periodontitis submitted to bariatric surgery. One hundred and fifty-four men and women aged 18-65 were conveniently distributed into four groups. Two groups were composed of individuals who underwent bariatric surgery with (BP) (n=40) and without (BNP) (n=39) periodontitis and two obese control groups with (CP) (n=35) and without (CNP) (n=40) periodontitis. The oral pathogens Porphyromonas gingivalis, Aggregatibacter actinomycetemcomitans, Parvimonas micra, Treponema denticola, Tannerella forsythia, Campylobacter rectus, and Helicobacter pylori were detected by a polymerase chain reaction technique using saliva, tongue and stomach biopsy samples. Statistical analysis demonstrated that periodontopathogens were highly frequent in the mouth (up to 91.4%). In the bariatric surgically treated group, orally, P. gingivalis, T. denticola and T. forsythia were more frequent in periodontitis, while C. rectus was more frequent in non-periodontitis subjects. Stomach biopsies also revealed the high frequency of five oral species in both candidates for bariatric surgery (91.6%) and the bariatric (83.3%) groups. H. pylori was frequently detected in the mouth (50.0%) and stomach (83.3%). In the stomach, oral species and H. pylori appeared in lower frequency in the bariatric group. Obese individuals showed high frequencies of periodontopathogens and H. pylori in their mouths and stomachs. Bariatric surgery showed an inverse microbial effect on oral and stomach environments by revealing higher oral and lower stomach bacterial frequencies.

  5. Frequency of periodontal pathogens and Helicobacter pylori in the mouths and stomachs of obese individuals submitted to bariatric surgery: a cross-sectional study

    PubMed Central

    PATARO, André Luiz; CORTELLI, Sheila Cavalca; ABREU, Mauro Henrique Nogueira Guimarães; CORTELLI, José Roberto; FRANCO, Gilson Cesar Nobre; AQUINO, Davi Romeiro; COTA, Luis Otavio Miranda; COSTA, Fernando Oliveira

    2016-01-01

    ABSTRACT Objectives This cross-sectional study compared the frequency of oral periodontopathogens and H. pylori in the mouths and stomachs of obese individuals with or without periodontitis submitted to bariatric surgery. Material and Methods One hundred and fifty-four men and women aged 18-65 were conveniently distributed into four groups. Two groups were composed of individuals who underwent bariatric surgery with (BP) (n=40) and without (BNP) (n=39) periodontitis and two obese control groups with (CP) (n=35) and without (CNP) (n=40) periodontitis. The oral pathogens Porphyromonas gingivalis, Aggregatibacter actinomycetemcomitans, Parvimonas micra, Treponema denticola, Tannerella forsythia, Campylobacter rectus, and Helicobacter pylori were detected by a polymerase chain reaction technique using saliva, tongue and stomach biopsy samples. Results Statistical analysis demonstrated that periodontopathogens were highly frequent in the mouth (up to 91.4%). In the bariatric surgically treated group, orally, P. gingivalis, T. denticola and T. forsythia were more frequent in periodontitis, while C. rectus was more frequent in non-periodontitis subjects. Stomach biopsies also revealed the high frequency of five oral species in both candidates for bariatric surgery (91.6%) and the bariatric (83.3%) groups. H. pylori was frequently detected in the mouth (50.0%) and stomach (83.3%). In the stomach, oral species and H. pylori appeared in lower frequency in the bariatric group. Conclusions Obese individuals showed high frequencies of periodontopathogens and H. pylori in their mouths and stomachs. Bariatric surgery showed an inverse microbial effect on oral and stomach environments by revealing higher oral and lower stomach bacterial frequencies. PMID:27383704

  6. TLR4, NOD1 and NOD2 mediate immune recognition of putative newly identified periodontal pathogens.

    PubMed

    Marchesan, J; Jiao, Y Z; Schaff, R A; Hao, J; Morelli, T; Kinney, J S; Gerow, E; Sheridan, R; Rodrigues, V; Paster, B J; Inohara, N; Giannobile, W V

    2016-06-01

    Periodontitis is a polymicrobial inflammatory disease that results from the interaction between the oral microbiota and the host immunity. Although the innate immune response is important for disease initiation and progression, the innate immune receptors that recognize both classical and putative periodontal pathogens that elicit an immune response have not been elucidated. By using the Human Oral Microbe Identification Microarray (HOMIM), we identified multiple predominant oral bacterial species in human plaque biofilm that strongly associate with severe periodontitis. Ten of the identified species were evaluated in greater depth, six being classical pathogens and four putative novel pathogens. Using human peripheral blood monocytes (HPBM) and murine bone-marrow-derived macrophages (BMDM) from wild-type (WT) and Toll-like receptor (TLR)-specific and MyD88 knockouts (KOs), we demonstrated that heat-killed Campylobacter concisus, Campylobacter rectus, Selenomonas infelix, Porphyromonas endodontalis, Porphyromonas gingivalis, and Tannerella forsythia mediate high immunostimulatory activity. Campylobacter concisus, C. rectus, and S. infelix exhibited robust TLR4 stimulatory activity. Studies using mesothelial cells from WT and NOD1-specific KOs and NOD2-expressing human embryonic kidney cells demonstrated that Eubacterium saphenum, Eubacterium nodatum and Filifactor alocis exhibit robust NOD1 stimulatory activity, and that Porphyromonas endodontalis and Parvimonas micra have the highest NOD2 stimulatory activity. These studies allowed us to provide important evidence on newly identified putative pathogens in periodontal disease pathogenesis showing that these bacteria exhibit different immunostimulatory activity via TLR4, NOD1, and NOD2 (Clinicaltrials.gov NCT01154855).

  7. Identification and evaluation of Forsythia germplasm using molecular markers

    USDA-ARS?s Scientific Manuscript database

    This study identified Forsythia germplasm and evaluated the genetic relationships of F. ×intermedia hybrids, cultivars and their putative parental species. Leaf samples of F. ×intermedia cultivars and species, such as F. koreana and F. suspensa, were collected in the Netherlands, Korea, and USA. T...

  8. Ultrasound-assisted extraction of phillyrin from Forsythia suspensa.

    PubMed

    Xia, En-Qin; Ai, Xu-Xia; Zang, Sheng-Ye; Guan, Ting-Ting; Xu, Xiang-Rong; Li, Hua-Bin

    2011-03-01

    Forsythia suspensa (Thunb.) Vahl is one of the most widely used traditional Chinese medicines, and possesses important biological activities, such as antibacterial, antiviral, anti-inflammatory and antioxidant activities. Phillyrin is the main bioactive component of Forsythia suspensa. In this paper, ultrasound-assisted extraction of phillyrin from Forsythia suspensa was studied with HPLC-photodiode array detection. Effects of several experimental parameters, such as type and concentration of extracting solvent, ratio of liquid to material, extraction temperature, and time of sonication on extraction efficiencies of phillyrin from Forsythia suspensa were evaluated. The optimal extraction conditions were 1g plant sample with 10 ml of 20% methanol and the extraction for 60 min at 60°C under ultrasonic irradiation. Under the optimum conditions, the yield of phillyrin was 0.713±0.009 mg/g. The results indicated that the ultrasound-assisted extraction is a very useful method for the extraction of important phytochemicals from plant materials. Copyright © 2010 Elsevier B.V. All rights reserved.

  9. Prevalence of periodontal pathogens as predictor of the evolution of periodontal status.

    PubMed

    Puig-Silla, Miriam; Montiel-Company, José María; Dasí-Fernández, Francisco; Almerich-Silla, José Manuel

    2016-11-25

    The aim of this study was to determine the relationship between the prevalence of Porphyromonas gingivalis, its fimA genotypes, Aggregatibacter actinomycetemcomitans, Tannerella forsythia, and Treponema denticola and the evolution of periodontal health. In a longitudinal prospective study, samples of subgingival plaque were taken from 114 patients (37 with chronic periodontitis, 17 with gingivitis, and 60 periodontally healthy) in the course of a full periodontal examination. PCR was employed to determine the presence of the periodontopathogenic bacteria. Four years later, a second examination and sample collection were performed in 90 of these patients (20 with chronic periodontitis, 12 with gingivitis, and 58 periodontally healthy). T. forsythia, P. gingivalis, and T. denticola are the most prevalent bacteria in patients with chronic periodontitis (78.4%, 62.2 y 56.8%, respectively). The P. gingivalis bacterium and its fimA genotypes I, II, and IV showed the highest correlation between the baseline and follow-up assessments. P. gingivalis fimA genotype II and T. forsythia were associated to a significant degree with unfavourable periodontal evolution. Of the variables studied, P. gingivalis fimA genotype II and T. forsythia increase the risk of an unfavourable evolution of periodontal status.

  10. The risk reduction of recurrent periodontal pathogens of local application minocycline HCl 2% gel, used as an adjunct to scaling and root planing for chronic periodontitis treatment

    PubMed Central

    Soeroso, Y; Akase, T; Sunarto, H; Kemal, Y; Salim, R; Octavia, M; Viandita, A; Setiawan, J; Bachtiar, BM

    2017-01-01

    Background The aim of this study was to evaluate the clinical and microbiological effects of local application minocycline HCl 2% gel, used as an adjunct to scaling and root planing (SRP) for treatment of chronic periodontitis (CP). CP is an inflammation of periodontal tissue that is caused mainly by bacterial infection, where periodontal destruction such as loss of attachment and bone destruction occurred. Methods A total of 81 subjects with moderate to severe periodontitis whose baseline clinical attachment loss (CAL) was ≥4 mm were randomly assigned to receive SRP alone (control group, N=39) or SRP followed by four times of local application of minocycline HCl gel (Periocline) once a week (test group, N=42). Pocket depth, CAL, and papilla bleeding index were examined at baseline, 21 days, 2, 3, and 6 months. Subgingival plaque samples were collected with sterile curettes and were analyzed by real-time polymerase chain reaction for the presence of three periodontal pathogens (Porphyromonas gingivalis [P.g.], Tannerella forsythia [T.f.], and Treponema denticola [T.d.]) at baseline, 2, 3, and 6 months. Results The number of bacteria was reduced in both groups at 2 months after baseline (SRP treatment). The changes (2–6 months) in T.d. and T.f. counts in the test group were significantly lower than those in the control group. In the control group, a significant regrowth of P.g., T.f., and T.d. was observed from 2 to 6 months and of P.g. and T.f. from 3 to 6 months. On the other hand, in the test group, the number of the three bacteria did not significantly increase during the 6-month period. Conclusion The results showed that local application of minocycline, used as an adjunct to SRP, was effective for suppressing regrowth of periodontal pathogens, suggesting its risk reduction of recurrent periodontal pathogens in CP. PMID:28331333

  11. Anti-inflammatory activity of arctigenin from Forsythiae Fructus.

    PubMed

    Kang, Hyo Sook; Lee, Ji Yun; Kim, Chang Jong

    2008-03-05

    Oleaceae Forsythiae Fructus has been used for anti-inflammatory, diuretics, antidote, and antibacterials in traditional herbal medicine. Our previous screening of medicinal plants showed that methanol (MeOH) extract of Forsythiae Fructus had significant anti-inflammatory activity, but the active ingredients remain unclear. For isolation of active ingredient of MeOH extract of Forsythiae Fructus, it was partitioned with n-hexane and ethylacetate (EtOAc), and arctigenin was isolated from EtOAc fraction by column chromatography with anti-inflammatory activity-guided separation. Its activity was evaluated in the animal models of inflammation including myeloperoxidase (MPO) and eosinophil peroxidase (EPO) activities in the edematous tissues homogenate, and silica-induced reactive oxygen species (ROS) production in the RAW 264.7 cell line. It was shown that arctigenin (100 mg/kg) had significantly decreased not only carrageenan-induced paw edema 3 and 4h after injection of carrageenan, arachidonic acid (AA)-induced ear edema at a painting dose of 0.1-1.0mg/ear, and acetic acid-induced writhing response and acetic acid-induced capillary permeability accentuation at an oral dose of 25-100, and 100 mg/kg, respectively, but also MPO and EPO activities at a painting dose of 0.1-1.0mg/ear in the AA-induced edematous tissues homogenate as indicators of neutrophils and eosinophils recruitment into the inflamed tissue. Further, arctigenin (0.1-10 microM) also significantly inhibited the intracellular ROS production by silica. These results indicate that arctigenin is a bioactive agent of Forsythiae Fructus having significant anti-inflammatory action by inhibition of the exudation, and leukocytes recruitment into the inflamed tissues. The pharmacologic mechanism of action of arctigenin may be due to the inhibition of release/production of inflammatory mediators such as AA metabolites and free radicals.

  12. Molecular analysis of 16S rRNA genes identifies potentially periodontal pathogenic bacteria and archaea in the plaque of partially erupted third molars.

    PubMed

    Mansfield, J M; Campbell, J H; Bhandari, A R; Jesionowski, A M; Vickerman, M M

    2012-07-01

    Small subunit rRNA sequencing and phylogenetic analysis were used to identify cultivable and uncultivable microorganisms present in the dental plaque of symptomatic and asymptomatic partially erupted third molars to determine the prevalence of putative periodontal pathogens in pericoronal sites. Template DNA prepared from subgingival plaque collected from partially erupted symptomatic and asymptomatic mandibular third molars and healthy incisors was used in polymerase chain reaction with broad-range oligonucleotide primers to amplify 16S rRNA bacterial and archaeal genes. Amplicons were cloned, sequenced, and compared with known nucleotide sequences in online databases to identify the microorganisms present. Two thousand three hundred two clones from the plaque of 12 patients carried bacterial sequences from 63 genera belonging to 11 phyla, including members of the uncultivable TM7, SR1, and Chloroflexi, and difficult-to-cultivate Synergistetes and Spirochaetes. Dialister invisus, Filifactor alocis, Fusobacterium nucleatum, Porphyromonas endodontalis, Prevotella denticola, Tannerella forsythia, and Treponema denticola, which have been associated with periodontal disease, were found in significantly greater abundance in pericoronal compared with incisor sites. Dialister invisus and F nucleatum were found in greater abundance in sites exhibiting clinical symptoms. The archaeal species, Methanobrevibacter oralis, which has been associated with severe periodontitis, was found in 3 symptomatic patients. These findings have provided new insights into the complex microbiota of pericoronitis. Several bacterial and archaeal species implicated in periodontal disease were recovered in greater incidence and abundance from the plaque of partially erupted third molars compared with incisors, supporting the hypothesis that the pericoronal region may provide a favored niche for periodontal pathogens in otherwise healthy mouths. Copyright © 2012 American Association of Oral and

  13. Effect of repeated adjunctive antimicrobial photodynamic therapy on subgingival periodontal pathogens in the treatment of chronic periodontitis.

    PubMed

    Petelin, Milan; Perkič, Katja; Seme, Katja; Gašpirc, Boris

    2015-08-01

    The aim of this study was to compare the effect of subgingival ultrasonic scaling followed by repeated (three times) antimicrobial photodynamic therapy (PDT), ultrasonic scaling alone (US), and scaling and root planing with hand instruments (SRP) for initial periodontal treatment. Twenty-seven non-smoking systemically healthy chronic periodontitis patients were included. Residual pockets ≥4 mm deep and bleeding on probing were debrided either with SRP, US alone, or US followed by a single episode of PDT during supportive periodontal treatment. Probing pocket depth (PPD), bleeding on probing (BOP), and clinical attachment level (CAL) were monitored over 12 months. The presence of five periodontal pathogens in the pockets was determined by a commercially available micro-IDent test. Intergroup and intragroup statistical analysis was performed. All three treatments resulted in a significant clinical improvement. Additional application of PDT to US failed to result in further improvement in terms of PPD reduction and CAL gain. However, it resulted in a higher reduction of BOP at 3 and 12 months comparing to US alone or SRP (PDT from 25 to 13 and to 9%, US from 23 to 16 and to 12%, and SRP from 17 to 10 and to 9%, respectively). PDT reduced the proportion of positive sites after 6 months for Treponema denticola (TD) significantly more effectively than US or SRP (p < 0.0001). Additionally, PDT resulted in a greater reduction of Aggregatibacter actinomycetemcomitans (AA), Tannerella forsythia (TF), and TD in medium pockets (4-6 mm) (p < 0.02) and of TD in deep pockets (>6 mm) compared to mechanical debridement alone (p < 0.05).

  14. Effectiveness of ozone against periodontal pathogenic microorganisms.

    PubMed

    Huth, Karin C; Quirling, Martina; Lenzke, Stefanie; Paschos, Ekaterini; Kamereck, Klaus; Brand, Korbinian; Hickel, Reinhard; Ilie, Nicoleta

    2011-06-01

    Ozone has been proposed as an adjunct antiseptic in periodontitis therapy. The aim of this study was to investigate the antimicrobial effectiveness of gaseous/aqueous ozone, in comparison with that of the established antiseptic chlorhexidine digluconate (CHX), against periodontal microorganisms. Aggregatibacter actinomycetemcomitans, Porphyromonas gingivalis, Tannerella forsythia, and Parvimonas micra in planktonic or biofilm cultures were exposed, for 1 min, to gaseous ozone, aqueous ozone, CHX, or phosphate-buffered saline (control). None of the agents was able to substantially reduce the A. actinomycetemcomitans count in biofilm cultures. In contrast, P. gingivalis, T. forsythia, and P. micra could be eliminated by 2% CHX or by ozone gas at 53 gm(-3) . Significantly greater antimicrobial effects were observed against planktonic cultures than against biofilm-associated bacteria. The rate of killing was influenced by the species of bacteria, and by the type and concentration of agent. There were no significant differences in the effectiveness of aqueous ozone (20 μg ml(-1) ) or gaseous ozone (≥ 4 gm(-3) ) compared with 2% CHX but they were more effective than 0.2% CHX. Therefore, high-concentrated gaseous and aqueous ozone merit further investigation as antiseptics in periodontitis therapy. A safe system for applying gaseous ozone into the periodontal pocket that avoids inhalation still needs to be developed.

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

    PubMed Central

    Velsko, Irina M.; Chukkapalli, Sasanka S.; Rivera-Kweh, Mercedes F.; Zheng, Donghang; Aukhil, Ikramuddin; Lucas, Alexandra R.; Larjava, Hannu

    2015-01-01

    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 of Porphyromonas gingivalis, Treponema denticola, Tannerella forsythia, and Fusobacterium nucleatum to colonize the periodontium and induce local and systemic inflammatory responses. Polymicrobially infected Itgβ6−/− 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 in Itgβ6−/− 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. Fluorescence in situ hybridization demonstrated active invasion of the aortic adventitial layer by P. 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

  16. Periodontal pathogens invade gingiva and aortic adventitia and elicit inflammasome activation in αvβ6 integrin-deficient mice.

    PubMed

    Velsko, Irina M; Chukkapalli, Sasanka S; Rivera-Kweh, Mercedes F; Zheng, Donghang; Aukhil, Ikramuddin; Lucas, Alexandra R; Larjava, Hannu; Kesavalu, Lakshmyya

    2015-12-01

    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 of Porphyromonas gingivalis, Treponema denticola, Tannerella forsythia, and Fusobacterium nucleatum to colonize the periodontium and induce local and systemic inflammatory responses. Polymicrobially infected Itgβ6(-/-) 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 in Itgβ6(-/-) 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. Fluorescence in situ hybridization demonstrated active invasion of the aortic adventitial layer by P. 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

  17. Forsythia suspensa extract alleviates hypersensitivity induced by soybean beta-conglycinin in weaned piglets.

    PubMed

    Hao, Yue; Li, Defa; Piao, Xianglan; Piao, Xiangshu

    2010-03-24

    Soybeans are known to stimulate food allergies; however, current therapies are lacking in alleviating hypersensitivity. The present study investigated whether Forsythia suspensa extract could attenuate purified soybean beta-conglycinin-induced anaphylactic reactions in weaned piglets. Eighteen 14-day-old piglets were sensitized and boosted by oral administration of purified beta-conglycinin. Forsythia suspensa extract was supplemented in the diet after the initial sensitization and continued for the remainder of the experiment. Piglets were challenged on day 28, and anaphylactic symptoms, passive cutaneous anaphylaxis, plasma histamine and intestinal microbial flora were analyzed. T-cell proliferative responses and cytokine production were also determined. Forsythia suspensa extract alleviated beta-conglycinin-induced anaphylactic symptoms by markedly reducing anaphylactic antibodies, mast cell degranulation, and histamine release while improving intestinal microbial flora. Furthermore, Forsythia suspensa extract significantly suppressed beta-conglycinin-induced T lymphocyte proliferation and IL-4 synthesis. Forsythia suspensa extract protected beta-conglycinin-sensitized piglets from anaphylactic reactions. Forsythia suspensa extract may provide a novel effective therapy for soybean allergy. Crown Copyright (c) 2010. Published by Elsevier Ireland Ltd. All rights reserved.

  18. Differences in Chemical Component and Anticancer Activity of Green and Ripe Forsythiae Fructus.

    PubMed

    Bao, Jiaolin; Ding, Ren-Bo; Liang, Yeer; Liu, Fang; Wang, Kai; Jia, Xuejing; Zhang, Chao; Chen, Meiwan; Li, Peng; Su, Huanxing; Wan, Jian-Bo; Wang, Yitao; He, Chengwei

    2017-09-25

    Forsythiae Fructus, Lianqiao in Chinese, is one of the most fundamental herbs in Traditional Chinese Medicine. Both green Forsythia (GF) and ripe Forsythia (RF) are referred to Forsythiae Fructus in medicinal applications. In most cases, they are used without distinction. In this study, a metabolomics approach was performed to compare componential differences of two Forsythiae Fructus aqueous extracts subtypes. Principal component analysis (PCA) score plots from the UPLC-MS data showed clear separation between the two subtypes, indicating there are significant differences in the chemical components between GF and RF. Meanwhile, the anticancer activity of them was also compared. GF exhibited much stronger antitumor activity than RF against B16-F10 murine melanoma both in vitro and in vivo. 15 chemical compounds were identified as specific markers for distinguishing GF and RF. Among these marker compounds, forsythoside I, forsythoside A, forsythoside E and pinoresinol were demonstrated to be key important active compounds that account for the different anticancer efficacies of GF and RF. Our data suggest that GF and RF should be distinctively used in clinical applications, particularly in the anticancer formulas, in which GF should be preferentially prescribed.

  19. Biodiesel from Forsythia suspense [(Thunb.) Vahl (Oleaceae)] seed oil.

    PubMed

    Jiao, Jiao; Gai, Qing-Yan; Wei, Fu-Yao; Luo, Meng; Wang, Wei; Fu, Yu-Jie; Zu, Yuan-Gang

    2013-09-01

    In the present work, Forsythia suspense seed oil (FSSO) was investigated for the first time as an alternative non-conventional feedstock for the preparation of biodiesel. The FSSO yield is 30.08±2.35% (dry weight of F. suspense seed basis), and the oil has low acid value (1.07 mg KOH/g). The fatty acid composition of FSSO exhibits the predominance of linoleic acid (72.89%) along with oleic acid (18.68%) and palmitic acid (5.65%), which is quite similar to that of sunflower oil. Moreover, microwave-assisted transesterification process of FSSO with methanol in the presence of potassium hydroxide catalyst was optimized and an optimal biodiesel yield (90.74±2.02%) was obtained. Furthermore, the fuel properties of the biodiesel product were evaluated as against ASTM D-6751 biodiesel standards and an acceptable agreement was observed except the cetane number. Overall, this study revealed the possibility of FSSO as a potential resource of biodiesel feedstock.

  20. Evaluation of periodontal pathogens of the mandibular third molar pericoronitis by using real time PCR.

    PubMed

    Sencimen, Metin; Saygun, Isil; Gulses, Aydin; Bal, Vehbi; Acikel, Cengiz H; Kubar, Ayhan

    2014-08-01

    The aim of this study was to investigate the mandibular third molar pericoronitis flora by using real-time polymerase chain reaction (PCR). The quantitative values of Aggregatibacter actinomycetemcomitans (Aa), Campylobacter rectus (Cr), Fusobacterium nucleatum (Fn), Porphyromonas gingivalis (Pg), Prevotella intermedia (Pi) and Tannerella forsythia (Tf) were evaluated in comparison with the healthy third molar flora by using real time PCR. Aa, Cr, Pg, and Pi were not statistically significant but numerically higher than the pericoronitis group. In contrast to samples from control subjects, statistically significant higher numbers of Tf were detected in samples from pericoronitis patients. The study revealed the strong relation between risk of pericoronitis and the presence of Tf. Individuals who have Tf in their samples present with an almost eight times relative risk of pericoronitis as the individuals with an absence of Tf in their samples. Tf plays an important role in the development of clinical symptoms related to pericoronitis. © 2014 FDI World Dental Federation.

  1. Effect of chito-oligosaccharide on the intestinal absorptions of phenylethanoid glycosides in Fructus Forsythiae extract.

    PubMed

    Zhou, Wei; Tan, Xiaobin; Shan, Jinjun; Liu, Ting; Cai, Baochang; Di, Liuqing

    2014-10-15

    Phenylethanoid glycosides, the main active ingredients in Fructus Forsythiae extract possesses strong antibacterial, antioxidant and antiviral effects, and their contents were higher largely than that of other ingredients such as lignans and flavones, but their absolute bioavailability orally was significantly low, which influenced clinical efficacies of its oral preparations seriously. In the present study, the absorption mechanism of phenylethanoid glycosides was studied using in vitro Caco-2 cell model. And the effect of chito-oligosaccharide (COS) on the intestinal absorption of phenylethanoid glycosides in Fructus Forsythiae extract was investigated using in vitro, in situ and in vivo models. The pharmacological effects such as antiviral activity improvement by COS were verified by MDCK cell damage inhibition rate after influenza virus propagation. The observations from in vitro Caco-2 cell showed that the absorption of phenylethanoid glycosides in Fructus Forsythiae extract so with that in monomers was mainly restricted by the tight junctions, and influenced by efflux transporters (P-gp and MRP2). Meanwhile, the absorption of phenylethanoid glycosides in Fructus Forsythiae extract could be improved by COS. Besides, COS at the same low, medium and high concentrations caused a significant, concentration-dependent increase in the Papp-value for phenylethanoid glycosides compared to the control group (p<0.05), and was all safe for the Caco-2 cells. The observations from single-pass intestinal perfusion in situ model showed that the intestinal absorption of phenylethanoid glycosides can be enhanced by COS. Meanwhile, the absorption enhancing effect of phenylethanoid glycosides might be saturable in different intestine sites. In pharmacokinetics study, COS at dosage of 25mg/kg improved the bioavailability of phenylethanoid glycosides in Fructus Forsythiae extract to the greatest extent, and was safe for gastrointestine from morphological observation. In addition

  2. Phytochemistry, pharmacology, quality control and future research of Forsythia suspensa (Thunb.) Vahl: A review.

    PubMed

    Wang, Zhaoyi; Xia, Qing; Liu, Xin; Liu, Wenxue; Huang, Wanzhen; Mei, Xue; Luo, Jun; Shan, Mingxu; Ma, Zhiqiang; Lin, Ruichao

    2017-09-05

    Forsythiae Fructus (called Lianqiao in Chinese), the fruit of Forsythia suspensa (Thunb.) Vahl, is utilized as a common traditional medicine in China, Japan and Korea. It is traditionally used to treat pyrexia, inflammation, gonorrhea, carbuncle and erysipelas. Depending on the different harvest time, Forsythiae Fructus can be classified into two forms, namely Qingqiao and Laoqiao. The greenish fruits that start to ripen are collected as Qingqiao, while the yellow fruits that are fully ripe are collected as Laoqiao. Both are applied to medical use. This review aims to provide a systematic summary of F. suspensa (Forsythia suspensa (Thunb.) Vahl) and to reveal the correlation between the traditional uses and pharmacological activities so as to offer inspiration for future research. All corresponding information about F. suspensa was searched by Scifinder and obtained from scientific databases including Springer, Science Direct, Wiley, Pubmed and China Knowledge Resource Integrated (CNKI). Local dissertations and books were searched as well. According to classical Chinese herbal texts and Chinese Pharmacopoeia, Forsythiae Fructus dominantly displays heat-clearing and detoxifying effects in TCM prescriptions. In modern research, more than 230 compounds were separated and identified from F. suspensa. 211 Of them were isolated from fruits. Lignans and phenylethanoid glycosides are considered as the characteristic and active constituents of this herb, such as forsythiaside, phillyrin, rutin and phillygenin. They exhibited anti-inflammatory, antioxidant, antibacterial, anti-virus, anti-cancer and anti-allergy effects, etc. Currently, there is no report on the toxicity of Forsythiae Fructus, despite slight toxicity of forsythiaside reported in local publications. Compared to Laoqiao, Qingqiao contains higher levels of forsythiaside, forsythoside C, cornoside, rutin, phillyrin, gallic acid and chlorogenic acid and lower levels of rengyol, β-glucose and S

  3. Periodontal pathogens and gestational diabetes mellitus.

    PubMed

    Dasanayake, A P; Chhun, N; Tanner, A C R; Craig, R G; Lee, M J; Moore, A F; Norman, R G

    2008-04-01

    In previous cross-sectional or case-control studies, clinical periodontal disease has been associated with gestational diabetes mellitus. To test the hypothesis that, in comparison with women who do not develop gestational diabetes mellitus, those who do develop it will have had a greater exposure to clinical and other periodontal parameters, we measured clinical, bacteriological (in plaque and cervico-vaginal samples), immunological, and inflammatory mediator parameters 7 weeks before the diagnosis of gestational diabetes mellitus in 265 predominantly Hispanic (83%) women in New York. Twenty-two cases of gestational diabetes mellitus emerged from the cohort (8.3%). When the cases were compared with healthy control individuals, higher pre-pregnancy body mass index (p=0.004), vaginal levels of Tannerella forsythia (p=0.01), serum C-reactive protein (p=0.01), and prior gestational diabetes mellitus (p=0.006) emerged as risk factors, even though the clinical periodontal disease failed to reach statistical significance (50% in those with gestational diabetes mellitus vs. 37.3% in the healthy group; p=0.38).

  4. Qat Chewing and Periodontal Pathogens in Health and Disease: Further Evidence for a Prebiotic-Like Effect

    PubMed Central

    Al-Alimi, Abdulrahman; Taiyeb-Ali, Tara; Jaafar, Nasruddin; Al-hebshi, Nezar Noor

    2015-01-01

    Aim. Qat chewing has been reported to induce subgingival microbial shifts suggestive of prebiotic-like properties. The objective here was to assess the effect of qat chewing on a panel of classical and new putative periopathogens in health and periodontitis. Materials and Methods. 40 qat chewers and 40 nonchewers, equally stratified by periodontal health status, were recruited. Taqman, real-time PCR was used to quantify total bacteria, Porphyromonas gingivalis, Tannerella forsythia, Treponema denticola, Parvimonas micra, Filifactor alocis, Synergistetes, and TM7s in pooled subgingival biofilm samples. Differences in microbial parameters between the study groups were analysed using ordinal regression. Results. In health, the qat chewers harboured significantly lower relative counts of P. gingivalis, T. forsythia, Synergistetes, and TM7s after adjustment for multiple comparisons (P ≤ 0.007). At nominal significance level, they also carried lower counts of TM7s and P. micra (P ≤ 0.05). In periodontitis, the chewers had lower counts of all taxa; however, only T. denticola withstood correction for multiple comparisons (P ≤ 0.0063). Conclusions. Qat chewing is associated with lower proportions of periopathogens, particularly in subjects with healthy periodontium, which supports previous reports of its prebiotic-like properties. This potentially beneficial biological effect can be exploited by attempting to isolate the active fraction. PMID:26351631

  5. Polymicrobial Infection with Major Periodontal Pathogens Induced Periodontal Disease and Aortic Atherosclerosis in Hyperlipidemic ApoEnull Mice

    PubMed Central

    Rivera, Mercedes F.; Lee, Ju-Youn; Aneja, Monika; Goswami, Vishalkant; Liu, Liying; Velsko, Irina M.; Chukkapalli, Sasanka S.; Bhattacharyya, Indraneel; Chen, Hao; Lucas, Alexandra R.; Kesavalu, Lakshmyya N.

    2013-01-01

    Periodontal disease (PD) and atherosclerosis are both polymicrobial and multifactorial and although observational studies supported the association, the causative relationship between these two diseases is not yet established. Polymicrobial infection-induced periodontal disease is postulated to accelerate atherosclerotic plaque growth by enhancing atherosclerotic risk factors of orally infected Apolipoprotein E deficient (ApoEnull) mice. At 16 weeks of infection, samples of blood, mandible, maxilla, aorta, heart, spleen, and liver were collected, analyzed for bacterial genomic DNA, immune response, inflammation, alveolar bone loss, serum inflammatory marker, atherosclerosis risk factors, and aortic atherosclerosis. PCR analysis of polymicrobial-infected (Porphyromonas gingivalis [P. gingivalis], Treponema denticola [T. denticola], and Tannerella forsythia [T. forsythia]) mice resulted in detection of bacterial genomic DNA in oral plaque samples indicating colonization of the oral cavity by all three species. Fluorescent in situ hybridization detected P. gingivalis and T. denticola within gingival tissues of infected mice and morphometric analysis showed an increase in palatal alveolar bone loss (p<0.0001) and intrabony defects suggesting development of periodontal disease in this model. Polymicrobial-infected mice also showed an increase in aortic plaque area (p<0.05) with macrophage accumulation, enhanced serum amyloid A, and increased serum cholesterol and triglycerides. A systemic infection was indicated by the detection of bacterial genomic DNA in the aorta and liver of infected mice and elevated levels of bacterial specific IgG antibodies (p<0.0001). This study was a unique effort to understand the effects of a polymicrobial infection with P. gingivalis, T. denticola and T. forsythia on periodontal disease and associated atherosclerosis in ApoEnull mice. PMID:23451182

  6. Pharmacokinetic of 5 components after oral administration of Fructus Forsythiae by HPLC-MS/MS and the effects of harvest time and administration times.

    PubMed

    Bai, Yang; Li, Jin; Liu, Wei; Jiao, Xiu-cheng; He, Jun; Liu, Jiao; Ma, Lin; Gao, Xiu-mei; Chang, Yan-xu

    2015-07-01

    The unripe Fructus Forsythiae (Qingqiao) and ripe Fructus Forsythiae (Laoqiao) are two types of the clinical forms of commercial fructus of Forsythia suspensa(Thunb.) Vahl. There is limited information available for differences in pharmacokinetic properties of active components between unripe and ripe Fructus Forsythiae in vivo. A rapid and sensitive liquid chromatography-tandem mass spectrometric (LC-MS/MS) method was developed and validated for the simultaneous determination of 9 typical components in rat plasma. The separation of nine analytes was performed on an Eclipse plus C18 (4.6mm×100mm, 1.8μm) column with the mobile phases consisted of a mixture of 0.1% formic acid in water and acetonitrile. Method validation indicated that the developed method was rapid, specific and sensitive. It was found that the AUC(0-24h) of 5 ingredients (forsythoside A, rutin, phillyrin, isorhamnetin and quercetin) in rats after single orally administrated unripe Fructus Forsythiae also had significant differences compared with those after single dose oral administration of ripe Fructus Forsythiae extract. The systemic exposure of 5 ingredients after multiple oral administration of Fructus Forsythiae extract had significantly increased than those after single oral administration. The results indicated that harvest time is not only effects the contents but the bioavailability of active components of Fructus Forsythiae, which suggests that the rate and extent of drug metabolism were altered when the clinical forms of commercial Fructus Forsythiae with different harvest time. The administration times could influence the bioavailability of active components of Fructus Forsythiae.

  7. Chemical Constituents from the Fruits of Forsythia suspensa and Their Antimicrobial Activity

    PubMed Central

    Chen, Guo-Feng; Yang, Mei-Lin; Lin, Ya-Hua; Peng, Chi-Chung

    2014-01-01

    Lignans and phenylethanoid glycosides purified from Forsythia suspensa were reported to display various bioactivities in the previous literature, including the antimicrobial activity. Therefore, the present research is aimed to purify and identify the chemical constituents of the methanol extracts of fruits of F. suspensa. The methanol extracts of fruits of F. suspensa were fractionated and further purified with the assistance of column chromatography to afford totally thirty-four compounds. Among these isolates, 3β-acetoxy-20α-hydroxyursan-28-oic acid (1) was reported from the natural sources for the first time. Some of the purified principles were subjected to the antimicrobial activity examinations against Escherichia coli to explore new natural lead compounds. PMID:24745011

  8. On the Stereoselective Synthesis of (+)-Pinoresinol in Forsythia Suspensa from its Achiral Precursor, Coniferyl Alcohol

    NASA Technical Reports Server (NTRS)

    Davin, Laurence B.; Bedgar, Diana L.; Katayama, Takeshi; Lewis, Norman G.

    1992-01-01

    The residue from Forsythia suspensa stems, upon removal of soluble enzymes, has provided the first evidence for a stereoselective coupling enzyme in lignan biosynthesis. This preparation catalyses the preferred formation (ca 65%) of (+)-[8,8'- C-14] pinoresinol from [8-C-14]coniferyl alcohol in the absence of exogenously provided cofactors; addition of H2O2 had little effect on enantiomeric composition. However, when NAD and malate were supplied, the stereoselectivity of the coupling reaction was significantly enhanced and pinoresinol consisting of ca 80% of the (+)-antipode was obtained. Clearly, the insoluble residue contains a specific coupling enzyme which catalyses (+)-pinoresinol formation from coniferyl alcohol. By contrast, when [8- C-14] sinapyl alcohol was employed as substrate, only racemic syringaresinols were formed: this non-stereoselective peroxidase-catalysed coupling reaction presumably accounts for the low levels of (-)-pinoresinol encountered in this system when coniferyl alcohol is used as a substrate.

  9. Tannerella forsythensis prtH genotype and association with periodontal status.

    PubMed

    Hamlet, Stephen M; Taiyeb-Ali, Tara B; Cullinan, Mary P; Westerman, Bill; Palmer, Janet E; Seymour, Gregory J

    2007-02-01

    The prtH gene of Tannerella forsythensis encodes for a cysteine protease possessing virulent properties. Subgingival colonization by T. forsythensis with this genotype has been suggested to be a discriminator between periodontal health and disease. This study examined the prevalence of T. forsythensis prtH genotype in subgingival plaque and its association with periodontal disease progression and current disease status. Subjects harboring T. forsythensis in their subgingival plaque were identified using real-time polymerase chain reaction (PCR). The presence or absence of the prtH genotype was assessed by conventional PCR. Probing depths and relative attachment levels were also assessed. The prtH genotype was detected in 13 of 56 (23.2%) subjects harboring T. forsythensis in their subgingival plaque. Periodontal disease progression was defined as two or more sites with > or = 2 mm attachment loss in the previous 2-year period; current disease was defined as four or more sites with probing depths > or = 4 mm. The odds of periodontal disease (progression and/or current disease) were 1.55 times greater in subjects harboring prtH genotype T. forsythensis than in subjects in whom prtH was not detected. The prtH genotype was associated with higher numbers of T. forsythensis. In subjects with high levels of T. forsythensis, prtH genotype was associated with an increased extent of periodontal disease 2 years subsequently. These results show that T. forsythensis prtH genotype is associated with high levels of T. forsythensis. However, further work is needed to determine whether it also is a useful marker of periodontal disease progression in T. forsythensis-infected subjects.

  10. Detection of herpesviruses and periodontal pathogens in subgingival plaque of patients with chronic periodontitis, generalized aggressive periodontitis, or gingivitis.

    PubMed

    Imbronito, Ana Vitória; Okuda, Osmar Shizuo; Maria de Freitas, Nivea; Moreira Lotufo, Roberto Fraga; Nunes, Fabio Daumas

    2008-12-01

    Herpesviruses may be related to the etiology of aggressive periodontitis (AgP) and chronic periodontitis (CP) by triggering periodontal destruction or by increasing the risk for bacterial infection. This case-control study evaluated the presence of herpes simplex virus type I (HSV-1), Epstein-Barr virus type I (EBV-1), human cytomegalovirus (HCMV), Aggregatibacter actinomycetemcomitans (previously Actinobacillus actinomycetemcomitans), Porphyromonas gingivalis, Prevotella intermedia, and Tannerella forsythia (previously T. forsythensis) in patients with generalized AgP (AgP group), CP (CP group), or gingivitis (G group) and in healthy individuals (C group). Subgingival plaque samples were collected with paper points from 30 patients in each group. The nested polymerase chain reaction (PCR) method was used to detect HSV-1, EBV-1, and HCMV. Bacteria were identified by 16S rRNA-based PCR. HSV-1, HCMV, and EBV-1 were detected in 86.7%, 46.7%, and 33.3% of the AgP group, respectively; in 40.0%, 50.0%, and 46.7% of the CP group, respectively; in 53.3%, 40.0%, and 20.0% of the G group, respectively; and in 20.0%, 56.7%, and 0.0% of the C group, respectively. A. actinomycetemcomitans was detected significantly more often in the AgP group compared to the other groups (P <0.005). P. gingivalis and T. forsythia were identified more frequently in AgP and CP groups, and AgP, CP, and G groups had higher frequencies of P. intermedia compared to the C group. In Brazilian patients, HSV-1 and EBV-1, rather than HCMV, were more frequently associated with CP and AgP.

  11. Formation of Lignans(-)-Secoisolariciresinol and (-)-Matairesinol with Forsythia intermedia Cell-Free Extracts

    NASA Technical Reports Server (NTRS)

    Umezawa, Toshiaki; Davin, Laurence B.; Lewis, Norman G.

    1991-01-01

    In vivo labeling experiments of Forsythia intermedia plant tissue with [8-(C-14)]- and [9,9-(2)H2,OC(2)H3]coniferyl alcohols revealed that the lignans, (-)-secoisolariciresinol and (-)-matairesinol, were derived from two coniferyl alcohol molecules; no evidence for the formation of the corresponding (+)-enantiomers was found. Administration of (+/-)-[Ar-(H-3)] secoisolariciresinols to excised shoots of F.intermedia resulted in a significant conversion into (-)-matairesinol; again, the (+)-antipode was not detected. Experiments using cell-free extracts of F.intermedia confirmed and extended these findings. In the presence of NAD(P)H and H2O2, the cell-free extracts catalyzed the formation of (-)- secoisolariciresinol, with either [8-(C-14)]- or [9,9-(2)H2,OC(2)H3]coniferyl alcohols as substrates. The (+)- enantiomer was not formed. Finally, when either (-)-[Ar-(H-3)] or (+/-)-[Ar-(H-2)]secoisolariciresinols were used as substrates, in the presence of NAD(P), only (-)- and not (+)-matairesinol formation occurred. The other antipode, (+)-secoisolariciresinol, did not serve as a substrate for the formation of either (+)- or (-)-matairesinol. Thus, in F.intermedia, the formation of the lignan, (-)-secoisolariciresinol, occurs under strict stereochemical control, in a reaction or reactions requiring NAD(P)H and H2O2 as cofactors. This stereoselectivity is retained in the subsequent conversion into (-)-matairesinol, since (+)-secoisolariciresinol is not a substrate. These are the first two enzymes to be discovered in lignan formation.

  12. Anti-inflammatory effects of Forsythia suspensa in dextran sulfate sodium-induced colitis.

    PubMed

    Hwang, Youn-Hwan; Kim, Dong-Gun; Li, Wei; Yang, Hye Jin; Yim, Nam-Hui; Ma, Jin Yeul

    2017-07-12

    Forsythia suspensa Fructus (FS) is used to treat various inflammatory disorders in traditional Oriental medicine, including gastrointestinal diseases, but its therapeutic potential in ulcerative colitis is unclear. Thus, we investigated any potential therapeutic effects of FS against intestinal inflammation and the bioactive constituents in FS. After the induction of colitis using 3% dextran sulfate sodium, FS (100mg/kg/day) was administered orally during the experimental period. We evaluated body weight, bloody diarrhea, colon length, and pro-inflammatory cytokine levels. Subsequently, the bioactive constituents of FS were identified using UPLC/MS/MS. FS significantly decreased the body weight loss, colon length shortening, and tumor necrosis factor-α and interleukin-6 elevations induced by colitis compared with the negative control (P < 0.05). Moreover, FS improved the colitis-induced histopathological damage to the colon, including epithelial necrosis, infiltration of inflammatory cells, ulceration, and submucosal edema. In phytochemical analyses, 7 flavonoids, 9 lignans, 13 phenolics, and 2 triterpenes were identified by comparison with the retention times and mass fragmentations of authentic standards. We demonstrated beneficial effects of FS and its constituents, suggesting their potential for treatment of intestinal inflammation. These data could provide useful information for managing ulcerative colitis. Copyright © 2017. Published by Elsevier B.V.

  13. Forsythia suspensa Suppresses House Dust Mite Extract-Induced Atopic Dermatitis in NC/Nga Mice

    PubMed Central

    Sung, Yoon-Young; Yoon, Taesook; Jang, Seol; Kim, Ho Kyoung

    2016-01-01

    Forsythia suspensa (F. suspensa) is a traditional medicine for treatment of inflammation. In this study, we evaluated the therapeutic effects of an ethanol extract from F. suspensa fruits on atopic dermatitis both in vivo and in vitro. We investigated the inhibitory effects of F. suspensa extract on the development of atopic dermatitis-like skin lesions in an NC/Nga mouse model exposed to Dermatophagoides farinae crude extract. Topical application of F. suspensa extract to the mice attenuated the atopic dermatitis symptoms, including increased dermatitis severity score, ear thickness, infiltration of inflammatory cells in the skin lesions, serum levels of IgE, TNF-α, and histamine, and expression of chemokines, cytokines, and adhesion molecules in ear tissue. In addition, F. suspensa extract inhibited the production of chemokines in TNF-α/IFN-γ-activated human keratinocytes. High-performance liquid chromatography analysis of FSE revealed the presence of four chemical constituents (forsythiaside, phillyrin, pinoresinol, and phylligenin). These compounds inhibited the production of chemokines in TNF-α/IFN-γ-activated human keratinocytes. These results suggest that the F. suspensa might be a useful candidate for treating allergic skin inflammatory disorders. PMID:27936051

  14. Protective effects of Forsythia suspensa extract against oxidative stress induced by diquat in rats.

    PubMed

    Lu, T; Piao, X L; Zhang, Q; Wang, D; Piao, X S; Kim, S W

    2010-02-01

    Forsythia suspensa extract has been proved as a potential antioxidant in the recent years. The present study was undertaken to obtain the optimal antioxidant fraction in vitro and examine its antioxidative potential against diquat-induced oxidative stress in male Sprague Dawley rats in vivo. In vitro, 1,1-diphenyl-2-picrylhydrazyl (DPPH) free radical scavenging experiment indicated that the CH2Cl2 fraction of F. suspensa (FSC) exerted the strongest scavenging activities; forsythoside A, forythialan A and phillygenin from it might be the major antioxidant constituents. In vivo, pretreatment of rats with different doses of FSC (25, 50 and 100 mg/kg bw) and vitamin C (100 mg/kg bw, positive control) for 15 days significantly lowered the tumor necrosis factor-alpha (TNF-alpha), interleukin-1beta (IL-1beta), and interleukin-6 (IL-6) in plasma compared to the negative control group. Also, FSC significantly increased the activities of superoxide dismutase (SOD), glutathione peroxidase (GSH-Px), and the levels of glutathione (GSH) in plasma, liver and kidney whereas it decreased the levels of malondialdehyde (MDA) in plasma and kidney. Moreover, the protective effect of FSC (100 mg/kg bw) was better than vitamin C. These results revealed that FSC exerted a protective effect against diquat-induced oxidative stress and is worthy of becoming a potential dietary antioxidant. Copyright 2009 Elsevier Ltd. All rights reserved.

  15. Molecular-level evaluation of selected periodontal pathogens from subgingival regions in canines and humans with periodontal disease.

    PubMed

    Gołyńska, Magdalena; Polkowska, Izabela; Bartoszcze-Tomaszewska, Małgorzata; Sobczyńska-Rak, Aleksandra; Matuszewski, Łukasz

    2017-03-30

    Dogs commonly serve as a model for various human conditions, including periodontal diseases. The aim of this study was to identify the anaerobic bacteria that colonize the subgingival areas in dogs and humans by using rapid real-time polymerase chain reaction (RT-PCR)-based tests and to compare the results obtained in each species. Bacterial microflora evaluations, both quantitative and qualitative, were performed by applying ready-made tests on twelve dogs and twelve humans. Five samples were collected from each subject's deepest gingival pockets and joined to form a collective sample. The results of the study revealed interspecies similarities in the prevalences of Porphyromonas (P.) gingivalis, Treponema denticola, Tannerella forsythia, and Fusobacterium nucleatum. Red complex bacteria comprised the largest portion of the studied bacterial complexes in all study groups, with P. gingivalis being the most commonly isolated bacterium. The results show similarities in the prevalence of bacterial microflora in dogs and humans. Microbiological analysis of gingival pockets by using rapid real-time PCR-based tests in clinical practice, both veterinary and human, can facilitate the choice of appropriate pharmacological treatment and can provide a basis for subsequent verification of the treatment's effectiveness.

  16. Molecular-level evaluation of selected periodontal pathogens from subgingival regions in canines and humans with periodontal disease

    PubMed Central

    Polkowska, Izabela; Bartoszcze-Tomaszewska, Małgorzata; Sobczyńska-Rak, Aleksandra; Matuszewski, Łukasz

    2017-01-01

    Dogs commonly serve as a model for various human conditions, including periodontal diseases. The aim of this study was to identify the anaerobic bacteria that colonize the subgingival areas in dogs and humans by using rapid real-time polymerase chain reaction (RT-PCR)-based tests and to compare the results obtained in each species. Bacterial microflora evaluations, both quantitative and qualitative, were performed by applying ready-made tests on twelve dogs and twelve humans. Five samples were collected from each subject's deepest gingival pockets and joined to form a collective sample. The results of the study revealed interspecies similarities in the prevalences of Porphyromonas (P.) gingivalis, Treponema denticola, Tannerella forsythia, and Fusobacterium nucleatum. Red complex bacteria comprised the largest portion of the studied bacterial complexes in all study groups, with P. gingivalis being the most commonly isolated bacterium. The results show similarities in the prevalence of bacterial microflora in dogs and humans. Microbiological analysis of gingival pockets by using rapid real-time PCR-based tests in clinical practice, both veterinary and human, can facilitate the choice of appropriate pharmacological treatment and can provide a basis for subsequent verification of the treatment's effectiveness. PMID:27297417

  17. An Extraordinary Accumulation of (-)-Pinoresinol in Cell-Free Extracts of Forsythia intermedia: Evidence for Enantiospecific Reduction of (+)-Pinoresinol

    NASA Technical Reports Server (NTRS)

    Katayama, Takeshi; Davin, Laurence B.; Lewis, Norman G.

    1992-01-01

    Stereoselective and enantiospecific transformation mechanisms in lignan biogenesis are only now yielding to scientific inquiry: it has been shown that soluble cell-free preparations from Forsythia intermedia catalysis the formation of the enantiomerically pure lignan, (-)-secoisolariciresinol, when incubated with coniferyl alcohol in the presence of NAD(P)H and H2O2. Surprisingly, (-)-pinoresinol also accumulates in this soluble cell-free assay mixture in greater than 96% enantiomeric excess, even though it is not the naturally occurring antipode present in Forsythia sp. But these soluble cell-free preparations do not engender stereoselective coupling; instead, racemic pinoresinols are first formed, catalysed by an H2O2-dependent peroxidase reaction. An enantiospecific NAD(P)H reductase then converts (+)- pinoresinol, and not the (-)-antipode, into (-)-secoisolariciresinol. Stereoselective syntheis of(+)-pinoresinol from E-coniferyl alcohol is, however, catalysed by an insoluble enzyme preparation in F. suspensa, obtained following removal of readily soluble and ionically bound enzymes; no exogenously supplied cofactors were required other than oxygen, although the reaction was stimulated by NAD-malate addition. Thus, the overall biochemical pathway to enantiomerically pure (-)-secoisolariciresinol has been delineated.

  18. Forsythia suspensa Extract Has the Potential to Substitute Antibiotic in Broiler Chicken

    PubMed Central

    Han, X.; Piao, X. S.; Zhang, H. Y.; Li, P. F.; Yi, J. Q.; Zhang, Q.; Li, P.

    2012-01-01

    Two experiments were conducted to investigate the potential for Forsythia suspensa extract (FSE) to substitute for antibiotic in broiler chicken. First, a well-diffusion assay procedure and a 2-fold dilution method were used to determine the bacteriostatic activity of FSE on Escherichia coli K88, staphylococcus aureus, and salmonella was assayed. An inhibitory effect of FSE was observed on the growth of these bacteria. This effect seems to be dose depended, which disappeared after 25.00, 12.50, 1.56 mg/ml. Second, a 42-d trial with 252 broiler chickens (d 1, 38.7±1.1 g BW) was conducted to evaluate the effect of dietary supplementation of FSE in broiler chicken. The feeding program consisted of a starter diet from d 1 to 21 and a finisher diet from d 22 to 42. Dietary treatments included were: i) NC: negative control fed a corn-soybean meal based diet; ii) PC: positive control group fed based diet with chlortetracycline; and iii) FC: a test group fed with 100 mg FSE/kg diet. In this study growth performance did not differ among treatments during the starter period. However, dietary supplemental chlortetracycline and FSE increased (p<0.05) average daily gain (ADG), average daily feed intake (ADFI) compared with NC during the finisher and overall phase. Apparent digestibility of calcium on d 21, digestibility of energy and calcium on d 42 of FC was greater (p<0.05) than NC. Moreover, cecal Escherichia coli counts for birds from FC were lower (p<0.05) than NC. Dietary FSE supplementation also improved (p<0.05) villus height and villus height to crypt depth ratios in both duodenum and ileum and decreased (p<0.05) crypt depth in the duodenum. Duodenum villus height and villus height to crypt depth ratio in both duodenum and ileum from the FC group were also greater (p<0.05). Serum growth hormone and IGF-1 were not influenced by different treatments. Apparently, FSE has the potential to substitute for antibiotic in broiler chicken. PMID:25049598

  19. Forsythia suspensa extract attenuates corticosterone-induced growth inhibition, oxidative injury, and immune depression in broilers.

    PubMed

    Zeng, Z K; Li, Q Y; Piao, X S; Liu, J D; Zhao, P F; Xu, X; Zhang, S; Niu, S

    2014-07-01

    Forsythia suspensa extract (FSE) has been demonstrated to attenuate physiological stress induced by high temperature or high stocking density. This experiment was conducted with 144 male Arbor Acre broilers (1-d-old, weighing 42.7 ± 1.7 g) to determine the effects of FSE on performance, nutrient digestibility, antioxidant activities, serum metabolites, and immune parameters for birds treated with corticosterone (CS). The birds were randomly allotted to 1 of 4 treatments in a 2 × 2 factorial arrangement that included FSE supplementation (0 or 100 mg/kg) and CS administration (0 or 20 mg/kg of diet for 7 consecutive days starting on d 14). The feeding program consisted of a starter diet from d 1 to 21 and a finisher diet from d 22 to 42. Corticosterone administration decreased (P < 0.01) ADG and impaired (P < 0.01) feed conversion ratio in both phases and overall, which were alleviated (P < 0.01) by dietary FSE supplementation in the finisher phase and overall. At d 21, CS administration caused decreases (P < 0.05) in the apparent digestibility of energy, relative weight of bursa and thymus, total antioxidant capacity, superoxide dismutase (SOD) activity, and antibody titers to Newcastle disease virus (NDV); however, serum malondialdehyde and uric acid were increased. All of these changes were attenuated (P < 0.05) by dietary FSE supplementation. At d 42, FSE supplementation improved (P < 0.05) the apparent digestibility of DM and CP, relative weights of bursa, SOD activity, and antibody titers to NDV, which were impaired by CS administration. Interactions (P < 0.05) were noted between CS and FSE for ADG and feed conversion ratio in the finisher phase and overall, as well as total antioxidant capacity, SOD activity, uric acid, and antibody titers to NDV at d 21, as well as relative weights of thymus at d 42. In conclusion, dietary FSE supplementation enhanced nutrient digestibility and performance of broiler possibly by reducing oxidative stress and immune

  20. Generation of Triple-Transgenic Forsythia Cell Cultures as a Platform for the Efficient, Stable, and Sustainable Production of Lignans.

    PubMed

    Murata, Jun; Matsumoto, Erika; Morimoto, Kinuyo; Koyama, Tomotsugu; Satake, Honoo

    2015-01-01

    Sesamin is a furofuran lignan biosynthesized from the precursor lignan pinoresinol specifically in sesame seeds. This lignan is shown to exhibit anti-hypertensive activity, protect the liver from damages by ethanol and lipid oxidation, and reduce lung tumor growth. Despite rapidly elevating demand, plant sources of lignans are frequently limited because of the high cost of locating and collecting plants. Indeed, the acquisition of sesamin exclusively depends on the conventional extraction of particular Sesamum seeds. In this study, we have created the efficient, stable and sustainable sesamin production system using triple-transgenic Forsythia koreana cell suspension cultures, U18i-CPi-Fk. These transgenic cell cultures were generated by stably introducing an RNAi sequence against the pinoresinol-glucosylating enzyme, UGT71A18, into existing CPi-Fk cells, which had been created by introducing Sesamum indicum sesamin synthase (CYP81Q1) and an RNA interference (RNAi) sequence against pinoresinol/lariciresinol reductase (PLR) into F. koreanna cells. Compared to its transgenic prototype, U18i-CPi-Fk displayed 5-fold higher production of pinoresinol aglycone and 1.4-fold higher production of sesamin, respectively, while the wildtype cannot produce sesamin due to a lack of any intrinsic sesamin synthase. Moreover, red LED irradiation of U18i-CPi-Fk specifically resulted in 3.0-fold greater production in both pinoresinol aglycone and sesamin than production of these lignans under the dark condition, whereas pinoresinol production was decreased in the wildtype under red LED. Moreover, we developed a procedure for sodium alginate-based long-term storage of U18i-CPi-Fk in liquid nitrogen. Production of sesamin in U18i-CPi-Fk re-thawed after six-month cryopreservation was equivalent to that of non-cryopreserved U18i-CPi-Fk. These data warrant on-demand production of sesamin anytime and anywhere. Collectively, the present study provides evidence that U18i-CP-Fk is an

  1. Quantitative analysis and chromatographic fingerprinting for the quality evaluation of Forsythia suspensa extract by HPLC coupled with photodiode array detector.

    PubMed

    Xia, Yonggang; Yang, Bingyou; Wang, Qiuhong; Liang, Jun; Wei, Youhe; Yu, Hedan; Zhang, Qingbo; Kuang, Haixue

    2009-12-01

    A simple and reproducible HPLC-photodiode array detector method has been described for evaluating and controlling quality of Forsythia suspensa extract (FSE). First, by analysis of chromatographic fingerprints, the similarities of chromatograms of FSE samples from the same pharmaceutical company exceeded 0.999, 0.997 and 0.960, respectively, although they were much lower from different pharmaceutical companies. Second, by further comparing many batches of extract chromatograph charts with the corresponding reference herb materials, the "common peaks" 3, 5, 7 and 10 were defined as "marker peaks", which were identified as (+)-pinoresinol-beta-D-glucoside, forsythiaside, phillyrin and phillygenin, respectively. Third, four "marker peaks" were simultaneously determined based on fingerprint chromatogram for further controlling the quality of FSE quantitatively. Namely, the newly developed method was successfully applied to analyze 38 batches of FSE samples supplied by three pharmaceutical factories, which showed acceptable linearity, intra-day precision (RSD<2.76%), inter-day precision (RSD<3.43%) and the average recovery rates in the range of (95.38+/-2.96)% to (101.60+/-3.08)%. At last, hierarchical clustering analysis and Bayes discriminant analysis statistical methods were used to classify and differentiate the 38 FSE samples to provide the basis for guiding reasonable use of FSE and controlling its quality better.

  2. [Relationship between herpesviruses and periodontal pathogenic bacteria in subgingival plaque].

    PubMed

    Ding, Fang; Feng, Xiang Hui; Meng, Huan Xin; Zhao, Yi Bing; Zhang, Li; Lu, Rui Fang; Chen, Zhi Bin

    2008-06-18

    To evaluate the prevalence rates of human cytomegalovirus(HCMV) and Epstein-Barr virus-1(EBV-1) in subgingival plaque and analyze the relationship between herpesviruses, periodontal pathogenic bacteria and periodontal clinical parameters in Chinese patients with aggressive periodontitis(AgP). A total of one hundred and twenty subgingival plaque samples were collected from 89 AgP patients and 31 healthy subjects. HCMV and EBV-1 were detected using nested polymerase chain reaction(PCR).Contemporaneously, 8 periodontal pathogenic bacteria including Actinobacillus actinomycetemcomitans(Aa), Porphyromonas gingivalis(Pg), Tannerella forsythensis(Tf), Prevotella intermedia(Pi), Campylobacter rectus(Cr),Fusobacterium nucleatum(Fn), Treponema denticola(Td), Prevotella nigrescens(Pn) were detected by 16S rRNA based PCR. HCMV was more frequently detected in AgP patients (43.8%) than in healthy controls (12.9%, P<0.01). The prevalence rates of HCMV and EBV-1 in AgP patients with 6-8 kinds of bacteria detected were 54.4% and 17.4%, respectively, significantly higher than those with 3-5 kinds of bacteria detected (P<0.05). The prevalence rates of HCMV and EBV was higher in AgP patients than in healthy controls. Herpesviruses and periodontal pathogenic bacteria may cooperate synergistically in the development of AgP, which could be considered as a pathogenetic consortium in future investigation of periodontaltitis.

  3. Subgingival and tongue microbiota during early periodontitis.

    PubMed

    Tanner, A C R; Paster, B J; Lu, S C; Kanasi, E; Kent, R; Van Dyke, T; Sonis, S T

    2006-04-01

    Periodontal infections have a microbial etiology. Association of species with early disease would be useful in determining which microbes initiate periodontitis. We hypothesized that the microbiota of subgingival and tongue samples would differ between early periodontitis and health. A cross-sectional evaluation of 141 healthy and early periodontitis adults was performed with the use of oligonucleotide probes and PCR. Most species differed in associations with sample sites; most subgingival species were associated with subgingival samples. Few species were detected more frequently in early periodontitis by DNA probes. Porphyromonas gingivalis and Tannerella forsythia (Tannerella forsythensis) were associated with early periodontitis by direct PCR. In conclusion, the microbiota of tongue samples was less sensitive than that of subgingival samples in detecting periodontal species, and there was overlap in species detected in health and early periodontitis. Detection of periodontal pathogens in early periodontitis suggests an etiology similar to that of more advanced disease.

  4. Forsythiae Fructus Inhibits B16 Melanoma Growth Involving MAPKs/Nrf2/HO-1 Mediated Anti-Oxidation and Anti-Inflammation.

    PubMed

    Bao, Jiaolin; Ding, Renbo; Zou, Lidi; Zhang, Chao; Wang, Kai; Liu, Fang; Li, Peng; Chen, Meiwan; Wan, Jian-Bo; Su, Huanxing; Wang, Yitao; He, Chengwei

    2016-01-01

    Forsythiae Fructus, the fruits of Forsythia suspensa (Thunb.) Vahl, Lianqiao in Chinese, is one of the most fundamental herbs in traditional Chinese medicine (TCM). It is a typical heat-clearing and detoxicating herb, according to TCM theory. In this study, we investigated the antitumor effect of Forsythiae Fructus aqueous extract (FAE) on B16-F10 melanoma cells in vivo. The transplanted B16-F10 melanoma in C57BL/6 mice was established and used for the evaluation of the in vivo antitumor effect of FAE. FAE strongly inhibited the growth of B16-F10 cells in vitro and the tumor in vivo. The survival time of tumor-bearing mice was significantly prolonged by FAE. FAE inhibited cancer cell proliferation and angiogenesis in the tumor, as indicated by the decreased expressions of Ki67 and CD31. The levels of ROS, MDA, TNF-[Formula: see text] and IL-6 decreased, while GSH increased in the FAE treatment group, indicating FAE possesses strong anti-oxidative and anti-inflammatory activity. The expression of anti-oxidant proteins Nrf-2 and HO-1, tumor suppressors P53 and p-PTEN, and the MAPK pathways in tumor tissues were upregulated by FAE treatment. These data demonstrated that FAE exhibited strong antitumor activity against B16-F10 murine melanoma both in vitro and in vivo. The antitumor effect of FAE involved decreases in oxidative stress and inflammation in the tumor, which is closely related to the heat-clearing and detoxicating properties of FAE.

  5. Study on the Main Components Interaction from Flos Lonicerae and Fructus Forsythiae and Their Dissolution In Vitro and Intestinal Absorption in Rats

    PubMed Central

    Zhou, Wei; Tan, Xiaobin; Shan, Jinjun; Wang, Shouchuan; Yin, Ailing; Cai, Baochang; Di, Liuqing

    2014-01-01

    The Flos Lonicerae-Fructus Forsythiae herb couple is the basic components of Chinese herbal preparations (Shuang-Huang-Lian tablet, Yin-Qiao-Jie-Du tablet and Fufang Qin-Lan oral liquid), and its pharmacological effects were significantly higher than that in Flos Lonicerae or Fructus Forsythiae, but the reasons remained unknown. In the present study, pattern recognition analysis (hierarchical cluster analysis (HCA) and principal component analysis (PCA)) combined with UHPLC-ESI/LTQ-Orbitrap MS system were performed to study the chemical constitution difference between co-decoction and mixed decoction in the term of chemistry. Besides, the pharmacokinetics in vivo and intestinal absorption in vitro combined with pattern recognition analysis were used to reveal the discrepancy between herb couple and single herbs in the view of biology. The observation from the chemical view in vitro showed that there was significant difference in quantity between co-decoction and mixed decoction by HCA, and the exposure level of isoforsythoside and 3, 5-dicaffeoylquinic acid in co-decoction, higher than that in mixed decoction, directly resulted in the discrepancy between co-decoction and mixed decoction using both PCA and HCA. The observation from the pharmacokinetics displayed that the exposure level in vivo of neochlorogenic acid, 3, 4-dicaffeoylquinic acid, isoforsythoside and forsythoside A, higher than that in single herbs, was the main factor contributing to the difference by both PCA and HCA, interestingly consistent with the results obtained from Caco-2 cells in vitro, which indicated that it was because of intestinal absorption improvement of neochlorogenic acid, 3, 4-dicaffeoylquinic acid, isoforsythoside and forsythoside A that resulted in a better efficacy of herb couple than that of single herbs from the perspective of biology. The results above illustrated that caffeic acid derivatives in Flos Lonicerae-Fructus Forsythiae herb couple could be considered as chemical

  6. De Novo Transcriptomes of Forsythia koreana Using a Novel Assembly Method: Insight into Tissue- and Species-Specific Expression of Lignan Biosynthesis-Related Gene.

    PubMed

    Shiraishi, Akira; Murata, Jun; Matsumoto, Erika; Matsubara, Shin; Ono, Eiichiro; Satake, Honoo

    2016-01-01

    Forsythia spp. are perennial woody plants which are one of the most extensively used medicinal sources of Chinese medicines and functional diets owing to their lignan contents. Lignans have received widespread attention as leading compounds in the development of antitumor drugs and healthy diets for reducing the risks of lifestyle-related diseases. However, the molecular basis of Forsythia has yet to be established. In this study, we have verified de novo deep transcriptome of Forsythia koreana leaf and callus using the Illumina HiSeq 1500 platform. A total of 89 million reads were assembled into 116,824 contigs using Trinity, and 1,576 of the contigs displayed the sequence similarity to the enzymes responsible for plant specialized metabolism including lignan biosynthesis. Notably, gene ontology (GO) analysis indicated the remarkable enrichment of lignan-biosynthetic enzyme genes in the callus transcriptome. Nevertheless, precise annotation and molecular phylogenetic analyses were hindered by partial sequences of open reading frames (ORFs) of the Trinity-based contigs. To obtain more numerous contigs harboring a full-length ORF, we developed a novel overlapping layout consensus-based procedure, virtual primer-based sequence reassembly (VP-seq). VP-seq elucidated 709 full-length ORFs, whereas only 146 full-length ORFs were assembled by Trinity. The comparison of expression profiles of leaf and callus using VP-seq-based full-length ORFs revealed 50-fold upregulation of secoisolariciresinol dehydrogenase (SIRD) in callus. Expression and phylogenetic cluster analyses predicted candidates for matairesinol-glucosylating enzymes. We also performed VP-seq analysis of lignan-biosynthetic enzyme genes in the transcriptome data of other lignan-rich plants, Linum flavum, Linum usitatissimum and Podophyllum hexandrum. The comparative analysis indicated both common gene clusters involved in biosynthesis upstream of matairesinol such as SIRD and plant lineage-specific gene

  7. De Novo Transcriptomes of Forsythia koreana Using a Novel Assembly Method: Insight into Tissue- and Species-Specific Expression of Lignan Biosynthesis-Related Gene

    PubMed Central

    Matsumoto, Erika; Matsubara, Shin; Ono, Eiichiro; Satake, Honoo

    2016-01-01

    Forsythia spp. are perennial woody plants which are one of the most extensively used medicinal sources of Chinese medicines and functional diets owing to their lignan contents. Lignans have received widespread attention as leading compounds in the development of antitumor drugs and healthy diets for reducing the risks of lifestyle-related diseases. However, the molecular basis of Forsythia has yet to be established. In this study, we have verified de novo deep transcriptome of Forsythia koreana leaf and callus using the Illumina HiSeq 1500 platform. A total of 89 million reads were assembled into 116,824 contigs using Trinity, and 1,576 of the contigs displayed the sequence similarity to the enzymes responsible for plant specialized metabolism including lignan biosynthesis. Notably, gene ontology (GO) analysis indicated the remarkable enrichment of lignan-biosynthetic enzyme genes in the callus transcriptome. Nevertheless, precise annotation and molecular phylogenetic analyses were hindered by partial sequences of open reading frames (ORFs) of the Trinity-based contigs. To obtain more numerous contigs harboring a full-length ORF, we developed a novel overlapping layout consensus-based procedure, virtual primer-based sequence reassembly (VP-seq). VP-seq elucidated 709 full-length ORFs, whereas only 146 full-length ORFs were assembled by Trinity. The comparison of expression profiles of leaf and callus using VP-seq-based full-length ORFs revealed 50-fold upregulation of secoisolariciresinol dehydrogenase (SIRD) in callus. Expression and phylogenetic cluster analyses predicted candidates for matairesinol-glucosylating enzymes. We also performed VP-seq analysis of lignan-biosynthetic enzyme genes in the transcriptome data of other lignan-rich plants, Linum flavum, Linum usitatissimum and Podophyllum hexandrum. The comparative analysis indicated both common gene clusters involved in biosynthesis upstream of matairesinol such as SIRD and plant lineage-specific gene

  8. II. Pathogens

    Treesearch

    Ned B. Klopfenstein; Brian W. Geils

    2011-01-01

    Invasive fungal pathogens have caused immeasurably large ecological and economic damage to forests. It is well known that invasive fungal pathogens can cause devastating forest diseases (e.g., white pine blister rust, chestnut blight, Dutch elm disease, dogwood anthracnose, butternut canker, Scleroderris canker of pines, sudden oak death, pine pitch canker) (Maloy 1997...

  9. Protective effects of Forsythia suspense extract with antioxidant and anti-inflammatory properties in a model of rotenone induced neurotoxicity.

    PubMed

    Zhang, Shuai; Shao, Si-Yuan; Song, Xiu-Yun; Xia, Cong-Yuan; Yang, Ya-Nan; Zhang, Pei-Cheng; Chen, Nai-Hong

    2016-01-01

    The present study investigated the neuroprotective effects of Forsythia suspense extract in a rotenone-induced neurotoxic model. FS8, one of the herbal extracts, markedly protected PC12 cells against rotenone toxicity and was selected for the in vivo study. Gavage administration of FS8 (50 and 200mg/kg, but not 10mg/kg) for 25 days significantly improved the behavior function, decreased the loss of dopaminergic neurons in substantia nigra (SN), and maintained the level of dopamine in striatum after unilateral infusion of rotenone in SN. Wherein, the protective effects of FS8 at the dose of 200mg/kg were better than selegiline. Further study indicated the excellent antioxidant activity of FS8 on the 5th and 21st days after intranigral injection of rotenone. Moreover, FS8 could inhibit microglia activity and accumulation in SN, and obviously decreased the expression of pro-inflammatory molecules (IL-6, TNF-α, iNOS and COX-2), which indicated the anti-inflammatory effects of FS8. In the PI3K/Akt/NF-κB and MAPK pathways, FS8 significantly down-regulated the protein expression of p-PI3K, p-Akt, p-IκB, p-P65, cleaved Caspase 8, p-p38 and p-JNK but not p-mTOR, cleaved Caspase 3 and p-ERK. Therefore, FS8 protected dopamine neurons against rotenone toxicity via antioxidant and anti-inflammatory effects, which suggested the promising application of FS8 in the prevention and treatment of Parkinson disease. Copyright © 2015 Elsevier Inc. All rights reserved.

  10. [Identification of key markers of normal and pathogenic microbiota determining health of periodontium by NGS-sequencing 16S-rDNA libraries of periodontal swabs].

    PubMed

    Zorina, O A; Petrukhina, N B; Basova, A A; Shibaeva, A V; Trubnikova, E V; Shevelev, A B

    2014-01-01

    By using NGS-sequencing libraries of DNA from periodontal swabs with primers specific to V6 region of 16S rDNA prevalence of bacterial genera and species in periodontal microbiota of patients with aggressive periodontitis and healthy donors was analyzed. Six genera of putative periodontal protectors and eight periodontal pathogens were identified with respect to aggressive (but not chronic) periodontitis. Statistically relevant over-colonization by general Porphyromonas, Treponema, Synergistes, Tannerella, Filifactor, Ruminococcus, Parvimonas and Mycoplasma was found to be associated with the condition. From these, only three genera Porphyromonas, Treponema and Tannerella are traditionally considered as periodontal pathogens. Statistically confidential over-colonization by genus Veillonella was found in healthy patients. This genus should be considered as a relevant marker of a healthy periodontium. Genera Streptococcus, Bergeyella, Granulicatella, Kingella and Corynebacterium may be considered as putative periodontal protectors. Comparison of data of NGS-sequencing and real-time PCR demonstrated a good agreement if different PCR efficiency using independent primer pairs is taken into account.

  11. Comparative pharmacokinetics of chlorogenic acid in beagles after oral administrations of single compound, the extracts of Lonicera japanica, and the mixture of chlorogenic acid, baicalin, and Forsythia suspense.

    PubMed

    Liu, Rong; Lai, Ke; Xiao, Yu; Ren, Jing

    2017-12-01

    Chlorogenic acid (ChA) is the major compound in Shuang-Huang-Lian (SHL), which is mainly composed of ChA, baicalin, and Forsythia suspense Thunb Vahl. The effects of co-existing compounds in SHL and Lonicera japanica Thunb on the absorption of ChA was investigated. According to 3 × 3 Latin-square test, ChA alone, the extracts of Lonicera japanica, or the mixture of ChA, baicalin and Forsythia suspense (ChA effective doses is 60 mg/kg) was separately given to six beagles for seven days. The oral pharmacokinetic parameters of ChA in plasma, urine and faeces were quantified by HPLC/UV and analyzed. The pharmacokinetic parameters of ChA alone, the extracts of Lonicera japanica, and the mixture of ChA, baicalin, and Forsythia suspense were as followed: Cmax (2.350 ± 0.483, 1.655 ± 0.576, 2.332 ± 0.606 μg/mL), AUC0-∞ (6.324 ± 1.853, 4.216 ± 1.886, 6.074 ± 1.473 μg·h/mL), t1/2 (0.911 ± 0.187, 1.204 ± 0.309, 1.094 ± 0.193 h), and Tmax (1.861 ± 0.499, 1.000 ± 0.459, 1.833 ± 0.279 h). Accumulative fraction excretion of ChA in urine were 0.73 ± 0.55, 1.25 ± 1.23, 1.05 ± 0.96%, while that in faeces were 0.68 ± 0.94, 0.19 ± 0.40, and 1.76 ± 3.57%. Co-existing compounds in SHL have no effect on the absorption of ChA, while the concomitant compounds in Lonicera japanica could decrease that of ChA. ChA in Beagles might have high biological transformation.

  12. Microbiological effects of periodontal therapy plus azithromycin in patients with diabetes: results from a randomized clinical trial.

    PubMed

    Hincapié, Juan P; Castrillón, Cesar A; Yepes, Fanny L; Roldan, Natalia; Becerra, María A; Moreno, Sandra M; Consuegra, Jessika; Contreras, Adolfo; Botero, Javier E

    2014-01-01

    Current evidence suggests that periodontal infection may aggravate diabetes control. The aim of this study was to determine the changes in the frequency with which Porphyromonas gingivalis, Tannerella forsythia, Treponema denticola and Aggregatibacter actinomycetemcomitans were detected in patients with diabetes with the use of non-surgical therapy plus azithromycin in a randomized clinical trial. One hundred and five (105) patients with diabetes and chronic periodontitis were randomly assigned to three treatment groups: subgingival mechanical therapy with azithromycin, subgingival mechanical therapy with placebo and supragingival prophylaxis with azithromycin. Complete periodontal clinical examinations and detection of periodontal pathogens using polymerase chain reaction were carried out at baseline, 3, 6 and 9 months after periodontal therapy. The frequency with which Porphyromonas gingivalis, Treponemadenticola and Aggregatibacter actinomycetemcomitans were detected decreased at 3 months in all groups. Tannerella forsythia increased after3 months in all groups. All organisms had similar frequencies at 9 months in all groups. Subgingival mechanical therapy with adjunctive azithromycin had no additional effect on the frequency with which the periodontal pathogens investigated were detected in patients with diabetes.

  13. Energy filtering transmission electron microscopy immunocytochemistry and antigen retrieval of surface layer proteins from Tannerella forsythensis using microwave or autoclave heating with citraconic anhydride

    PubMed Central

    2012-01-01

    Tannerella forsythensis (Bacteroides forsythus), an anaerobic Gram-negative species of bacteria that plays a role in the progression of periodontal disease, has a unique bacterial protein profile. It is characterized by two unique protein bands with molecular weights of more than 200 kDa. It also is known to have a typical surface layer (S-layer) consisting of regularly arrayed subunits outside the outer membrane. We examined the relationship between high molecular weight proteins and the S-layer using electron microscopic immunolabeling with chemical fixation and an antigen retrieval procedure consisting of heating in a microwave oven or autoclave with citraconic anhydride. Immunogold particles were localized clearly at the outermost cell surface. We also used energy-filtering transmission electron microscopy (EFTEM) to visualize 3, 3′-diaminobenzidine tetrahydrochloride (DAB) reaction products after microwave antigen retrieval with 1% citraconic anhydride. The three-window method for electron spectroscopic images (ESI) of nitrogen by the EFTEM reflected the presence of moieties demonstrated by the DAB reaction with horseradish peroxidase (HRP)-conjugated secondary antibodies instead of immunogold particles. The mapping patterns of net nitrogen were restricted to the outermost cell surface. PMID:22984898

  14. Energy filtering transmission electron microscopy immunocytochemistry and antigen retrieval of surface layer proteins from Tannerella forsythensis using microwave or autoclave heating with citraconic anhydride.

    PubMed

    Moriguchi, K; Mitamura, Y; Iwami, J; Hasegawa, Y; Higuchi, N; Murakami, Y; Maeda, H; Yoshimura, F; Nakamura, H; Ohno, N

    2012-11-01

    Tannerella forsythensis (Bacteroides forsythus), an anaerobic Gram-negative species of bacteria that plays a role in the progression of periodontal disease, has a unique bacterial protein profile. It is characterized by two unique protein bands with molecular weights of more than 200 kDa. It also is known to have a typical surface layer (S-layer) consisting of regularly arrayed subunits outside the outer membrane. We examined the relationship between high molecular weight proteins and the S-layer using electron microscopic immunolabeling with chemical fixation and an antigen retrieval procedure consisting of heating in a microwave oven or autoclave with citraconic anhydride. Immunogold particles were localized clearly at the outermost cell surface. We also used energy-filtering transmission electron microscopy (EFTEM) to visualize 3, 3'-diaminobenzidine tetrahydrochloride (DAB) reaction products after microwave antigen retrieval with 1% citraconic anhydride. The three-window method for electron spectroscopic images (ESI) of nitrogen by the EFTEM reflected the presence of moieties demonstrated by the DAB reaction with horseradish peroxidase (HRP)-conjugated secondary antibodies instead of immunogold particles. The mapping patterns of net nitrogen were restricted to the outermost cell surface.

  15. Optimization of simultaneous ultrasonic-assisted extraction of water-soluble and fat-soluble characteristic constituents from Forsythiae Fructus Using response surface methodology and high-performance liquid chromatography

    PubMed Central

    Xia, Yong-Gang; Yang, Bing-You; Liang, Jun; Wang, Di; Yang, Qi; Kuang, Hai-Xue

    2014-01-01

    Background: The compounds (+)-pinoresinol-β-glucoside (1) forsythiaside, (2) phillyrin (3) and phillygenin (4) were elucidated to be the characteristic constituents for quality control of Forsythiae Fructus extract by chromatographic fingerprint in 2010 edition of Chinese Pharmacopoeia due to their numerous important pharmacological actions. It is of great interest to extract these medicinally active constituents from Forsythiae Fructus simultaneously. Materials and Methods: In this study, a new ultrasound-assisted extraction (UAE) method was developed for the simultaneous extraction of biological components 1-4 in Forsythiae Fructus. The quantitative effects of extraction time, ratio of liquid to solid, extraction temperature, and methanol concentration on yield of these four important biological constituents from Forsythiae Fructus were investigated using response surface methodology with Box-Behnken design. The compounds 1-4 extracted by UAE were quantitative analysis by high-performance liquid chromatography-photodiode array detect (HPLC-PAD), and overall desirability (OD), the geometric mean of the contents of four major biological components, was used as a marker to evaluate the extraction efficiency. Results: By solving the regression equation and analyzing 3-D plots, the optimum condition was at extraction temperature 70°C, time 60 min, ratio of liquid to solid 20, and methanol concentration 76.6%. Under these conditions, extraction yields of compounds 1-4 were 2.92 mg/g, 52.10 mg/g, 0.90 mg/g and 0.57 mg/g, respectively, which were in good agreement with the predicted OD values. In order to achieve a similar yield as UAE, soxhlet extraction required at least 6 h and maceration extraction required much longer time of 24 h. Established UAE method has been successfully applied to sample preparation for the quality control of Forsythiae Fructus. Additionally, a quadrupole time-of-flight mass spectrometry was applied to the structural confirmation of analytes

  16. Prevalence of Periodontal Pathogens in Dental Plaque of Children

    PubMed Central

    Gafan, Gavin P.; Lucas, Victoria S.; Roberts, Graham J.; Petrie, Aviva; Wilson, Michael; Spratt, David A.

    2004-01-01

    Porphyromonas gingivalis, Actinobacillus actinomycetemcomitans, and Tannerella forsythensis have been implicated as the main etiological agents of periodontal disease. The purpose of this work was to estimate the prevalence of these organisms in plaque from children without gingivitis (group 1; n = 65) and from those with gingivitis (group 2; n = 53). Extracted DNA from plaque was subjected to two rounds of PCR targeting the 16S rRNA gene using both universal primers and species-specific primers. The results were as follows: group 1, P. gingivalis, 49%; A. actinomycetemcomitans, 55%; and T. forsythensis, 65%; group 2, P. gingivalis, 47%; A. actinomycetemcomitans, 59%; and T. forsythensis, 45%. T. forsythensis was detected more frequently in children with no gingivitis than in those with gingivitis (P = 0.03). There was no significant difference between the two groups with respect to the presence of P. gingivalis or A. actinomycetemcomitans in either group (P > 0.05). Logistic regression analysis revealed that the odds of a patient having gingivitis were 2.3 times greater in the absence of T. forsythensis. In conclusion, the results of this study have shown that the three pathogens can be detected in the dental plaque of healthy children and of those with gingivitis and that T. forsythensis is associated with dental plaque at sites with no gingivitis. PMID:15365002

  17. [Effect of Er:YAG laser on the dynamic changes in subgingival flora in type 2 diabetic patients with periodontitis].

    PubMed

    Guo, Bin; Liang, Qianqian; Lü, Yan; Fu, Min; Chen, Yuanyuan; Yuan, Yifang; Li, Yingchao

    2014-04-01

    To observe the changes in subgingival microflora before and after Er:YAG laser treatment on diabetic patients with periodontitis, and to compare with the subgingival microflora of chronic periodontitis. Subgingival plaque of 13 pairs of teeth (26 sites) was selected from type 2 diabetic patients at pretreatment, one month post-treatment, and three months post-treatment. Subgingival plaque was also obtained from 11 cases of moderate to severe chronic periodontitis with similar severity of periodontitis. The DNA of the subgingival plaque samples was extracted. Whole bacterial 16S rDNA gene fragments separated by denaturing gradient gel electrophoresis. Specific DNA bands were then chosen for retrieval and sequencing. The gene sequencing results of the special DNA bands of subgingival plaque samples show that the pathogenic bacteria of both diabetic periodontitis and simple chronic periodontitis were Prevotella intermedia and Tannerella forsythia, respectively. The composition of the subgingival microflora before and after laser treatment changed. Some DNA bands, including that of Tannerella forsythia, disappeared or weakened one month after treatment. A new strip appeared, which belonged to Actinomyces sp. The profiles of the subgingival microflora changed after treatment, and one month was indicated as an important stage. Er:YAG laser may have an important function in delaying microflora recolonization.

  18. Association between periodontal pathogens and risk of nonfatal myocardial infarction.

    PubMed

    Andriankaja, Oelisoa; Trevisan, Maurizio; Falkner, Karen; Dorn, Joan; Hovey, Kathleen; Sarikonda, Sreenivasa; Mendoza, Tania; Genco, Robert

    2011-04-01

    The direct effect of periodontal pathogens on atherosclerotic plaque development has been suggested as a potential mechanism for the observed association between periodontal disease and coronary heart disease, but few studies have tested this theory. (i) To assess the association of periodontal pathogens in periodontal pockets with the risk of myocardial infarction (MI) and (ii) to assess whether an increase in the number of periodontal bacterial species increases the risk of MI. A total of 313 cases and 747 controls, consisting of Caucasian men and women from Western New York, aged 35 to 69 years, were recruited for this study. The presence of microorganisms was assessed by indirect immunofluorescence microscopy, using species-specific polyclonal and monoclonal serodiagnostic reagents. The presence of six periodontal pathogens, Porphyromonas gingivalis (Pg), Tannerella forsythensis (Tf), Prevotella intermedia (Pi), Campylobacter recta (Cr), Fusobacterium nucleatum (Fn), and Eubacterium saburreum (Es), and their co-occurrence (0-6) was compared with the odds of having myocardial infarction. Univariate analyses revealed a higher percentage of the presence of each bacterium in cases compared to controls. In multivariate analyses, only Tf and Pi were statistically associated with an increase in the odds of having MI [Odds ratio OR=1.62; 95% CI (1.18-2.22); and 1.40; 95% (1.02-1.92), respectively] after adjusting for age, gender, education, cholesterol, high blood pressure, diabetes, and total pack-years of cigarette smoking. An increase in the number of different periodontal bacteria in pockets was also found to increase the odds of MI [adjusted OR=1.14; 95% CI (1.03-1.26)]. Participants who had three species or more of periodontal pathogens had about 2-fold increase in odds of having nonfatal MI than those who did not have any type of bacterial species [OR=2.01 (1.31-3.08)]. The presence of periodontal pathogens, specifically Tf or Pi, and an increase in total burden

  19. Anti-melanoma activity of Forsythiae Fructus aqueous extract in mice involves regulation of glycerophospholipid metabolisms by UPLC/Q-TOF MS-based metabolomics study.

    PubMed

    Bao, Jiaolin; Liu, Fang; Zhang, Chao; Wang, Kai; Jia, Xuejing; Wang, Xiaotong; Chen, Meiwan; Li, Peng; Su, Huanxing; Wang, Yitao; Wan, Jian-Bo; He, Chengwei

    2016-12-19

    Metabolomics is a comprehensive assessment of endogenous metabolites of a biological system in a holistic context. In this study, we evaluated the in vivo anti-melanoma activity of aqueous extract of Forsythiae Fructus (FAE) and globally explored the serum metabolome characteristics of B16-F10 melanoma-bearing mice. UPLC/Q-TOF MS combined with pattern recognition approaches were employed to examine the comprehensive metabolic signatures and differentiating metabolites. The results demonstrated that FAE exhibited remarkable antitumor activity against B16-F10 melanoma in C57BL/6 mice and restored the disturbed metabolic profile by tumor insult. We identified 17 metabolites which were correlated with the antitumor effect of FAE. Most of these metabolites are involved in glycerophospholipid metabolisms. Notably, several lysophosphatidylcholines (LysoPCs) significantly decreased in tumor model group, while FAE treatment restored the changes of these phospholipids to about normal condition. Moreover, we found that lysophosphatidylcholine acyltransferase 1 (LPCAT1) and autotaxin (ATX) were highly expressed in melanoma, and FAE markedly down-regulated their expression. These findings indicated that modulation of glycerophospholipid metabolisms may play a pivotal role in the growth of melanoma and the antitumor activity of FAE. Besides, our results suggested that serum LysoPCs could be potential biomarkers for the diagnosis and prognosis of melanoma and other malignant tumors.

  20. Anti-melanoma activity of Forsythiae Fructus aqueous extract in mice involves regulation of glycerophospholipid metabolisms by UPLC/Q-TOF MS-based metabolomics study

    PubMed Central

    Bao, Jiaolin; Liu, Fang; Zhang, Chao; Wang, Kai; Jia, Xuejing; Wang, Xiaotong; Chen, Meiwan; Li, Peng; Su, Huanxing; Wang, Yitao; Wan, Jian-Bo; He, Chengwei

    2016-01-01

    Metabolomics is a comprehensive assessment of endogenous metabolites of a biological system in a holistic context. In this study, we evaluated the in vivo anti-melanoma activity of aqueous extract of Forsythiae Fructus (FAE) and globally explored the serum metabolome characteristics of B16-F10 melanoma-bearing mice. UPLC/Q-TOF MS combined with pattern recognition approaches were employed to examine the comprehensive metabolic signatures and differentiating metabolites. The results demonstrated that FAE exhibited remarkable antitumor activity against B16-F10 melanoma in C57BL/6 mice and restored the disturbed metabolic profile by tumor insult. We identified 17 metabolites which were correlated with the antitumor effect of FAE. Most of these metabolites are involved in glycerophospholipid metabolisms. Notably, several lysophosphatidylcholines (LysoPCs) significantly decreased in tumor model group, while FAE treatment restored the changes of these phospholipids to about normal condition. Moreover, we found that lysophosphatidylcholine acyltransferase 1 (LPCAT1) and autotaxin (ATX) were highly expressed in melanoma, and FAE markedly down-regulated their expression. These findings indicated that modulation of glycerophospholipid metabolisms may play a pivotal role in the growth of melanoma and the antitumor activity of FAE. Besides, our results suggested that serum LysoPCs could be potential biomarkers for the diagnosis and prognosis of melanoma and other malignant tumors. PMID:27991567

  1. Study on the Rationality for Antiviral Activity of Flos Lonicerae Japonicae-Fructus Forsythiae Herb Chito-Oligosaccharide via Integral Pharmacokinetics.

    PubMed

    Zhou, Wei; Yin, Ailing; Shan, Jinjun; Wang, Shouchuan; Cai, Baochang; Di, Liuqing

    2017-04-20

    In the present study, the rationality for the antiviral effect (H1N1 virus) of Flos Lonicerae Japonicae (FLJ, named JinYinHua)-Fructus forsythiae (FF, named LianQiao) herb couple preparations improved by chito-oligosaccharide (COS) was investigated. We found that the improvement of antiviral activity for four preparations attributed to the enhancement of bioavailability for the FLJ-FF herb couple in vivo, and that caffeic acid derivatives are the most important type of components for antiviral activity. The anti-Influenza virus activity-half maximal inhibitory concentration (IC50), not area under concentration (AUC) was considered as the weighting factor for integrating the pharmacokinetics of caffeic acid derivatives. It was found that the integral absorption, both in vitro and in vivo, especially that in Shuang-Huang-Lian, can be improved significantly by COS, an absorption enhancer based on tight junction. The results indicated that the antiviral activity in four preparations improved by COS was mainly attributed to the integral absorption enhancement of caffeic acid derivatives.

  2. Rapid analysis of Fructus forsythiae essential oil by ionic liquids-assisted microwave distillation coupled with headspace single-drop microextraction followed by gas chromatography-mass spectrometry.

    PubMed

    Jiao, Jiao; Ma, Dan-Hui; Gai, Qing-Yan; Wang, Wei; Luo, Meng; Fu, Yu-Jie; Ma, Wei

    2013-12-04

    A rapid, green and effective miniaturized sample preparation and analytical technique, i.e. ionic liquids-assisted microwave distillation coupled with headspace single-drop microextraction (ILAMD-HS-SDME) followed by gas chromatography-mass spectrometry (GC-MS) was developed for the analysis of essential oil (EO) in Fructus forsythiae. In this work, ionic liquids (ILs) were not only used as the absorption medium of microwave irradiation but also as the destruction agent of plant cell walls. 1-Ethyl-3-methylimidazolium acetate ([C2mim]OAc) was chosen as the optimal ILs. Moreover, n-heptadecane (2.0 μL) was selected as the appropriate suspended solvent for the extraction and concentration of EO. Extraction conditions of the proposed method were optimized using the relative peak area of EO constituents as the index, and the optimal operational parameters were obtained as follows: irradiation power (300 W), sample mass (0.7 g), mass ratio of ILs to sample (2.4), temperature (78°C) and time (3.4 min). In comparison to previous reports, the proposed method was faster and required smaller sample amount but could equally monitor all EO constituents with no significant differences. Copyright © 2013 Elsevier B.V. All rights reserved.

  3. Pathogene Mikroorganismen

    NASA Astrophysics Data System (ADS)

    Wagner, Martin

    Infektionen, die vom Tier auf den Menschen übertragen werden, werden als Zoonosen bezeichnet. Pathogene Mikroorganismen können entweder durch Mensch-Mensch, Mensch-Tier-Kontakt oder durch Kontakt mit kontaminierten Vektoren übertragen werden [39]. Vektoren können einerseits belebt (z. B. blutsaugende Insekten), andererseits unbelebt sein. Kontaminierte Lebensmittel und Wasser gehören zu den wichtigsten unbelebten Vektoren. Neben Lebensmitteln können aber auch kontaminierte Gegenstände oder der Kontakt mit Kontaminationsquellen in der Umwelt Auslöser von Krankheitsfällen sein. Weltweit sind mehr als 1400 krankheitsverursachende biologische Agentien bekannt, von denen über 60 % ein zoonotisches Potenzial aufweisen. Als Ergebnis von Expertengesprächen wurde kürzlich berichtet, dass etwa 3 bis 4, meist virale, neu auftretende Infektionskrankheiten ("emerging diseases“) pro Jahr erwartet werden können [15]. Es handelt sich bei diesen Vorgängen aber nicht nur um das Auftauchen vollkommen neuer oder unbeschriebener Spezies, sondern auch um evolutionsbedingte Anpassungen von mikrobiellen Populationen an neue Bedingungen in ihrem Ökosystem [7]. Molekulare Analysen an Umweltchlamydien erbrachten Hinweise, dass die Evolution erste genetische Pathogenitätsmerkmale in dieser Spezies schon vor 700 Mio. Jahren entstehen ließ [14]. Viele Faktoren befeuern den Prozess der Anpassung, unter anderem auch alle Strategien, mit denen der Mensch seit Jahrtausenden versucht, Lebensmittel sicher und haltbar zu machen. Als die treibenden Kräfte des Auftretens neuer Krankheitserreger werden in der Gegenwart vor allem das sich ändernde Weltklima, die globalen Warenströme und die sich verändernden Konsumgewohnheiten genannt. Es steht auch außer Zweifel, dass viele dieser Erreger Tiere als ihr natürliches Reservoir haben werden, d. h. Zoonosen im klassischen Sinne sind [15].

  4. Occurrence of herpes simplex virus 1 and three periodontal bacteria in patients with chronic periodontitis and necrotic pulp.

    PubMed

    Nishiyama, Sheila Alexandra Belini; Nakano, Viviane; Velásquez-Melendez, Gustavo; Avila-Campos, Mario Julio

    2008-04-01

    Viral and bacterial associations appear to be implicated in the development of periodontal infections. Little information is available describing the periodontopathic agents in root canals with necrotic pulp. In this study, the occurrence and the combinations among herpes simplex virus type 1 (HSV-1) and Dialister pneumosintes, Tannerella forsythia, and Treponema denticola in patients with chronic periodontitis and necrotic pulp were evaluated. Clinical samples from healthy subjects and patients with periodontal or pulp infections were analyzed using a nested polymerase chain reaction PCR to detect HSV and PCR to detect the 3 periodontal bacteria. The presence of Tannerella forsythia and Treponema denticola was observed in healthy, periodontitis, and necrotic pulp patients. HSV was observed in periodontitis and necrotic pulp patients, and no healthy subject harbored D. pneumosintes or HSV. The occurrence of Tannerella forsythia was not statistically significant in patients with necrotic pulp (P = 0.704). Periodontal bacteria were observed varying from 10.3% to 20.7% in periodontitis and necrotic pulp patients. The presence of Treponema denticola - HSV association was predominant in patients showing necrotic pulp (24.1%); however, HSV alone was observed in one patient with periodontitis and in another patient with necrotic pulp. The presence of double association among bacteria or bacteria - HSV could indicate a role in both periodontitis and necrotic pulp, and Tannerella forsythia - Treponema denticola - HSV and Tannerella forsythia - D. pneumosintes - Treponema denticola - HSV associations might be important in periodontitis.

  5. Oral and endotracheal tubes colonization by periodontal bacteria: a case-control ICU study.

    PubMed

    Porto, A N; Cortelli, S C; Borges, A H; Matos, F Z; Aquino, D R; Miranda, T B; Oliveira Costa, F; Aranha, A F; Cortelli, J R

    2016-03-01

    Periodontal infection is a possible risk factor for respiratory disorders; however, no studies have assessed the colonization of periodontal pathogens in endotracheal tubes (ET). This case-control study analyzed whether periodontal pathogens are able to colonize ET of dentate and edentulous patients in intensive care units (ICU) and whether oral and ET periodontal pathogen profiles have any correlation between these patients. We selected 18 dentate and 18 edentulous patients from 78 eligible ICU patients. Oral clinical examination including probing depth, clinical attachment level, gingival index , and plaque index was performed by a single examiner, followed by oral and ET sampling and processing by quantitative polymerase chain reaction (total bacterial load, Aggregatibacter actinomycetemcomitans, Porphyromonas gingivalis, and Tannerella forsythia). Data were statistically analyzed by Mann-Whitney U, two-way analysis of variance (p < 0.05). Among dentate, there was no correlation between clinical parameters and ET bacterial levels. Both dentate and edentulous patients showed similar ET bacterial levels. Dentate patients showed no correlation between oral and ET bacterial levels, while edentulous patients showed positive correlations between oral and ET levels of A. actinomycetemcomitans, P. gingivalis, and T. forsythia. Periodontal pathogens can colonize ET and the oral cavity of ICU patients. Periodontal pathogen profiles tend to be similar between dentate and edentulous ICU patients. In ICU patients, oral cavity represents a source of ET contamination. Although accompanied by higher oral bacterial levels, teeth do not seem to influence ET bacterial profiles.

  6. Dynamic ultrasonic nebulisation extraction coupled with headspace ionic liquid-based single-drop microextraction for the analysis of the essential oil in Forsythia suspensa.

    PubMed

    Yang, Jinjuan; Wei, Hongmin; Teng, Xiane; Zhang, Hanqi; Shi, Yuhua

    2014-01-01

    Ionic liquids have attracted much attention as an extraction solvent instead of traditional organic solvent in single-drop microextraction. However, non-volatile ionic liquids are difficult to couple with gas chromatography. Thus, the following injection system for the determination of organic compounds is described. To establish an environmentally friendly, simple, and effective extraction method for preparation and analysis of the essential oil from aromatic plants. The dynamic ultrasonic nebulisation extraction was coupled with headspace ionic liquid-based single-drop microextraction(UNE-HS/IL/SDME)for the extraction of essential oils from Forsythia suspense fruits. After 13 min of extraction for 50 mg sample, the extracts in ionic liquid were evaporated rapidly in the gas chromatography injector through a thermal desorption unit (5 s). The traditional extraction method was carried out for comparative study. The optimum conditions were: 3 μL of 1-methyl-3-octylimidazolium hexafluorophosphate was selected as the extraction solvent, the sample amount was 50 mg, the flow rate of purging gas was 200 mL/min, the extraction time was 13 min, the injection volume was 2 μL, and the thermal desorption temperature and time were 240 °C and 5 s respectively. Comparing with hydrodistillation (HD), the proposed method was environment friendly and efficient. The proposed method is environmentally friendly, time saving, with high efficiency and low consumption. It would extend the application range of the HS/SDME and would be useful especially for aromatic plants analysis. Copyright © 2013 John Wiley & Sons, Ltd.

  7. PATHOGENS: VIEWS OF EPA'S PATHOGEN EQUIVALENCY COMMITTEE

    EPA Science Inventory

    This presentation reviews the pathogenic microorganisms that may be found in municipal sewage sludge and the commonly employed Class A and B processes for controlling pathogens. It notes how extensively they are used and discusses issues and concerns with their application. Pre...

  8. Examination of periodontal pathogens in stenotic valve specimens and in whole blood samples in patients affected by aortic valve stenosis and chronic periodontitis.

    PubMed

    Raffaelli, L; Santangelo, R; Falchetti, P; Galluccio, F; Luciani, N; Anselmi, A; Nowzari, H; Verdugo, F; Fadda, G; D'Addona, A

    2010-01-01

    Periodontitis may be a risk factor for atherosclerosis and coronary heart disease. The influence of periodontal pathogens in cardiovascular diseases needs further investigation. Therefore, the aims of this clinical study are: to test the presence of periodontal bacteria DNA in aortic valves and to assess the concomitant presence of the same periodontal bacteria DNA in whole blood samples in patients affected by aortic valve stenosis and chronic periodontitis. Nineteen consecutive patients (12 males and 7 females, age: 49-85 years) were enrolled in this study after having been subjected to a complete periodontal evaluation to confirm the diagnosis of chronic periodontitis. All patients were scheduled for aortic valve replacement surgery. After clinical and microbial periodontal examination, the aortic valve tissue specimens were obtained by excision during valve replacement surgery and the patients were subjected to the whole blood sampling before the surgery. The polymerase chain reaction technology was used to detect the putative periodontal pathogens Tannerella forshytia, Porphyromonas gingivalis, Aggregatibacter actinomycetemcomitans, Prevotella intermedia, Fusobacterium nucleatum, Campylobacter rectus, Eikenella corrodens and Treponema denticola. Neither the 19 aortic valve specimens nor the blood samples were positive for the genoma of the selected periodontal pathogens. The selected periodontal pathogens did not colonize the aortic valve of patients affected by stenosis and bacterial genoma was not present in whole blood samples. A high blood pressure at the aortic valve may prevent the adhesion and proliferation of bacterial colonies.

  9. SAM Pathogen Methods Query

    EPA Pesticide Factsheets

    Laboratories measuring target pathogen analytes in environmental samples can use this online query tool to identify analytical methods in EPA's Selected Analytical Methods for Environmental Remediation and Recovery for select pathogens.

  10. Pathogens affecting beef

    USDA-ARS?s Scientific Manuscript database

    Mankind has long recognized that animals harbor disease. Zoonotic pathogens are agents from animals that cause disease in humans. The pathogens may be broad spectrum and cause disease in animals and humans, or the animal may simply be an asymptomatic reservoir for a human pathogen. The human dise...

  11. A Study on the Chemical Compositions of the Yinqiaosan (Lonicerae and Forsythiae Powder) at Different Time of Later-decoction by Gas Chromatography Mass Spectrometry.

    PubMed

    Shu, Yachun; Chen, Yajun; Qin, Kunming; Liu, Xiao; Cai, Baochang

    2016-01-01

    Yinqiaosan (Lonicerae and Forsythiae Powder), as a famous prescription of Dr. Wu Jutong in Qing dynasty of China, has the effects of diaphoresis cooling, fire-purging, and detoxicaton. It is mainly used in the treatment of influenza, hand-foot-mouth disease, esophagitis, pneumonia, acute tonsillitis, mumps, and other viral infections. It is one of the widely used traditional Chinese medicine prescriptions with proven curative effects in clinical use. To research the material basis of Yinqiaosan decoction when decocting mint, herba schizonepetae in different length of later-decoction time, to find the influence on volatile components of Yinqiaosan decoction decocted later in different length of time, to lay the foundation to further clarify the after-decoction mechanism of Yinqiaosan, and the specification of Yinqiaosan decoction process. Gas chromatography mass spectrometry method is used to analyze the volatile components of Yinqiaosan decoction samples decocted for 0, 3, 5, 8, and 10 min. Later-decocting mint and herba schizonepetae at different time when decocting Yinqiaosan had a significant influence on the volatile components of the solution. 54 different chemical components were identified: 25 were identified when later-decocting the sample for 3 min; 13 were identified when later-decocting the sample for 5 min; 11 were identified when later-decocting the sample for 8 min; 7 were identified when later-decocting the sample for 10 min; and 26 were identified when later-decocting the sample for 0 min. There were more volatile components in the sample after-decocted for 3 min. A total of 54 different chemical components were identified in different later-decocting solution samples. These components form the basis of the Yinqiaosan drug effect. The length of later-decoction time of mint and herba schizonepetae was confirmed to be 3 min when decocting Yinqiaosan. Later-decocting mint and herba schizonepetae at different time had a significant influence on the

  12. A Study on the Chemical Compositions of the Yinqiaosan (Lonicerae and Forsythiae Powder) at Different Time of Later-decoction by Gas Chromatography Mass Spectrometry

    PubMed Central

    Shu, Yachun; Chen, Yajun; Qin, Kunming; Liu, Xiao; Cai, Baochang

    2016-01-01

    Background: Yinqiaosan (Lonicerae and Forsythiae Powder), as a famous prescription of Dr. Wu Jutong in Qing dynasty of China, has the effects of diaphoresis cooling, fire-purging, and detoxicaton. It is mainly used in the treatment of influenza, hand-foot-mouth disease, esophagitis, pneumonia, acute tonsillitis, mumps, and other viral infections. It is one of the widely used traditional Chinese medicine prescriptions with proven curative effects in clinical use. Objective: To research the material basis of Yinqiaosan decoction when decocting mint, herba schizonepetae in different length of later-decoction time, to find the influence on volatile components of Yinqiaosan decoction decocted later in different length of time, to lay the foundation to further clarify the after-decoction mechanism of Yinqiaosan, and the specification of Yinqiaosan decoction process. Materials and Methods: Gas chromatography mass spectrometry method is used to analyze the volatile components of Yinqiaosan decoction samples decocted for 0, 3, 5, 8, and 10 min. Results: Later-decocting mint and herba schizonepetae at different time when decocting Yinqiaosan had a significant influence on the volatile components of the solution. 54 different chemical components were identified: 25 were identified when later-decocting the sample for 3 min; 13 were identified when later-decocting the sample for 5 min; 11 were identified when later-decocting the sample for 8 min; 7 were identified when later-decocting the sample for 10 min; and 26 were identified when later-decocting the sample for 0 min. There were more volatile components in the sample after-decocted for 3 min. A total of 54 different chemical components were identified in different later-decocting solution samples. These components form the basis of the Yinqiaosan drug effect. Conclusions: The length of later-decoction time of mint and herba schizonepetae was confirmed to be 3 min when decocting Yinqiaosan. SUMMARY Later-decocting mint and

  13. PCR methodology as a valuable tool for identification of endodontic pathogens.

    PubMed

    Siqueira, José F; Rôças, Isabela N

    2003-07-01

    This paper reviews the principles of polymerase chain reaction (PCR) methodology, its application in identification of endodontic pathogens and the perspectives regarding the knowledge to be reached with the use of this highly sensitive, specific and accurate methodology as a microbial identification test. Studies published in the medical, dental and biological literature. Evaluation of published epidemiological studies examining the endodontic microbiota through PCR methodology. PCR technology has enabled the detection of bacterial species that are difficult or even impossible to culture as well as cultivable bacterial strains showing a phenotypically divergent or convergent behaviour. Moreover, PCR is more rapid, much more sensitive, and more accurate when compared with culture. Its use in endodontics to investigate the microbiota associated with infected root canals has expanded the knowledge on the bacteria involved in the pathogenesis of periradicular diseases. For instance, Tannerella forsythensis (formerly Bacteroides forsythus), Treponema denticola, other Treponema species, Dialister pneumosintes, and Prevotella tannerae were detected in infected root canals for the first time and in high prevalence when using PCR analysis. The diversity of endodontic microbiota has been demonstrated by studies using PCR amplification, cloning and sequencing of the PCR products. Moreover, other fastidious bacterial species, such as Porphyromonas endodontalis, Porphyromonas gingivalis and some Eubacterium spp., have been reported in endodontic infections at a higher prevalence than those reported by culture procedures.

  14. Bacterial profile of aggressive periodontitis in Morocco: a cross-sectional study.

    PubMed

    Chahboun, Hanane; Arnau, Maria Minguez; Herrera, David; Sanz, Mariano; Ennibi, Oum Keltoum

    2015-02-24

    Aggressive periodontitis (AgP) is one of the most severe forms of periodontal diseases. In Morocco, Aggregatibacter actinomycetemcomitans has been strongly associated with AgP, however limited knowledge is available about the implication of other periodontal pathogens in this entity. Therefore, the main aim of this study was to evaluate the composition of the subgingival microbiota in Moroccan patients with AgP. Subgingival plaque samples were collected from 50 aggressive, 13 localized and 37 generalized periodontitis patients. Samples from 20 chronic periodontitis (ChP) patients were taken as controls. Samples collected from the four deepest periodontal pockets in each patient were pooled in pre-reduced transport fluid and examined by culture. A. actinomycetemcomitans was significantly more frequent (p = 0.004) in generalised AgP compared to ChP, and Porphyromonas gingivalis was less prevalent in localized AgP, when compared with generalized AgP (p = 0.040) or ChP (p = 0.016). Prevotella intermedia, Fusobacterium nucleatum and Tannerella forsythia were also frequently detected in all groups. Mean proportions of A. actinomycetemcomitans were significantly higher in AgP groups, when compared to ChP, and generalized AgP patients harbored significantly higher proportions of P. gingivalis and T. forsythia, when compared to localized AgP or ChP. A. actinomycetemcomitans, P. gingivalis, T. forsythia, P. intermedia and F. nucleatum were frequently detected in this Moroccan population with AgP. Differences in frequency of detection, counts and proportions of A. actinomycetemcomitans, P. gingivalis and T. forsythia suggests the presence of distinct microbiological profiles for localized AgP, generalized AgP and ChP patients.

  15. Periodontal disease-associated micro-organisms in peri-menopausal and post-menopausal women using or not using hormone replacement therapy. A two-year follow-up study.

    PubMed

    Tarkkila, Laura; Kari, Kirsti; Furuholm, Jussi; Tiitinen, Aila; Meurman, Jukka H

    2010-04-29

    Despite conflicting results on the use of hormone replacement therapy (HRT) there is no doubt that many women benefit from it. Women using HRT are known to be more health conscious in general with putative positive implications in the mouth. However, we observed recently in our cohort hardly any difference in oral health status between HRT-users and non-users. There are only a few studies about HRT and oral microbiota. We hypothesized that counts of periodontal micro-organisms are lower in health-conscious HRT-users than non-users. Two-year open follow-up study was conducted on originally 200 HRT-users and 200 non-users from age cohorts of 50-58 years. After clinical examination pooled subgingival plaque samples were taken for polymerase chain reaction analyses. The results of finally 135 women meeting the inclusion criteria were analyzed with cross-tabulation and chi-square test. Explanatory factors were studied by step-wise logistic regression analysis. In HRT group, the numbers of positive samples for Porphyromonas gingivalis (P. gingivalis, p < 0.07), Prevotella intermedia (P. intermedia, p < 0.05)and Tannerella forsythia (T. forsythia, p < 0.01) decreased in women with >or= 4-mm-deep pockets. Respectively in HRT users with >or= 6-mm-deep pockets the numbers of positive samples for P. gingivalis (p < 0.05) and T. forsythia (p < 0.01) were decreased. No corresponding differences were observed in the non-HRT group. In logistic regression, the existence of deep periodontal pockets explained the majority of cases harboring specific micro-organisms in both groups. Although use of HRT did not correlate with periodontal health status, HRT led to decreasing numbers of positive samples of the periodontal pathogens P. gingivalis and T. forsythia. Further studies with longer observation time are needed to observe the clinical relevance of the results.

  16. Pathogen Phytosensing: Plants to Report Plant Pathogens.

    PubMed

    Mazarei, Mitra; Teplova, Irina; Hajimorad, M Reza; Stewart, C Neal

    2008-04-14

    Real-time systems that provide evidence of pathogen contamination in crops can be an important new line of early defense in agricultural centers. Plants possess defense mechanisms to protect against pathogen attack. Inducible plant defense is controlled by signal transduction pathways, inducible promoters and cis-regulatory elements corresponding to key genes involved in defense, and pathogen-specific responses. Identified inducible promoters and cis-acting elements could be utilized in plant sentinels, or 'phytosensors', by fusing these to reporter genes to produce plants with altered phenotypes in response to the presence of pathogens. Here, we have employed cis-acting elements from promoter regions of pathogen inducible genes as well as those responsive to the plant defense signal molecules salicylic acid, jasmonic acid, and ethylene. Synthetic promoters were constructed by combining various regulatory elements supplemented with the enhancer elements from the Cauliflower mosaic virus (CaMV) 35S promoter to increase basal level of the GUS expression. The inducibility of each synthetic promoter was first assessed in transient expression assays using Arabidopsis thaliana protoplasts and then examined for efficacy in stably transgenic Arabidopsis and tobacco plants. Histochemical and fluorometric GUS expression analyses showed that both transgenic Arabidopsis and tobacco plants responded to elicitor and phytohormone treatments with increased GUS expression when compared to untreated plants. Pathogen-inducible phytosensor studies were initiated by analyzing the sensitivity of the synthetic promoters against virus infection. Transgenic tobacco plants infected with Alfalfa mosaic virus showed an increase in GUS expression when compared to mock-inoculated control plants, whereas Tobacco mosaic virus infection caused no changes in GUS expression. Further research, using these transgenic plants against a range of different pathogens with the regulation of detectable

  17. Oral microflora and periodontal disease: new technology for diagnosis in dentistry

    PubMed Central

    Carinci, Francesco; Scapoli, Luca; Girardi, Ambra; Cura, Francesca; Lauritano, Dorina; Nardi, Gianna Maria; Palmieri, Annalisa

    2013-01-01

    Summary Periodontitis is a disease that affects and destroys the tissues that support teeth. Tissues damage results from a prolonged inflammatory response to an ecological shift in the composition of subgingival biofilms. Three bacterial species that constitute the red complex group, Porphyromonas gingivalis, Tannerella forsythia, and Treponema denticola, are considered the main pathogens involved in periodontitis. In the present study a real-time PCR based assay was designed to detect and quantify red complex species, then used to investigate 146 periodontal pocket samples from 66 periodontitis patients and 80 controls. Results demonstrated a significant higher prevalence of red complex species and increased amount of P. gingivalis and T. denticola in periodontal pocket of periodontitis patients. PMID:23991267

  18. Life in a Diverse Oral Community – Strategies for Oxidative Stress Survival

    PubMed Central

    Henry, Leroy G.; Boutrin, Marie-Claire; Aruni, Wilson; Robles, Antonette; Ximinies, Alexia; Fletcher, Hansel M.

    2015-01-01

    Background While the oral cavity harbors more than 680 bacterial species, the interaction and association of selected bacterial species play a role in periodontal diseases. Bacterial species including Porphyromonas gingivalis, Treponema denticola and Tannerella forsythia, a consortium previously designated as the “red complex” is now being expanded to include other new emerging pathogens that are significantly associated with periodontal disease. Highlight In addition to novel mechanisms for oxidative resistance of individual species, community dynamics may lead to an overall strategy for survival in the inflammatory environment of the periodontal pocket. Complex systems controlled by response regulators protect against oxidative and nitrosative stress. Conclusion The combination of these multifaceted strategies would provide a comprehensive defense and support system against the repetitive host immune response to promote microbial persistence and disease. PMID:26744578

  19. Plant Pathogenic Fungi.

    PubMed

    Doehlemann, Gunther; Ökmen, Bilal; Zhu, Wenjun; Sharon, Amir

    2017-01-01

    Fungi are among the dominant causal agents of plant diseases. To colonize plants and cause disease, pathogenic fungi use diverse strategies. Some fungi kill their hosts and feed on dead material (necrotrophs), while others colonize the living tissue (biotrophs). For successful invasion of plant organs, pathogenic development is tightly regulated and specialized infection structures are formed. To further colonize hosts and establish disease, fungal pathogens deploy a plethora of virulence factors. Depending on the infection strategy, virulence factors perform different functions. While basically all pathogens interfere with primary plant defense, necrotrophs secrete toxins to kill plant tissue. In contrast, biotrophs utilize effector molecules to suppress plant cell death and manipulate plant metabolism in favor of the pathogen. This article provides an overview of plant pathogenic fungal species and the strategies they use to cause disease.

  20. Prevalence of selected bacterial named species and uncultivated phylotypes in endodontic abscesses from two geographic locations.

    PubMed

    Rôças, Isabela N; Baumgartner, J Craig; Xia, Tian; Siqueira, José F

    2006-12-01

    Evidence is mounting that the prevalence of some putative endodontic pathogens can significantly vary according to the geographic location in which samples were taken. This study aimed to provide additional knowledge on this subject by comparing the frequencies of 10 selected candidate endodontic pathogens in samples of acute apical abscesses obtained from two distinct geographic locations; Portland, OR, and Rio de Janeiro, Brazil. DNA was extracted from aspirates and used as template in nested PCR assays using 16S rRNA gene taxon-specific oligonucleotide primers. Of the target species/phylotypes, Treponema denticola (73% of the cases), Porphyromonas endodontalis (70%), and Tannerella forsythia (57%) were the most prevalent taxa found in Brazilian samples. Dialister invisus (70% of the cases), P. endodontalis (63%) and Dialister pneumosintes (55%) were the most frequent taxa in the Portland, OR samples. Data analysis revealed that T. denticola and T. forsythia were significantly more detected in Brazilian samples than in the Portland, OR samples. Although D. invisus, Filifactor alocis, and Synergistes oral clone W090 were detected in many more samples from the Portland, OR patients, differences were not found to be statistically significant. These findings confirmed that some bacterial taxa can markedly differ in the frequencies they occur in samples from different locations. It remains to be clarified whether this observation translates into relevant therapeutic implications.

  1. BACTERIAL WATERBORNE PATHOGENS

    EPA Science Inventory

    Bacterial pathogens are examples of classical etiological agents of waterborne disease. While these agents no longer serve as major threats to U.S. water supplies, they are still important pathogens in areas with substandard sanitation and poor water treatment facilities. In th...

  2. Emerging Escherichia Pathogen

    PubMed Central

    Permpalung, Nitipong; Sentochnik, Deborah E.

    2013-01-01

    Escherichia hermannii was first identified as a new species in 1982. It has rarely been reported as a human pathogen. We report the first case of E. hermannii as the sole pathogen in a catheter-related bloodstream infection. PMID:23740732

  3. Plant pathogen resistance

    DOEpatents

    Greenberg, Jean T; Jung, Ho Won; Tschaplinski, Timothy

    2012-11-27

    Azelaic acid or its derivatives or analogs induce a robust and a speedier defense response against pathogens in plants. Azelaic acid treatment alone does not induce many of the known defense-related genes but activates a plant's defense signaling upon pathogen exposure.

  4. BACTERIAL WATERBORNE PATHOGENS

    EPA Science Inventory

    Bacterial pathogens are examples of classical etiological agents of waterborne disease. While these agents no longer serve as major threats to U.S. water supplies, they are still important pathogens in areas with substandard sanitation and poor water treatment facilities. In th...

  5. Plant pathogen resistance

    DOEpatents

    Greenberg, Jean T.; Jung, Ho Won; Tschaplinski, Timothy

    2015-10-20

    Azelaic acid or its derivatives or analogs induce a robust and a speedier defense response against pathogens in plants. Azelaic acid treatment alone does not induce many of the known defense-related genes but activates a plant's defense signaling upon pathogen exposure.

  6. Emerging foodborne pathogens

    USDA-ARS?s Scientific Manuscript database

    The emergence of new foodborne pathogens is due to a number of factors. An important factor is the globalization of the food supply with the possibility of the introduction of foodborne pathogens from other countries. Animal husbandry, food production, food processing, and food distribution system...

  7. Identification of Candidate Periodontal Pathogens and Beneficial Species by Quantitative 16S Clonal Analysis†

    PubMed Central

    Kumar, Purnima S.; Griffen, Ann L.; Moeschberger, Melvin L.; Leys, Eugene J.

    2005-01-01

    Most studies of the bacterial etiology of periodontitis have used either culture-based or targeted DNA approaches, and so it is likely that pathogens remain undiscovered. The purpose of this study was to use culture-independent, quantitative analysis of biofilms associated with chronic periodontitis and periodontal health to identify pathogens and beneficial species. Samples from subjects with periodontitis and controls were analyzed using ribosomal 16S cloning and sequencing. Several genera, many of them uncultivated, were associated with periodontitis, the most numerous of which were gram positive, including Peptostreptococcus and Filifactor. The genera Megasphaera and Desulfobulbus were elevated in periodontitis, and the levels of several species or phylotypes of Campylobacter, Selenomonas, Deferribacteres, Dialister, Catonella, Tannerella, Streptococcus, Atopobium, Eubacterium, and Treponema were elevated in disease. Streptococcus and Veillonella spp. were found in high numbers in all samples and accounted for a significantly greater fraction of the microbial community in healthy subjects than in those with periodontitis. The microbial profile of periodontal health also included the less-abundant genera Campylobacter, Abiotrophia, Gemella, Capnocytophaga, and Neisseria. These newly identified candidates outnumbered Porphyromonas gingivalis and other species previously implicated as periodontopathogens, and it is not clear if newly identified and more numerous species may play a more important role in pathogenesis. Finally, more differences were found in the bacterial profile between subjects with periodontitis and healthy subjects than between deep and shallow sites within the same subject. This suggests that chronic periodontitis is the result of a global perturbation of the oral bacterial ecology rather than a disease-site specific microbial shift. PMID:16081935

  8. Screening for periodontopathogenic bacteria in severe chronic periodontitis in a Moroccan population.

    PubMed

    Benrachadi, L; Bouziane, A; Azziman, Z; Bouziane-Ouartini, F; Ennibi, O

    2012-12-01

    Bacteria play an important role in destructive periodontitis. The aim of this study was to screen for five highly pathogenic bacteria: Aggregatibacter actinomycetemcomitans, Porphyromonas gingivalis, Prevotella intermedia, Tannerella forsythia, and Treponema denticola, in Moroccan patients presenting with severe chronic periodontitis and to compare results with those of patients presenting with severe aggressive periodontitis. Twenty-three patients were included at the periodontology unit (School of dental medicine, University Mohammed 5 Souissi, Rabat, Morocco). The study was made on two groups: a test group of patients presenting with severe chronic periodontitis, and a control group of patients presenting with severe aggressive periodontitis. Plaque sampling was performed at the four deepest sites in each patient. The five studied bacteria were detected by PCR. The prevalence of A. actinomycetemcomitans and T. denticola was relatively low in the test group (13.3% and 20% respectively) compared with controls (37.5% and 37.5% respectively), without any statistical difference between the two groups. Furthermore, P. gingivalis and T. forsythia were frequently detected in both groups, without any statistical difference. The results of this preliminary study proved the presence of the studied periodontopathogenic bacteria both in severe chronic periodontitis and severe aggressive periodontitis. Copyright © 2012 Elsevier Masson SAS. All rights reserved.

  9. Stomata and pathogens

    PubMed Central

    Gudesblat, Gustavo E; Torres, Pablo S

    2009-01-01

    Bacteria and fungi are capable of triggering stomatal closure through pathogen-associated molecular patterns (PAMPs), which prevents penetration through these pores. Therefore, the stomata can be considered part of the plant innate immune response. Some pathogens have evolved mechanisms to evade stomatal defense. The bacterial pathogen Xanthomonas campestris pv. campestris (Xcc), which infects plants of the Brassicaceae family mainly through hydathodes, has also been reported to infect plants through stomata. A recent report shows that penetration of Xcc in Arabidopsis leaves through stomata depends on a secreted small molecule whose synthesis is under control of the rpf/diffusible signal factor (DSF) cell-to-cell signaling system, which also controls genes involved in biofilm formation and pathogenesis. The same reports shows that Arabidopsis ROS- and PAMP-activated MAP kinase 3 (MPK3) is essential for stomatal innate response. Other recent and past findings about modulation of stomatal behaviour by pathogens are also discussed. In all, these findings support the idea that PAMP-triggered stomatal closure might be a more effective and widespread barrier against phytopathogens than previously thought, which has in turn led to the evolution in pathogens of several mechanisms to evade stomatal defense. PMID:20514224

  10. Bioterrorism: pathogens as weapons.

    PubMed

    Anderson, Peter D; Bokor, Gyula

    2012-10-01

    Biowarfare has been used for centuries. The use of biological weapons in terrorism remains a threat. Biological weapons include infectious agents (pathogens) and toxins. The most devastating bioterrorism scenario would be the airborne dispersal of pathogens over a concentrated population area. Characteristics that make a specific pathogen a high-risk for bioterrorism include a low infective dose, ability to be aerosolized, high contagiousness, and survival in a variety of environmental conditions. The most dangerous potential bioterrorism agents include the microorganisms that produce anthrax, plague, tularemia, and smallpox. Other diseases of interest to bioterrorism include brucellosis, glanders, melioidosis, Q fever, and viral encephalitis. Food safety and water safety threats are another area of concern.

  11. Evolution of intracellular pathogens.

    PubMed

    Casadevall, Arturo

    2008-01-01

    The evolution of intracellular pathogens is considered in the context of ambiguities in basic definitions and the diversity of host-microbe interactions. Intracellular pathogenesis is a subset of a larger world of host-microbe interactions that includes amoeboid predation and endosymbiotic existence. Intracellular pathogens often reveal genome reduction. Despite the uniqueness of each host-microbe interaction, there are only a few general solutions to the problem of intracellular survival, especially in phagocytic cells. Similarities in intracellular pathogenic strategies between phylogenetically distant microbes suggest convergent evolution. For discerning such patterns, it is useful to consider whether the microbe is acquired from another host or directly from the environment. For environmentally acquired microbes, biotic pressures, such as amoeboid predators, may select for the capacity for virulence. Although often viewed as a specialized adaptation, the capacity for intracellular survival may be widespread among microbes, thus questioning whether the intracellular lifestyle warrants a category of special distinctiveness.

  12. Candida albicans pathogenicity mechanisms

    PubMed Central

    Mayer, François L.; Wilson, Duncan; Hube, Bernhard

    2013-01-01

    The polymorphic fungus Candida albicans is a member of the normal human microbiome. In most individuals, C. albicans resides as a lifelong, harmless commensal. Under certain circumstances, however, C. albicans can cause infections that range from superficial infections of the skin to life-threatening systemic infections. Several factors and activities have been identified which contribute to the pathogenic potential of this fungus. Among them are molecules which mediate adhesion to and invasion into host cells, the secretion of hydrolases, the yeast-to-hypha transition, contact sensing and thigmotropism, biofilm formation, phenotypic switching and a range of fitness attributes. Our understanding of when and how these mechanisms and factors contribute to infection has significantly increased during the last years. In addition, novel virulence mechanisms have recently been discovered. In this review we present an update on our current understanding of the pathogenicity mechanisms of this important human pathogen. PMID:23302789

  13. Bloodborne Pathogens Program

    NASA Technical Reports Server (NTRS)

    Blasdell, Sharon

    1993-01-01

    The final rule on the Occupational Exposure to Bloodborne Pathogens was published in the Federal Register on Dec. 6, 1991. This Standard, 29 CFR Part 1910.130, is expected to prevent 8,900 hepatitis B infections and nearly 200 deaths a year in healthcare workers in the U.S. The Occupational Medicine and Environmental Health Services at KSC has been planning to implement this standard for several years. Various aspects of this standard and its Bloodborne Pathogens Program at KSC are discussed.

  14. Waterborne Pathogens: The Protozoans.

    PubMed

    Moss, Joseph Anthony

    2016-09-01

    Waterborne diseases associated with polluted recreational and potable waters have been documented for more than a century. Key microbial protozoan parasites, such as Cryptosporidium and Giardia, are causative agents for gastrointestinal disease worldwide. Although not a first-line diagnostic approach for these diseases, medical imaging, such as radiography, computed tomography, magnetic resonance imaging, ultrasonography, and nuclear medicine technologies, can be used to evaluate patients with long-term effects. This article describes protozoan pathogens that affect human health, treatment of common waterborne pathogen-related diseases, and associated medical imaging.

  15. Influence of Type 2 Diabetes on Prevalence of Key Periodontal Pathogens, Salivary Matrix Metalloproteinases, and Bone Remodeling Markers in Sudanese Adults with and without Chronic Periodontitis

    PubMed Central

    Mohamed, Hasaan Gassim; Idris, Shaza Bushra; Mustafa, Manal; Ahmed, Mutaz Faisal; Åstrøm, Anne Nordrehaug; Mustafa, Kamal; Ibrahim, Salah Osman

    2016-01-01

    This study compared the influence of type 2 diabetes on the occurrence of six periodontal pathogens in plaque samples of patients with and without chronic periodontitis. Levels of salivary MMP-8, MMP-9, RANKL, and OPG were also investigated. The study enrolled 31 patients with type 2 diabetes and chronic periodontitis (DM + CP), 29 with chronic periodontitis (CP), and 20 with type 2 diabetes (DM). Questionnaire-guided interviews were conducted and plaque index, bleeding on probing, and pocket depth were recorded. Polymerase chain reaction (PCR) was utilized to determine the prevalence of the bacteria. The levels of salivary molecules were determined by enzyme immunosorbent assay (ELISA). The CP group had the highest prevalence of P. gingivalis (81.5%), followed by the DM + CP (59.3%) and DM (55.0%) groups (P > 0.05). Similar trends were observed for P. intermedia and T. denticola. The prevalence of T. forsythia was 100% in both periodontitis groups compared to 90% in the DM group. There were no significant differences between the groups regarding the concentrations of MMP-8, MMP-9, or OPG. RANKL concentrations were below the detection limit. Our data show that type 2 diabetes has no significant influence on the prevalence of the investigated periodontal pathogens, or the levels of salivary MMP-8, MMP-9, and OPG. PMID:26989414

  16. Influence of Type 2 Diabetes on Prevalence of Key Periodontal Pathogens, Salivary Matrix Metalloproteinases, and Bone Remodeling Markers in Sudanese Adults with and without Chronic Periodontitis.

    PubMed

    Mohamed, Hasaan Gassim; Idris, Shaza Bushra; Mustafa, Manal; Ahmed, Mutaz Faisal; Åstrøm, Anne Nordrehaug; Mustafa, Kamal; Ibrahim, Salah Osman

    2016-01-01

    This study compared the influence of type 2 diabetes on the occurrence of six periodontal pathogens in plaque samples of patients with and without chronic periodontitis. Levels of salivary MMP-8, MMP-9, RANKL, and OPG were also investigated. The study enrolled 31 patients with type 2 diabetes and chronic periodontitis (DM + CP), 29 with chronic periodontitis (CP), and 20 with type 2 diabetes (DM). Questionnaire-guided interviews were conducted and plaque index, bleeding on probing, and pocket depth were recorded. Polymerase chain reaction (PCR) was utilized to determine the prevalence of the bacteria. The levels of salivary molecules were determined by enzyme immunosorbent assay (ELISA). The CP group had the highest prevalence of P. gingivalis (81.5%), followed by the DM + CP (59.3%) and DM (55.0%) groups (P > 0.05). Similar trends were observed for P. intermedia and T. denticola. The prevalence of T. forsythia was 100% in both periodontitis groups compared to 90% in the DM group. There were no significant differences between the groups regarding the concentrations of MMP-8, MMP-9, or OPG. RANKL concentrations were below the detection limit. Our data show that type 2 diabetes has no significant influence on the prevalence of the investigated periodontal pathogens, or the levels of salivary MMP-8, MMP-9, and OPG.

  17. Detection of five potentially periodontal pathogenic bacteria in peri-implant disease: A comparison of PCR and real-time PCR.

    PubMed

    Schmalz, Gerhard; Tsigaras, Sandra; Rinke, Sven; Kottmann, Tanja; Haak, Rainer; Ziebolz, Dirk

    2016-07-01

    The aim of this study was to compare the microbial analysis methods of polymerase chain reaction (PCR) and real-time PCR (RT-PCR) in terms of detection of five selected potentially periodontal pathogenic bacteria in peri-implant disease. Therefore 45 samples of healthy, mucositis and peri-implantitis (n = 15 each) were assessed according to presence of the following bacteria using PCR (DNA-strip technology) and RT-PCR (fluorescent dye SYBR green-system): Aggregatibacter actinomycetemcomitans (Aa), Porphyromonas gingivalis (Pg), Treponema denticola (Td), Tanerella forsythia (Tf), and Fusobacterium nucleatum (Fn). There were no significant correlations between the bacterial and disease patterns, so the benefit of using microbiological tests for the diagnosis of peri-implant diseases is questionable. Correlations between the methods were highest for Tf (Kendall's Tau: 0.65, Spearman: 0.78), Fn (0.49, 0.61) and Td (0.49, 0.59). For Aa (0.38, 0.42) and Pg (0.04, 0.04), lower correlation values were detected. Accordingly, conventional semi-quantitative PCR seems to be sufficient for analyzing potentially periodontal pathogenic bacterial species.

  18. Ionic Liquid-Based Ultrasonic-Assisted Extraction of Forsythosides from the Leaf of Forsythia suspensa (Thunb.) Vahl and Subsequent Separation and Purification by High-Speed Counter-Current Chromatography.

    PubMed

    Sun, Yinshi; Hou, Zhiguang; Liu, Zhengbo; Wang, Jianhua

    2016-09-01

    An ionic liquid-based ultrasonic-assisted extraction (ILUAE) method was developed for the extraction of the two forsythosides, namely forsythosides I and A from the leaf of Forsythia suspensa (Thunb.) Vahl. Three kinds of l-alkyl-3-methylimidazolium ionic liquids with different alkyl chain and anion were investigated. The results indicated that ionic liquids showed remarkable effects on the extraction yields of forsythosides. In addition, several ILUAE ultrasonic parameters, such as the solvent concentration, solvent to solid ratio and extraction time have been optimized. Under these optimal conditions (e.g., with 0.6 M [C6MIM]Br, solvent to solid ratio of 15 mL/g and extraction time of 10 min), this approach gained the highest extraction yields of forsythoside I (0.89%) and forsythoside A (10.74%). Meanwhile, forsythosides in the ILUAE extract were separated and purified successfully through the high-speed counter-current chromatography with a two-phase solvent system consisting of ethyl acetate-ethanol-acetic acid-water (4 : 1 : 0.25 : 6, v/v). 5.4 mg of forsythoside I and 59.7 mg of forsythoside A were obtained from 120 mg of the prepurified sample in one-step separation, with the purity of 96.1 and 97.9%, respectively, as determined by high-performance liquid chromatography. Their structures were identified by (1)H nuclear magnetic resonance (NMR) and (13)C NMR.

  19. DISINFECTION OF EMERGING PATHOGENS

    EPA Science Inventory

    There is a growing awareness of the need to control waterborne microbial pathogens. This presentation will concentate on the role of chemical inactivation, using chlorine, chloramines and ozone as a means of controlling bacterial and protozoan species. Information will be present...

  20. Marine Viral Pathogens.

    DTIC Science & Technology

    2007-11-02

    toxin producing microalgae (Raphidophyceae). Although we have not definitively shown that the pathogen is viral, it has many characteristics that...Society America, Miami, FL, June 1994. 40.Hennes, K.P. and C.A. Suttle. 1994. The use of cyanine dyes for quantifying free viruses in natural water

  1. Pathogenicity and virulence

    USDA-ARS?s Scientific Manuscript database

    Many pathogenic microorganisms are host-specific in that they parasitize only one or a few animal species. For example, the cause of equine strangles, Streptococcus equi subspecies equi, is essentially limited to infection of horses. Others—certain Salmonella serotypes, for example—have a broad host...

  2. Leafhopper viral pathogens

    USDA-ARS?s Scientific Manuscript database

    Four newly discovered viral pathogens in leafhopper vectors of Pierce’s disease of grapes, have been shown to replicate in sharpshooter leafhoppers; the glassy-winged sharpshooter, GWSS, Homalodisca vitripennis, and Oncometopia nigricans (Hemiptera: Cicadellidae). The viruses were classified as memb...

  3. DISINFECTION OF EMERGING PATHOGENS

    EPA Science Inventory

    There is a growing awareness of the need to control waterborne microbial pathogens. This presentation will concentate on the role of chemical inactivation, using chlorine, chloramines and ozone as a means of controlling bacterial and protozoan species. Information will be present...

  4. PATHOGEN EQUIVALENCY COMMITTEE (PEC)

    EPA Science Inventory

    The U.S. Environmental Protection Agency created the PEC in 1985 to make recommendations to EPA and State managers on the equivalency of unproven sewage sludge disinfection technologies/processes to either a Process to Significantly Reduce Pathogens (PSRP) or a Process to Further...

  5. PATHOGEN EQUIVALENCY COMMITTEE (PEC)

    EPA Science Inventory

    The U.S. Environmental Protection Agency created the PEC in 1985 to make recommendations to EPA and State managers on the equivalency of unproven sewage sludge disinfection technologies/processes to either a Process to Significantly Reduce Pathogens (PSRP) or a Process to Further...

  6. The association between detectable plasmatic human immunodeficiency virus (HIV) viral load and different subgingival microorganisms in Brazilian adults with HIV: a multilevel analysis.

    PubMed

    Pereira, Viviane Tiago; Pavan, Priscila; Souza, Rodrigo Carvalho; Souto, Renata; Vettore, Mario Vianna; Torres, Sandra Regina; Colombo, Ana Paula Vieira; de Uzeda, Milton; Sansone, Carmelo; Gonçalves, Lucio Souza

    2014-05-01

    This study investigates the association between detectable plasmatic human immunodeficiency virus (HIV) viral load (HVL) and high levels of periodontal- and non-periodontal-related microorganisms in the subgingival microbiota of individuals with HIV. Thirty-seven individuals with HIV were divided into two groups: 1) detectable HVL (n = 15); and 2) undetectable HVL (n = 22). Subgingival biofilm samples were obtained, and the levels of 35 microbial species were determined by the checkerboard DNA-DNA hybridization method. Periodontal clinical measures and laboratory and sociodemographic data were also registered. χ(2) test, Fisher exact test, and Mann-Whitney U test were used to compare groups. Multilevel ordinal regression models were used to test the association between HVL and the levels of 35 microbial species in subgingival biofilm, adjusted for confounders. Of the 35 species studied, 11 (31.4%) showed higher mean levels in the detectable HVL group than undetectable HVL group (P <0.001). These species included Actinomyces naeslundii II, Actinomyces israelii, Actinomyces odontolyticus, Veillonella parvula, Capnocytophaga gingivalis, Eikenella corrodens, Campylobacter concisus, Porphyromonas gingivalis, Tannerella forsythia, Treponema denticola, and Candida albicans. Significant associations between detectable HVL and high levels of microorganisms, adjusted for confounders, were observed for A. naeslundii I, Actinomyces gerencseriae, C. gingivalis, E. corrodens, C. concisus, Prevotella nigrescens, T. forsythia, and Dialister pneumosintes. Detectable plasmatic HVL in individuals with HIV was associated with elevated levels of known periodontal pathogens, such as P. nigrescens, T. forsythia, and E. corrodens, as well as C. concisus, C. gingivalis, and D. pneumosintes in the subgingival biofilm.

  7. Outer Membrane Vesicles Prime and Activate Macrophage Inflammasomes and Cytokine Secretion In Vitro and In Vivo

    PubMed Central

    Cecil, Jessica D.; O’Brien-Simpson, Neil M.; Lenzo, Jason C.; Holden, James A.; Singleton, William; Perez-Gonzalez, Alexis; Mansell, Ashley; Reynolds, Eric C.

    2017-01-01

    Outer membrane vesicles (OMVs) are proteoliposomes blebbed from the surface of Gram-negative bacteria. Chronic periodontitis is associated with an increase in subgingival plaque of Gram-negative bacteria, Porphyromonas gingivalis, Treponema denticola, and Tannerella forsythia. In this study, we investigated the immune-modulatory effects of P. gingivalis, T. denticola, and T. forsythia OMVs on monocytes and differentiated macrophages. All of the bacterial OMVs were phagocytosed by monocytes, M(naïve) and M(IFNγ) macrophages in a dose-dependent manner. They also induced NF-κB activation and increased TNFα, IL-8, and IL-1β cytokine secretion. P. gingivalis OMVs were also found to induce anti-inflammatory IL-10 secretion. Although unprimed monocytes and macrophages were resistant to OMV-induced cell death, lipopolysaccharide or OMV priming resulted in a significantly reduced cell viability. P. gingivalis, T. denticola, and T. forsythia OMVs all activated inflammasome complexes, as monitored by IL-1β secretion and ASC speck formation. ASC was critical for OMV-induced inflammasome formation, while AIM2−/− and Caspase-1−/− cells had significantly reduced inflammasome formation and NLRP3−/− cells exhibited a slight reduction. OMVs were also found to provide both priming and activation of the inflammasome complex. High-resolution microscopy and flow cytometry showed that P. gingivalis OMVs primed and activated macrophage inflammasomes in vivo with 80% of macrophages exhibiting inflammasome complex formation. In conclusion, periodontal pathogen OMVs were found to have significant immunomodulatory effects upon monocytes and macrophages and should therefore influence pro-inflammatory host responses associated with disease. PMID:28890719

  8. Hemipterans as plant pathogens.

    PubMed

    Kaloshian, Isgouhi; Walling, Linda L

    2005-01-01

    Integration of the tools of genetics, genomics, and biochemistry has provided new approaches for identifying genes responding to herbivory. As a result, a picture of the complexity of plant-defense signaling to different herbivore feeding guilds is emerging. Plant responses to hemipteran insects have substantial overlap with responses mounted against microbial pathogens, as seen in changes in RNA profiles and emission of volatiles. Responses to known defense signals and characterization of the signaling pathways controlled by the first cloned insect R gene (Mi-1) indicate that perception and signal transduction leading to resistance may be similar to plant-pathogen interactions. Additionally, novel signaling pathways are emerging as important components of plant defense to insects. The availability of new tools and approaches will further enhance our understanding of the nature of defense in plant-hemipteran interactions.

  9. WATERBORNE PATHOGENS IN URBAN WATERSHEDS

    EPA Science Inventory

    Pathogens are microorganisms that can cause sickness or even death. A serious concern for managers of water resources, pathogens in the urban environment easily enter waters through a number of pathways, including discharge of inadequately treated sewage, stormwater runoff, combi...

  10. WATERBORNE PATHOGENS IN URBAN WATERSHEDS

    EPA Science Inventory

    Pathogens are microorganisms that can cause sickness or even death. A serious concern for managers of water resources, pathogens in the urban environment easily enter waters through a number of pathways, including discharge of inadequately treated sewage, stormwater runoff, combi...

  11. Multiplex detection of agricultural pathogens

    DOEpatents

    Siezak, Thomas R.; Gardner, Shea; Torres, Clinton; Vitalis, Elizabeth; Lenhoff, Raymond J.

    2013-01-15

    Described are kits and methods useful for detection of agricultural pathogens in a sample. Genomic sequence information from agricultural pathogens was analyzed to identify signature sequences, e.g., polynucleotide sequences useful for confirming the presence or absence of a pathogen in a sample. Primer and probe sets were designed and optimized for use in a PCR based, multiplexed Luminex assay and/or an array assay to successfully identify the presence or absence of pathogens in a sample.

  12. Multiplex detection of agricultural pathogens

    DOEpatents

    McBride, Mary Teresa; Slezak, Thomas Richard; Messenger, Sharon Lee

    2010-09-14

    Described are kits and methods useful for detection of seven agricultural pathogens (BPSV; BHV; BVD; FMDV; BTV; SVD; and VESV) in a sample. Genomic sequence information from 7 agricultural pathogens was analyzed to identify signature sequences, e.g., polynucleotide sequences useful for confirming the presence or absence of a pathogen in a sample. Primer and probe sets were designed and optimized for use in a PCR based, multiplexed Luminex assay to successfully identify the presence or absence of pathogens in a sample.

  13. Pathogenicity Islands in Bacterial Pathogenesis

    PubMed Central

    Schmidt, Herbert; Hensel, Michael

    2004-01-01

    In this review, we focus on a group of mobile genetic elements designated pathogenicity islands (PAI). These elements play a pivotal role in the virulence of bacterial pathogens of humans and are also essential for virulence in pathogens of animals and plants. Characteristic molecular features of PAI of important human pathogens and their role in pathogenesis are described. The availability of a large number of genome sequences of pathogenic bacteria and their benign relatives currently offers a unique opportunity for the identification of novel pathogen-specific genomic islands. However, this knowledge has to be complemented by improved model systems for the analysis of virulence functions of bacterial pathogens. PAI apparently have been acquired during the speciation of pathogens from their nonpathogenic or environmental ancestors. The acquisition of PAI not only is an ancient evolutionary event that led to the appearance of bacterial pathogens on a timescale of millions of years but also may represent a mechanism that contributes to the appearance of new pathogens within a human life span. The acquisition of knowledge about PAI, their structure, their mobility, and the pathogenicity factors they encode not only is helpful in gaining a better understanding of bacterial evolution and interactions of pathogens with eukaryotic host cells but also may have important practical implications such as providing delivery systems for vaccination, tools for cell biology, and tools for the development of new strategies for therapy of bacterial infections. PMID:14726454

  14. A Filifactor alocis-centered co-occurrence group associates with periodontitis across different oral habitats

    PubMed Central

    Chen, Hui; Liu, Ying; Zhang, Menghui; Wang, Guoyang; Qi, Zhengnan; Bridgewater, Laura; Zhao, Liping; Tang, Zisheng; Pang, Xiaoyan

    2015-01-01

    Periodontitis is a highly prevalent polymicrobial disease worldwide, yet the synergistic pattern of the multiple oral pathogens involved is still poorly characterized. Here, saliva, supragingival and subgingival plaque samples from periodontitis patients and periodontally healthy volunteers were collected and profiled with 16S rRNA gene pyrosequencing. Different oral habitats harbored significantly different microbiota, and segregation of microbiota composition between periodontitis and health was observed as well. Two-step redundancy analysis identified twenty-one OTUs, including Porphyromonas gingivalis, Tannerella forsythia and Filifactor alocis, as potential pathogens that were significantly associated with periodontitis and with two periodontitis diagnostic parameters (pocket depth and attachment loss) in both saliva and supragingival plaque habitats. Interestingly, pairwise correlation analysis among the 21 OTUs revealed that Filifactor alocis was positively correlated with seven other putative pathogens (R > 0.6, P < 0.05), forming a co-occurrence group that was remarkably enriched in all three habitats of periodontitis patients. This bacterial cluster showed a higher diagnostic value for periodontitis than did any individual potential pathogens, especially in saliva. Thus, our study identified a potential synergistic ecological pattern involving eight co-infecting pathogens across various oral habitats, providing a new framework for understanding the etiology of periodontitis and developing new diagnoses and therapies. PMID:25761675

  15. Preferential Amplification of Pathogenic Sequences.

    PubMed

    Ge, Fang; Parker, Jayme; Chul Choi, Sang; Layer, Mark; Ross, Katherine; Jilly, Bernard; Chen, Jack

    2015-06-11

    The application of next generation sequencing (NGS) technology in the diagnosis of human pathogens is hindered by the fact that pathogenic sequences, especially viral, are often scarce in human clinical specimens. This known disproportion leads to the requirement of subsequent deep sequencing and extensive bioinformatics analysis. Here we report a method we called "Preferential Amplification of Pathogenic Sequences (PATHseq)" that can be used to greatly enrich pathogenic sequences. Using a computer program, we developed 8-, 9-, and 10-mer oligonucleotides called "non-human primers" that do not match the most abundant human transcripts, but instead selectively match transcripts of human pathogens. Instead of using random primers in the construction of cDNA libraries, the PATHseq method recruits these short non-human primers, which in turn, preferentially amplifies non-human, presumably pathogenic sequences. Using this method, we were able to enrich pathogenic sequences up to 200-fold in the final sequencing library. This method does not require prior knowledge of the pathogen or assumption of the infection; therefore, it provides a fast and sequence-independent approach for detection and identification of human viruses and other pathogens. The PATHseq method, coupled with NGS technology, can be broadly used in identification of known human pathogens and discovery of new pathogens.

  16. Ecology of Fungal Plant Pathogens.

    PubMed

    Termorshuizen, Aad J

    2016-12-01

    Fungal plant pathogens are ubiquitous and highly diverse. Key to their success is high host density, which notably is the case in agroecosystems. Several hypotheses related to the effects of plant pathogens on plant diversity (the Janzen-Connell hypothesis, the dilution effect hypothesis) and the phenomenon of higher biomass in plant mixtures (i.e., overyielding) can all be explained by the quantitative interplay between host and pathogen density. In many agroecosystems, fungal plant pathogens cause great losses, since in monocultures diseased plants cannot be replaced by healthy plants. On the other hand, in natural ecosystems fungal plant pathogens shape the succession of vegetation and enhance the biodiversity of forests and grasslands. When pathogens are introduced into areas outside their natural range, they may behave differently, causing severe damage. Once introduced, changes may occur such as hybridization with other closely related pathogens or host shifts, host jumps, or horizontal gene transfer. Such changes can be hazardous for both agricultural and natural ecosystems.

  17. Portable pathogen detection system

    DOEpatents

    Colston, Billy W.; Everett, Matthew; Milanovich, Fred P.; Brown, Steve B.; Vendateswaran, Kodumudi; Simon, Jonathan N.

    2005-06-14

    A portable pathogen detection system that accomplishes on-site multiplex detection of targets in biological samples. The system includes: microbead specific reagents, incubation/mixing chambers, a disposable microbead capture substrate, and an optical measurement and decoding arrangement. The basis of this system is a highly flexible Liquid Array that utilizes optically encoded microbeads as the templates for biological assays. Target biological samples are optically labeled and captured on the microbeads, which are in turn captured on an ordered array or disordered array disposable capture substrate and then optically read.

  18. Cryptosporidium Pathogenicity and Virulence

    PubMed Central

    Bouzid, Maha; Chalmers, Rachel M.; Tyler, Kevin M.

    2013-01-01

    Cryptosporidium is a protozoan parasite of medical and veterinary importance that causes gastroenteritis in a variety of vertebrate hosts. Several studies have reported different degrees of pathogenicity and virulence among Cryptosporidium species and isolates of the same species as well as evidence of variation in host susceptibility to infection. The identification and validation of Cryptosporidium virulence factors have been hindered by the renowned difficulties pertaining to the in vitro culture and genetic manipulation of this parasite. Nevertheless, substantial progress has been made in identifying putative virulence factors for Cryptosporidium. This progress has been accelerated since the publication of the Cryptosporidium parvum and C. hominis genomes, with the characterization of over 25 putative virulence factors identified by using a variety of immunological and molecular techniques and which are proposed to be involved in aspects of host-pathogen interactions from adhesion and locomotion to invasion and proliferation. Progress has also been made in the contribution of host factors that are associated with variations in both the severity and risk of infection. Here we provide a review comprised of the current state of knowledge on Cryptosporidium infectivity, pathogenesis, and transmissibility in light of our contemporary understanding of microbial virulence. PMID:23297262

  19. Tropism and Pathogenicity of Rickettsiae

    PubMed Central

    Uchiyama, Tsuneo

    2012-01-01

    Rickettsiae are obligate intracellular parasitic bacteria that cause febrile exanthematous illnesses such as Rocky Mountain spotted fever, Mediterranean spotted fever, epidemic, and murine typhus, etc. Although the vector ranges of each Rickettsia species are rather restricted; i.e., ticks belonging to Arachnida and lice and fleas belonging to Insecta usually act as vectors for spotted fever group (SFG) and typhus group (TG) rickettsiae, respectively, it would be interesting to elucidate the mechanisms controlling the vector tropism of rickettsiae. This review discusses the factors determining the vector tropism of rickettsiae. In brief, the vector tropism of rickettsiae species is basically consistent with their tropism toward cultured tick and insect cells. The mechanisms responsible for rickettsiae pathogenicity are also described. Recently, genomic analyses of rickettsiae have revealed that they possess several genes that are homologous to those affecting the pathogenicity of other bacteria. Analyses comparing the genomes of pathogenic and non-pathogenic strains of rickettsiae have detected many factors that are related to rickettsial pathogenicity. It is also known that a reduction in the rickettsial genome has occurred during the course of its evolution. Interestingly, Rickettsia species with small genomes, such as Rickettsia prowazekii, are more pathogenic to humans than those with larger genomes. This review also examines the growth kinetics of pathogenic and non-pathogenic species of SFG rickettsiae (SFGR) in mammalian cells. The growth of non-pathogenic species is restricted in these cells, which is mediated, at least in part, by autophagy. The superinfection of non-pathogenic rickettsiae-infected cells with pathogenic rickettsiae results in an elevated yield of the non-pathogenic rickettsiae and the growth of the pathogenic rickettsiae. Autophagy is restricted in these cells. These results are discussed in this review. PMID:22737150

  20. 16S rDNA-based metagenomic analysis of dental plaque and lung bacteria in patients with severe acute exacerbations of chronic obstructive pulmonary disease.

    PubMed

    Tan, L; Wang, H; Li, C; Pan, Y

    2014-12-01

    Acute exacerbations of chronic obstructive pulmonary disease (AE-COPD) are leading causes of mortality in hospital intensive care units. We sought to determine whether dental plaque biofilms might harbor pathogenic bacteria that can eventually cause lung infections in patients with severe AE-COPD. Paired samples of subgingival plaque biofilm and tracheal aspirate were collected from 53 patients with severe AE-COPD. Total bacterial DNA was extracted from each sample individually for polymerase chain reaction amplification and/or generation of bacterial 16S rDNA sequences and cDNA libraries. We used a metagenomic approach, based on bacterial 16S rDNA sequences, to compare the distribution of species present in dental plaque and lung. Analysis of 1060 sequences (20 clones per patient) revealed a wide range of aerobic, anaerobic, pathogenic, opportunistic, novel and uncultivable bacterial species. Species indistinguishable between the paired subgingival plaque and tracheal aspirate samples (97-100% similarity in 16S rDNA sequence) were dental plaque pathogens (Aggregatibacter actinomycetemcomitans, Capnocytophaga sputigena, Porphyromonas gingivalis, Tannerella forsythia and Treponema denticola) and lung pathogens (Acinetobacter baumannii, Klebsiella pneumoniae, Pseudomonas aeruginosa and Streptococcus pneumoniae). Real-time polymerase chain reaction of 16S rDNA indicated lower levels of Pseudomonas aeruginosa and Porphyromonas gingivalis colonizing the dental plaques compared with the paired tracheal aspirate samples. These results support the hypothesis that dental bacteria may contribute to the pathology of severe AE-COPD. © 2014 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  1. Respiratory Pathogens in Monkeys

    PubMed Central

    Good, Robert C.; May, Bessie D.

    1971-01-01

    Respiratory disease in a dynamic colony of nonhuman primates during a 4-year period was due primarily to infections caused by Klebsiella pneumoniae, Diplococcus pneumoniae, Bordetella bronchiseptica, Pasteurella multocida, and Haemophilus influenzae. The principal secondary invaders were Escherichia coli, Staphylococcus aureus, and streptococci. A high fatality rate was associated with infections caused by each of the primary pathogens, and females appeared to be more susceptible than males. Incidence of respiratory disease was greatest in the fall and early winter; however, at all times newly colonized monkeys had a higher infection rate than conditioned monkeys. Infections were occasionally confined only to the lungs and were sometimes present without grossly observable lung lesions. The information given on susceptibility of 10 species of nonhuman primates to respiratory infections provides a basis for developing disease models. PMID:16557951

  2. Flagella and bacterial pathogenicity.

    PubMed

    Duan, Qiangde; Zhou, Mingxu; Zhu, Liqian; Zhu, Guoqiang

    2013-01-01

    As locomotive organelles, flagella allow bacteria to move toward favorable environments. A flagellum consists of three parts: the basal structure (rotary motor), the hook (universal joint), and the filament (helical propeller). For ages, flagella have been generally regarded as important virulence factors, mainly because of their motility property. However, flagella are getting recognized to play multiple roles with more functions besides motility and chemotaxis. Recent evidence has pinpointed that the bacterial flagella participate in many additional processes including adhesion, biofilm formation, virulence factor secretion, and modulation of the immune system of eukaryotic cells. This mini-review summarizes data from recent studies that elucidated how flagella, as a virulence factor, contribute to bacterial pathogenicity.

  3. [Pathogenic factors of mycoplasma].

    PubMed

    Shimizu, Takashi

    2015-01-01

    Mycoplasmas are smallest organisms capable of self-replication and cause various diseases in human. Especially, Mycoplasma pneumoniae is known as an etiological agent of pneumonia. From 2010 to 2012, epidemics of M. pneumoniae infections were reported worldwide (e.g., in France, Israel, and Japan). In the diseases caused by mycoplasmas, strong inflammatory responses induced by mycoplasmas have been thought to be important. However, mycoplasmas lack of cell wall and do not possess inflammation-inducing endotoxin such as lipopolysaccharide (LPS). We purified inflammation-inducing factors from pathogenic mycoplasmas and identified that they were lipoproteins. Lipoproteins derived from mycoplasmas induced inflammatory responses through Toll-like receptor (TLR) 2. In addition, we demonstrated that cytadherent property of M. pneumoniae played an important role in induction of inflammatory responses. Cytadherent property of M. pneumoniae induced inflammatory responses through TLR2 independent pathway. TLR4, inflammasomes, and autophagy were involved in this TLR2 independent induction of inflammatory responses.

  4. [Streptococcus pyogenes pathogenic factors].

    PubMed

    Bidet, Ph; Bonacorsi, S

    2014-11-01

    The pathogenicity of ß-hemolytic group A streptococcus (GAS) is particularly diverse, ranging from mild infections, such as pharyngitis or impetigo, to potentially debilitating poststreptococcal diseases, and up to severe invasive infections such as necrotizing fasciitis or the dreaded streptococcal toxic shock syndrome. This variety of clinical expressions, often radically different in individuals infected with the same strain, results from a complex interaction between the bacterial virulence factors, the mode of infection and the immune system of the host. Advances in comparative genomics have led to a better understanding of how, following this confrontation, GAS adapts to the immune system's pressure, either peacefully by reducing the expression of certain virulence factors to achieve an asymptomatic carriage, or on the contrary, by overexpressing them disproportionately, resulting in the most severe forms of invasive infection.

  5. Probiotics against Campylobacter Pathogens.

    PubMed

    Sorokulova; Kirik; Pinchuk

    1997-12-01

    Background: The subject matter of this study was to investigate, for the first time, the immediate-preventive effect of probiotics, composed of bacillus species, in a murine model of Campylobacter infection. Methods: An established model of Campylobacter infection in mice with a defined LD50 was utilized to assess the protective effect of probiotics. Results: The results obtained demonstrate that the level of animal protection, after a single administration of the new probiotics biosporin and subalin, reached 90-100% at LD50 and 80% at LD100. Conclusions: Such efficacy of probiotics is considered to be due to their high antagonistic activity against those pathogens registered in vitro. Antagonistic activity of other tested probiotics (bactisubtil and cereobiogen) to different cultures of Campylobacter was not manifested.

  6. Rapid Detection of Pathogens

    SciTech Connect

    David Perlin

    2005-08-14

    Pathogen identification is a crucial first defense against bioterrorism. A major emphasis of our national biodefense strategy is to establish fast, accurate and sensitive assays for diagnosis of infectious diseases agents. Such assays will ensure early and appropriate treatment of infected patients. Rapid diagnostics can also support infection control measures, which monitor and limit the spread of infectious diseases agents. Many select agents are highly transmissible in the early stages of disease, and it is critical to identify infected patients and limit the risk to the remainder of the population and to stem potential panic in the general population. Nucleic acid-based molecular approaches for identification overcome many of the deficiencies associated with conventional culture methods by exploiting both large- and small-scale genomic differences between organisms. PCR-based amplification of highly conserved ribosomal RNA (rRNA) genes, intergenic sequences, and specific toxin genes is currently the most reliable approach for bacterial, fungal and many viral pathogenic agents. When combined with fluorescence-based oligonucleotide detection systems, this approach provides real-time, quantitative, high fidelity analysis capable of single nucleotide allelic discrimination (4). These probe systems offer rapid turn around time (<2 h) and are suitable for high throughput, automated multiplex operations that are critical for clinical diagnostic laboratories. In this pilot program, we have used molecular beacon technology invented at the Public health Research Institute to develop a new generation of molecular probes to rapidly detect important agents of infectious diseases. We have also developed protocols to rapidly extract nucleic acids from a variety of clinical specimen including and blood and tissue to for detection in the molecular assays. This work represented a cooperative research development program between the Kramer-Tyagi/Perlin labs on probe development

  7. Multiplex detection of respiratory pathogens

    DOEpatents

    McBride, Mary [Brentwood, CA; Slezak, Thomas [Livermore, CA; Birch, James M [Albany, CA

    2012-07-31

    Described are kits and methods useful for detection of respiratory pathogens (influenza A (including subtyping capability for H1, H3, H5 and H7 subtypes) influenza B, parainfluenza (type 2), respiratory syncytial virus, and adenovirus) in a sample. Genomic sequence information from the respiratory pathogens was analyzed to identify signature sequences, e.g., polynucleotide sequences useful for confirming the presence or absence of a pathogen in a sample. Primer and probe sets were designed and optimized for use in a PCR based, multiplexed Luminex assay to successfully identify the presence or absence of pathogens in a sample.

  8. Host Specificity of Bacterial Pathogens

    PubMed Central

    Bäumler, Andreas; Fang, Ferric C.

    2013-01-01

    Most pathogens are able to infect multiple hosts but some are highly adapted to a single-host species. A detailed understanding of the basis of host specificity can provide important insights into molecular pathogenesis, the evolution of pathogenic microbes, and the potential for pathogens to cross the species barrier to infect new hosts. Comparative genomics and the development of humanized mouse models have provided important new tools with which to explore the basis of generalism and specialism. This review will examine host specificity of bacterial pathogens with a focus on generalist and specialist serovars of Salmonella enterica. PMID:24296346

  9. Pathogenic agents in freshwater resources

    NASA Astrophysics Data System (ADS)

    Geldreich, Edwin E.

    1996-02-01

    Numerous pathogenic agents have been found in freshwaters used as sources for water supplies, recreational bathing and irrigation. These agents include bacterial pathogens, enteric viruses, several protozoans and parasitic worms more common to tropical waters. Although infected humans are a major source of pathogens, farm animals (cattle, sheep, pigs), animal pets (dogs, cats) and wildlife serve as significant reservoirs and should not be ignored. The range of infected individuals within a given warm-blooded animal group (humans included) may range from 1 to 25%. Survival times for pathogens in the water environment may range from a few days to as much as a year (Ascaris, Taenia eggs), with infective dose levels varying from one viable cell for several primary pathogenic agents to many thousands of cells for a given opportunistic pathogen.As pathogen detection in water is complex and not readily incorporated into routine monitoring, a surrogate is necessary. In general, indicators of faecal contamination provide a positive correlation with intestinal pathogen occurrences only when appropriate sample volumes are examined by sensitive methodology.Pathways by which pathogens reach susceptible water users include ingestion of contaminated water, body contact with polluted recreational waters and consumption of salad crops irrigated by polluted freshwaters. Major contributors to the spread of various water-borne pathogens are sewage, polluted surface waters and stormwater runoff. All of these contributions are intensified during periods of major floods. Several water-borne case histories are cited as examples of breakdowns in public health protection related to water supply, recreational waters and the consumption of contaminated salad crops. In the long term, water resource management must focus on pollution prevention from point sources of waste discharges and the spread of pathogens in watershed stormwater runoff.

  10. Proteomics of Foodborne Bacterial Pathogens

    NASA Astrophysics Data System (ADS)

    Fagerquist, Clifton K.

    This chapter is intended to be a relatively brief overview of proteomic techniques currently in use for the identification and analysis of microorganisms with a special emphasis on foodborne pathogens. The chapter is organized as follows. First, proteomic techniques are introduced and discussed. Second, proteomic applications are presented specifically as they relate to the identification and qualitative/quantitative analysis of foodborne pathogens.

  11. USEPA PATHOGEN EQUIVALENCY COMMITTEE RETREAT

    EPA Science Inventory

    The Pathogen Equivalency Committee held its retreat from September 20-21, 2005 at Hueston Woods State Park in College Corner, Ohio. This presentation will update the PEC’s membership on emerging pathogens, analytical methods, disinfection techniques, risk analysis, preparat...

  12. USEPA PATHOGEN EQUIVALENCY COMMITTEE RETREAT

    EPA Science Inventory

    The Pathogen Equivalency Committee held its retreat from September 20-21, 2005 at Hueston Woods State Park in College Corner, Ohio. This presentation will update the PEC’s membership on emerging pathogens, analytical methods, disinfection techniques, risk analysis, preparat...

  13. Physical constraints for pathogen movement.

    PubMed

    Schwarz, Ulrich S

    2015-10-01

    In this pedagogical review, we discuss the physical constraints that pathogens experience when they move in their host environment. Due to their small size, pathogens are living in a low Reynolds number world dominated by viscosity. For swimming pathogens, the so-called scallop theorem determines which kinds of shape changes can lead to productive motility. For crawling or gliding cells, the main resistance to movement comes from protein friction at the cell-environment interface. Viruses and pathogenic bacteria can also exploit intracellular host processes such as actin polymerization and motor-based transport, if they present the appropriate factors on their surfaces. Similar to cancer cells that also tend to cross various barriers, pathogens often combine several of these strategies in order to increase their motility and therefore their chances to replicate and spread. Copyright © 2015 Elsevier Ltd. All rights reserved.

  14. Molecular pathogenicity of Streptococcus anginosus.

    PubMed

    Asam, D; Spellerberg, B

    2014-08-01

    Streptococcus anginosus and the closely related species Streptococcus constellatus and Streptococcus intermedius, are primarily commensals of the mucosa. The true pathogenic potential of this group has been under-recognized for a long time because of difficulties in correct species identification as well as the commensal nature of these species. In recent years, streptococci of the S. anginosus group have been increasingly found as relevant microbial pathogens in abscesses and blood cultures and they play a pathogenic role in cystic fibrosis. Several international studies have shown a surprisingly high frequency of infections caused by the S. anginosus group. Recent studies and a genome-wide comparative analysis suggested the presence of multiple putative virulence factors that are well-known from other streptococcal species. However, very little is known about the molecular basis of pathogenicity in these bacteria. This review summarizes our current knowledge of pathogenicity factors and their regulation in S. anginosus.

  15. Genomics of clostridial pathogens: implication of extrachromosomal elements in pathogenicity.

    PubMed

    Brüggemann, Holger

    2005-10-01

    The recently decoded genomes of the major clostridial toxin-producing pathogens Clostridium perfringens, Clostridium tetani, Clostridium botulinum and Clostridium difficile have provided a huge amount of new sequence data. Recent studies have focused on the identification and investigation of pathogenic determinants and the regulatory events governing their expression. The sequence data revealed also the genomic background of virulence genes, as well as the contribution of extrachromosomal elements to a pathogenic phenotype. This has generated new insights in clostridial pathogenesis - and will continue to do so in the future - and has deepened our understanding of the anaerobic lifestyle of clostridial species.

  16. Host-Pathogen Interactions

    PubMed Central

    English, Patricia D.; Jurale, Joseph Byrne; Albersheim, Peter

    1971-01-01

    The effect of a number of physiological variables on the secretion of polysaccharide-degrading enzymes by culture-grown Colletotrichum lindemuthianum (Saccardo and Magnus) Scribner was determined. The number of spores used to inoculate cultures grown on isolated bean hypocotyl cell walls affects the time after inoculation at which enzyme secretion occurs, but has no significant effect on the maximal amount of enzyme ultimately secreted. Cell walls isolated from bean leaves, first internodes, or hypocotyls (susceptible to C. lindemuthianum infection), when used as carbon source for C. lindemuthianum growth, stimulate the fungus to secrete more α-galactosidase than do cell walls isolated from roots (resistant to infection). The concentration of carbon source used for fungal growth determines the final level of enzyme activity in the culture fluid. The level of enzyme secretion is not proportional to fungal growth; rather, enzyme secretion is induced. Maximal α-galactosidase activity in the culture medium is found when the concentration of cell walls used as carbon source is 1% or greater. A higher concentration of cell walls is necessary for maximal α-arabinosidase activity. Galactose, when used as the carbon source, stimulates α-galactosidase secretion but, at comparable concentrations, is less effective in doing so than are cell walls. Polysaccharide-degrading enzymes are secreted by C. lindemuthianum at different times during growth of the pathogen on isolated cell walls. Pectinase and α-arabinosidase are secreted first, followed by β-xylosidase and cellulase, then β-glucosidase, and, finally, α-galactosidase. PMID:16657562

  17. Chair-side detection of Prevotella Intermedia in mature dental plaque by its fluorescence.

    PubMed

    Nomura, Yoshiaki; Takeuchi, Hiroaki; Okamoto, Masaaki; Sogabe, Kaoru; Okada, Ayako; Hanada, Nobuhiro

    2017-06-01

    Prevotella intermedia/nigrescens is one of the well-known pathogens causing periodontal diseases, and the red florescence excited by the visible blue light caused by the protoporphyrin IX in the bacterial cells could be useful for the chair-side detection. The aim of this study was to evaluated levels of periodontal pathogen, especially P. intermedia in clinical samples of red fluorescent dental plaque. Thirty two supra gingival plaque samples from six individuals were measured its fluorescence at 640nm wavelength excited by 409nm. Periodontopathic bacteria were counted by the Invader PLUS PCR assay. Co-relations the fluorescence intensity and bacterial counts were analyzed by Person's correlation coefficient and simple and multiple regression analysis. Positive and negative predictive values of the fluorescence intensities for with or without P. intermedia in supragingival plaque was calculated. When relative fluorescence unit (RFU) were logarithmic transformed, statistically significant linear relations between RFU and bacterial counts were obtained for P. intermedia, Porphyromonas gingivalis and Tannerella forsythia. By the multiple regression analysis, only P. intermedia had statistically significant co-relation with fluorescence intensities. All of the fluorescent dental plaque contained P. intermedia m. In contrast, 28% of non-fluorescent plaques contained P. intermedia. To check the fluorescence dental plaque in the oral cavity could be the simple chair-side screening of the mature dental plaque before examining the periodontal pathogens especially P. intermedia by the PCR method. Copyright © 2017 Elsevier B.V. All rights reserved.

  18. Subgingival plaque microbiota in HIV positive patients.

    PubMed

    Aas, J A; Barbuto, S M; Alpagot, T; Olsen, I; Dewhirst, F E; Paster, B J

    2007-03-01

    To describe and compare the predominant bacterial and fungal species associated with gingivitis, periodontitis, and linear gingival erythema (LGE), in HIV positive subjects with different immune status. Viral loads and CD4 levels determined HIV disease status. From pooled subgingival plaque, 16S and 18S rDNA were cloned and sequenced to determine species identity. One hundred and nine bacterial species were identified from 14 subjects. Nearly half of the species were not cultivable. Notably, the classical putative periodontal pathogens, Treponema denticola, Porphyromonas gingivalis and Tannerella forsythia were below the limit of detection and were not detected. Species of Gemella, Dialister, Streptococcus and Veillonella were predominant. In one HIV positive subject with periodontitis and low viral load, Gemella morbillorum, a known opportunistic pathogen, constituted 84% of the clones. Saccharomyces cerevisiae was the only fungal species detected in an LGE subject and in periodontitis subjects with high viral loads. In periodontitis patients with low viral loads, Candida albicans was predominant, while S. cerevisiae was only a minor component. These case studies suggest that other bacterial species, rather than the classical periodontal pathogens, may be involved in periodontal diseases of subjects with HIV. These data are indicative of opportunistic infections in a highly susceptible immunocompromised host.

  19. Subgingival microbiome in patients with healthy and ailing dental implants

    PubMed Central

    Zheng, Hui; Xu, Lixin; Wang, Zicheng; Li, Lianshuo; Zhang, Jieni; Zhang, Qian; Chen, Ting; Lin, Jiuxiang; Chen, Feng

    2015-01-01

    Dental implants are commonly used to replace missing teeth. However, the dysbiotic polymicrobial communities of peri-implant sites are responsible for peri-implant diseases, such as peri-implant mucositis and peri-implantitis. In this study, we analyzed the microbial characteristics of oral plaque from peri-implant pockets or sulci of healthy implants (n = 10), peri-implant mucositis (n = 8) and peri-implantitis (n = 6) sites using pyrosequencing of the 16S rRNA gene. An increase in microbial diversity was observed in subgingival sites of ailing implants, compared with healthy implants. Microbial co-occurrence analysis revealed that periodontal pathogens, such as Porphyromonas gingivalis, Tannerella forsythia, and Prevotella intermedia, were clustered into modules in the peri-implant mucositis network. Putative pathogens associated with peri-implantitis were present at a moderate relative abundance in peri-implant mucositis, suggesting that peri-implant mucositis an important early transitional phase during the development of peri-implantitis. Furthermore, the relative abundance of Eubacterium was increased at peri-implantitis locations, and co-occurrence analysis revealed that Eubacterium minutum was correlated with Prevotella intermedia in peri-implantitis sites, which suggests the association of Eubacterium with peri-implantitis. This study indicates that periodontal pathogens may play important roles in the shifting of healthy implant status to peri-implant disease. PMID:26077225

  20. Porphyromonas gingivalis Periodontal Infection and Its Putative Links with Alzheimer's Disease

    PubMed Central

    Singhrao, Sim K.; Harding, Alice; Poole, Sophie; Kesavalu, Lakshmyya; Crean, StJohn

    2015-01-01

    Periodontal disease (PD) and Alzheimer's disease (AD) are inflammatory conditions affecting the global adult population. In the pathogenesis of PD, subgingival complex bacterial biofilm induces inflammation that leads to connective tissue degradation and alveolar bone resorption around the teeth. In health, junctional epithelium seals the gingiva to the tooth enamel, thus preventing bacteria from entering the gingivae. Chronic PD involves major pathogens (Porphyromonas gingivalis, Treponema denticola, and Tannerella forsythia) which have an immune armoury that can circumvent host's immune surveillance to create and maintain an inflammatory mediator rich and toxic environment to grow and survive. The neurodegenerative condition, AD, is characterised by poor memory and specific hallmark proteins; periodontal pathogens are increasingly being linked with this dementing condition. It is therefore becoming important to understand associations of periodontitis with relevance to late-onset AD. The aim of this review is to discuss the relevance of finding the keystone periodontal pathogen P. gingivalis in AD brains and its plausible contribution to the aetiological hypothesis of this dementing condition. PMID:26063967

  1. Polymicrobial infection alter inflammatory microRNA in rat salivary glands during periodontal disease.

    PubMed

    Nayar, Gautam; Gauna, Adrienne; Chukkapalli, Sasanka; Velsko, Irina; Kesavalu, Lakshmyya; Cha, Seunghee

    2016-04-01

    Periodontal disease initiated by subgingival pathogens is linked with diminished secretion of saliva, and implies pathogenic bacteria dissemination to or affects secondary sites such as the salivary glands. MicroRNAs activated in response to bacteria may modulate immune responses against pathogens. Therefore, Sprague-Dawley rats were infected by oral lavage consisting of polymicrobial inocula, namely Porphyromonas gingivalis, Tannerella forsythia, and Treponema denticola, or sham-infected for 12 weeks (n = 6). We quantified inflammatory miRNA expression levels of miRNA-132, miR-146a, and miR-155 at secondary sites to the primary infection of the gingiva, including submandibular salivary glands, lacrimal glands, and pancreas. The presence of bacteria was detected in situ at secondary sites. Infected rat gingiva showed increased relative expression of miR-155. In contrast, miRNA-155 expression was decreased in submandibular salivary glands, along with positive identification of P. gingivalis in 2/6 and T. denticola in 1/6 rat salivary glands. Furthermore, miRNA-132 and miRNA-146a were significantly decreased in the pancreas of infected rats. This study is the first to show primary periodontal infections can alter miRNA profiles in secondary sites such as the salivary gland and pancreas. Whether these alterations contribute to pathologies of salivary glands in Sjögren's syndrome or of pancreas in diabetes warrants further investigation. Copyright © 2015 Elsevier Ltd. All rights reserved.

  2. Porphyromonas gingivalis Periodontal Infection and Its Putative Links with Alzheimer's Disease.

    PubMed

    Singhrao, Sim K; Harding, Alice; Poole, Sophie; Kesavalu, Lakshmyya; Crean, StJohn

    2015-01-01

    Periodontal disease (PD) and Alzheimer's disease (AD) are inflammatory conditions affecting the global adult population. In the pathogenesis of PD, subgingival complex bacterial biofilm induces inflammation that leads to connective tissue degradation and alveolar bone resorption around the teeth. In health, junctional epithelium seals the gingiva to the tooth enamel, thus preventing bacteria from entering the gingivae. Chronic PD involves major pathogens (Porphyromonas gingivalis, Treponema denticola, and Tannerella forsythia) which have an immune armoury that can circumvent host's immune surveillance to create and maintain an inflammatory mediator rich and toxic environment to grow and survive. The neurodegenerative condition, AD, is characterised by poor memory and specific hallmark proteins; periodontal pathogens are increasingly being linked with this dementing condition. It is therefore becoming important to understand associations of periodontitis with relevance to late-onset AD. The aim of this review is to discuss the relevance of finding the keystone periodontal pathogen P. gingivalis in AD brains and its plausible contribution to the aetiological hypothesis of this dementing condition.

  3. Transient virulence of emerging pathogens.

    PubMed

    Bolker, Benjamin M; Nanda, Arjun; Shah, Dharmini

    2010-05-06

    Should emerging pathogens be unusually virulent? If so, why? Existing theories of virulence evolution based on a tradeoff between high transmission rates and long infectious periods imply that epidemic growth conditions will select for higher virulence, possibly leading to a transient peak in virulence near the beginning of an epidemic. This transient selection could lead to high virulence in emerging pathogens. Using a simple model of the epidemiological and evolutionary dynamics of emerging pathogens, along with rough estimates of parameters for pathogens such as severe acute respiratory syndrome, West Nile virus and myxomatosis, we estimated the potential magnitude and timing of such transient virulence peaks. Pathogens that are moderately evolvable, highly transmissible, and highly virulent at equilibrium could briefly double their virulence during an epidemic; thus, epidemic-phase selection could contribute significantly to the virulence of emerging pathogens. In order to further assess the potential significance of this mechanism, we bring together data from the literature for the shapes of tradeoff curves for several pathogens (myxomatosis, HIV, and a parasite of Daphnia) and the level of genetic variation for virulence for one (myxomatosis). We discuss the need for better data on tradeoff curves and genetic variance in order to evaluate the plausibility of various scenarios of virulence evolution.

  4. Transient virulence of emerging pathogens

    PubMed Central

    Bolker, Benjamin M.; Nanda, Arjun; Shah, Dharmini

    2010-01-01

    Should emerging pathogens be unusually virulent? If so, why? Existing theories of virulence evolution based on a tradeoff between high transmission rates and long infectious periods imply that epidemic growth conditions will select for higher virulence, possibly leading to a transient peak in virulence near the beginning of an epidemic. This transient selection could lead to high virulence in emerging pathogens. Using a simple model of the epidemiological and evolutionary dynamics of emerging pathogens, along with rough estimates of parameters for pathogens such as severe acute respiratory syndrome, West Nile virus and myxomatosis, we estimated the potential magnitude and timing of such transient virulence peaks. Pathogens that are moderately evolvable, highly transmissible, and highly virulent at equilibrium could briefly double their virulence during an epidemic; thus, epidemic-phase selection could contribute significantly to the virulence of emerging pathogens. In order to further assess the potential significance of this mechanism, we bring together data from the literature for the shapes of tradeoff curves for several pathogens (myxomatosis, HIV, and a parasite of Daphnia) and the level of genetic variation for virulence for one (myxomatosis). We discuss the need for better data on tradeoff curves and genetic variance in order to evaluate the plausibility of various scenarios of virulence evolution. PMID:19864267

  5. Opportunistic Premise Plumbing Pathogens: Increasingly Important Pathogens in Drinking Water

    PubMed Central

    Falkinham, Joseph O.; Pruden, Amy; Edwards, Marc

    2015-01-01

    Opportunistic premise plumbing pathogens are responsible for a significant number of infections whose origin has been traced to drinking water. These opportunistic pathogens represent an emerging water borne disease problem with a major economic cost of at least $1 billion annually. The common features of this group of waterborne pathogens include: disinfectant-resistance, pipe surface adherence and biofilm formation, growth in amoebae, growth on low organic concentrations, and growth at low oxygen levels. Their emergence is due to the fact that conditions resulting from drinking water treatment select for them. As such, there is a need for novel approaches to reduce exposure to these pathogens. In addition to much-needed research, controls to reduce numbers and human exposure can be instituted independently by utilities and homeowners and hospital- and building-operators. PMID:26066311

  6. Host pathogen relations: exploring animal models for fungal pathogens.

    PubMed

    Harwood, Catherine G; Rao, Reeta P

    2014-06-30

    Pathogenic fungi cause superficial infections but pose a significant public health risk when infections spread to deeper tissues, such as the lung. Within the last three decades, fungi have been identified as the leading cause of nosocomial infections making them the focus of research. This review outlines the model systems such as the mouse, zebrafish larvae, flies, and nematodes, as well as ex vivo and in vitro systems available to study common fungal pathogens.

  7. Host Pathogen Relations: Exploring Animal Models for Fungal Pathogens

    PubMed Central

    Harwood, Catherine G.; Rao, Reeta P.

    2014-01-01

    Pathogenic fungi cause superficial infections but pose a significant public health risk when infections spread to deeper tissues, such as the lung. Within the last three decades, fungi have been identified as the leading cause of nosocomial infections making them the focus of research. This review outlines the model systems such as the mouse, zebrafish larvae, flies, and nematodes, as well as ex vivo and in vitro systems available to study common fungal pathogens. PMID:25438011

  8. Functional genomics of pathogenic bacteria.

    PubMed Central

    Moxon, E R; Hood, D W; Saunders, N J; Schweda, E K H; Richards, J C

    2002-01-01

    Microbial diseases remain the commonest cause of global mortality and morbidity. Automated-DNA sequencing has revolutionized the investigation of pathogenic microbes by making the immense fund of information contained in their genomes available at reasonable cost. The challenge is how this information can be used to increase current understanding of the biology of commensal and virulence behaviour of pathogens with particular emphasis on in vivo function and novel approaches to prevention. One example of the application of whole-genome-sequence information is afforded by investigations of the pathogenic role of Haemophilus influenzae lipopolysaccharide and its candidacy as a vaccine. PMID:11839188

  9. Future research needs involving pathogens in groundwater

    USDA-ARS?s Scientific Manuscript database

    Contamination of groundwater by enteric pathogens has commonly been associated with disease outbreaks. Proper management and treatment of pathogen sources are important barriers to preventing groundwater contamination. However, non-point sources of pathogen contamination are frequently difficult to ...

  10. Pathogen detection using engineered bacteriophages.

    PubMed

    Smartt, Abby E; Xu, Tingting; Jegier, Patricia; Carswell, Jessica J; Blount, Samuel A; Sayler, Gary S; Ripp, Steven

    2012-04-01

    Bacteriophages, or phages, are bacterial viruses that can infect a broad or narrow range of host organisms. Knowing the host range of a phage allows it to be exploited in targeting various pathogens. Applying phages for the identification of microorganisms related to food and waterborne pathogens and pathogens of clinical significance to humans and animals has a long history, and there has to some extent been a recent revival in these applications as phages have become more extensively integrated into novel detection, identification, and monitoring technologies. Biotechnological and genetic engineering strategies applied to phages are responsible for some of these new methods, but even natural unmodified phages are widely applicable when paired with appropriate innovative detector platforms. This review highlights the use of phages as pathogen detector interfaces to provide the reader with an up-to-date inventory of phage-based biodetection strategies.

  11. Evolution of Immunity and Pathogens.

    PubMed

    Jack, Robert S

    2015-01-01

    Host and pathogen engage in a constant evolutionary struggle known as a "Red Queen Paradigm". In this struggle, natural selection favours the pathogen which evolves effective virulence mechanisms and the host which is able to field adequate resistance strategies. A number of factors limit what each side can do. These include the fact that the elaboration of virulence or resistance mechanisms results in costs in genetic fitness and requires the use of ever more of the limited number of genes available in the genome. In addition, since the pathogen usually has a very much shorter generation time than the host, it can fix new virulence mutations much more quickly than the host can evolve matching resistance mechanisms. Finally, the host must ensure that its defence system does not result in unacceptable levels of collateral damage to its own tissues. This chapter briefly outlines how these considerations shape host-pathogen interactions.

  12. Palmitoylation, pathogens and their host.

    PubMed

    Blanc, Mathieu; Blaskovic, Sanja; van der Goot, F Gisou

    2013-02-01

    S-Palmitoylation, the only reversible post-translational lipid modification, confers unique biochemical and functional properties to proteins. Although it has long been known that viral proteins are palmitoylated, recent studies reveal that this modification plays a critical role for pathogens of all kinds and at multiple steps of their life cycle. The present review examines the involvement of S-palmitoylation in infection by viruses, bacteria and parasites and illustrates how pathogens have evolved to manipulate the host palmitoylation machinery.

  13. Foodborne pathogens and their toxins.

    PubMed

    Martinović, Tamara; Andjelković, Uroš; Gajdošik, Martina Šrajer; Rešetar, Dina; Josić, Djuro

    2016-09-16

    Foodborne pathogens, mostly bacteria and fungi, but also some viruses, prions and protozoa, contaminate food during production and processing, but also during storage and transport before consuming. During their growth these microorganisms can secrete different components, including toxins, into the extracellular environment. Other harmful substances can be also liberated and can contaminate food after disintegration of food pathogens. Some bacterial and fungal toxins can be resistant to inactivation, and can survive harsh treatment during food processing. Many of these molecules are involved in cellular processes and can indicate different mechanisms of pathogenesis of foodborne organisms. More knowledge about food contaminants can also help understand their inactivation. In the present review the use of proteomics, peptidomics and metabolomics, in addition to other foodomic methods for the detection of foodborne pathogenic fungi and bacteria, is overviewed. Furthermore, it is discussed how these techniques can be used for discovering biomarkers for pathogenicity of foodborne pathogens, determining the mechanisms by which they act, and studying their resistance upon inactivation in food of animal and plant origin. Comprehensive and comparative view into the genome and proteome of foodborne pathogens of bacterial or fungal origin and foodomic, mostly proteomic, peptidomic and metabolomic investigation of their toxin production and their mechanism of action is necessary in order to get further information about their virulence, pathogenicity and survival under stress conditions. Furthermore, these data pave the way for identification of biomarkers to trace sources of contamination with food-borne microorganisms and their endo- and exotoxins in order to ensure food safety and prevent the outbreak of food-borne diseases. Therefore, detection of pathogens and their toxins during production, transport and before consume of food produce, as well as protection against

  14. Waterborne pathogens in urban watersheds.

    PubMed

    Arnone, Russell D; Walling, Joyce Perdek

    2007-03-01

    A serious concern for managers of water resources, pathogens in the urban environment easily enter waters through a number of pathways, including discharge of inadequately treated sewage, stormwater runoff, combined sewer overflows and sanitary sewer overflows. Pathogens in US ambient water bodies are regulated under the Clean Water Act (CWA), while pathogens in drinking water supplies are regulated under the Safe Drinking Water Act. Total maximum daily loads (TMDLs) are developed in accordance with CWA regulations for ambient water bodies with bacterial concentrations exceeding the water quality standard, which generally is a measure of a bacterial indicator organism. However, developing a TMDL for a supplementary indicator or pathogen is also required if a use impairment would still exist even after the water body is in compliance with the standard. This occurs because indicator organisms do not reflect the presence of pathogen contamination with complete certainty. The evaluation of pathogen indicators and summary of epidemiological studies presented are resources for those developing TMDLs to achieve water quality standards and restore water bodies to their intended uses.

  15. Biosensors for plant pathogen detection.

    PubMed

    Khater, Mohga; de la Escosura-Muñiz, Alfredo; Merkoçi, Arben

    2017-07-15

    Infectious plant diseases are caused by pathogenic microorganisms such as fungi, bacteria, viruses, viroids, phytoplasma and nematodes. Worldwide, plant pathogen infections are among main factors limiting crop productivity and increasing economic losses. Plant pathogen detection is important as first step to manage a plant disease in greenhouses, field conditions and at the country boarders. Current immunological techniques used to detect pathogens in plant include enzyme-linked immunosorbent assays (ELISA) and direct tissue blot immunoassays (DTBIA). DNA-based techniques such as polymerase chain reaction (PCR), real time PCR (RT-PCR) and dot blot hybridization have also been proposed for pathogen identification and detection. However these methodologies are time-consuming and require complex instruments, being not suitable for in-situ analysis. Consequently, there is strong interest for developing new biosensing systems for early detection of plant diseases with high sensitivity and specificity at the point-of-care. In this context, we revise here the recent advancement in the development of advantageous biosensing systems for plant pathogen detection based on both antibody and DNA receptors. The use of different nanomaterials such as nanochannels and metallic nanoparticles for the development of innovative and sensitive biosensing systems for the detection of pathogens (i.e. bacteria and viruses) at the point-of-care is also shown. Plastic and paper-based platforms have been used for this purpose, offering cheap and easy-to-use really integrated sensing systems for rapid on-site detection. Beside devices developed at research and development level a brief revision of commercially available kits is also included in this review. Copyright © 2016 Elsevier B.V. All rights reserved.

  16. Characterization of Pathogenicity, Virulence and Host-Pathogen Interractions

    SciTech Connect

    Krishnan, A; Folta, P

    2006-07-27

    The threats of bio-terrorism and newly emerging infectious diseases pose serious challenges to the national security infrastructure. Rapid detection and diagnosis of infectious disease in human populations, as well as characterizing pathogen biology, are critical for reducing the morbidity and mortality associated with such threats. One of the key challenges in managing an infectious disease outbreak, whether through natural causes or acts of overt terrorism, is detection early enough to initiate effective countermeasures. Much recent attention has been directed towards the utility of biomarkers or molecular signatures that result from the interaction of the pathogen with the host for improving our ability to diagnose and mitigate the impact of a developing infection during the time window when effective countermeasures can be instituted. Host responses may provide early signals in blood even from localized infections. Multiple innate and adaptive immune molecules, in combination with other biochemical markers, may provide disease-specific information and new targets for countermeasures. The presence of pathogen specific markers and an understanding of the molecular capabilities and adaptations of the pathogen when it interacts with its host may likewise assist in early detection and provide opportunities for targeting countermeasures. An important question that needs to be addressed is whether these molecular-based approaches will prove useful for early diagnosis, complement current methods of direct agent detection, and aid development and use of countermeasures. Lawrence Livermore National Laboratory (LLNL) will host a workshop to explore the utility of host- and pathogen-based molecular diagnostics, prioritize key research issues, and determine the critical steps needed to transition host-pathogen research to tools that can be applied towards a more effective national bio-defense strategy. The workshop will bring together leading researchers/scientists in the

  17. Systemic Immune Responses in Pregnancy and Periodontitis: Relationship to Pregnancy Outcomes in the Obstetrics and Periodontal Therapy (OPT) Study

    PubMed Central

    Ebersole, Jeffrey L.; Novak, M. John; Michalowicz, Bryan S.; Hodges, James S.; Steffen, Michelle J.; Ferguson, James E.; DiAngelis, Anthony; Buchanan, William; Mitchell, Dennis A.; Papapanou, Panos N.

    2014-01-01

    Background Our previous studies reported on the obstetric, periodontal, and microbiologic outcomes of women participating in the Obstetrics and Periodontal Therapy (OPT) Study. This article describes the systemic antibody responses to selected periodontal bacteria in the same patients. Methods Serum samples, obtained from pregnant women at baseline (13 to 16 weeks; 6 days of gestation) and 29 to 32 weeks, were analyzed by enzyme-linked immunosorbent assay for serum immunoglobulin G (IgG) antibody to Aggregatibacter actinomycetemcomitans (previously Actinobacillus actinomycetemcomitans), Campylobacter rectus, Fusobacterium nucleatum, Porphyromonas gingivalis, Prevotella intermedia, Tannerella forsythia (previously T. forsythensis), and Treponema denticola. Results At baseline, women who delivered live preterm infants had significantly lower total serum levels of IgG antibody to the panel of periodontal pathogens (P = 0.0018), to P. gingivalis (P = 0.0013), and to F. nucleatum (P = 0.0200) than women who delivered at term. These differences were not significant at 29 to 32 weeks. Changes in IgG levels between baseline and 29 to 32 weeks were not associated with preterm birth when adjusted for treatment group, clinical center, race, or age. In addition, delivery of low birth weight infants was not associated with levels of antibody at baseline or with antibody changes during pregnancy. Conclusions Live preterm birth is associated with decreased levels of IgG antibody to periodontal pathogens in women with periodontitis when assessed during the second trimester. Changes in IgG antibody during pregnancy are not associated with birth outcomes. PMID:19485826

  18. Effect of periodontal therapy on the subgingival microbiota over a 2-year monitoring period. I. Overall effect and kinetics of change

    PubMed Central

    Socransky, S.S.; Haffajee, A.D.; Teles, R.; Wennstrom, J.; Lindhe, J.; Bogren, A.; Hasturk, H.; van Dyke, T; Wang, X.; Goodson, J.M.

    2013-01-01

    Objective To examine the 2 year post-therapy kinetics of change in the composition of subgingival biofilms. Material and Methods 178 chronic periodontitis subjects were recruited and clinically monitored at baseline, 3, 6, 12, 18 and 24 months after therapy. All subjects received SRP and 156 one or more of periodontal surgery, systemically administered amoxicillin + metronidazole or local tetracycline at pockets ≥5 mm. Subgingival biofilm samples taken from each subject at each time point were analyzed for their content of 40 bacterial species using checkerboard DNA-DNA hybridization. The significance of changes in median species counts over time was sought using the Wilcoxon or Friedman tests and adjusted for multiple comparisons. Results Mean counts were significantly reduced from baseline to 2 years for 30 of the 40 taxa. Marked reductions were observed for periodontal pathogens including Tannerella forsythia, Treponema denticola and Eubacterium nodatum. The kinetics of change differed from species to species. When data were subset according to baseline PD, patterns of change in the microbial profiles were generally similar. Conclusion Periodontal therapy leads to a rapid reduction in periodontal pathogens, followed by a slower reduction in other taxa that can be sustained for at least 2 years. PMID:23710672

  19. Effect of periodontal therapy on the subgingival microbiota over a 2-year monitoring period. I. Overall effect and kinetics of change.

    PubMed

    Socransky, Sigmund S; Haffajee, Anne D; Teles, Ricardo; Wennstrom, Jan L; Lindhe, Jan; Bogren, Anna; Hasturk, Hatice; van Dyke, Thomas; Wang, Xiaoshan; Goodson, Jo Max

    2013-08-01

    To examine the 2-year post-therapy kinetics of change in the composition of subgingival biofilms. In this study, 178 chronic periodontitis subjects were recruited and clinically monitored at baseline, 3, 6, 12, 18 and 24 months after therapy. All subjects received scaling and root planing and 156 one or more of periodontal surgery, systemically administered amoxicillin + metronidazole or local tetracycline at pockets ≥5 mm. Subgingival biofilm samples taken from each subject at each time point were analysed for their content of 40 bacterial species using checkerboard DNA-DNA hybridization. The significance of changes in median species counts over time was sought using the Wilcoxon or Friedman tests and adjusted for multiple comparisons. Mean counts were significantly reduced from baseline to 2 years for 30 of the 40 taxa. Marked reductions were observed for periodontal pathogens including Tannerella forsythia, Treponema denticola and Eubacterium nodatum. The kinetics of change differed from species to species. When data were subset according to baseline PD, patterns of change in the microbial profiles were generally similar. Periodontal therapy leads to a rapid reduction in periodontal pathogens, followed by a slower reduction in other taxa that can be sustained for at least 2 years. © 2013 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  20. Root Canal Microbiota of Teeth with Chronic Apical Periodontitis▿ †

    PubMed Central

    Rôças, I. N.; Siqueira, J. F.

    2008-01-01

    Samples from infected root canals of 43 teeth with chronic apical periodontitis were analyzed for the presence and relative levels of 83 oral bacterial species and/or phylotypes using a reverse-capture checkerboard hybridization assay. Associations between the most frequently detected taxa were also recorded. The most prevalent taxa were Olsenella uli (74%), Eikenella corrodens (63%), Porphyromonas endodontalis (56%), Peptostreptococcus anaerobius (54%), and Bacteroidetes oral clone X083 (51%). When prevalence was considered only for bacteria present at levels >105, Bacteroidetes clone X083 was the most frequently isolated bacterium (37%), followed by Parvimonas micra (28%), E. corrodens (23%), and Tannerella forsythia (19%). The number of target taxa per canal was directly proportional to the size of the apical periodontitis lesion, with lesions >10 mm in diameter harboring a mean number of approximately 20 taxa. Several positive associations for the most prevalent taxa were disclosed for the first time and may have important ecological and pathogenic implications. In addition to strengthening the association of several cultivable named species with chronic apical periodontitis, the present findings using a large-scale analysis allowed the inclusion of some newly named species and as-yet-uncultivated phylotypes in the set of candidate pathogens associated with this disease. PMID:18768651

  1. Pathogen evolution and the immunological niche.

    PubMed

    Cobey, Sarah

    2014-07-01

    Host immunity is a major driver of pathogen evolution and thus a major determinant of pathogen diversity. Explanations for pathogen diversity traditionally assume simple interactions between pathogens and the immune system, a view encapsulated by the susceptible-infected-recovered (SIR) model. However, there is growing evidence that the complexity of many host-pathogen interactions is dynamically important. This revised perspective requires broadening the definition of a pathogen's immunological phenotype, or what can be thought of as its immunological niche. After reviewing evidence that interactions between pathogens and host immunity drive much of pathogen evolution, I introduce the concept of a pathogen's immunological phenotype. Models that depart from the SIR paradigm demonstrate the utility of this perspective and show that it is particularly useful in understanding vaccine-induced evolution. This paper highlights questions in immunology, evolution, and ecology that must be answered to advance theories of pathogen diversity.

  2. Compositions and methods for pathogen transport

    DOEpatents

    El-Etr, Sahar; Farquar, George R.

    2016-01-26

    This disclosure provides a method for transporting a pathogen under ambient conditions, by culturing the pathogen with an amoeba under conditions that favor the incorporation of the pathogen into a trophozoite, starving the amoeba until it encysts, then culturing under conditions that favor conversion of the amoeba back to a trophozoite. In one aspect, the conditions that favor incorporation of the pathogen into the cyst of the amoeba comprises contacting the pathogen with the amoeba in an iron rich environment. Virus and/or bacteria are pathogens that can be transported by the disclosed method. Amoeba that are useful in the disclosed methods include, without limitation Acanthamoeba castellanii, Hartmannella vermiformis and Naegleria gruberi. The disclosed methods have utility in: transporting pathogens from military field hospitals and clinics to the laboratory; transporting pathogens from global satellite laboratories to clinical laboratories; long term storage of pathogens; enriching contaminated patient samples for pathogens of interest; biosurveillance and detection efforts.

  3. Pathogen evolution and the immunological niche

    PubMed Central

    Cobey, Sarah

    2014-01-01

    Host immunity is a major driver of pathogen evolution and thus a major determinant of pathogen diversity. Explanations for pathogen diversity traditionally assume simple interactions between pathogens and the immune system, a view encapsulated by the susceptible–infected–recovered (SIR) model. However, there is growing evidence that the complexity of many host–pathogen interactions is dynamically important. This revised perspective requires broadening the definition of a pathogen's immunological phenotype, or what can be thought of as its immunological niche. After reviewing evidence that interactions between pathogens and host immunity drive much of pathogen evolution, I introduce the concept of a pathogen's immunological phenotype. Models that depart from the SIR paradigm demonstrate the utility of this perspective and show that it is particularly useful in understanding vaccine-induced evolution. This paper highlights questions in immunology, evolution, and ecology that must be answered to advance theories of pathogen diversity. PMID:25040161

  4. The Main Aeromonas Pathogenic Factors

    PubMed Central

    Tomás, J. M.

    2012-01-01

    The members of the Aeromonas genus are ubiquitous, water-borne bacteria. They have been isolated from marine waters, rivers, lakes, swamps, sediments, chlorine water, water distribution systems, drinking water and residual waters; different types of food, such as meat, fish, seafood, vegetables, and processed foods. Aeromonas strains are predominantly pathogenic to poikilothermic animals, and the mesophilic strains are emerging as important pathogens in humans, causing a variety of extraintestinal and systemic infections as well as gastrointestinal infections. The most commonly described disease caused by Aeromonas is the gastroenteritis; however, no adequate animal model is available to reproduce this illness caused by Aeromonas. The main pathogenic factors associated with Aeromonas are: surface polysaccharides (capsule, lipopolysaccharide, and glucan), S-layers, iron-binding systems, exotoxins and extracellular enzymes, secretion systems, fimbriae and other nonfilamentous adhesins, motility and flagella. PMID:23724321

  5. Acinetobacter: an underrated foodborne pathogen?

    PubMed

    Amorim, Angelo Maximo Batista de; Nascimento, Janaína Dos Santos

    2017-02-28

    The increasing prevalence of foodborne diseases observed in developing countries has been linked to a rise in the consumption of raw foods. However, unlike the classical pathogens that are commonly implicated in foodborne illnesses, members of the genus Acinetobacter are rarely associated with diarrheal disease, probably because of the difficulty in isolating these Gram-negative bacteria from food sources. Nevertheless, several species of Acinetobacter, especially A. baumannii, possess many of the characteristics associated with successful pathogens and exhibit a prodigious ability to acquire the multiple-drug resistance (MDR) phenotype. In this mini-review, we summarize the epidemiological data relating to MDR Acinetobacter and consider evidence suggesting that contaminated dairy products, along with raw fruit and vegetables, constitute extra-hospital reservoirs of this underrated pathogen, and may represent an increased risk to immunocompromised individuals and young children in healthcare settings.

  6. [Population genetics of plant pathogens].

    PubMed

    Zhu, Wen; Zhan, Jia-Sui

    2012-02-01

    Comparing to natural ecosystems, the evolution of plant pathogens in agricultural ecosystems is generally faster due to high-density monocultures, large-scale application of agrochemicals, and international trade in agricultural products. Knowledge of the population genetics and evolutionary biology of plant pathogens is necessary to understand disease epidemiology, effectively breed and use resistant cultivars, and control plant diseases. In this article, we outlined the aims of population genetic studies in plant pathogens, discuss contributions of five evolutionary forces (i.e., mutation, gene flow, recombination, random genetic drift, and natural selection) to origin, maintenance, and distribution of genetic variation in time and space, and gave an overview of current research status in this field.

  7. Metabolic traits of pathogenic streptococci.

    PubMed

    Willenborg, Jörg; Goethe, Ralph

    2016-11-01

    Invasive and noninvasive diseases caused by facultative pathogenic streptococci depend on their equipment with virulence factors and on their ability to sense and adapt to changing nutrients in different host environments. The knowledge of the principal metabolic mechanisms which allow these bacteria to recognize and utilize nutrients in host habitats is a prerequisite for our understanding of streptococcal pathogenicity and the development of novel control strategies. This review aims to summarize and compare the central carbohydrate metabolic and amino acid biosynthetic pathways of a selected group of streptococcal species, all belonging to the naso-oropharyngeal microbiome in humans and/or animals. We also discuss the urgent need of comprehensive metabolomics approaches for a better understanding of the streptococcal metabolism during host-pathogen interaction. © 2016 Federation of European Biochemical Societies.

  8. Infectious pathogens and bronchiolitis outcomes.

    PubMed

    Hasegawa, Kohei; Mansbach, Jonathan M; Camargo, Carlos A

    2014-07-01

    Bronchiolitis is a common early childhood illness and an important cause of morbidity, it is the number one cause of hospitalization among US infants. Bronchiolitis is also an active area of research, and recent studies have advanced our understanding of this illness. Although it has long been the conventional wisdom that the infectious etiology of bronchiolitis does not affect outcomes, a growing number of studies have linked specific pathogens of bronchiolitis (e.g., rhinovirus) to short- and long-term outcomes, such as future risk of developing asthma. The authors review the advent of molecular diagnostic techniques that have demonstrated diverse pathogens in bronchiolitis, and they review recent studies on the complex link between infectious pathogens of bronchiolitis and the development of childhood asthma.

  9. Pathogens and the placental fortress.

    PubMed

    Robbins, Jennifer R; Bakardjiev, Anna I

    2012-02-01

    Placental infections are major causes of maternal and fetal disease. This review introduces a new paradigm for placental infections based on current knowledge of placental defenses and how this barrier can be breached. Transmission of pathogens from mother to fetus can occur at two sites of direct contact between maternal cells and specialized fetal cells (trophoblasts) in the human placenta: firstly, maternal immune and endothelial cells juxtaposed to extravillous trophoblasts in the uterine implantation site and secondly, maternal blood surrounding the syncytiotrophoblast (SYN). Recent findings suggest that the primary vulnerability is in the implantation site. We explore evidence that the placental SYN evolved as a defense against pathogens, and that inflammation-mediated spontaneous abortion may benefit mother and pathogen. Copyright © 2011 Elsevier Ltd. All rights reserved.

  10. Pathogens and the Placental Fortress

    PubMed Central

    Robbins, Jennifer R.

    2011-01-01

    Summary Placental infections are major causes of maternal and fetal disease. This review introduces a new paradigm for placental infections based on current knowledge of placental defenses and how this barrier can be breached. Transmission of pathogens from mother to fetus can occur at two sites of direct contact between maternal cells and specialized fetal cells (trophoblasts) in the human placenta: (i) maternal immune and endothelial cells juxtaposed to extravillous trophoblasts in the uterine implantation site and (ii) maternal blood surrounding the syncytiotrophoblast. Recent findings suggest that the primary vulnerability is in the implantation site. We explore evidence that the placental syncytiotrophoblast evolved as a defense against pathogens, and that inflammation-mediated spontaneous abortion may benefit mother and pathogen. PMID:22169833

  11. Proteomics of Plant Pathogenic Fungi

    PubMed Central

    González-Fernández, Raquel; Prats, Elena; Jorrín-Novo, Jesús V.

    2010-01-01

    Plant pathogenic fungi cause important yield losses in crops. In order to develop efficient and environmental friendly crop protection strategies, molecular studies of the fungal biological cycle, virulence factors, and interaction with its host are necessary. For that reason, several approaches have been performed using both classical genetic, cell biology, and biochemistry and the modern, holistic, and high-throughput, omic techniques. This work briefly overviews the tools available for studying Plant Pathogenic Fungi and is amply focused on MS-based Proteomics analysis, based on original papers published up to December 2009. At a methodological level, different steps in a proteomic workflow experiment are discussed. Separate sections are devoted to fungal descriptive (intracellular, subcellular, extracellular) and differential expression proteomics and interactomics. From the work published we can conclude that Proteomics, in combination with other techniques, constitutes a powerful tool for providing important information about pathogenicity and virulence factors, thus opening up new possibilities for crop disease diagnosis and crop protection. PMID:20589070

  12. Picturing pathogen infection in plants.

    PubMed

    Barón, Matilde; Pineda, Mónica; Pérez-Bueno, María Luisa

    2016-09-01

    Several imaging techniques have provided valuable tools to evaluate the impact of biotic stress on host plants. The use of these techniques enables the study of plant-pathogen interactions by analysing the spatial and temporal heterogeneity of foliar metabolism during pathogenesis. In this work we review the use of imaging techniques based on chlorophyll fluorescence, multicolour fluorescence and thermography for the study of virus, bacteria and fungi-infected plants. These studies have revealed the impact of pathogen challenge on photosynthetic performance, secondary metabolism, as well as leaf transpiration as a promising tool for field and greenhouse management of diseases. Images of standard chlorophyll fluorescence (Chl-F) parameters obtained during Chl-F induction kinetics related to photochemical processes and those involved in energy dissipation, could be good stress indicators to monitor pathogenesis. Changes on UV-induced blue (F440) and green fluorescence (F520) measured by multicolour fluorescence imaging in pathogen-challenged plants seem to be related with the up-regulation of the plant secondary metabolism and with an increase in phenolic compounds involved in plant defence, such as scopoletin, chlorogenic or ferulic acids. Thermal imaging visualizes the leaf transpiration map during pathogenesis and emphasizes the key role of stomata on innate plant immunity. Using several imaging techniques in parallel could allow obtaining disease signatures for a specific pathogen. These techniques have also turned out to be very useful for presymptomatic pathogen detection, and powerful non-destructive tools for precision agriculture. Their applicability at lab-scale, in the field by remote sensing, and in high-throughput plant phenotyping, makes them particularly useful. Thermal sensors are widely used in crop fields to detect early changes in leaf transpiration induced by both air-borne and soil-borne pathogens. The limitations of measuring photosynthesis by

  13. From multiple pathogenicity islands to a unique organized pathogenicity archipelago

    PubMed Central

    Bouyioukos, Costas; Reverchon, Sylvie; Képès, François

    2016-01-01

    Pathogenicity islands are sets of successive genes in a genome that determine the virulence of a bacterium. In a growing number of studies, bacterial virulence appears to be determined by multiple islands scattered along the genome. This is the case in a family of seven plant pathogens and a human pathogen that, under KdgR regulation, massively secrete enzymes such as pectinases that degrade plant cell wall. Here we show that their multiple pathogenicity islands form together a coherently organized, single “archipelago” at the genome scale. Furthermore, in half of the species, most genes encoding secreted pectinases are expressed from the same DNA strand (transcriptional co-orientation). This genome architecture favors DNA conformations that are conducive to genes spatial co-localization, sometimes complemented by co-orientation. As proteins tend to be synthetized close to their encoding genes in bacteria, we propose that this architecture would favor the efficient funneling of pectinases at convergent points within the cell. The underlying functional hypothesis is that this convergent funneling of the full blend of pectinases constitutes a crucial strategy for successful degradation of the plant cell wall. Altogether, our work provides a new approach to describe and predict, at the genome scale, the full virulence complement. PMID:27302835

  14. Pathogenic rickettsiae as bioterrorism agents.

    PubMed

    Azad, Abdu F

    2007-07-15

    Because of their unique biological characteristics, such as environmental stability, small size, aerosol transmission, persistence in infected hosts, low infectious dose, and high associated morbidity and mortality, Rickettsia prowazekii and Coxiella burnetii have been weaponized. These biological attributes would make the pathogenic rickettsiae desirable bioterrorism agents. However, production of highly purified, virulent, weapon-quality rickettsiae is a daunting task that requires expertise and elaborate, state-of-the art laboratory procedures to retain rickettsial survival and virulence. Another drawback to developing rickettsial pathogens as biological weapons is their lack of direct transmission from host to host and the availability of very effective therapeutic countermeasures against these obligate intracellular bacteria.

  15. New trends in emerging pathogens.

    PubMed

    Skovgaard, Niels

    2007-12-15

    The emergence of pathogens is the result of a number of impact in all parts of the food chain. The emerging technologies in food production explain how new pathogens can establish themselves in the food chain and compromise food safety. The impact of the food technology is analysed for several bacteria, such as Yersinia, Campylobacter, Arcobacter, Helicobacter pullorum, Enterobacter sakazakii, Mycobacterium avium spp. paratuberculosis, prions related to vCJD and others. The importance of the ability of many microbes to form VBNC forms is elaborated on. Research on culture independent methods may address this outstanding issue to the better understanding of emerging pathogens. The "demerging" of pathogens also occur, and examples of this are explained. The reaction of bacteria to stresses and sublethal treatments, and how exposure to one stress factor can confer resistance to other stresses, literally speaking causing contagious resistance, are explained. The implication of this e.g. in modern approaches of food preservation, such as Minimally processed Foods, is considerable. Intestinal colonization of EHEC may be regulated by Quorum sensing, and this ability of microbes plays an important role in the colonization of microbes in food and on food processing equipment, an important factor in the emergence of pathogens. The emergence of Saccharomyces cerevisiae, as an opportunistic human pathogen, used for centuries for food and production of alcoholic beverages, calls for research in molecular tools to distinguish between probiotic and clinical strains. Cyclospora cayetanensis and Norovirus outbreaks can no longer be designated as emerging pathogens, they share however one characteristic in the epidemiology of emerging nature, the importance of the hygiene in the primary production stage, including supply of potable water, and the application of GMP and the HACCP principles in the beginning of the food chain. Hepatitis E virus is a potential emerging food borne

  16. Suppuration-associated bacteria in patients with chronic and aggressive periodontitis.

    PubMed

    Silva-Boghossian, Carina M; Neves, Aline B; Resende, Fátima A R; Colombo, Ana Paula V

    2013-09-01

    Suppuration (SUP) on probing may be an indication of active periodontal breakdown. The aim of the present study is to analyze which subgingival species are associated with SUP in patients with chronic (CP) and aggressive (AgP) periodontitis. A total of 156 patients with CP and 66 with AgP were submitted to full-mouth periodontal examination and subgingival biofilm sampling (14 sites/patient). The counts of 44 bacterial species were determined by checkerboard. Comparisons between groups and sites were analyzed by the Mann-Whitney and Wilcoxon tests, respectively. Associations between frequency of SUP and bacterial species were analyzed by the Spearman correlation coefficient. The prevalence of SUP in patients with CP was 24.4%, and in patients with AgP it was 30.3%, and the percentage of SUP sites in the groups was 5.72% ± 1.06% and 6.96% ± 1.70%, respectively (P >0.05). SUP sites from patients with CP had significantly higher counts of Veillonella parvula, Dialister pneumosintes, Tannerella forsythia, and Prevotella nigrescens than SUP sites from patients with AgP (P <0.005). Significant positive correlations between high frequency of SUP and high levels of Actinomyces spp, Streptococcus spp., members of the orange complex, Acinetobacter baumannii, and Pseudomonas aeruginosa were observed in patients with CP (P <0.05). In patients with AgP, Actinomyces oris, Propionibacterium acnes, P. aeruginosa, Staphylococcus aureus, and Streptococcus sanguinis were positively associated with SUP, whereas Prevotella intermedia presented a negative association with SUP (P <0.05). SUP sites from patients with CP harbored significantly higher counts of several periodontal species than SUP sites from patients with AgP. Actinomyces spp., Streptococcus spp., members of the orange complex, T. forsythia, and certain non-oral pathogens were associated with a high number of sites with SUP.

  17. Microbial colonization at the implant-abutment interface and its possible influence on periimplantitis: A systematic review and meta-analysis.

    PubMed

    Tallarico, Marco; Canullo, Luigi; Caneva, Martina; Özcan, Mutlu

    2017-07-01

    The aim of this systematic review and meta-analysis was to evaluate the microbial colonization at the implant-abutment interfaces (IAI) on bone-level implants and to identify possible association with peri-implant conditions. The focus question aimed to answer whether two-piece osseointegrated implants, in function for at least 1 year, in human, relate to higher bacterial count and the onset of periimplantitis, compared to healthy peri-implant conditions. Search strategy encompassed the on-line (MedLine, Google scholar, Cochrane library) literature from 1990 up to March 2015 published in English using combinations of MeSH (Medical Subject Headings) and search terms. Quality assessment of selected full-text articles was performed according to the ARRIVE and CONSORT statement guidelines. For data analysis, the total bacterial count of Porphyromonas gingivalis, Tannerella forsythia, Treponema denticola, Prevotella intermedia, and Fusobacterium nucleatum was calculated and compared to IAI with or without peri-implant pathology. A total of 14 articles, reporting data from 1126 implants, fulfilled the inclusion criteria and subjected to quality assessment. The selected studies revealed contamination of the IAI, in patients who received two-piece implant systems. Meta-analysis indicated significant difference in total bacterial count between implants affected by periimplantitis versus healthy peri-implant tissues (0.387±0.055; 95% CI 0.279-0.496). Less bacterial counts were identified in the healthy IAI for all the investigated gram-negative bacteria except for T. forsythia. Significantly higher bacterial counts were found for periodontal pathogenic bacteria within the IAI of implants in patients with periimplantitis compared to those implants surrounded by healthy peri-implant tissues. Copyright © 2017 Japan Prosthodontic Society. Published by Elsevier Ltd. All rights reserved.

  18. Apical root canal microbiota as determined by reverse-capture checkerboard analysis of cryogenically ground root samples from teeth with apical periodontitis.

    PubMed

    Rôças, Isabela N; Alves, Flávio R F; Santos, Adriana L; Rosado, Alexandre S; Siqueira, José F

    2010-10-01

    Bacteria located in the apical root canal system potentially participate in the pathogenesis of apical periodontitis. Detection and identification of apical bacteria can be compromised because of limitations in conventional sampling and identification procedures. This study identified several bacterial taxa in the apical and middle/coronal segments of primarily infected root canal system by using pulverized root segments and a culture-independent molecular method. Seventeen extracted teeth with attached apical periodontitis lesions were sectioned to obtain 2 root fragments (apical and middle/coronal segments). Root fragments were cryogenically ground, and DNA was extracted from samples. After multiple displacement amplification, DNA from samples was used as template in a reverse-capture checkerboard hybridization assay targeting 28 bacterial taxa. Bacterial DNA was detected in all samples. The most prevalent taxa in the apical root canal system were Olsenella uli (76.5%), Prevotella baroniae (71%), Porphyromonas endodontalis (65%), Fusobacterium nucleatum (53%), and Tannerella forsythia (47%). O. uli, P. endodontalis, and Propionibacterium acnes were as frequently detected in apical samples as they were in middle/coronal samples. P. baroniae, T. forsythia, and F. nucleatum were found more frequently in the apical part of the canal as compared with matched coronal segments. Streptococcus species were more prevalent in middle/coronal samples. The median and mean of shared bacterial taxa between matched apical and middle/coronal segments were 27% and 41%, respectively. Several candidate endodontic pathogens were very prevalent in the apical root canal system. The apical microbiota was usually complex and differed in species composition when compared with the microbiota of middle/coronal samples from the same tooth. Copyright © 2010 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

  19. Pathogen pollution and the emergence of a deadly amphibian pathogen.

    PubMed

    McKenzie, Valerie J; Peterson, Anna C

    2012-11-01

    Imagine a single pathogen that is responsible for mass mortality of over a third of an entire vertebrate class. For example, if a single pathogen were causing the death, decline and extinction of 30% of mammal species (including humans), the entire world would be paying attention. This is what has been happening to the world's amphibians - the frogs, toads and salamanders that are affected by the chytrid fungal pathogen, Batrachochytrium dendrobatidis (referred to as Bd), which are consequently declining at an alarming rate. It has aptly been described as the worst pathogen in history in terms of its effects on biodiversity (Kilpatrick et al. 2010). The pathogen was only formally described about 13 years ago (Longcore et al. 1999), and scientists are still in the process of determining where it came from and investigating the question: why now? Healthy debate has ensued as to whether Bd is a globally endemic organism that only recently started causing high mortality due to shifting host responses and/or environmental change (e.g. Pounds et al. 2006) or whether a virulent strain of the pathogen has rapidly disseminated around the world in recent decades, affecting new regions with a vengeance (e.g. Morehouse et al. 2003; Weldon et al. 2004; Lips et al. 2008). We are finally beginning to shed more light on this question, due to significant discoveries that have emerged as a result of intensive DNA-sequencing methods comparing Bd isolates from different amphibian species across the globe. Evidence is mounting that there is indeed a global panzootic lineage of Bd (BdGPL) in addition to what appear to be more localized endemic strains (Fisher et al. 2009; James et al. 2009; Farrer et al. 2011). Additionally, BdGPL appears to be a hypervirulent strain that has resulted from the hybridization of different Bd strains that came into contact in recent decades, and is now potentially replacing the less-virulent endemic strains of the pathogen (Farrer et al. 2011

  20. Bloodborne Pathogens Exposure Control Plan.

    ERIC Educational Resources Information Center

    National Child Care Association, Atlanta, GA.

    This sample exposure control plan is a guide to assist child care providers in complying with the blood-borne pathogens standard issued by the Occupational Safety and Health Administration (OSHA). The standard requires employers to establish a written exposure control plan by May 5, 1992 (for exposure to microorganisms in human blood that cause…

  1. MANAGING URBAN WATERSHED PATHOGEN CONTAMINATION

    EPA Science Inventory

    This presentation is a summary of the EPA National Risk Management Research Laboratory (NRMRL) publication entitled Managing Urban Watershed Pathogen Contamination, EPA/600/R-03/111 (September 2003). It is available on the internet at http://www.epa.gov/ednnrmrl/repository/water...

  2. USEPA PERSPECTIVE ON CONTROLLING PATHOGENS

    EPA Science Inventory

    EPA minimizes the risk of infectious diseases from the beneficial use of sludge by requiring its treatment to reduce pathogen levels below the detection limit. How new treatment processes can be shown equivalent to ones specified in 40CFR503 will be discussed together with ways t...

  3. Microbial Forensics and Plant Pathogens

    USDA-ARS?s Scientific Manuscript database

    New awareness of the vulnerability of a nation's agricultural infrastructure to the intentional introduction of pathogens or pests has led to the enhancement of programs for prevention and preparedness. A necessary component of a balanced bio-security plan is the capability to determine whether an ...

  4. MANAGING URBAN WATERSHED PATHOGEN CONTAMINATION

    EPA Science Inventory

    This document is written as a resource for state and local watershed managers who have the responsibility of managing pathogen contamination in urban watersheds. In addition it can be an information source for members of the public interested in watershed mitigation efforts aime...

  5. MANAGING URBAN WATERSHED PATHOGEN CONTAMINATION

    EPA Science Inventory

    This presentation is a summary of the EPA National Risk Management Research Laboratory (NRMRL) publication entitled Managing Urban Watershed Pathogen Contamination, EPA/600/R-03/111 (September 2003). It is available on the internet at http://www.epa.gov/ednnrmrl/repository/water...

  6. USEPA PERSPECTIVE ON CONTROLLING PATHOGENS

    EPA Science Inventory

    EPA minimizes the risk of infectious diseases from the beneficial use of sludge by requiring its treatment to reduce pathogen levels below the detection limit. How new treatment processes can be shown equivalent to ones specified in 40CFR503 will be discussed together with ways t...

  7. The Evolution of Foodborne Pathogens

    NASA Astrophysics Data System (ADS)

    Abu-Ali, Galeb S.; Manning, Shannon D.

    Despite continuous advances in food safety and disease surveillance, control, and prevention, foodborne bacterial infections remain a major public health concern. Because foodborne pathogens are commonly exposed to multiple environmental stressors, such as low pH and antibiotics, most have evolved specific mechanisms to facilitate survival in adverse environments.

  8. MANAGING URBAN WATERSHED PATHOGEN CONTAMINATION

    EPA Science Inventory

    This document is written as a resource for state and local watershed managers who have the responsibility of managing pathogen contamination in urban watersheds. In addition it can be an information source for members of the public interested in watershed mitigation efforts aime...

  9. Pathogenicity of Shigella in chickens.

    PubMed

    Shi, Run; Yang, Xia; Chen, Lu; Chang, Hong-tao; Liu, Hong-ying; Zhao, Jun; Wang, Xin-wei; Wang, Chuan-qing

    2014-01-01

    Shigellosis in chickens was first reported in 2004. This study aimed to determine the pathogenicity of Shigella in chickens and the possibility of cross-infection between humans and chickens. The pathogenicity of Shigella in chickens was examined via infection of three-day-old SPF chickens with Shigella strain ZD02 isolated from a human patient. The virulence and invasiveness were examined by infection of the chicken intestines and primary chicken intestinal epithelial cells. The results showed Shigella can cause death via intraperitoneal injection in SPF chickens, but only induce depression via crop injection. Immunohistochemistry and transmission electron microscopy revealed the Shigella can invade the intestinal epithelia. Immunohistochemistry of the primary chicken intestinal epithelial cells infected with Shigella showed the bacteria were internalized into the epithelial cells. Electron microscopy also confirmed that Shigella invaded primary chicken intestinal epithelia and was encapsulated by phagosome-like membranes. Our data demonstrate that Shigella can invade primary chicken intestinal epithelial cells in vitro and chicken intestinal mucosa in vivo, resulting in pathogenicity and even death. The findings suggest Shigella isolated from human or chicken share similar pathogenicity as well as the possibility of human-poultry cross-infection, which is of public health significance.

  10. Biosignatures of Pathogen and Host

    SciTech Connect

    Fitch, J P; Chromy, B A; Forde, C E; Garcia, E; Gardner, S N; Gu, P P; Kuczmarksi, T A; Melius, C F; McCutchen-Maloney, S L; Milanovich, F P; Motin, V L; Ott, L L; Quong, A A; Quong, J N; Rocco, J M; Slezak, T R; Sokhansanj, B A; Vitalis, E A; Zemla, A T; McCready, P M

    2002-08-27

    In information theory, a signature is characterized by the information content as well as noise statistics of the communication channel. Biosignatures have analogous properties. A biosignature can be associated with a particular attribute of a pathogen or a host. However, the signature may be lost in backgrounds of similar or even identical signals from other sources. In this paper, we highlight statistical and signal processing challenges associated with identifying good biosignatures for pathogens in host and other environments. In some cases it may be possible to identify useful signatures of pathogens through indirect but amplified signals from the host. Discovery of these signatures requires new approaches to modeling and data interpretation. For environmental biosignal collections, it is possible to use signal processing techniques from other applications (e.g., synthetic aperture radar) to track the natural progression of microbes over large areas. We also present a computer-assisted approach to identify unique nucleic-acid based microbial signatures. Finally, an understanding of host-pathogen interactions will result in better detectors as well as opportunities in vaccines and therapeutics.

  11. Bloodborne Pathogens Exposure Control Plan.

    ERIC Educational Resources Information Center

    National Child Care Association, Atlanta, GA.

    This sample exposure control plan is a guide to assist child care providers in complying with the blood-borne pathogens standard issued by the Occupational Safety and Health Administration (OSHA). The standard requires employers to establish a written exposure control plan by May 5, 1992 (for exposure to microorganisms in human blood that cause…

  12. Pathogenicity of Shigella in Chickens

    PubMed Central

    Chen, Lu; Chang, Hong-tao; Liu, Hong-ying; Zhao, Jun; Wang, Xin-wei; Wang, Chuan-qing

    2014-01-01

    Shigellosis in chickens was first reported in 2004. This study aimed to determine the pathogenicity of Shigella in chickens and the possibility of cross-infection between humans and chickens. The pathogenicity of Shigella in chickens was examined via infection of three-day-old SPF chickens with Shigella strain ZD02 isolated from a human patient. The virulence and invasiveness were examined by infection of the chicken intestines and primary chicken intestinal epithelial cells. The results showed Shigella can cause death via intraperitoneal injection in SPF chickens, but only induce depression via crop injection. Immunohistochemistry and transmission electron microscopy revealed the Shigella can invade the intestinal epithelia. Immunohistochemistry of the primary chicken intestinal epithelial cells infected with Shigella showed the bacteria were internalized into the epithelial cells. Electron microscopy also confirmed that Shigella invaded primary chicken intestinal epithelia and was encapsulated by phagosome-like membranes. Our data demonstrate that Shigella can invade primary chicken intestinal epithelial cells in vitro and chicken intestinal mucosa in vivo, resulting in pathogenicity and even death. The findings suggest Shigella isolated from human or chicken share similar pathogenicity as well as the possibility of human-poultry cross-infection, which is of public health significance. PMID:24949637

  13. Pathogenicity of Aseptic Bursaphelenchus xylophilus

    PubMed Central

    Zhu, Li-hua; Ye, Jianren; Negi, Sapna; Xu, Xu-ling; Wang, Zhang-li; Ji, Jin-yi

    2012-01-01

    Pine wilt is a disease of pine (Pinus spp.) caused by the pine wood nematode (PWN), Bursaphelenchus xylophilus. However, the pathogenic mechanism of pine wilt disease (PWD) remains unclear. Although the PWN was thought to be the only pathogenic agent associated with this disease, a potential role for bacterial symbionts in the disease process was recently proposed. Studies have indicated that aseptic PWNs do not cause PWD in aseptic pine trees, while PWNs associated with bacteria cause wilting symptoms. To investigate the pathogenicity of the PWN and its associated bacteria, 3-month-old microcuttings derived from certain clones of Pinus densiflora Siebold & Zucc. produced in vitro were inoculated under aseptic conditions with aseptic PWNs, non-aseptic PWNs and bacteria isolated from the nematodes. Six-month-old aseptic P. densiflora microcuttings and 7-month-old P. massoniana seedlings were also inoculated under aseptic conditions with aseptic PWNs and non-aseptic PWNs. The results showed that the aseptic microcuttings and seedlings inoculated with aseptic PWNs or non-aseptic PWNs wilted, while those inoculated with bacterial isolates did not wilt. Nematodes were recovered from wilted microcuttings and seedlings inoculated with aseptic PWNs and non-aseptic PWNs, and the asepsis of nematodes recovered from aseptic PWN-inoculated microcuttings and seedlings was reconfirmed by culturing them in NB liquid medium at 30°C for more than 7 days. Taken together, the results indicate that the asepsis of PWN did not cause the loss of pathogenicity. PMID:22662271

  14. Lectins in human pathogenic fungi.

    PubMed

    Gallegos, Belém; Martínez, Ruth; Pérez, Laura; Del Socorro Pina, María; Perez, Eduardo; Hernández, Pedro

    2014-01-01

    Lectins are carbohydrate-binding proteins widely distributed in nature. They constitute a highly diverse group of proteins consisting of many different protein families that are, in general, structurally unrelated. In the last few years, mushroom and other fungal lectins have attracted wide attention due to their antitumour, antiproliferative and immunomodulatory activities. The present mini-review provides concise information about recent developments in understanding lectins from human pathogenic fungi. A bibliographic search was performed in the Science Direct and PubMed databases, using the following keywords "lectin", "fungi", "human" and "pathogenic". Lectins present in fungi have been classified; however, the role played by lectins derived from human pathogenic fungi in infectious processes remains uncertain; thus, this is a scientific field requiring more research. This manuscript is part of the series of works presented at the "V International Workshop: Molecular genetic approaches to the study of human pathogenic fungi" (Oaxaca, Mexico, 2012). Copyright © 2013 Revista Iberoamericana de Micología. Published by Elsevier Espana. All rights reserved.

  15. Kicking Out Pathogens in Exosomes.

    PubMed

    Sergeeva, Oksana A; van der Goot, F Gisou

    2015-06-04

    Host-pathogen interactions involve a series of attacks and counter-attacks. Miao et al. show that, although some invading bacteria can take shelter in lysosomes by neutralizing their pH, this respite is temporary, as host cells can expel them in exosomes. Copyright © 2015 Elsevier Inc. All rights reserved.

  16. Genetic analysis of Porphyromonas gingivalis (fimA), Aggregatibacter actinomycetemcomitans, and red complex in coronary plaque.

    PubMed

    Mahendra, Jaideep; Mahendra, Little; Felix, John; Romanos, Georgios E

    2014-08-01

    The objective of the present study was to detect the presence of Porphyromonas gingivalis (fimA), Aggregatibacter actinomycetemcomitans, and red complex in the coronary plaque of patients with coronary artery disease. The study population consisted of 51 patients with chronic periodontitis undergoing coronary artery bypass grafting. DNA was extracted from subgingival and coronary atherosclerotic plaque samples. Polymerase chain reaction was used to amplify the part of 16S rRNA gene to detect the presence of Aggregatibacter actinomycetemcomitans, Porphyromonas gingivalis (fimA), Porphyromonas gingivalis, Tannerella forsythia, and Treponema denticola. Aggregatibacter actinomycetemcomitans, Tannerella forsythia, Porphyromonas gingivalis, Porphyromonas gingivalis (fimA), and Treponema denticola were detected in 0%, 31.4%, 45.1%, 39.2%, and 51% of the atherosclerotic plaque samples, respectively. In both subgingival and coronary atherosclerotic plaque samples, Tannerella forsythia was detected in 19.6%, Porphyromonas gingivalis in 39.2%, Porphyromonas gingivalis (fimA) in 33.3%, and Treponema denticola in 35.3% of the samples. The study confirmed the detection of red complex bacteria in coronary plaque samples. However Aggregatibacter actinomycetemcomitans could not be detected in these samples. © 2013 Wiley Publishing Asia Pty Ltd.

  17. Pathogenicity, morphology, and differentiation of Acanthamoeba.

    PubMed

    Khan, N A

    2001-12-01

    Acanthamoeba keratitis is sight threatening corneal infection caused by pathogenic Acanthamoeba. Previous studies have shown the genotypic differences between pathogenic and non-pathogenic species/strains of Acanthamoeba. In this study, we examined the morphological differences between pathogenic and non-pathogenic species/strains using scanning electron microscopy. Pathogenic Acanthamoeba exhibited higher number of acanthopodia (structures associated with the binding of amoeba to the target cells) as compared to non-pathogens. In addition, interactions of amoeba with the corneal epithelial cells were studied. Only pathogenic amoeba exhibited adhesion to epithelial cells. Further results indicated that phagocytosis occurs in the pathogenic amoeba by the formation of amoebastome (characteristic of amoeba phagocyte). This study showed that Acanthamoeba phagocytosis may be both an efficient means of obtaining nutrients for the amoeba and a significant factor in the pathogenesis of Acanthamoeba infections.

  18. Discovery of the Plague Pathogen: Lessons Learned.

    PubMed

    Yang, Ruifu; Butler, Thomas

    2016-01-01

    Plague resulted in three pandemics in history; however, its causative pathogen was isolated until the third pandemic in Hong Kong in 1894. At that time, two famous researchers, Dr. Alexandre Yersin and Dr. Shibasaburo Kitasato, went to HK, in order to identify the pathogen. The two great researchers had done a lot of work to isolate and identify the causative pathogen. However, Dr. Alexandre Yersin reported the real pathogen for plague, and we now acknowledge his work by nominating the pathogen's genus as Yersinia. In this chapter, we discussed the lessons learned from the two researchers' experience on isolation and identification of plague pathogen.

  19. Spiramycin resistance in human periodontitis microbiota.

    PubMed

    Rams, Thomas E; Dujardin, Sebastien; Sautter, Jacqueline D; Degener, John E; van Winkelhoff, Arie J

    2011-08-01

    The occurrence of in vitro resistance to therapeutic concentrations of spiramycin, amoxicillin, and metronidazole was determined for putative periodontal pathogens isolated in the United States. Subgingival plaque specimens from 37 consecutive adults with untreated severe periodontitis were anaerobically cultured, and isolated putative periodontal pathogens were identified to a species level. In vitro resistance to spiramycin at 4 μg/ml, amoxicillin at 8 μg/ml, and/or metronidazole at 16 μg/ml was noted when putative periodontal pathogen growth was noted on the respective antibiotic-supplemented primary culture plates. A total of 18 (48.7%) subjects yielded antibiotic-resistant putative periodontal pathogens with spiramycin at 4 μg/ml in drug-supplemented primary isolation plates, as compared to 23 (62.2%) subjects with amoxicillin at 8 μg/ml, and 10 (27.0%) subjects with metronidazole at 16 μg/ml. Spiramycin in vitro resistance occurred among species of Fusobacterium nucleatum (44.4% of organism-positive subjects), Prevotella intermedia/nigrescens (11.1%), Parvimonas micra (10.8%), Streptococcus constellatus (10%), Streptococcus intermedius (10%), Porphyromonas gingivalis (6.7%), and Tannerella forsythia (5.3%). Amoxicillin in vitro resistance was found in P. intermedia/nigrescens (55.5%), T. forsythia (15.8%), S. constellatus (10%), F. nucleatum (5.6%), and P. micra (2.7%). Only S. constellatus (70%) and S. intermedius (40%) exhibited in vitro resistance to metronidazole. When subject-based resistance data for spiramycin and metronidazole were jointly considered, all isolated putative periodontal pathogens were inhibited in vitro by one or the other of the antibiotic concentrations, except for one strain each of S. constellatus and S. intermedius from one study subject. Similarly, either amoxicillin or metronidazole at the drug concentrations tested inhibited in vitro all recovered putative periodontal pathogens, except S. constellatus in one subject. In

  20. Periodontal pathogens in erupting third molars of periodontally healthy subjects.

    PubMed

    Rajasuo, A; Sihvonen, O J; Peltola, M; Meurman, J H

    2007-09-01

    The presence of Actinobacillus actinomycetemcomitans, Porphyromonas gingivalis, Prevotella intermedia and Tannerella forsythensis in bacteriologic samples of 5-7-mm deep mandibular third-molar pericoronal pockets was analysed by polymerase chain reaction, to test the hypothesis that these sites would harbour the bacteria. The patients were periodontally healthy 20-year-old Finnish male conscripts. Sixteen had acute pericoronitis, 28 chronic pericoronitis, and 15 were symptom-free controls. A. actinomycetemcomitans was detected in only 7% of the samples from chronic pericoronitis cases, whereas P. gingivalis was positive in 20% of the symptom-free versus 69% (P = 0.018) of the acute and 57% (P = 0.044) of the chronic cases. The percentages for P. intermedia were 93, 94 and 93%, and for T. forsythensis 47, 63 and 57%, respectively. These results confirm that, apart from A. actinomycetemcomitans, periodontopathogens are common in third-molar sites in periodontally healthy individuals.

  1. Lagenidium giganteum pathogenicity in mammals.

    PubMed

    Vilela, Raquel; Taylor, John W; Walker, Edward D; Mendoza, Leonel

    2015-02-01

    Infections of mammals by species in the phylum Oomycota taxonomically and molecularly similar to known Lagenidium giganteum strains have increased. During 2013-2014, we conducted a phylogenetic study of 21 mammalian Lagenidium isolates; we found that 11 cannot be differentiated from L. giganteum strains that the US Environmental Protection Agency approved for biological control of mosquitoes; these strains were later unregistered and are no longer available. L. giganteum strains pathogenic to mammals formed a strongly supported clade with the biological control isolates, and both types experimentally infected mosquito larvae. However, the strains from mammals grew well at 25°C and 37°C, whereas the biological control strains developed normally at 25°C but poorly at higher temperatures. The emergence of heat-tolerant strains of L. giganteum pathogenic to lower animals and humans is of environmental and public health concern.

  2. Antimicrobial resistance of mastitis pathogens.

    PubMed

    Oliver, Stephen P; Murinda, Shelton E

    2012-07-01

    Antibiotics are used extensively in the dairy industry to combat disease and to improve animal performance. Antibiotics such as penicillin, cephalosporin, streptomycin, and tetracycline are used for the treatment and prevention of diseases affecting dairy cows caused by a variety of gram-positive and gram-negative bacteria. Antibiotics are often administrated routinely to entire herds to prevent mastitis during the dry period. An increase in the incidence of disease in a herd generally results in increased use of antimicrobials, which in turn increases the potential for antibiotic residues in milk and the potential for increased bacterial resistance to antimicrobials. Continued use of antibiotics in the treatment and prevention of diseases of dairy cows will continue to be scrutinized. It is clear that strategies employing the prudent use of antimicrobials are needed. This clearly illustrates the importance of effective herd disease prevention and control programs. Based on studies published to date, scientific evidence does not support widespread, emerging resistance among mastitis pathogens to antibacterial drugs even though many of these antibiotics have been used in the dairy industry for treatment and prevention of disease for several decades. However, it is clear that use of antibiotics in dairy cows can contribute to increased antimicrobial resistance. While antimicrobial resistance does occur, we are of the opinion that the advantages of using antibiotics for the treatment of mastitis far outweigh the disadvantages. The clinical consequences of antimicrobial resistance of dairy pathogens affecting humans appear small. Antimicrobial resistance among dairy pathogens, particularly those found in milk, is likely not a human health concern as long as the milk is pasteurized. However, there are an increasing number of people who choose to consume raw milk. Transmission of an antimicrobial-resistant mastitis pathogen and/or foodborne pathogen to humans could occur

  3. Bacteriophage biocontrol of foodborne pathogens.

    PubMed

    Kazi, Mustafa; Annapure, Uday S

    2016-03-01

    Bacteriophages are viruses that only infect bacterial cells. Phages are categorized based on the type of their life cycle, the lytic cycle cause lysis of the bacterium with the release of multiple phage particles where as in lysogenic phase the phage DNA is incorporated into the bacterial genome. Lysogeny does not result in lysis of the host. Lytic phages have several potential applications in the food industry as biocontrol agents, biopreservatives and as tools for detecting pathogens. They have also been proposed as alternatives to antibiotics in animal health. Two unique features of phage relevant for food safety are that they are harmless to mammalian cells and high host specificity, keeping the natural microbiota undisturbed. However, the recent approval of bacteriophages as food additives has opened the discussion about 'edible viruses'. This article reviews in detail the application of phages for the control of foodborne pathogens in a process known as "biocontrol".

  4. Lagenidium giganteum Pathogenicity in Mammals

    PubMed Central

    Vilela, Raquel; Taylor, John W.; Walker, Edward D.

    2015-01-01

    Infections of mammals by species in the phylum Oomycota taxonomically and molecularly similar to known Lagenidium giganteum strains have increased. During 2013–2014, we conducted a phylogenetic study of 21 mammalian Lagenidium isolates; we found that 11 cannot be differentiated from L. giganteum strains that the US Environmental Protection Agency approved for biological control of mosquitoes; these strains were later unregistered and are no longer available. L. giganteum strains pathogenic to mammals formed a strongly supported clade with the biological control isolates, and both types experimentally infected mosquito larvae. However, the strains from mammals grew well at 25°C and 37°C, whereas the biological control strains developed normally at 25°C but poorly at higher temperatures. The emergence of heat-tolerant strains of L. giganteum pathogenic to lower animals and humans is of environmental and public health concern. PMID:25625190

  5. APDS: Autonomous Pathogen Detection System

    SciTech Connect

    Langlois, R G; Brown, S; Burris, L; Colston, B; Jones, L; Makarewicz, T; Mariella, R; Masquelier, D; McBride, M; Milanovich, F; Masarabadi, S; Venkateswaran, K; Marshall, G; Olson, D; Wolcott, D

    2002-02-14

    An early warning system to counter bioterrorism, the Autonomous Pathogen Detection System (APDS) continuously monitors the environment for the presence of biological pathogens (e.g., anthrax) and once detected, it sounds an alarm much like a smoke detector warns of a fire. Long before September 11, 2001, this system was being developed to protect domestic venues and events including performing arts centers, mass transit systems, major sporting and entertainment events, and other high profile situations in which the public is at risk of becoming a target of bioterrorist attacks. Customizing off-the-shelf components and developing new components, a multidisciplinary team developed APDS, a stand-alone system for rapid, continuous monitoring of multiple airborne biological threat agents in the environment. The completely automated APDS samples the air, prepares fluid samples in-line, and performs two orthogonal tests: immunoassay and nucleic acid detection. When compared to competing technologies, APDS is unprecedented in terms of flexibility and system performance.

  6. Resistant Pathogens, Fungi, and Viruses

    PubMed Central

    Guidry, Christopher A.; Mansfield, Sara A.; Sawyer, Robert G.; Cook, Charles H.

    2014-01-01

    The first reports of antibiotic pathogens occurred a few short years after the introduction of these powerful new agents, heralding a new kind of war between medicine and pathogens. Although originally described in Staphylococcus aureus, resistance among bacteria has now become a grim race to determine which classes of bacteria will become more resistant, pitting the Gram positive staphylococci, enterococci, and streptococci against the increasingly resistant Gram negative pathogens, e. g., carbapenemase-resistant enterobacteriaceae. In addition, the availability of antibacterial agents has allowed the development of whole new kinds of diseases caused by non-bacterial pathogens, related largely to fungi that are inherently resistant to antibacterials. All of these organisms are becoming more prevalent and, ultimately, more clinically relevant for surgeons. It is ironic that despite their ubiquity in our communities, there is seldom a second thought given to viral infections in patients with surgical illness. The extent of most surgeon’s interest in viral infections ends with hepatitis and HIV, no doubt related to transmissibility as well as the implications that these viruses might have in a patient’s hepatic or immune functions. There are chapters and even textbooks written about these viruses so these will not be considered here. Instead, we will present the growing body of knowledge of the herpes family viruses and their occurrence and consequences in patients with concomitant surgical disease or critical illness. We have also chosen to focus this chapter on previously immune competent patients, as the impact of herpes family viruses in immunosuppressed patients such as transplant or AIDS patients has received thorough treatment elsewhere. PMID:25440119

  7. Host-Pathogen Coupled Interactions

    DTIC Science & Technology

    2015-01-04

    number of Yersinia outer proteins ( Yops ) via a type 3 secretion system, and one of these (YopJ) accumulates in the cytosol of macrophages where it...pathogen behavior during the initial course of infection. Progress: Mitogen Activated Protein Kinase (MAPK) and Nuclear Factor-kappa B (NF-kB...macrophage death. The macrophage MAPK pathway signaling produces genomic transcription and cytokine expressed protein products that are emitted from

  8. Molecular Mechanisms of Bacterial Pathogenicity

    NASA Astrophysics Data System (ADS)

    Fuchs, Thilo Martin

    Cautious optimism has arisen over recent decades with respect to the long struggle against bacteria, viruses, and parasites. This has been offset, however, by a fatal complacency stemming from previous successes such as the development of antimicrobial drugs, the eradication of smallpox, and global immunization programs. Infectious diseases nevertheless remain the world's leading cause of death, killing at least 17 million persons annually [61]. Diarrheal diseases caused by Vibrio cholerae or Shigella dysenteriae kill about 3 million persons every year, most of them young children: Another 4 million die of tuberculosis or tetanus. Outbreaks of diphtheria in Eastern Europe threatens the population with a disease that had previously seemed to be overcome. Efforts to control infectious diseases more comprehensively are undermined not only by socioeconomic conditions but also by the nature of the pathogenic organisms itself; some isolates of Staphylococcus aureus and Enterobacter have become so resistant to drugs by horizontal gene transfer that they are almost untreatable. In addition, the mechanism of genetic variability helps pathogens to evade the human immune system, thus compromising the development of powerful vaccines. Therefore detailed knowledge of the molecular mechanisms of microbial pathogenicity is absolutely necessary to develop new strategies against infectious diseases and thus to lower their impact on human health and social development.

  9. Taxonomy of bacterial fish pathogens.

    PubMed

    Austin, Brian

    2011-02-02

    Bacterial taxonomy has progressed from reliance on highly artificial culture-dependent techniques involving the study of phenotype (including morphological, biochemical and physiological data) to the modern applications of molecular biology, most recently 16S rRNA gene sequencing, which gives an insight into evolutionary pathways (= phylogenetics). The latter is applicable to culture-independent approaches, and has led directly to the recognition of new uncultured bacterial groups, i.e. "Candidatus", which have been associated as the cause of some fish diseases, including rainbow trout summer enteritic syndrome. One immediate benefit is that 16S rRNA gene sequencing has led to increased confidence in the accuracy of names allocated to bacterial pathogens. This is in marked contrast to the previous dominance of phenotyping, and identifications, which have been subsequently challenged in the light of 16S rRNA gene sequencing. To date, there has been some fluidity over the names of bacterial fish pathogens, with some, for example Vibrio anguillarum, being divided into two separate entities (V. anguillarum and V. ordalii). Others have been combined, for example V. carchariae, V. harveyi and V. trachuri as V. harveyi. Confusion may result with some organisms recognized by more than one name; V. anguillarum was reclassified as Beneckea and Listonella, with Vibrio and Listonella persisting in the scientific literature. Notwithstanding, modern methods have permitted real progress in the understanding of the taxonomic relationships of many bacterial fish pathogens.

  10. Mapping population and pathogen movements

    PubMed Central

    Tatem, Andrew J.

    2014-01-01

    For most of human history, populations have been relatively isolated from each other, and only recently has there been extensive contact between peoples, flora and fauna from both old and new worlds. The reach, volume and speed of modern travel are unprecedented, with human mobility increasing in high income countries by over 1000-fold since 1800. This growth is putting people at risk from the emergence of new strains of familiar diseases, and from completely new diseases, while ever more cases of the movement of both disease vectors and the diseases they carry are being seen. Pathogens and their vectors can now move further, faster and in greater numbers than ever before. Equally however, we now have access to the most detailed and comprehensive datasets on human mobility and pathogen distributions ever assembled, in order to combat these threats. This short review paper provides an overview of these datasets, with a particular focus on low income regions, and covers briefly approaches used to combine them to help us understand and control some of the negative effects of population and pathogen movements. PMID:24480992

  11. Taxonomy of bacterial fish pathogens

    PubMed Central

    2011-01-01

    Bacterial taxonomy has progressed from reliance on highly artificial culture-dependent techniques involving the study of phenotype (including morphological, biochemical and physiological data) to the modern applications of molecular biology, most recently 16S rRNA gene sequencing, which gives an insight into evolutionary pathways (= phylogenetics). The latter is applicable to culture-independent approaches, and has led directly to the recognition of new uncultured bacterial groups, i.e. "Candidatus", which have been associated as the cause of some fish diseases, including rainbow trout summer enteritic syndrome. One immediate benefit is that 16S rRNA gene sequencing has led to increased confidence in the accuracy of names allocated to bacterial pathogens. This is in marked contrast to the previous dominance of phenotyping, and identifications, which have been subsequently challenged in the light of 16S rRNA gene sequencing. To date, there has been some fluidity over the names of bacterial fish pathogens, with some, for example Vibrio anguillarum, being divided into two separate entities (V. anguillarum and V. ordalii). Others have been combined, for example V. carchariae, V. harveyi and V. trachuri as V. harveyi. Confusion may result with some organisms recognized by more than one name; V. anguillarum was reclassified as Beneckea and Listonella, with Vibrio and Listonella persisting in the scientific literature. Notwithstanding, modern methods have permitted real progress in the understanding of the taxonomic relationships of many bacterial fish pathogens. PMID:21314902

  12. Plant innate immunity against human bacterial pathogens

    PubMed Central

    Melotto, Maeli; Panchal, Shweta; Roy, Debanjana

    2014-01-01

    Certain human bacterial pathogens such as the enterohemorrhagic Escherichia coli and Salmonella enterica are not proven to be plant pathogens yet. Nonetheless, under certain conditions they can survive on, penetrate into, and colonize internal plant tissues causing serious food borne disease outbreaks. In this review, we highlight current understanding on the molecular mechanisms of plant responses against human bacterial pathogens and discuss salient common and contrasting themes of plant interactions with phytopathogens or human pathogens. PMID:25157245

  13. The enemy within: phloem-limited pathogens

    USDA-ARS?s Scientific Manuscript database

    The growing impact of phloem-limited pathogens on high-value crops has led to a renewed interest in understanding how they cause disease. Although these pathogens cause substantial crop losses, many are poorly characterized. In this review, we present examples of phloem-limited pathogens that includ...

  14. Response of soybean pathogens to glyceollin

    USDA-ARS?s Scientific Manuscript database

    The ability to recognize pathogens and respond biochemically to prevent or inhibit pathogen invasion and colonization in plant cells is an active disease resistance response in plants. The involvement of soybean phytoalexin glyceollin in defense responses to the soybean pathogens Diaporthe phaseolor...

  15. Evasion of inflammasome activation by microbial pathogens

    PubMed Central

    Ulland, Tyler K.; Ferguson, Polly J.; Sutterwala, Fayyaz S.

    2015-01-01

    Activation of the inflammasome occurs in response to infection with a wide array of pathogenic microbes. The inflammasome serves as a platform to activate caspase-1, which results in the subsequent processing and secretion of the proinflammatory cytokines IL-1β and IL-18 and the initiation of an inflammatory cell death pathway termed pyroptosis. Effective inflammasome activation is essential in controlling pathogen replication as well as initiating adaptive immune responses against the offending pathogens. However, a number of pathogens have developed strategies to evade inflammasome activation. In this Review, we discuss these pathogen evasion strategies as well as the potential infectious complications of therapeutic blockade of IL-1 pathways. PMID:25642707

  16. Epigenetic control of effectors in plant pathogens.

    PubMed

    Gijzen, Mark; Ishmael, Chelsea; Shrestha, Sirjana D

    2014-01-01

    Plant pathogens display impressive versatility in adapting to host immune systems. Pathogen effector proteins facilitate disease but can become avirulence (Avr) factors when the host acquires discrete recognition capabilities that trigger immunity. The mechanisms that lead to changes to pathogen Avr factors that enable escape from host immunity are diverse, and include epigenetic switches that allow for reuse or recycling of effectors. This perspective outlines possibilities of how epigenetic control of Avr effector gene expression may have arisen and persisted in filamentous plant pathogens, and how it presents special problems for diagnosis and detection of specific pathogen strains or pathotypes.

  17. Oral bacteria in placental tissues: increased molecular detection in pregnant periodontitis patients.

    PubMed

    Blanc, V; O'Valle, F; Pozo, E; Puertas, A; León, R; Mesa, F

    2015-10-01

    The objective of this study was to identify the DNA of oral bacteria in placental samples from women with and without periodontitis who had or had not had preterm births and/or low birthweight (PB/LBW) neonates. Data were gathered from 57 puerperal women in relation to socio-demographic, gynaecological, and periodontal variables and to placental histomorphology. Fifty-seven biopsies, 28 from mothers with periodontitis, were taken aseptically from preterm placentas (n = 36) and from full-term placentas (n = 21). Total DNA was extracted, and the presence of 15 oral bacteria was assessed using Nested-PCR. The placentas from women with periodontitis showed a higher prevalence of periodontopathogens compared to those from women without periodontitis (P = 0.009). Samples showed low prevalences of Actinomyces israelii, Parvimonas micra and Tannerella forsythia. An association was found between Eikenella corrodens in placenta and periodontitis (P = 0.002). The most ubiquitous bacterium, Fusobacterium nucleatum, was more prevalent in mothers with periodontitis and PB/LBW (P = 0.033). Porphyromonas gingivalis, Treponema denticola, Prevotella intermedia and Aggregatibacter actinomycetemcomitans were not detected. These results, along with previous findings, show that oral bacteria may be normally present in the placenta, however, the levels of certain oral pathogens in the placenta would highly depend on the mother's periodontal state. © 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  18. The detection of BANA micro-organisms in adult periodontitis before and after scaling and root planing by BANA-Enzymatic™ test kit: An in vivo study.

    PubMed

    Dhalla, Nipun; Patil, Sudhir; Chaubey, Krishna Kumar; Narula, Inderpreet Singh

    2015-01-01

    Many paraclinical methods are available today for an accurate assessment of the periodontal status prior and during the periodontal treatment. The microbial-enzymatic N-benzoyl-DL-arginine-2-napthylamide (BANA) test is one of the modern alternatives to bacterial cultures. It detects the presence of three periodontal pathogens in the subgingival plaque (Porphyromonas gingivalis, Treponema denticola and Tannerella forsythia). The aim and objective of this study was to detect the presence of BANA micro-organisms and also to determine the effect of scaling and root planning in adult periodontitis patients. A total number of 20 patients (80 sites) all having periodontitis were selected. Four test sites (permanent molar from each quadrant) were selected from each patient and assessed for plaque index, bleeding index and pocket depth before and after scaling and root planning. BANA test was used for the detection and prevalence of the "red complex" bacteria in plaque samples. Showed that the BANA tests are statistically correlated with the severity of periodontal destruction. There was a significant correlation between the BANA test results and the quantity of bacterial plaque, the test being influenced by the composition of bacterial plaque. This study encourages the use of such chair-side tests for a proper diagnosis of periodontal disease and for a good evaluation of the treatment results.

  19. Detection of Periodontal Markers in Chronic Periodontitis

    PubMed Central

    Leonhardt, Åsa; Carlén, Anette; Bengtsson, Lisbeth; Dahlén, Gunnar

    2011-01-01

    The aim was to compare the detection frequency of periodontopathogens by using the Pado Test 4.5 and checkerboard DNA-DNA hybridization technique in chronic periodontitis patients. Thirty patients with chronic periodontitis were tested cross-sectionally with DNA/RNA oligogenomic probe method (IAI Pado Test 4.5) and DNA/DNA whole genomic probe (checkerboard) method. Samples were taken by two paper points at the deepest site in each of the four quadrants and pooled into one sample for each of the two methods. The samples were sent to the two laboratories (IAI, Zuchwil, Switzerland, and Oral Microbiology Laboratory, University of Gothenburg, Sweden) and were analyzed in a routine setting for the presence and amount of Aggregatibacter actinomycetemcomitans, Porphyromonas gingivalis, Tannerella forsythia and Treponema denticola. While Pado Test 4.5 detected the four periodontal pathogens in 11 (36.7%) of the patients, the checkerboard method showed presence in all patients (100%) using the lower score (Score 1 corresponding to 104 bacterial cells) and 16 (53.3%) using a higher treshold (score 3 corresponding to between >105 and 106 cells). The results of the present study showed low agreement for a positive microbiological outcome using the two diagnostic methods. It was also concluded that microbiological analysis in practice should include a larger number of bacterial species to better serve as markers for a diseased associated flora in chronic periodontitis cases. PMID:21769304

  20. Effects of Hangeshashinto on Growth of Oral Microorganisms

    PubMed Central

    Fukamachi, Haruka; Matsumoto, Chinami; Omiya, Yuji; Arimoto, Takafumi; Morisaki, Hirobumi; Kataoka, Hideo; Kadena, Miki; Funatsu, Takahiro; Fukutake, Masato; Kase, Yoshio; Kuwata, Hirotaka

    2015-01-01

    Oral mucositis (OM) in cancer patients induced by chemotherapy or radiotherapy has a significant impact on quality of life, and causes considerable morbidity. Oral microorganisms are likely to intensify the inflammatory process and aggravate the formation of ulcers. Hangeshashinto (HST), a Japanese kampo medicine, has been reported to be effective when used as a gargle for the treatment of OM. To clarify the effects of HST on oral microorganisms, we assessed its antimicrobial activity against 27 microbial species, including 19 oral bacteria and one fungus. HST extract inhibited the growth of Gram-negative bacteria, including Fusobacterium nucleatum, Porphyromonas gingivalis, Porphyromonas endodontalis, Prevotella intermedia, Prevotella melaninogenica, Tannerella forsythia, Treponema denticola, and Porphyromonas asaccharolytica, though inhibitory effects were less pronounced for Gram-positive bacteria and the fungal strain. We then investigated the effects of antibacterial activities on 15 purified ingredients of HST and determined that baicalein, berberine, coptisine, [6]-shogaol, and homogentisic acid actively inhibited the growth of these bacteria. These findings showed that HST inhibits the growth of specific Gram-negative periodontopathogenic bacteria, which are significant pathogens in OM, without disturbing the normal oral flora. Our data suggest that HST may be a useful treatment for OM in patients undergoing anticancer treatment. PMID:26170876

  1. P. gingivalis in Periodontal Disease and Atherosclerosis – Scenes of Action for Antimicrobial Peptides and Complement

    PubMed Central

    Hussain, Mehak; Stover, Cordula M.; Dupont, Aline

    2015-01-01

    According to the NHS, it is estimated that over 50% of the adult population are, to some extent, affected by gum disease and approximately 15% of UK population have been diagnosed with severe periodontitis. Periodontitis, a chronic polymicrobial disease of the gums, causes inflammation in its milder form, whereas in its severe form affects the surrounding tissues and can result in tooth loss. During periodontitis, plaque accumulates and sits between the junctional epithelium and the tooth itself, resulting in inflammation and the formation of a periodontal pocket. An interface is formed directly between the subgingival bacteria and the junctional epithelial cells. Bacterial pathogens commonly associated with periodontal disease are, among others, Porphyromonas gingivalis, Tannerella forsythia, and Treponema denticola, together known as the “red complex.” This review will mostly concentrate on the role of P. gingivalis, a Gram-negative anaerobic bacterium and one of the major and most studied contributors of this disease. Because periodontal disease is associated with the development of atherosclerosis, it is important to understand the local immune response to P. gingivalis. Innate immune players, in particular, complement and antimicrobial peptides and their effects with regard to P. gingivalis during periodontitis and in the development of atherosclerosis will be presented. PMID:25713575

  2. Future research needs involving pathogens in groundwater

    NASA Astrophysics Data System (ADS)

    Bradford, Scott A.; Harvey, Ronald W.

    2016-12-01

    Contamination of groundwater by enteric pathogens has commonly been associated with disease outbreaks. Proper management and treatment of pathogen sources are important prerequisites for preventing groundwater contamination. However, non-point sources of pathogen contamination are frequently difficult to identify, and existing approaches for pathogen detection are costly and only provide semi-quantitative information. Microbial indicators that are readily quantified often do not correlate with the presence of pathogens. Pathogens of emerging concern and increasing detections of antibiotic resistance among bacterial pathogens in groundwater are topics of growing concern. Adequate removal of pathogens during soil passage is therefore critical for safe groundwater extraction. Processes that enhance pathogen transport (e.g., high velocity zones and preferential flow) and diminish pathogen removal (e.g., reversible retention and enhanced survival) are of special concern because they increase the risk of groundwater contamination, but are still incompletely understood. Improved theory and modeling tools are needed to analyze experimental data, test hypotheses, understand coupled processes and controlling mechanisms, predict spatial and/or temporal variability in model parameters and uncertainty in pathogen concentrations, assess risk, and develop mitigation and best management approaches to protect groundwater.

  3. Future research needs involving pathogens in groundwater

    NASA Astrophysics Data System (ADS)

    Bradford, Scott A.; Harvey, Ronald W.

    2017-06-01

    Contamination of groundwater by enteric pathogens has commonly been associated with disease outbreaks. Proper management and treatment of pathogen sources are important prerequisites for preventing groundwater contamination. However, non-point sources of pathogen contamination are frequently difficult to identify, and existing approaches for pathogen detection are costly and only provide semi-quantitative information. Microbial indicators that are readily quantified often do not correlate with the presence of pathogens. Pathogens of emerging concern and increasing detections of antibiotic resistance among bacterial pathogens in groundwater are topics of growing concern. Adequate removal of pathogens during soil passage is therefore critical for safe groundwater extraction. Processes that enhance pathogen transport (e.g., high velocity zones and preferential flow) and diminish pathogen removal (e.g., reversible retention and enhanced survival) are of special concern because they increase the risk of groundwater contamination, but are still incompletely understood. Improved theory and modeling tools are needed to analyze experimental data, test hypotheses, understand coupled processes and controlling mechanisms, predict spatial and/or temporal variability in model parameters and uncertainty in pathogen concentrations, assess risk, and develop mitigation and best management approaches to protect groundwater.

  4. Future research needs involving pathogens in groundwater

    USGS Publications Warehouse

    Bradford, Scott A.; Harvey, Ronald W.

    2017-01-01

    Contamination of groundwater by enteric pathogens has commonly been associated with disease outbreaks. Proper management and treatment of pathogen sources are important prerequisites for preventing groundwater contamination. However, non-point sources of pathogen contamination are frequently difficult to identify, and existing approaches for pathogen detection are costly and only provide semi-quantitative information. Microbial indicators that are readily quantified often do not correlate with the presence of pathogens. Pathogens of emerging concern and increasing detections of antibiotic resistance among bacterial pathogens in groundwater are topics of growing concern. Adequate removal of pathogens during soil passage is therefore critical for safe groundwater extraction. Processes that enhance pathogen transport (e.g., high velocity zones and preferential flow) and diminish pathogen removal (e.g., reversible retention and enhanced survival) are of special concern because they increase the risk of groundwater contamination, but are still incompletely understood. Improved theory and modeling tools are needed to analyze experimental data, test hypotheses, understand coupled processes and controlling mechanisms, predict spatial and/or temporal variability in model parameters and uncertainty in pathogen concentrations, assess risk, and develop mitigation and best management approaches to protect groundwater.

  5. Pathogen evolution under host avoidance plasticity.

    PubMed

    McLeod, David V; Day, Troy

    2015-09-07

    Host resistance consists of defences that limit pathogen burden, and can be classified as either adaptations targeting recovery from infection or those focused upon infection avoidance. Conventional theory treats avoidance as a fixed strategy which does not vary from one interaction to the next. However, there is increasing empirical evidence that many avoidance strategies are triggered by external stimuli, and thus should be treated as phenotypically plastic responses. Here, we consider the implications of avoidance plasticity for host-pathogen coevolution. We uncover a number of predictions challenging current theory. First, in the absence of pathogen trade-offs, plasticity can restrain pathogen evolution; moreover, the pathogen exploits conditions in which the host would otherwise invest less in resistance, causing resistance escalation. Second, when transmission trades off with pathogen-induced mortality, plasticity encourages avirulence, resulting in a superior fitness outcome for both host and pathogen. Third, plasticity ensures the sterilizing effect of pathogens has consequences for pathogen evolution. When pathogens castrate hosts, selection forces them to minimize mortality virulence; moreover, when transmission trades off with sterility alone, resistance plasticity is sufficient to prevent pathogens from evolving to fully castrate. © 2015 The Author(s).

  6. Internalization of fresh produce by foodborne pathogens.

    PubMed

    Erickson, Marilyn C

    2012-01-01

    Recent studies addressing the internalization of fresh produce by foodborne pathogens arose in response to the growing number of recent and high profile outbreaks involving fresh produce. Because chemical sanitizing agents used during harvest and minimal processing are unlikely to reach enteric pathogens residing within plant tissue, it is imperative that paths for pathogen entry be recognized and minimized. Using both microscopy and microbial enumeration tools, enteric pathogens have been shown to enter plant tissues through both natural apertures (stomata, lateral junctions of roots, flowers) and damaged (wounds, cut surfaces) tissue. In studies revealing preharvest internalization via plant roots or leaf stomata, experimental conditions have primarily involved exposure of plants to high pathogen concentrations (≥ 6 log g⁻¹ soil or 6 log ml⁻¹ water), but those pathogens internalized appear to have short-term persistence. Postharvest internalization of pathogens via cut surfaces may be minimized by maintaining effective levels of sanitizing agents in waters during harvesting and minimal processing.

  7. Contamination of water resources by pathogenic bacteria.

    PubMed

    Pandey, Pramod K; Kass, Philip H; Soupir, Michelle L; Biswas, Sagor; Singh, Vijay P

    2014-01-01

    Water-borne pathogen contamination in water resources and related diseases are a major water quality concern throughout the world. Increasing interest in controlling water-borne pathogens in water resources evidenced by a large number of recent publications clearly attests to the need for studies that synthesize knowledge from multiple fields covering comparative aspects of pathogen contamination, and unify them in a single place in order to present and address the problem as a whole. Providing a broader perceptive of pathogen contamination in freshwater (rivers, lakes, reservoirs, groundwater) and saline water (estuaries and coastal waters) resources, this review paper attempts to develop the first comprehensive single source of existing information on pathogen contamination in multiple types of water resources. In addition, a comprehensive discussion describes the challenges associated with using indicator organisms. Potential impacts of water resources development on pathogen contamination as well as challenges that lie ahead for addressing pathogen contamination are also discussed.

  8. Contamination of water resources by pathogenic bacteria

    PubMed Central

    2014-01-01

    Water-borne pathogen contamination in water resources and related diseases are a major water quality concern throughout the world. Increasing interest in controlling water-borne pathogens in water resources evidenced by a large number of recent publications clearly attests to the need for studies that synthesize knowledge from multiple fields covering comparative aspects of pathogen contamination, and unify them in a single place in order to present and address the problem as a whole. Providing a broader perceptive of pathogen contamination in freshwater (rivers, lakes, reservoirs, groundwater) and saline water (estuaries and coastal waters) resources, this review paper attempts to develop the first comprehensive single source of existing information on pathogen contamination in multiple types of water resources. In addition, a comprehensive discussion describes the challenges associated with using indicator organisms. Potential impacts of water resources development on pathogen contamination as well as challenges that lie ahead for addressing pathogen contamination are also discussed. PMID:25006540

  9. Complement Evasion by Pathogenic Leptospira

    PubMed Central

    Fraga, Tatiana Rodrigues; Isaac, Lourdes; Barbosa, Angela Silva

    2016-01-01

    Leptospirosis is a neglected infectious disease caused by spirochetes from the genus Leptospira. Pathogenic microorganisms, notably those which reach the blood circulation such as Leptospira, have evolved multiple strategies to escape the host complement system, which is important for innate and acquired immunity. Leptospira avoid complement-mediated killing through: (i) recruitment of host complement regulators; (ii) acquisition of host proteases that cleave complement proteins on the bacterial surface; and, (iii) secretion of proteases that inactivate complement proteins in the Leptospira surroundings. The recruitment of host soluble complement regulatory proteins includes the acquisition of Factor H (FH) and FH-like-1 (alternative pathway), C4b-binding protein (C4BP) (classical and lectin pathways), and vitronectin (Vn) (terminal pathway). Once bound to the leptospiral surface, FH and C4BP retain cofactor activity of Factor I in the cleavage of C3b and C4b, respectively. Vn acquisition by leptospires may result in terminal pathway inhibition by blocking C9 polymerization. The second evasion mechanism lies in plasminogen (PLG) binding to the leptospiral surface. In the presence of host activators, PLG is converted to enzymatically active plasmin, which is able to degrade C3b, C4b, and C5 at the surface of the pathogen. A third strategy used by leptospires to escape from complement system is the active secretion of proteases. Pathogenic, but not saprophytic leptospires, are able to secrete metalloproteases that cleave C3 (central complement molecule), Factor B (alternative pathway), and C4 and C2 (classical and lectin pathways). The purpose of this review is to fully explore these complement evasion mechanisms, which act together to favor Leptospira survival and multiplication in the host. PMID:28066433

  10. Complement Evasion by Pathogenic Leptospira.

    PubMed

    Fraga, Tatiana Rodrigues; Isaac, Lourdes; Barbosa, Angela Silva

    2016-01-01

    Leptospirosis is a neglected infectious disease caused by spirochetes from the genus Leptospira. Pathogenic microorganisms, notably those which reach the blood circulation such as Leptospira, have evolved multiple strategies to escape the host complement system, which is important for innate and acquired immunity. Leptospira avoid complement-mediated killing through: (i) recruitment of host complement regulators; (ii) acquisition of host proteases that cleave complement proteins on the bacterial surface; and, (iii) secretion of proteases that inactivate complement proteins in the Leptospira surroundings. The recruitment of host soluble complement regulatory proteins includes the acquisition of Factor H (FH) and FH-like-1 (alternative pathway), C4b-binding protein (C4BP) (classical and lectin pathways), and vitronectin (Vn) (terminal pathway). Once bound to the leptospiral surface, FH and C4BP retain cofactor activity of Factor I in the cleavage of C3b and C4b, respectively. Vn acquisition by leptospires may result in terminal pathway inhibition by blocking C9 polymerization. The second evasion mechanism lies in plasminogen (PLG) binding to the leptospiral surface. In the presence of host activators, PLG is converted to enzymatically active plasmin, which is able to degrade C3b, C4b, and C5 at the surface of the pathogen. A third strategy used by leptospires to escape from complement system is the active secretion of proteases. Pathogenic, but not saprophytic leptospires, are able to secrete metalloproteases that cleave C3 (central complement molecule), Factor B (alternative pathway), and C4 and C2 (classical and lectin pathways). The purpose of this review is to fully explore these complement evasion mechanisms, which act together to favor Leptospira survival and multiplication in the host.

  11. ICU Pathogens: A Continuous Challenge.

    PubMed

    Hafeez, Amira; Munir, Tehmina; Najeeb, Sara; Rehman, Sabahat; Gilani, Mehreen; Ansari, Maliha; Saad, Nadia

    2016-07-01

    To determine the frequency and antibiogram of pathogens in an intensive care unit (ICU). Cross-sectional, observational study. Department of Microbiology, Army Medical College, National University of Science and Technology, Islamabad, from January 2013 to January 2014. Clinical samples, received from patients admitted in ICU, were inoculated on various medias like blood agar, chocolate agar, MacConkey agar and urine samples on CLED. These were then incubated at 37°C for 24 hours. Isolates were identified by colony morphology, Gram reaction, catalase test, oxidase test. Species identification in case of Gram Negative Rods was done by using API 20E (BioMérieux). Antibiotic susceptibility was done by using modified KirbyBauer disc diffusion technique. Bacterial isolates were prepared and inoculated on Mueller-Hinton agar plates followed by application of various antibiotic disc (Oxoid, UK) as per manufacturer's instructions. The plates were then incubated at 37°C aerobically for 18 - 24 hours. Zone diameters were measured and interpreted as sensitive and resistant, according to Clinical and Laboratory Standards Institute (CLSI) guidelines. Out of the 367 positive cultures, 116 (31.08%) were Acinetobacter baumanniisusceptible to minocycline and tigecycline followed by Klebsiella pneumoniae (n=71, 16%) susceptible to tigecycline and meropenem. Others were Pseudomonas aeruginosa, Escherichia coli,Coagulase Negative Staphylococcus, Staphylococcus aureus, Enterococcus spp., Streptococcus spp., Klebsiella oxytoca, Stenotrophomonas maltophilia,and Candida spp. Acinetobacter baumanniiwas the most frequently isolated pathogen. Most of the cultures yielding pathogens were from respiratory tract samples. Gram negative isolates were multidrug resistant but most were tigecycline and susceptible to meropenem.

  12. The Autonomous Pathogen Detection System

    SciTech Connect

    Dzenitis, J M; Makarewicz, A J

    2009-01-13

    We developed, tested, and now operate a civilian biological defense capability that continuously monitors the air for biological threat agents. The Autonomous Pathogen Detection System (APDS) collects, prepares, reads, analyzes, and reports results of multiplexed immunoassays and multiplexed PCR assays using Luminex{copyright} xMAP technology and flow cytometer. The mission we conduct is particularly demanding: continuous monitoring, multiple threat agents, high sensitivity, challenging environments, and ultimately extremely low false positive rates. Here, we introduce the mission requirements and metrics, show the system engineering and analysis framework, and describe the progress to date including early development and current status.

  13. Molecular Epidemiology of Foodborne Pathogens

    NASA Astrophysics Data System (ADS)

    Chen, Yi; Brown, Eric; Knabel, Stephen J.

    The purpose of this chapter is to describe the basic principles and advancements in the molecular epidemiology of foodborne pathogens. Epidemiology is the study of the distribution and determinants of infectious diseases and/or the dynamics of disease transmission. The goals of epidemiology include the identification of physical sources, routes of transmission of infectious agents, and distribution and relationships of different subgroups. Molecular epidemiology is the study of epidemiology at the molecular level. It has been defined as "a science that focuses on the contribution of potential genetic and environmental risk factors, identified at the molecular level, to the etiology, distribution and prevention of diseases within families and across populations".

  14. Autonomous pathogen detection system 2001

    SciTech Connect

    Langlois, R G; Wang, A; Colston, B; Masquelier, D; Jones, L; Venkateswaran, K S; Nasarabadi, S; Brown, S; Ramponi, A; Milanovich, F P

    2001-01-09

    The objective of this project is to design, fabricate and field-demonstrate a fully Autonomous Pathogen Detector (identifier) System (APDS). This will be accomplished by integrating a proven flow cytometer and real-time polymerase chain reaction (PCR) detector with sample collection, sample preparation and fluidics to provide a compact, autonomously operating instrument capable of simultaneously detecting multiple pathogens and/or toxins. The APDS will be designed to operate in fixed locations, where it continuously monitors air samples and automatically reports the presence of specific biological agents. The APDS will utilize both multiplex immuno and nucleic acid assays to provide ''quasi-orthogonal'', multiple agent detection approaches to minimize false positives and increase the reliability of identification. Technical advancements across several fronts must first be made in order to realize the full extent of the APDS. Commercialization will be accomplished through three progressive generations of instruments. The APDS is targeted for domestic applications in which (1) the public is at high risk of exposure to covert releases of bioagent such as in major subway systems and other transportation terminals, large office complexes, and convention centers; and (2) as part of a monitoring network of sensors integrated with command and control systems for wide area monitoring of urban areas and major gatherings (e.g., inaugurations, Olympics, etc.). In this latter application there is potential that a fully developed APDS could add value to Defense Department monitoring architectures.

  15. Sterol biosynthesis in oomycete pathogens.

    PubMed

    Gaulin, Elodie; Bottin, Arnaud; Dumas, Bernard

    2010-03-01

    Oomycetes are a diverse group of filamentous eukaryotic microbes comprising devastating animal and plant pathogens. They share many characteristics with fungi, including polarized hyphal extension and production of spores, but phylogenetics studies have clearly placed oomycetes outside the fungal kingdom, in the kingdom Stramenopila which also includes marine organisms such as diatoms and brown algae. Oomycetes display various specific biochemical features, including sterol metabolism. Sterols are essential isoprenoid compounds involved in membrane function and hormone signaling. Oomycetes belonging to Peronosporales, such as Phytophthora sp., are unable to synthesize their own sterols and must acquire them from their plant or animal hosts. In contrast, a combination of biochemical and molecular approaches allowed us to decipher a nearly complete sterol biosynthetic pathway leading to fucosterol in the legume pathogen Aphanomyces euteiches, an oomycete belonging to Saprolegniales. Importantly, sterol demethylase, a key enzyme from this pathway, is susceptible to chemicals widely used in agriculture and medicine as antifungal drugs, suggesting that similar products could be used against plant and animal diseases caused by Saprolegniales.

  16. Sterol biosynthesis in oomycete pathogens

    PubMed Central

    Gaulin, Elodie; Bottin, Arnaud

    2010-01-01

    Oomycetes are a diverse group of filamentous eukaryotic microbes comprising devastating animal and plant pathogens. They share many characteristics with fungi, including polarized hyphal extension and production of spores, but phylogenetics studies have clearly placed oomycetes outside the fungal kingdom, in the kingdom Stramenopila which also includes marine organisms such as diatoms and brown algae. Oomycetes display various specific biochemical features, including sterol metabolism. Sterols are essential isoprenoid compounds involved in membrane function and hormone signaling. Oomycetes belonging to Peronosporales, such as Phytophthora sp., are unable to synthesize their own sterols and must acquire them from their plant or animal hosts. In contrast, a combination of biochemical and molecular approaches allowed us to decipher a nearly complete sterol biosynthetic pathway leading to fucosterol in the legume pathogen Aphanomyces euteiches, an oomycete belonging to Saprolegniales. Importantly, sterol demethylase, a key enzyme from this pathway, is susceptible to chemicals widely used in agriculture and medicine as antifungal drugs, suggesting that similar products could be used against plant and animal diseases caused by Saprolegniales. PMID:20023385

  17. How old are bacterial pathogens?

    PubMed Central

    2016-01-01

    Only few molecular studies have addressed the age of bacterial pathogens that infected humans before the beginnings of medical bacteriology, but these have provided dramatic insights. The global genetic diversity of Helicobacter pylori, which infects human stomachs, parallels that of its human host. The time to the most recent common ancestor (tMRCA) of these bacteria approximates that of anatomically modern humans, i.e. at least 100 000 years, after calibrating the evolutionary divergence within H. pylori against major ancient human migrations. Similarly, genomic reconstructions of Mycobacterium tuberculosis, the cause of tuberculosis, from ancient skeletons in South America and mummies in Hungary support estimates of less than 6000 years for the tMRCA of M. tuberculosis. Finally, modern global patterns of genetic diversity and ancient DNA studies indicate that during the last 5000 years plague caused by Yersinia pestis has spread globally on multiple occasions from China and Central Asia. Such tMRCA estimates provide only lower bounds on the ages of bacterial pathogens, and additional studies are needed for realistic upper bounds on how long humans and animals have suffered from bacterial diseases. PMID:27534956

  18. Bacteriophage-Based Pathogen Detection

    NASA Astrophysics Data System (ADS)

    Ripp, Steven

    Considered the most abundant organism on Earth, at a population approaching 1031, bacteriophage, or phage for short, mediate interactions with myriad bacterial hosts that has for decades been exploited in phage typing schemes for signature identification of clinical, food-borne, and water-borne pathogens. With over 5,000 phage being morphologically characterized and grouped as to susceptible host, there exists an enormous cache of bacterial-specific sensors that has more recently been incorporated into novel bio-recognition assays with heightened sensitivity, specificity, and speed. These assays take many forms, ranging from straightforward visualization of labeled phage as they attach to their specific bacterial hosts to reporter phage that genetically deposit trackable signals within their bacterial hosts to the detection of progeny phage or other uniquely identifiable elements released from infected host cells. A comprehensive review of these and other phage-based detection assays, as directed towards the detection and monitoring of bacterial pathogens, will be provided in this chapter.

  19. Pathogenic Mechanisms in Centronuclear Myopathies

    PubMed Central

    Jungbluth, Heinz; Gautel, Mathias

    2014-01-01

    Centronuclear myopathies (CNMs) are a genetically heterogeneous group of inherited neuromuscular disorders characterized by clinical features of a congenital myopathy and abundant central nuclei as the most prominent histopathological feature. The most common forms of congenital myopathies with central nuclei have been attributed to X-linked recessive mutations in the MTM1 gene encoding myotubularin (“X-linked myotubular myopathy”), autosomal-dominant mutations in the DNM2 gene encoding dynamin-2 and the BIN1 gene encoding amphiphysin-2 (also named bridging integrator-1, BIN1, or SH3P9), and autosomal-recessive mutations in BIN1, the RYR1 gene encoding the skeletal muscle ryanodine receptor, and the TTN gene encoding titin. Models to study and rescue the affected cellular pathways are now available in yeast, C. elegans, drosophila, zebrafish, mouse, and dog. Defects in membrane trafficking have emerged as a key pathogenic mechanisms, with aberrant T-tubule formation, abnormalities of triadic assembly, and disturbance of the excitation–contraction machinery the main downstream effects studied to date. Abnormal autophagy has recently been recognized as another important collateral of defective membrane trafficking in different genetic forms of CNM, suggesting an intriguing link to primary disorders of defective autophagy with overlapping histopathological features. The following review will provide an overview of clinical, histopathological, and genetic aspects of the CNMs in the context of the key pathogenic mechanism, outline unresolved questions, and indicate promising future lines of enquiry. PMID:25566070

  20. Pathogenic Potential of Campylobacter ureolyticus

    PubMed Central

    Burgos-Portugal, Jose A.; Kaakoush, Nadeem O.; Raftery, Mark J.

    2012-01-01

    The recent detection and isolation of the aflagellate Campylobacter ureolyticus (previously known as Bacteroides ureolyticus) from intestinal biopsy specimens and fecal samples of children with newly diagnosed Crohn's disease led us to investigate the pathogenic potential of this bacterium. Adherence and gentamicin protection assays were employed to quantify the levels of adherence to and invasion into host cells. C. ureolyticus UNSWCD was able to adhere to the Caco-2 intestinal epithelial cell line with a value of 5.341% ± 0.74% but was not able to invade the Caco-2 cells. The addition of two proinflammatory cytokines, tumor necrosis factor alpha (TNF-α) and gamma interferon (IFN-γ), to the cell line did not affect attachment or invasion, with attachment levels being 4.156% ± 0.61% (P = 0.270) for TNF-α and 6.472% ± 0.61% (P = 0.235) for IFN-γ. Scanning electron microscopy visually confirmed attachment and revealed that C. ureolyticus UNSWCD colonizes and adheres to intestinal cells, inducing cellular damage and microvillus degradation. Purification and identification of the C. ureolyticus UNSWCD secretome detected a total of 111 proteins, from which 29 were bioinformatically predicted to be secretory proteins. Functional classification revealed three putative virulence and colonization factors: the surface antigen CjaA, an outer membrane fibronectin binding protein, and an S-layer RTX toxin. These results suggest that C. ureolyticus has the potential to be a pathogen of the gastrointestinal tract. PMID:22124656

  1. Plants versus pathogens: an evolutionary arms race

    PubMed Central

    Anderson, Jonathan P.; Gleason, Cynthia A.; Foley, Rhonda C.; Thrall, Peter H.; Burdon, Jeremy B.; Singh, Karam B.

    2011-01-01

    The analysis of plant–pathogen interactions is a rapidly moving research field and one that is very important for productive agricultural systems. The focus of this review is on the evolution of plant defence responses and the coevolution of their pathogens, primarily from a molecular-genetic perspective. It explores the evolution of the major types of plant defence responses including pathogen associated molecular patterns and effector triggered immunity as well as the forces driving pathogen evolution, such as the mechanisms by which pathogen lineages and species evolve. Advances in our understanding of plant defence signalling, stomatal regulation, R gene–effector interactions and host specific toxins are used to highlight recent insights into the coevolutionary arms race between pathogens and plants. Finally, the review considers the intriguing question of how plants have evolved the ability to distinguish friends such as rhizobia and mycorrhiza from their many foes. PMID:21743794

  2. The Interaction between Respiratory Pathogens and Mucus.

    PubMed

    Zanin, Mark; Baviskar, Pradyumna; Webster, Robert; Webby, Richard

    2016-02-10

    The interaction between respiratory pathogens and their hosts is complex and incompletely understood. This is particularly true when pathogens encounter the mucus layer covering the respiratory tract. The mucus layer provides an essential first host barrier to inhaled pathogens that can prevent pathogen invasion and subsequent infection. Respiratory mucus has numerous functions and interactions, both with the host and with pathogens. This review summarizes the current understanding of respiratory mucus and its interactions with the respiratory pathogens Pseudomonas aeruginosa, respiratory syncytial virus and influenza viruses, with particular focus on influenza virus transmissibility and host-range specificity. Based on current findings we propose that respiratory mucus represents an understudied host-restriction factor for influenza virus. Copyright © 2016 Elsevier Inc. All rights reserved.

  3. Hard Tick Factors Implicated in Pathogen Transmission

    PubMed Central

    Liu, Xiang Ye; Bonnet, Sarah I.

    2014-01-01

    Ticks are the most common arthropod vector, after mosquitoes, and are capable of transmitting the greatest variety of pathogens. For both humans and animals, the worldwide emergence or re-emergence of tick-borne disease is becoming increasingly problematic. Despite being such an important issue, our knowledge of pathogen transmission by ticks is incomplete. Several recent studies, reviewed here, have reported that the expression of some tick factors can be modulated in response to pathogen infection, and that some of these factors can impact on the pathogenic life cycle. Delineating the specific tick factors required for tick-borne pathogen transmission should lead to new strategies in the disruption of pathogen life cycles to combat emerging tick-borne disease. PMID:24498444

  4. Divergent and Convergent Evolution of Fungal Pathogenicity.

    PubMed

    Shang, Yanfang; Xiao, Guohua; Zheng, Peng; Cen, Kai; Zhan, Shuai; Wang, Chengshu

    2016-05-12

    Fungal pathogens of plants and animals have multifarious effects; they cause devastating damages to agricultures, lead to life-threatening diseases in humans, or induce beneficial effects by reducing insect pest populations. Many virulence factors have been determined in different fungal pathogens; however, the molecular determinants contributing to fungal host selection and adaptation are largely unknown. In this study, we sequenced the genomes of seven ascomycete insect pathogens and performed the genome-wide analyses of 33 species of filamentous ascomycete pathogenic fungi that infect insects (12 species), plants (12), and humans (9). Our results revealed that the genomes of plant pathogens encode more proteins and protein families than the insect and human pathogens. Unexpectedly, more common orthologous protein groups are shared between the insect and plant pathogens than between the two animal group pathogens. We also found that the pathogenicity of host-adapted fungi evolved multiple times, and that both divergent and convergent evolutions occurred during pathogen-host cospeciation thus resulting in protein families with similar features in each fungal group. However, the role of phylogenetic relatedness on the evolution of protein families and therefore pathotype formation could not be ruled out due to the effect of common ancestry. The evolutionary correlation analyses led to the identification of different protein families that correlated with alternate pathotypes. Particularly, the effector-like proteins identified in plant and animal pathogens were strongly linked to fungal host adaptation, suggesting the existence of similar gene-for-gene relationships in fungus-animal interactions that has not been established before. These results well advance our understanding of the evolution of fungal pathogenicity and the factors that contribute to fungal pathotype formation. © The Author 2016. Published by Oxford University Press on behalf of the Society for

  5. Antibody-based resistance to plant pathogens.

    PubMed

    Schillberg, S; Zimmermann, S; Zhang, M Y; Fischer, R

    2001-01-01

    Plant diseases are a major threat to the world food supply, as up to 15% of production is lost to pathogens. In the past, disease control and the generation of resistant plant lines protected against viral, bacterial or fungal pathogens, was achieved using conventional breeding based on crossings, mutant screenings and backcrossing. Many approaches in this field have failed or the resistance obtained has been rapidly broken by the pathogens. Recent advances in molecular biotechnology have made it possible to obtain and to modify genes that are useful for generating disease resistant crops. Several strategies, including expression of pathogen-derived sequences or anti-pathogenic agents, have been developed to engineer improved pathogen resistance in transgenic plants. Antibody-based resistance is a novel strategy for generating transgenic plants resistant to pathogens. Decades ago it was shown that polyclonal and monoclonal antibodies can neutralize viruses, bacteria and selected fungi. This approach has been improved recently by the development of recombinant antibodies (rAbs). Crop resistance can be engineered by the expression of pathogen-specific antibodies, antibody fragments or antibody fusion proteins. The advantages of this approach are that rAbs can be engineered against almost any target molecule, and it has been demonstrated that expression of functional pathogen-specific rAbs in plants confers effective pathogen protection. The efficacy of antibody-based resistance was first shown for plant viruses and its application to other plant pathogens is becoming more established. However, successful use of antibodies to generate plant pathogen resistance relies on appropriate target selection, careful antibody design, efficient antibody expression, stability and targeting to appropriate cellular compartments.

  6. The Candida Pathogenic Species Complex

    PubMed Central

    Turner, Siobhán A.; Butler, Geraldine

    2014-01-01

    Candida species are the most common causes of fungal infection. Approximately 90% of infections are caused by five species: Candida albicans, Candida glabrata, Candida tropicalis, Candida parapsilosis, and Candida krusei. Three (C. albicans, C. tropicalis, and C. parapsilosis) belong to the CTG clade, in which the CTG codon is translated as serine and not leucine. C. albicans remains the most commonly isolated but is decreasing relative to the other species. The increasing incidence of C. glabrata is related to its reduced susceptibility to azole drugs. Genome analysis suggests that virulence in the CTG clade is associated with expansion of gene families, particularly of cell wall genes. Similar independent processes took place in the C. glabrata species group. Gene loss and expansion in an ancestor of C. glabrata may have resulted in preadaptations that enabled pathogenicity. PMID:25183855

  7. Staphylococcus aureus: a community pathogen.

    PubMed

    Miller, Loren G; Kaplan, Sheldon L

    2009-03-01

    Staphylococcus aureus is a common human pathogen. S aureus infections most commonly clinically manifest as skin infections. There has been much interest in S aureus infections in the community over the past decade because of the rise of community-associated methicillin-resistant S aureus (CA-MRSA) infections, which have emerged globally over a relatively short period of time. In contrast to health care-associated methicillin resistant S aureus (HA-MRSA), circulating strains of CA-MRSA have characteristic pathogenesis, strain characteristics, epidemiology, and clinical manifestations that are distinct from HA-MRSA. In fact, CA-MRSA probably behaves more like community-associated methicillin-sensitive S aureus (MSSA). This article reviews current knowledge of the epidemiology and clinical manifestations of community-associated S aureus and CA-MRSA infections.

  8. Pathogenic diversity of Helicobacter pylori.

    PubMed

    Mégraud, F

    1997-04-01

    Helicobacter pylori has been shown to possess a very heterogeneous genoma despite its common phenotypic properties. Some characteristics relevant to pathogenesis have also been found to be heterogeneous. This is the case for adherence properties and the amount of urease produced, but it was not possible to relate these properties to disease entities. A vacuolating cytotoxin which alters epithelial cells has been found in about 60% of strains isolated from patients with ulcers versus 30% from those with gastritis only. The cagA gene can be used as a marker to detect the cag pathogenicity island. This DNA fragment seems to induce an increased inflammation in the gastric tissue via release of interleukin 8 by the epithelial cells. The association of this marker is strongly linked with ulcers compared with gastritis only (80% vs 55%, respectively). A number of other properties may be heterogeneous, but the low number of strains studied does not allow conclusions to be drawn.

  9. A streptomycete pathogenic to fish

    USGS Publications Warehouse

    Rucker, R.R.

    1949-01-01

    A streptomycete and pseutdomonad were isolated from blueback salmon, Oncorhynchuis nerka (WValbaum), and shown to be pathogenic to fish. Trhese organisms were isolated from young blueback salmon taken from a gr'oup that developed an increasing mortality after feeding about a month at the United States Fishery Station, Leavenworth, Washington. A superficial examination revealed only the presence of fungus (probably Sap0olcynia parasitica), which wvas on the gills and was eliminated by treatment with a quaternary ammonium salt. Although the fungus infection was eliminated, the mortality continued. It was observed by the station biologist at the time that the majority of the fish in the hatchery troughs were healthy, but that there w-as alwzays present an apathetic group that hud(dled on the bottom, refused food, ancl eventually weakene(l and died. The bulk of the daily mortality was composedI of fish from this group. The apathetic group received constant recruitment from the more vigorous stock, and their number showed a gradual increase rather than clepletion. A more critical examination of the larger affected fish revealedl that thc kICidneys and spleens weIe disintegrating; mycelial masses w-ere sporadically observed in the body cavity; congestion wN-as present in the gastrointestinal tract; some hemorrhagic areas were present in the body musculature; an(l a few fish had a perforating ulceration of the body wall. Furi'unculosis was immediately suspected, and attempts were made to isolate from the diseaseti fish Bacteriim .salininicida Lehmann and Netumann, the etiological agent of furunculosis. B. salmornicida Awas not recovered, however, even after repeated attempts at isolation. Subsequently it was discovered that two other organisms, a streptomycete and a pseudomonad, were characteristically present in the diseased fish. Both organisms were found experimentally to be pathogenic to fish.

  10. Pathogenic Roles for Fungal Melanins

    PubMed Central

    Jacobson, Eric S.

    2000-01-01

    Melanins represent virulence factors for several pathogenic fungi; the number of examples is growing. Thus, albino mutants of several genera (in one case, mutated precisely in the melanizing enzyme) exhibit decreased virulence in mice. We consider the phenomenon in relation to known chemical properties of melanin, beginning with biosynthesis from ortho-hydroquinone precursors which, when oxidized enzymatically to quinones, polymerize spontaneously to melanin. It follows that melanizing intermediates are cross-linking reagents; melanization stabilizes the external cell wall against hydrolysis and is thought to determine semipermeability in the osmotic ram (the appressorium) of certain plant pathogens. Polymeric melanins undergo reversible oxidation-reduction reactions between cell wall-penetrating quinone and hydroquinone oxidation states and thus represent polymeric redox buffers; using strong oxidants, it is possible to titrate the melanin on living cells and thereby demonstrate protection conferred by melanin in several species. The amount of buffering per cell approximately neutralizes the amount of oxidant generated by a single macrophage. Moreover, the intermediate oxidation state, the semiquinone, is a very stable free radical and is thought to trap unpaired electrons. We have suggested that the oxidation state of external melanin may be regulated by external Fe(II). An independent hypothesis holds that in Cryptococcus neoformans, an important function of the melanizing enzyme (apart from melanization) is the oxidation of Fe(II) to Fe(III), thereby forestalling generation of the harmful hydroxyl radical from H2O2. Thus, problems in fungal pathogenesis have led to evolving hypotheses regarding melanin functioning. PMID:11023965

  11. Chronic Bacterial Pathogens: Mechanisms of Persistence

    PubMed Central

    Byndloss, Mariana X.; Tsolis, Renee M

    2015-01-01

    Summary Many bacterial pathogens can cause acute infections that are cleared with onset of adaptive immunity, however a subset of these pathogens can establish persistent, and sometimes lifelong infections. While bacteria causing chronic infections are phylogenetically diverse, they share common features in their interactions with the host that enable a protracted period of colonization. This chapter will compare the persistence strategies of two chronic pathogens from the Proteobacteria, Brucella abortus, and Salmonella enterica serovar Typhi (S. Typhi) to consider how these two pathogens, which are very different at the genomic level, can utilize common strategies to evade immune clearance to cause chronic intracellular infections of the mononuclear phagocyte system. PMID:27227304

  12. [Research progress in pathogenicity of Ureaplasma urealyticum].

    PubMed

    Huang, Jun; Zhang, Jun; Song, Tiejun; Xie, Xinyou

    2013-07-01

    Ureaplasma urealyticum (UU) is closely related to human diseases including non-gonococcal urethritis (NGU), infertility, premature membranes and neonatal bronchopulmonary dysplasia. Researches on the pathogenicity of UU have become a hot topic in recent years, and suggest that many potential pathogenicity genes or putative pathogenicity islands are involved in its virulence. Moreover, the biovar and serum types of UU, the infection concentration and the state of the host immune system are also important to determine whether UU can cause human disease or not. In this article the recent progress of researches in the pathogenicity of UU is reviewed.

  13. Centrality in the host-pathogen interactome is associated with pathogen fitness during infection

    NASA Astrophysics Data System (ADS)

    Crua Asensio, Núria; Muñoz Giner, Elisabet; de Groot, Natalia Sánchez; Torrent Burgas, Marc

    2017-01-01

    To perform their functions proteins must interact with each other, but how these interactions influence bacterial infection remains elusive. Here we demonstrate that connectivity in the host-pathogen interactome is directly related to pathogen fitness during infection. Using Y. pestis as a model organism, we show that the centrality-lethality rule holds for pathogen fitness during infection but only when the host-pathogen interactome is considered. Our results suggest that the importance of pathogen proteins during infection is directly related to their number of interactions with the host. We also show that pathogen proteins causing an extensive rewiring of the host interactome have a higher impact in pathogen fitness during infection. Hence, we conclude that hubs in the host-pathogen interactome should be explored as promising targets for antimicrobial drug design.

  14. Centrality in the host–pathogen interactome is associated with pathogen fitness during infection

    PubMed Central

    Crua Asensio, Núria; Muñoz Giner, Elisabet; de Groot, Natalia Sánchez; Torrent Burgas, Marc

    2017-01-01

    To perform their functions proteins must interact with each other, but how these interactions influence bacterial infection remains elusive. Here we demonstrate that connectivity in the host–pathogen interactome is directly related to pathogen fitness during infection. Using Y. pestis as a model organism, we show that the centrality-lethality rule holds for pathogen fitness during infection but only when the host–pathogen interactome is considered. Our results suggest that the importance of pathogen proteins during infection is directly related to their number of interactions with the host. We also show that pathogen proteins causing an extensive rewiring of the host interactome have a higher impact in pathogen fitness during infection. Hence, we conclude that hubs in the host–pathogen interactome should be explored as promising targets for antimicrobial drug design. PMID:28090086

  15. Divergent and Convergent Evolution of Fungal Pathogenicity

    PubMed Central

    Shang, Yanfang; Xiao, Guohua; Zheng, Peng; Cen, Kai; Zhan, Shuai; Wang, Chengshu

    2016-01-01

    Fungal pathogens of plants and animals have multifarious effects; they cause devastating damages to agricultures, lead to life-threatening diseases in humans, or induce beneficial effects by reducing insect pest populations. Many virulence factors have been determined in different fungal pathogens; however, the molecular determinants contributing to fungal host selection and adaptation are largely unknown. In this study, we sequenced the genomes of seven ascomycete insect pathogens and performed the genome-wide analyses of 33 species of filamentous ascomycete pathogenic fungi that infect insects (12 species), plants (12), and humans (9). Our results revealed that the genomes of plant pathogens encode more proteins and protein families than the insect and human pathogens. Unexpectedly, more common orthologous protein groups are shared between the insect and plant pathogens than between the two animal group pathogens. We also found that the pathogenicity of host-adapted fungi evolved multiple times, and that both divergent and convergent evolutions occurred during pathogen–host cospeciation thus resulting in protein families with similar features in each fungal group. However, the role of phylogenetic relatedness on the evolution of protein families and therefore pathotype formation could not be ruled out due to the effect of common ancestry. The evolutionary correlation analyses led to the identification of different protein families that correlated with alternate pathotypes. Particularly, the effector-like proteins identified in plant and animal pathogens were strongly linked to fungal host adaptation, suggesting the existence of similar gene-for-gene relationships in fungus–animal interactions that has not been established before. These results well advance our understanding of the evolution of fungal pathogenicity and the factors that contribute to fungal pathotype formation. PMID:27071652

  16. Clinical periodontal and microbiologic parameters in patients with rheumatoid arthritis.

    PubMed

    Ziebolz, Dirk; Pabel, Sven O; Lange, Katharina; Krohn-Grimberghe, Berndt; Hornecker, Else; Mausberg, Rainer F

    2011-10-01

    A limited number of studies suggest a prevalence of periodontal pathogens in patients with rheumatoid arthritis (RA); however, results are inconsistent. The aim of this study is to investigate clinical periodontal and microbiologic parameters in patients with RA. Sixty-six patients with RA, aged 49.5 ± 8.4 years, participated in the study. The periodontal classification was assessed with the periodontal screening index (PSR/PSI) allocated to the following parameters: 1) healthy; 2) gingivitis (PSR/PSI score 0 to 2, maximum one sextant score; 3) moderate periodontitis (>1 sextant PSR/PSI score 3, maximum one sextant score; or, 4) severe periodontitis (>1 sextant PSR/PSI score 4). Pool samples were taken for microbiologic (polymerase chain reaction) analysis for the presence of 11 periodontal pathogens. Statistical analysis was by non-parametric analysis of covariance. No patients were periodontally healthy: 24 patients were classified as having gingivitis; 18 patients had moderate periodontitis; 23 patients had severe periodontitis; and one patient was toothless. For most patients, Fusobacterium nucleatum (98%), Eikenella corrodens (91%), and Parvimonas micra (previously Peptostreptococcus micros; 88%) were above the detection threshold. Strong periodontal pathogens were less frequently detected: Aggregatibacter actinomycetemcomitans (previously Actinobacillus actinomycetemcomitans, 16%); Porphyromonas gingivalis (58%); and Tannerella forsythia (previously T. forsythensis, 78%). Statistical analysis showed no significant influence of rheumatic factor (P = 0.33) on periodontal classification and on microbiologic parameters (P >0.05). Only smoking showed a significant influence (P = 0.0004) on the periodontal classification and in the case of E. corrodens (P = 0.02). Most patients with RA in this study showed moderate-to-severe periodontitis and the presence of periodontal pathogens. No association was found between rheumatic factor on periodontal classification and

  17. Higher plant diversity promotes higher diversity of fungal pathogens, while it decreases pathogen infection per plant.

    PubMed

    Rottstock, Tanja; Joshi, Jasmin; Kummer, Volker; Fischer, Markus

    2014-07-01

    Fungal plant pathogens are common in natural communities where they affect plant physiology, plant survival, and biomass production. Conversely, pathogen transmission and infection may be regulated by plant community characteristics such as plant species diversity and functional composition that favor pathogen diversity through increases in host diversity while simultaneously reducing pathogen infection via increased variability in host density and spatial heterogeneity. Therefore, a comprehensive understanding of multi-host multi-pathogen interactions is of high significance in the context of biodiversity-ecosystem functioning. We investigated the relationship between plant diversity and aboveground obligate parasitic fungal pathogen ("pathogens" hereafter) diversity and infection in grasslands of a long-term, large-scale, biodiversity experiment with varying plant species (1-60 species) and plant functional group diversity (1-4 groups). To estimate pathogen infection of the plant communities, we visually assessed pathogen-group presence (i.e., rusts, powdery mildews, downy mildews, smuts, and leaf-spot diseases) and overall infection levels (combining incidence and severity of each pathogen group) in 82 experimental plots on all aboveground organs of all plant species per plot during four surveys in 2006. Pathogen diversity, assessed as the cumulative number of pathogen groups on all plant species per plot, increased log-linearly with plant species diversity. However, pathogen incidence and severity, and hence overall infection, decreased with increasing plant species diversity. In addition, co-infection of plant individuals by two or more pathogen groups was less likely with increasing plant community diversity. We conclude that plant community diversity promotes pathogen-community diversity while at the same time reducing pathogen infection levels of plant individuals.

  18. Determinants of pathogenicity of H5N1 highly pathogenic avian influenza viruses in ducks

    USDA-ARS?s Scientific Manuscript database

    Ducks have been implicated in the dissemination and evolution of the H5N1 highly pathogenic avian influenza (HPAI) viruses. The pathogenicity of H5N1 HPAI viruses in domestic ducks has increased over time with some viruses producing 100% mortality in very short time. The determinants of pathogenic...

  19. Filter-based pathogen enrichment technology for detection of multiple viable foodborne pathogens in 1 day.

    PubMed

    Murakami, Taku

    2012-09-01

    Conventional foodborne pathogen assays currently used in the food industry often require long culture enrichments to increase pathogen levels so they can be detected. Even using sensitive real-time PCR assays, culture enrichment at least overnight is necessary especially for detection of pathogens with slow growth rates such as Listeria monocytogenes. To eliminate this cumbersome enrichment step and detect minute amounts of pathogens within 1 day, filter-based pathogen enrichment technology was developed utilizing a unique combination of glass fiber depth filter and porous filter aid materials to efficiently separate pathogens from food homogenates and avoid filter clogging by food particles. After pathogen immobilization in depth filters, only viable pathogens were selectively collected in a small volume of growth medium via microbial multiplication and migration; nonviable pathogens remained inside the filters. By assaying viable pathogens using real-time PCRs, multiple species of foodborne pathogens were detected, including L. monocytogenes, Salmonella enterica, and Escherichia coli O157:H7, at around 1 CFU/ml or 1 CFU/g in various food samples. This filter-based pathogen enrichment technology is a unique bacterial enrichment alternative to the conventional culture enrichment step and can significantly shorten the time necessary to obtain assay results.

  20. Digital PCR for detection of citrus pathogens

    USDA-ARS?s Scientific Manuscript database

    Citrus trees are often infected with multiple pathogens of economic importance, especially those with insect or mite vectors. Real-time/quantitative PCR (qPCR) has been used for high-throughput detection and relative quantification of pathogens; however, target reference or standards are required. I...

  1. Microsatellite markers in plant pathogenic fungi

    USDA-ARS?s Scientific Manuscript database

    Knowing the genetic diversity of plant pathogenic fungi is essential in the management of crops and disease. The genetic variability of fungal pathogens can be evaluated using molecular markers, among which, microsatellites are a relatively inexpensive source of information. We have developed an e...

  2. The Brucella pathogens are polarized bacteria.

    PubMed

    Van der Henst, Charles; de Barsy, Marie; Zorreguieta, Angeles; Letesson, Jean-Jacques; De Bolle, Xavier

    2013-12-01

    Brucella pathogens are responsible for brucellosis, a worldwide zoonosis. They are facultative intracellular pathogens characterized by their asymmetric division and their unipolar growth. This growth modality generates poles with specialized functions (through polar recruitment of polar adhesins or of cell cycle regulators) and progeny cells with potentially different fates. Copyright © 2013 Institut Pasteur. Published by Elsevier Masson SAS. All rights reserved.

  3. Arthropods vector grapevine trunk disease pathogens.

    PubMed

    Moyo, P; Allsopp, E; Roets, F; Mostert, L; Halleen, F

    2014-10-01

    Arthropod-mediated dispersal of pathogens is known in many cropping systems but has never been demonstrated for grapevine trunk disease pathogens. Arthropods from vineyards were screened for the presence of pathogens associated with Petri disease and esca using cultural and molecular techniques. The ability of the most abundant pathogen-carrying species to inoculate healthy grapevine vascular tissues was also determined. Millipedes and ants were allowed to associate with a DsRed- Express-transformed Phaeomoniella chlamydospora, after which they were exposed to freshly pruned healthy grapevines under controlled conditions and wounds were monitored for subsequent infection. In addition, the possibility of millipede excreta, commonly found on pruning wounds in the field, to act as inoculum source was determined. A diverse arthropod fauna was associated with declining grapevines and many of these carried trunk disease pathogens. However, spiders, the ant Crematogaster peringueyi, and the millipede Ommattoiulus moreleti were the most abundant pathogen carriers. The ant and millipede species fed on pruning wound sap and effectively transmitted trunk disease pathogens. Millipede excreta contained viable spores of Phaeomoniella chlamydospora and may serve as an inoculum source. Numerous arthropods, including beneficial predators, are potential vectors of grapevine trunk disease pathogens. Our results highlight the need for an integrated approach, including targeted management of ants and millipedes at the time of pruning, to limit the spread of grapevine trunk diseases.

  4. Insect pathogens: molecular approaches and techniques

    USDA-ARS?s Scientific Manuscript database

    This book serves as a primer for molecular techniques in insect pathology and is tailored for a wide scientific audience. Contributing authors are internationally recognized experts. The book comprises four sections: 1) pathogen identification and diagnostics, 2) pathogen population genetics and p...

  5. 76 FR 24793 - Highly Pathogenic Avian Influenza

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-05-03

    ... Inspection Service 9 CFR Parts 93, 94, and 95 RIN 0579-AC36 Highly Pathogenic Avian Influenza AGENCY: Animal... products from regions where any subtype of highly pathogenic avian influenza is considered to exist. The... vaccinated for certain types of avian influenza, or that have moved through regions where any subtype of...

  6. Immunity to plant pathogens and iron homeostasis.

    PubMed

    Aznar, Aude; Chen, Nicolas W G; Thomine, Sebastien; Dellagi, Alia

    2015-11-01

    Iron is essential for metabolic processes in most living organisms. Pathogens and their hosts often compete for the acquisition of this nutrient. However, iron can catalyze the formation of deleterious reactive oxygen species. Hosts may use iron to increase local oxidative stress in defense responses against pathogens. Due to this duality, iron plays a complex role in plant-pathogen interactions. Plant defenses against pathogens and plant response to iron deficiency share several features, such as secretion of phenolic compounds, and use common hormone signaling pathways. Moreover, fine tuning of iron localization during infection involves genes coding iron transport and iron storage proteins, which have been shown to contribute to immunity. The influence of the plant iron status on the outcome of a given pathogen attack is strongly dependent on the nature of the pathogen infection strategy and on the host species. Microbial siderophores emerged as important factors as they have the ability to trigger plant defense responses. Depending on the plant species, siderophore perception can be mediated by their strong iron scavenging capacity or possibly via specific recognition as pathogen associated molecular patterns. This review highlights that iron has a key role in several plant-pathogen interactions by modulating immunity.

  7. Characterization of Potential Surrogates for Produce Pathogens

    USDA-ARS?s Scientific Manuscript database

    Background Escherichia coli (E. coli) is commonly used as a surrogate for pathogens in research to identify sources of agricultural contamination and to characterize how pathogens persist on plant surfaces. However, E. coli strains are highly diverse, exhibiting differences in physical, chemical and...

  8. Hunting for insect pathogens: A genomics approach

    USDA-ARS?s Scientific Manuscript database

    Emerging methods within the field of genomics have increased the number of insect pathogens being discovered and characterized each year. These pathogens provide a rich resource for biological control agents, gene expression systems, and other molecular tools. Using Metagenomics, and gene expression...

  9. Nutrient and chemical sensing by intestinal pathogens

    PubMed Central

    Hernandez-Doria, Juan D.; Sperandio, Vanessa

    2013-01-01

    Pathogenic gut bacteria, such as those comprising the Enterobacteriaceae family, have evolved sophisticated virulence mechanisms, including nutrient and chemical sensing, to escape host defense strategies and produce disease. In this review we describe the mechanisms utilized by the enteric pathogen enterohemorrhagic E. coli (EHEC) O157:H7 to achieve successful colonization of its mammalian host. PMID:23850657

  10. Pathogen threat assessment is predictive plant pathology

    USDA-ARS?s Scientific Manuscript database

    The American Society of Plant Pathologists has maintained a formal effort to prioritize threatening and emerging crop pathogens for over 70 years, and the APS Emerging Pathogens and Diseases Committee is continuing the process. In order to accomplish prioritization in a rigorous fashion, criteria mu...

  11. Population genomics of fungal and oomycete pathogens

    USDA-ARS?s Scientific Manuscript database

    We are entering a new era in plant pathology where whole-genome sequences of many individuals of a pathogen species are becoming readily available. This era of pathogen population genomics will provide new opportunities and challenges, requiring new computational and analytical tools. Population gen...

  12. Microbial pathogen quality criteria of rendered products.

    PubMed

    Pandey, Pramod K; Biswas, Sagor; Kass, Philip

    2016-06-01

    The North American rendering industry processes approximately 24 million metric tons (Mt) of raw materials and produces more than 8 million Mt of rendered products. More than 85 % of rendered products produced annually in the USA are used for producing animal feed. Pathogen contamination in rendered products is an important and topical issue. Although elevated temperatures (115-140 °C) for 40-90 min during the standard rendering processes are mathematically sufficient to completely destroy commonly found pathogens, the presence of pathogens in rendered products has nevertheless been reported. Increased concern over the risk of microbial contamination in rendered products may require additional safeguards for producing pathogen-free rendered products. This study provides an overview of rendered products, existing microbial pathogen quality criteria of rendered products (MPQCR), limitations, and the scope of improving the MPQCR.

  13. Rickettsial pathogens and their arthropod vectors.

    PubMed Central

    Azad, A. F.; Beard, C. B.

    1998-01-01

    Rickettsial diseases, important causes of illness and death worldwide, exist primarily in endemic and enzootic foci that occasionally give rise to sporadic or seasonal outbreaks. Rickettsial pathogens are highly specialized for obligate intracellular survival in both the vertebrate host and the invertebrate vector. While studies often focus primarily on the vertebrate host, the arthropod vector is often more important in the natural maintenance of the pathogen. Consequently, coevolution of rickettsiae with arthropods is responsible for many features of the host-pathogen relationship that are unique among arthropod-borne diseases, including efficient pathogen replication, long-term maintenance of infection, and transstadial and transovarial transmission. This article examines the common features of the host-pathogen relationship and of the arthropod vectors of the typhus and spotted fever group rickettsiae. PMID:9621188

  14. Heme Synthesis and Acquisition in Bacterial Pathogens

    PubMed Central

    Choby, Jacob E.; Skaar, Eric P.

    2016-01-01

    Bacterial pathogens require the iron-containing cofactor heme to cause disease. Heme is essential to the function of hemoproteins, which are involved in energy generation by the electron transport chain, detoxification of host immune effectors, and other processes. During infection, bacterial pathogens must synthesize heme or acquire heme from the host; however, host heme is sequestered in high-affinity hemoproteins. Pathogens have evolved elaborate strategies to acquire heme from host sources, particularly hemoglobin, and both heme acquisition and synthesis are important for pathogenesis. Paradoxically, excess heme is toxic to bacteria and pathogens must rely on heme detoxification strategies. Heme is a key nutrient in the struggle for survival between host and pathogen, and its study has offered significant insight into the molecular mechanisms of bacterial pathogenesis. PMID:27019298

  15. Oomycete pathogens encode RNA silencing suppressors.

    PubMed

    Qiao, Yongli; Liu, Lin; Xiong, Qin; Flores, Cristina; Wong, James; Shi, Jinxia; Wang, Xianbing; Liu, Xigang; Xiang, Qijun; Jiang, Shushu; Zhang, Fuchun; Wang, Yuanchao; Judelson, Howard S; Chen, Xuemei; Ma, Wenbo

    2013-03-01

    Effectors are essential virulence proteins produced by a broad range of parasites, including viruses, bacteria, fungi, oomycetes, protozoa, insects and nematodes. Upon entry into host cells, pathogen effectors manipulate specific physiological processes or signaling pathways to subvert host immunity. Most effectors, especially those of eukaryotic pathogens, remain functionally uncharacterized. Here, we show that two effectors from the oomycete plant pathogen Phytophthora sojae suppress RNA silencing in plants by inhibiting the biogenesis of small RNAs. Ectopic expression of these Phytophthora suppressors of RNA silencing enhances plant susceptibility to both a virus and Phytophthora, showing that some eukaryotic pathogens have evolved virulence proteins that target host RNA silencing processes to promote infection. These findings identify RNA silencing suppression as a common strategy used by pathogens across kingdoms to cause disease and are consistent with RNA silencing having key roles in host defense.

  16. Host Range and Emerging and Reemerging Pathogens

    PubMed Central

    Gowtage-Sequeria, Sonya

    2005-01-01

    An updated literature survey identified 1,407 recognized species of human pathogen, 58% of which are zoonotic. Of the total, 177 are regarded as emerging or reemerging. Zoonotic pathogens are twice as likely to be in this category as are nonzoonotic pathogens. Emerging and reemerging pathogens are not strongly associated with particular types of nonhuman hosts, but they are most likely to have the broadest host ranges. Emerging and reemerging zoonoses are associated with a wide range of drivers, but changes in land use and agriculture and demographic and societal changes are most commonly cited. However, although zoonotic pathogens do represent the most likely source of emerging and reemerging infectious disease, only a small minority have proved capable of causing major epidemics in the human population. PMID:16485468

  17. Alginate Production by Plant-Pathogenic Pseudomonads

    PubMed Central

    Fett, William F.; Osman, Stanley F.; Fishman, Marshall L.; Siebles, T. S.

    1986-01-01

    Eighteen plant-pathogenic and three non-plant-pathogenic pseudomonads were tested for the ability to produce alginic acid as an exopolysaccharide in vitro. Alginate production was demonstrated for 10 of 13 fluorescent plant-pathogenic pseudomonads tested with glucose or gluconate as the carbon source, but not for all 5 nonfluorescent plant pathogens and all 3 non-plant pathogens tested. With sucrose as the carbon source, some strains produced alginate while others produced both polyfructan (levan) and alginate. Alginates ranged from <1 to 28% guluronic acid, were acetylated, and had number-average molecular weights of 11.3 × 103 to 47.1 × 103. Polyfructans and alginates were not elicitors of the soybean phytoalexin glyceollin when applied to wounded cotyledon surfaces and did not induce prolonged water soaking of soybean leaf tissues. All or most pseudomonads in rRNA-DNA homology group I may be capable of synthesizing alginate as an exopolysaccharide. PMID:16347146

  18. How eukaryotic filamentous pathogens evade plant recognition.

    PubMed

    Oliveira-Garcia, Ely; Valent, Barbara

    2015-08-01

    Plant pathogenic fungi and oomycetes employ sophisticated mechanisms for evading host recognition. After host penetration, many fungi and oomycetes establish a biotrophic interaction. It is assumed that different strategies employed by these pathogens to avoid triggering host defence responses, including establishment of biotrophic interfacial layers between the pathogen and host, masking of invading hyphae and active suppression of host defence mechanisms, are essential for a biotrophic parasitic lifestyle. During the infection process, filamentous plant pathogens secrete various effectors, which are hypothesized to be involved in facilitating effective host infection. Live-cell imaging of fungi and oomycetes secreting fluorescently labeled effector proteins as well as functional characterization of the components of biotrophic interfaces have led to the recent progress in understanding how eukaryotic filamentous pathogens evade plant recognition.

  19. New insights into animal pathogenic oomycetes.

    PubMed

    Phillips, Andrew J; Anderson, Victoria L; Robertson, Emma J; Secombes, Chris J; van West, Pieter

    2008-01-01

    Many species of oomycetes cause economic and environmental damage owing to their ability to infect a range of plants and animals. Although research on plant pathogenic oomycetes has flourished in recent years, the animal pathogenic oomycetes have received less attention. This is unfortunate because several species are responsible for devastating diseases in aquaculture and natural ecosystems and proper treatments are not available or are limited. Therefore, momentum is being created to revive research into this neglected group of pathogens. Here, we discuss the latest developments in our current understanding of the biology, host-pathogen interactions and environmental and economical impact of the animal pathogenic oomycetes and review the recent advances in this emerging field.

  20. Regulation of multidrug resistance in pathogenic fungi.

    PubMed

    Morschhäuser, Joachim

    2010-02-01

    Infections by opportunistic pathogenic fungi, especially Candida species, Cryptococcus neoformans, and Aspergillus fumigatus, are a serious medical problem in immunocompromised patients. Different classes of antimycotic drugs are available to treat fungal infections, but the pathogens can develop resistance to all these agents. A major mechanism of antifungal drug resistance is the overexpression of efflux pumps of the ABC transporter and major facilitator superfamilies, which confer resistance to many structurally and functionally unrelated toxic compounds. For some pathogenic fungi, like Candida albicans and Candida glabrata, the most important drug transporters, transcription factors controlling their expression, and mutations that cause the constitutive upregulation of the efflux pumps in drug-resistant clinical isolates have been identified. For other important pathogens comparatively little is known about the role of transporters in antimycotic resistance. This review summarizes our current knowledge about efflux pump-mediated drug resistance and its regulation in human-pathogenic fungi.

  1. The Pathogenic Potential of a Microbe

    PubMed Central

    2017-01-01

    ABSTRACT Virulence is a microbial property that is realized only in susceptible hosts. There is no absolute measurement for virulence, and consequently it is always measured relative to a standard, usually another microbe or host. This article introduces the concept of pathogenic potential, which provides a new approach to measuring the capacity of microbes for virulence. The pathogenic potential is proportional to the fraction of individuals who become symptomatic after infection with a defined inoculum and can include such attributes as mortality, communicability, and the time from infection to disease. The calculation of the pathogenic potential has significant advantages over the use of the lethal dose that kills 50% of infected individuals (LD50) and allows direct comparisons between individual microbes. An analysis of the pathogenic potential of several microbes for mice reveals a continuum, which in turn supports the view that there is no dividing line between pathogenic and nonpathogenic microbes. PMID:28251180

  2. Rapid Waterborne Pathogen Detection with Mobile Electronics

    PubMed Central

    Wu, Tsung-Feng; Chen, Yu-Chen; Wang, Wei-Chung; Kucknoor, Ashwini S.; Lin, Che-Jen; Lo, Yu-Hwa; Yao, Chun-Wei; Lian, Ian

    2017-01-01

    Pathogen detection in water samples, without complex and time consuming procedures such as fluorescent-labeling or culture-based incubation, is essential to public safety. We propose an immunoagglutination-based protocol together with the microfluidic device to quantify pathogen levels directly from water samples. Utilizing ubiquitous complementary metal–oxide–semiconductor (CMOS) imagers from mobile electronics, a low-cost and one-step reaction detection protocol is developed to enable field detection for waterborne pathogens. 10 mL of pathogen-containing water samples was processed using the developed protocol including filtration enrichment, immune-reaction detection and imaging processing. The limit of detection of 10 E. coli O157:H7 cells/10 mL has been demonstrated within 10 min of turnaround time. The protocol can readily be integrated into a mobile electronics such as smartphones for rapid and reproducible field detection of waterborne pathogens. PMID:28598391

  3. Quorum Sensing of Periodontal Pathogens.

    PubMed

    Plančak, Darije; Musić, Larisa; Puhar, Ivan

    2015-09-01

    The term 'quorum sensing' describes intercellular bacterial communication which regulates bacterial gene expression according to population cell density. Bacteria produce and secrete small molecules, named autoinducers, into the intercellular space. The concentration of these molecules increases as a function of population cell density. Once the concentration of the stimulatory threshold is reached, alteration in gene expression occurs. Gram-positive and Gram-negative bacteria possess different types of quorum sensing systems. Canonical LuxI/R-type/acyl homoserine lactone mediated quorum sensing system is the best studied quorum sensing circuit and is described in Gram-negative bacteria which employ it for inter-species communication mostly. Gram-positive bacteria possess a peptide-mediated quorum sensing system. Bacteria can communicate within their own species (intra-species) but also between species (inter-species), for which they employ an autoinducer-2 quorum sensing system which is called the universal language of the bacteria. Periodontal pathogenic bacteria possess AI-2 quorum sensing systems. It is known that they use it for regulation of biofilm formation, iron uptake, stress response and virulence factor expression. A better understanding of bacterial communication mechanisms will allow the targeting of quorum sensing with quorum sensing inhibitors to prevent and control disease.

  4. Pathogenicity and virulence: another view.

    PubMed Central

    Isenberg, H D

    1988-01-01

    The concepts of pathogenicity and virulence have governed our perception of microbial harmfulness since the time of Pasteur and Koch. These concepts resulted in the recognition and identification of numerous etiological agents and provided natural and synthetic agents effective in therapy and prevention of diseases. However, Koch's postulates--the premier product of this view--place the onus of harmfulness solely on the microbial world. Our recent experiences with polymicrobic and nosocomial infections, legionellosis, and acquired immunodeficiency syndrome point to the host as the major determinant of disease. The principles of parasitism, enunciated by Theobold Smith, approximate more accurately the disturbances of the host-parasite equilibrium we designate as infection. Many complex attributes of microbial anatomy and physiology have been obscured by our dependency on the pure-culture technique. For example, bacterial attachment organelles and the production of exopolysaccharides enable microorganisms to interact with mammalian glycocalyces and specific receptors. In addition, selection, through the use of therapeutic agents, aids in the progression of environmental organisms to members of the intimate human biosphere, with the potential to complicate the recovery of patients. These factors emphasize further the pivotal significance of host reactions in infections. Parasitism, in its negative aspects, explains the emergence of "new" infections that involve harm to more than host organs and cells: we may encounter subtler infections that reveal parasitic and host cell nucleic acid interactions in a form of genomic parasitism. PMID:3060244

  5. New and emerging yeast pathogens.

    PubMed Central

    Hazen, K C

    1995-01-01

    The most common yeast species that act as agents of human disease are Candida albicans, Candida tropicalis, Candida glabrata, Candida parapsilosis, and Cryptococcus neoformans. The incidence of infections by other yeasts has increased during the past decade. The most evident emerging pathogens are Malassezia furfur, Trichosporon beigelii, Rhodotorula species, Hansenula anomala, Candida lusitaniae, and Candida krusei. Organisms once considered environmental contaminants or only industrially important, such as Candida utilis and Candida lipolytica, have now been implicated as agents of fungemia, onychomycosis, and systemic disease. The unusual yeasts primarily infect immunocompromised patients, newborns, and the elderly. The role of central venous catheter removal and antifungal therapy in patient management is controversial. The antibiograms of the unusual yeasts range from resistant to the most recent azoles and amphotericin B to highly susceptible to all antifungal agents. Current routine methods for yeast identification may be insufficient to identify the unusual yeasts within 2 days after isolation. The recognition of unusual yeasts as agents of sometimes life-threatening infection and their unpredictable antifungal susceptibilities increase the burden on the clinical mycology laboratory to pursue complete species identification and MIC determinations. Given the current and evolving medical practices for management of seriously ill patients, further evaluations of the clinically important data about these yeasts are needed. PMID:8665465

  6. Pathogen profile update: Fusarium oxysporum.

    PubMed

    Michielse, Caroline B; Rep, Martijn

    2009-05-01

    Kingdom Fungi; Phylum Ascomycota; Class Sordariomycetes; Order Hypocreales; Family Nectriaceae; genus Fusarium. Very broad at the species level. More than 120 different formae speciales have been identified based on specificity to host species belonging to a wide range of plant families. Initial symptoms of vascular wilt include vein clearing and leaf epinasty, followed by stunting, yellowing of the lower leaves, progressive wilting, defoliation and, finally, death of the plant. On fungal colonization, the vascular tissue turns brown, which is clearly visible in cross-sections of the stem. Some formae speciales are not primarily vascular pathogens, but cause foot and root rot or bulb rot. Can cause severe losses in many vegetables and flowers, field crops, such as cotton, and plantation crops, such as banana, date palm and oil palm. Use of resistant varieties is the only practical measure for controlling the disease in the field. In glasshouses, soil sterilization can be performed. http://www.broad.mit.edu/annotation/genome/fusarium_group/MultiHome.html; http://www.fgsc.net/Fusarium/fushome.htm; http://www.phi-base.org/query.php

  7. [Granulomatous diseases and pathogenic microorganism].

    PubMed

    Inoue, Yoshikazu; Suga, Moritaka

    2008-02-01

    Granuloma formation is a chronic inflammatory reaction where macrophage system and other inflammatory cells are involved. After some antigen exposure and processing, T cells, macrophages, epithelioid cells, and giant cell are activated, and granulomas are formed. Granuloma is considered as a defense mechanism against antigens, which stay in the organs without inactivation. Granulomas including fibroblasts extra-cellular matrix surround and isolate the antigens. Granulomas are classified to noninfectious granulomas and infectious granulomas. However recent studies revealed pathogenic microorganism are suspected to be a cause of granuloma in non-inflammatory diseases. Balance between pathogenic microorganisms and defense mechanisms of the host might be important in the special immunologic reaction. In some cases, it is hard to clearly classify infectious and noninfectious granulomas. Recently, Eishi et al. reported that latent infection of Propionibacterium acnes might be cause of sarcoidosis. Several hypersensitivity pneumonias are considered to be caused by exogenous microorganisms. The symposium was organized to know and clarify the new mechanisms of non-infectious granulomatous lung diseases and pathogenic microorganisms. This report is a summary of a symposium entitled "Granulomatous Diseases and Pathogenic Microorganism", organized in the 82nd Japanese Society for Tuberculosis (president Dr. Mitsunori Sakatani, M.D.). 1. Imaging of Granulomatous Lung Diseases: Masanori AKIRA (Department of Radiology, National Hospital Organization Kinki-chuo Chest Medical Center) High-resolution computed tomography (HRCT) is a useful tool in the evaluation of parenchymal changes in patients with a granulomatous lung disease. In sarcoidosis, the HRCT findings include small, well-defined nodules in relation to lymphatic roots, lymph node enlargement, and middle or upper lobe predominance. The appearances of subacute hypersensitivity pneumonitis include ill-defined centrilobular

  8. Quorum Sensing of Periodontal Pathogens

    PubMed Central

    Plančak, Darije; Musić, Larisa

    2015-01-01

    The term ‘quorum sensing’ describes intercellular bacterial communication which regulates bacterial gene expression according to population cell density. Bacteria produce and secrete small molecules, named autoinducers, into the intercellular space. The concentration of these molecules increases as a function of population cell density. Once the concentration of the stimulatory threshold is reached, alteration in gene expression occurs. Gram-positive and Gram-negative bacteria possess different types of quorum sensing systems. Canonical LuxI/R-type/acyl homoserine lactone mediated quorum sensing system is the best studied quorum sensing circuit and is described in Gram-negative bacteria which employ it for inter-species communication mostly. Gram-positive bacteria possess a peptide-mediated quorum sensing system. Bacteria can communicate within their own species (intra-species) but also between species (inter-species), for which they employ an autoinducer-2 quorum sensing system which is called the universal language of the bacteria. Periodontal pathogenic bacteria possess AI-2 quorum sensing systems. It is known that they use it for regulation of biofilm formation, iron uptake, stress response and virulence factor expression. A better understanding of bacterial communication mechanisms will allow the targeting of quorum sensing with quorum sensing inhibitors to prevent and control disease. PMID:27688408

  9. Algae as reservoirs for coral pathogens.

    PubMed

    Sweet, Michael J; Bythell, John C; Nugues, Maggy M

    2013-01-01

    Benthic algae are associated with coral death in the form of stress and disease. It's been proposed that they release exudates, which facilitate invasion of potentially pathogenic microbes at the coral-algal interface, resulting in coral disease. However, the original source of these pathogens remains unknown. This study examined the ability of benthic algae to act as reservoirs of coral pathogens by characterizing surface associated microbes associated with major Caribbean and Indo-Pacific algal species/types and by comparing them to potential pathogens of two dominant coral diseases: White Syndrome (WS) in the Indo-Pacific and Yellow Band Disease (YBD) in the Caribbean. Coral and algal sampling was conducted simultaneously at the same sites to avoid spatial effects. Potential pathogens were defined as those absent or rare in healthy corals, increasing in abundance in healthy tissues adjacent to a disease lesion, and dominant in disease lesions. Potentially pathogenic bacteria were detected in both WS and YBD and were also present within the majority of algal species/types (54 and 100% for WS and YBD respectively). Pathogenic ciliates were associated only with WS and not YBD lesions and these were also present in 36% of the Indo-Pacific algal species. Although potential pathogens were associated with many algal species, their presence was inconsistent among replicate algal samples and detection rates were relatively low, suggestive of low density and occurrence. At the community level, coral-associated microbes irrespective of the health of their host differed from algal-associated microbes, supporting that algae and corals have distinctive microbial communities associated with their tissue. We conclude that benthic algae are common reservoirs for a variety of different potential coral pathogens. However, algal-associated microbes alone are unlikely to cause coral death. Initial damage or stress to the coral via other competitive mechanisms is most likely a

  10. Algae as Reservoirs for Coral Pathogens

    PubMed Central

    Sweet, Michael J.; Bythell, John C.; Nugues, Maggy M.

    2013-01-01

    Benthic algae are associated with coral death in the form of stress and disease. It's been proposed that they release exudates, which facilitate invasion of potentially pathogenic microbes at the coral-algal interface, resulting in coral disease. However, the original source of these pathogens remains unknown. This study examined the ability of benthic algae to act as reservoirs of coral pathogens by characterizing surface associated microbes associated with major Caribbean and Indo-Pacific algal species/types and by comparing them to potential pathogens of two dominant coral diseases: White Syndrome (WS) in the Indo-Pacific and Yellow Band Disease (YBD) in the Caribbean. Coral and algal sampling was conducted simultaneously at the same sites to avoid spatial effects. Potential pathogens were defined as those absent or rare in healthy corals, increasing in abundance in healthy tissues adjacent to a disease lesion, and dominant in disease lesions. Potentially pathogenic bacteria were detected in both WS and YBD and were also present within the majority of algal species/types (54 and 100% for WS and YBD respectively). Pathogenic ciliates were associated only with WS and not YBD lesions and these were also present in 36% of the Indo-Pacific algal species. Although potential pathogens were associated with many algal species, their presence was inconsistent among replicate algal samples and detection rates were relatively low, suggestive of low density and occurrence. At the community level, coral-associated microbes irrespective of the health of their host differed from algal-associated microbes, supporting that algae and corals have distinctive microbial communities associated with their tissue. We conclude that benthic algae are common reservoirs for a variety of different potential coral pathogens. However, algal-associated microbes alone are unlikely to cause coral death. Initial damage or stress to the coral via other competitive mechanisms is most likely a

  11. Patterns of pathogenesis: discrimination of pathogenic and non-pathogenic microbes by the innate immune system

    PubMed Central

    Vance, Russell E.; Isberg, Ralph R.; Portnoy, Daniel A.

    2009-01-01

    The dominant conceptual framework for understanding innate immunity has been that host cells respond to evolutionarily conserved molecular features of pathogens called ‘pathogen-associated molecular patterns’ (PAMPs). PAMPs should be understood in the context of how they are naturally presented by pathogens. This can be experimentally challenging since pathogens, almost by definition, bypass host defense. Nevertheless, in this review, we explore the idea that the immune system responds to PAMPs in the context of additional signals that derive from common ‘patterns of pathogenesis’ employed by pathogens to infect, multiply within, and spread among their hosts. PMID:19616762

  12. Host-Pathogen Interactions: VII. Plant Pathogens Secrete Proteins which Inhibit Enzymes of the Host Capable of Attacking the Pathogen.

    PubMed

    Albersheim, P; Valent, B S

    1974-05-01

    The results presented demonstrate that microbial pathogens of plants have the ability to secrete proteins which effectively inhibit an enzyme synthesized by the host; an enzyme whose substrate is a constituent of the cell wall of the pathogen. The system in which this was discovered is the anthracnose-causing fungal pathogen (Colletotrichum lindemuthianum) and its host, the French bean (Phaseolus vulgaris). An endo-beta-1, 3-glucanase present in the bean leaves is specifically inhibited by a protein secreted by C. lindemuthianum. The cell walls of C. lindemuthianum are shown to be composed largely of a 1, 3-glucan.

  13. Endemicity of chytridiomycosis features pathogen overdispersion.

    PubMed

    Grogan, Laura F; Phillott, Andrea D; Scheele, Benjamin C; Berger, Lee; Cashins, Scott D; Bell, Sara C; Puschendorf, Robert; Skerratt, Lee F

    2016-05-01

    Pathogens can be critical drivers of the abundance and distribution of wild animal populations. The presence of an overdispersed pathogen load distribution between hosts (where few hosts harbour heavy parasite burdens and light infections are common) can have an important stabilizing effect on host-pathogen dynamics where infection intensity determines pathogenicity. This may potentially lead to endemicity of an introduced pathogen rather than extirpation of the host and/or pathogen. Overdispersed pathogen load distributions have rarely been considered in wild animal populations as an important component of the infection dynamics of microparasites such as bacteria, viruses, protozoa and fungi. Here we examined the abundance, distribution and transmission of the model fungal pathogen Batrachochytrium dendrobatidis (Bd, cause of amphibian chytridiomycosis) between wild-caught Litoria rheocola (common mist frogs) to investigate the effects of an overdispersed pathogen load distribution on the host population in the wild. We quantified host survival, infection incidence and recovery probabilities relative to infectious burden, and compared the results of models where pathogen overdispersion either was or was not considered an important feature of host-pathogen dynamics. We found the distribution of Bd load between hosts to be highly overdispersed. We found that host survival was related to infection burden and that accounting for pathogen overdispersion allowed us to better understand infection dynamics and their implications for disease control. In addition, we found that the pattern of host infections and recoveries varied markedly with season whereby (i) infections established more in winter, consistent with temperature-dependent effects on fungal growth, and (ii) recoveries (loss of infection) occurred frequently in the field throughout the year but were less likely in winter. Our results suggest that pathogen overdispersion is an important feature of endemic

  14. Comparative genome analysis of pathogenic and non-pathogenic Clavibacter strains reveals adaptations to their lifestyle.

    PubMed

    Załuga, Joanna; Stragier, Pieter; Baeyen, Steve; Haegeman, Annelies; Van Vaerenbergh, Johan; Maes, Martine; De Vos, Paul

    2014-05-22

    The genus Clavibacter harbors economically important plant pathogens infecting agricultural crops such as potato and tomato. Although the vast majority of Clavibacter strains are pathogenic, there is an increasing number of non-pathogenic isolates reported. Non-pathogenic Clavibacter strains isolated from tomato seeds are particularly problematic because they affect the current detection and identification tests for Clavibacter michiganensis subsp. michiganensis (Cmm), which is regulated with a zero tolerance in tomato seed. Their misidentification as pathogenic Cmm hampers a clear judgment on the seed quality and health. To get more insight in the genetic features linked to the lifestyle of these bacteria, a whole-genome sequence of the tomato seed-borne non-pathogenic Clavibacter LMG 26808 was determined. To gain a better understanding of the molecular determinants of pathogenicity, the genome sequence of LMG 26808 was compared with that of the pathogenic Cmm strain (NCPPB 382). The comparative analysis revealed that LMG 26808 does not contain plasmids pCM1 and pCM2 and also lacks the majority of important virulence factors described so far for pathogenic Cmm. This explains its apparent non-pathogenic nature in tomato plants. Moreover, the genome analysis of LMG 26808 detected sequences from a plasmid originating from a member of Enterobacteriaceae/Klebsiella relative. Genes received that way and coding for antibiotic resistance may provide a competitive advantage for survival of LMG 26808 in its ecological niche. Genetically, LMG 26808 was the most similar to the pathogenic Cmm NCPPB 382 but contained more mobile genetic elements. The genome of this non-pathogenic Clavibacter strain contained also a high number of transporters and regulatory genes. The genome sequence of the non-pathogenic Clavibacter strain LMG 26808 and the comparative analyses with other pathogenic Clavibacter strains provided a better understanding of the genetic bases of virulence and

  15. Waterborne Pathogens: Detection Methods and Challenges

    PubMed Central

    Ramírez-Castillo, Flor Yazmín; Loera-Muro, Abraham; Jacques, Mario; Garneau, Philippe; Avelar-González, Francisco Javier; Harel, Josée; Guerrero-Barrera, Alma Lilián

    2015-01-01

    Waterborne pathogens and related diseases are a major public health concern worldwide, not only by the morbidity and mortality that they cause, but by the high cost that represents their prevention and treatment. These diseases are directly related to environmental deterioration and pollution. Despite the continued efforts to maintain water safety, waterborne outbreaks are still reported globally. Proper assessment of pathogens on water and water quality monitoring are key factors for decision-making regarding water distribution systems’ infrastructure, the choice of best water treatment and prevention waterborne outbreaks. Powerful, sensitive and reproducible diagnostic tools are developed to monitor pathogen contamination in water and be able to detect not only cultivable pathogens but also to detect the occurrence of viable but non-culturable microorganisms as well as the presence of pathogens on biofilms. Quantitative microbial risk assessment (QMRA) is a helpful tool to evaluate the scenarios for pathogen contamination that involve surveillance, detection methods, analysis and decision-making. This review aims to present a research outlook on waterborne outbreaks that have occurred in recent years. This review also focuses in the main molecular techniques for detection of waterborne pathogens and the use of QMRA approach to protect public health. PMID:26011827

  16. REPRODUCIBLE AND SHAREABLE QUANTIFICATIONS OF PATHOGENICITY.

    PubMed

    Manrai, Arjun K; Wang, Brice L; Patel, Chirag J; Kohane, Isaac S

    2016-01-01

    There are now hundreds of thousands of pathogenicity assertions that relate genetic variation to disease, but most of this clinically utilized variation has no accepted quantitative disease risk estimate. Recent disease-specific studies have used control sequence data to reclassify large amounts of prior pathogenic variation, but there is a critical need to scale up both the pace and feasibility of such pathogenicity reassessments across human disease. In this manuscript we develop a shareable computational framework to quantify pathogenicity assertions. We release a reproducible "digital notebook" that integrates executable code, text annotations, and mathematical expressions in a freely accessible statistical environment. We extend previous disease-specific pathogenicity assessments to over 6,000 diseases and 160,000 assertions in the ClinVar database. Investigators can use this platform to prioritize variants for reassessment and tailor genetic model parameters (such as prevalence and heterogeneity) to expose the uncertainty underlying pathogenicity-based risk assessments. Finally, we release a website that links users to pathogenic variation for a queried disease, supporting literature, and implied disease risk calculations subject to user-defined and disease-specific genetic risk models in order to facilitate variant reassessments.

  17. Waterborne pathogens: detection methods and challenges.

    PubMed

    Ramírez-Castillo, Flor Yazmín; Loera-Muro, Abraham; Jacques, Mario; Garneau, Philippe; Avelar-González, Francisco Javier; Harel, Josée; Guerrero-Barrera, Alma Lilián

    2015-05-21

    Waterborne pathogens and related diseases are a major public health concern worldwide, not only by the morbidity and mortality that they cause, but by the high cost that represents their prevention and treatment. These diseases are directly related to environmental deterioration and pollution. Despite the continued efforts to maintain water safety, waterborne outbreaks are still reported globally. Proper assessment of pathogens on water and water quality monitoring are key factors for decision-making regarding water distribution systems' infrastructure, the choice of best water treatment and prevention waterborne outbreaks. Powerful, sensitive and reproducible diagnostic tools are developed to monitor pathogen contamination in water and be able to detect not only cultivable pathogens but also to detect the occurrence of viable but non-culturable microorganisms as well as the presence of pathogens on biofilms. Quantitative microbial risk assessment (QMRA) is a helpful tool to evaluate the scenarios for pathogen contamination that involve surveillance, detection methods, analysis and decision-making. This review aims to present a research outlook on waterborne outbreaks that have occurred in recent years. This review also focuses in the main molecular techniques for detection of waterborne pathogens and the use of QMRA approach to protect public health.

  18. REPRODUCIBLE AND SHAREABLE QUANTIFICATIONS OF PATHOGENICITY

    PubMed Central

    Manrai, Arjun K; Wang, Brice L; Patel, Chirag J; Kohane, Isaac S

    2016-01-01

    There are now hundreds of thousands of pathogenicity assertions that relate genetic variation to disease, but most of this clinically utilized variation has no accepted quantitative disease risk estimate. Recent disease-specific studies have used control sequence data to reclassify large amounts of prior pathogenic variation, but there is a critical need to scale up both the pace and feasibility of such pathogenicity reassessments across human disease. In this manuscript we develop a shareable computational framework to quantify pathogenicity assertions. We release a reproducible “digital notebook” that integrates executable code, text annotations, and mathematical expressions in a freely accessible statistical environment. We extend previous disease-specific pathogenicity assessments to over 6,000 diseases and 160,000 assertions in the ClinVar database. Investigators can use this platform to prioritize variants for reassessment and tailor genetic model parameters (such as prevalence and heterogeneity) to expose the uncertainty underlying pathogenicity-based risk assessments. Finally, we release a website that links users to pathogenic variation for a queried disease, supporting literature, and implied disease risk calculations subject to user-defined and disease-specific genetic risk models in order to facilitate variant reassessments. PMID:26776189

  19. Common themes in microbial pathogenicity revisited.

    PubMed Central

    Finlay, B B; Falkow, S

    1997-01-01

    Bacterial pathogens employ a number of genetic strategies to cause infection and, occasionally, disease in their hosts. Many of these virulence factors and their regulatory elements can be divided into a smaller number of groups based on the conservation of similar mechanisms. These common themes are found throughout bacterial virulence factors. For example, there are only a few general types of toxins, despite a large number of host targets. Similarly, there are only a few conserved ways to build the bacterial pilus and nonpilus adhesins used by pathogens to adhere to host substrates. Bacterial entry into host cells (invasion) is a complex mechanism. However, several common invasion themes exist in diverse microorganisms. Similarly, once inside a host cell, pathogens have a limited number of ways to ensure their survival, whether remaining within a host vacuole or by escaping into the cytoplasm. Avoidance of the host immune defenses is key to the success of a pathogen. Several common themes again are employed, including antigenic variation, camouflage by binding host molecules, and enzymatic degradation of host immune components. Most virulence factors are found on the bacterial surface or secreted into their immediate environment, yet virulence factors operate through a relatively small number of microbial secretion systems. The expression of bacterial pathogenicity is dependent upon complex regulatory circuits. However, pathogens use only a small number of biochemical families to express distinct functional factors at the appropriate time that causes infection. Finally, virulence factors maintained on mobile genetic elements and pathogenicity islands ensure that new strains of pathogens evolve constantly. Comprehension of these common themes in microbial pathogenicity is critical to the understanding and study of bacterial virulence mechanisms and to the development of new "anti-virulence" agents, which are so desperately needed to replace antibiotics. PMID

  20. Pathogen Webs in Collapsing Honey Bee Colonies

    PubMed Central

    Cornman, R. Scott; Tarpy, David R.; Chen, Yanping; Jeffreys, Lacey; Lopez, Dawn; Pettis, Jeffery S.; vanEngelsdorp, Dennis; Evans, Jay D.

    2012-01-01

    Recent losses in honey bee colonies are unusual in their severity, geographical distribution, and, in some cases, failure to present recognized characteristics of known disease. Domesticated honey bees face numerous pests and pathogens, tempting hypotheses that colony collapses arise from exposure to new or resurgent pathogens. Here we explore the incidence and abundance of currently known honey bee pathogens in colonies suffering from Colony Collapse Disorder (CCD), otherwise weak colonies, and strong colonies from across the United States. Although pathogen identities differed between the eastern and western United States, there was a greater incidence and abundance of pathogens in CCD colonies. Pathogen loads were highly covariant in CCD but not control hives, suggesting that CCD colonies rapidly become susceptible to a diverse set of pathogens, or that co-infections can act synergistically to produce the rapid depletion of workers that characterizes the disorder. We also tested workers from a CCD-free apiary to confirm that significant positive correlations among pathogen loads can develop at the level of individual bees and not merely as a secondary effect of CCD. This observation and other recent data highlight pathogen interactions as important components of bee disease. Finally, we used deep RNA sequencing to further characterize microbial diversity in CCD and non-CCD hives. We identified novel strains of the recently described Lake Sinai viruses (LSV) and found evidence of a shift in gut bacterial composition that may be a biomarker of CCD. The results are discussed with respect to host-parasite interactions and other environmental stressors of honey bees. PMID:22927991

  1. Pathogen webs in collapsing honey bee colonies.

    PubMed

    Cornman, R Scott; Tarpy, David R; Chen, Yanping; Jeffreys, Lacey; Lopez, Dawn; Pettis, Jeffery S; vanEngelsdorp, Dennis; Evans, Jay D

    2012-01-01

    Recent losses in honey bee colonies are unusual in their severity, geographical distribution, and, in some cases, failure to present recognized characteristics of known disease. Domesticated honey bees face numerous pests and pathogens, tempting hypotheses that colony collapses arise from exposure to new or resurgent pathogens. Here we explore the incidence and abundance of currently known honey bee pathogens in colonies suffering from Colony Collapse Disorder (CCD), otherwise weak colonies, and strong colonies from across the United States. Although pathogen identities differed between the eastern and western United States, there was a greater incidence and abundance of pathogens in CCD colonies. Pathogen loads were highly covariant in CCD but not control hives, suggesting that CCD colonies rapidly become susceptible to a diverse set of pathogens, or that co-infections can act synergistically to produce the rapid depletion of workers that characterizes the disorder. We also tested workers from a CCD-free apiary to confirm that significant positive correlations among pathogen loads can develop at the level of individual bees and not merely as a secondary effect of CCD. This observation and other recent data highlight pathogen interactions as important components of bee disease. Finally, we used deep RNA sequencing to further characterize microbial diversity in CCD and non-CCD hives. We identified novel strains of the recently described Lake Sinai viruses (LSV) and found evidence of a shift in gut bacterial composition that may be a biomarker of CCD. The results are discussed with respect to host-parasite interactions and other environmental stressors of honey bees.

  2. Real Time Detection of Foodborne Pathogens

    NASA Astrophysics Data System (ADS)

    Velusamy, V.; Arshak, K.; Korostynka, O.; Vaseashta, Ashok; Adley, C.

    Contamination of foods by harmful bacteria by natural events or malicious intent poses a serious threat to public health and safety. This review introduces current technologies in detecting pathogens in food and foodborne illnesses. Causes of foodborne diseases and trends impacting foodborne diseases such as globalization and changes in micro-organisms, human populations, lifestyles, and climates are addressed. In addition, a review of the limitations in detecting pathogens with conventional technologies is presented. Finally, a review of nanostructured and nanomaterials based sensing technologies by pathogen, detection limits, and advantages is described.

  3. Laser inactivation of pathogenic viruses in water

    NASA Astrophysics Data System (ADS)

    Grishkanich, Alexander; Zhevlakov, Alexander; Kascheev, Sergey; Sidorov, Igor; Ruzankina, Julia; Yakovlev, Alexey; Mak, Andrey

    2016-03-01

    Currently there is a situation that makes it difficult to provide the population with quality drinking water for the sanitary-hygienic requirements. One of the urgent problems is the need for water disinfection. Since the emergence of microorganisms that are pathogens transmitted through water such as typhoid, cholera, etc. requires constant cleansing of waters against pathogenic bacteria. In the water treatment process is destroyed up to 98% of germs, but among the remaining can be pathogenic viruses, the destruction of which requires special handling. As a result, the conducted research the following methods have been proposed for combating harmful microorganisms: sterilization of water by laser radiation and using a UV lamp.

  4. Acinetobacter baumannii: an emerging opportunistic pathogen.

    PubMed

    Howard, Aoife; O'Donoghue, Michael; Feeney, Audrey; Sleator, Roy D

    2012-05-01

    Acinetobacter baumannii is an opportunistic bacterial pathogen primarily associated with hospital-acquired infections. The recent increase in incidence, largely associated with infected combat troops returning from conflict zones, coupled with a dramatic increase in the incidence of multidrug-resistant (MDR) strains, has significantly raised the profile of this emerging opportunistic pathogen. Herein, we provide an overview of the pathogen, discuss some of the major factors that have led to its clinical prominence and outline some of the novel therapeutic strategies currently in development.

  5. Guarding against the most dangerous emerging pathogens.

    PubMed Central

    Ewald, P. W.

    1996-01-01

    Control of emerging infectious diseases will be difficult because of the large number of disease-causing organisms that are emerging or could emerge and the great diversity of geographic areas in which emergence can occur. The modern view of the evolution of pathogen virulence--specifically its focus on the tradeoff between costs and benefits to the pathogen from increased host exploitation--allows control programs to identify and focus on the most dangerous pathogens (those that can be established with high virulence in human populations). PMID:8969242

  6. Assessment of periodontal and opportunistic flora in patients with peri-implantitis.

    PubMed

    Albertini, Matteo; López-Cerero, Lorena; O'Sullivan, Manuel G; Chereguini, Carlos F; Ballesta, Sofia; Ríos, Vicente; Herrero-Climent, Mariano; Bullón, Pedro

    2015-08-01

    To assess the presence of periodontal and opportunistic organisms in patients with peri-implantitis. Thirty-three partially edentulous subjects (22 women, 11 men), aged 32-90 years, who had one or more implants with peri-implantitis were included. Peri-implantitis was defined as: (i) the presence of bleeding on probing and/or suppuration and (ii) radiographic images showed marginal bone loss >1.8 mm after 1 year in function. Criteria for inclusion were: (i) partially edentulous patients having at least one implant diagnosed with peri-implantitis; (ii) no antibiotic therapy for 6 months prior to clinical examination. Following this definition, a total of 48 implants were diagnosed with peri-implantitis. Subgingival bacterial samples were obtained with sterile paper points from infected implants and selected teeth of each individual. Periodontopathogens (Aggregatibacter actinomycetemcomitans, Porphyromonas gingivalis, Prevotella intermedia, Tannerella forsythia and Treponema denticola) were detected by multiplex PCR targeting 16S rDNA. Samples were placed in reduced transport medium and cultured for opportunistic pathogens (Staphylococcus aureus, enteric bacteria, Pseudomonas and yeasts). Twenty-two patients yielded positive results for P. gingivalis, 25 for T. forsythia, eight for P. intermedia and 13 for T. denticola. None of the patients yielded a positive result for A. actinomycetemcomitans. Non-periodontal species were found in five patients (15% of total). P. aeruginosa was found in four (12%) patients, and C. albicans (3%) and S. aureus in one patient (3%) each. In two cases of peri-implantitis, none of the periodontal or opportunistic microorganisms studied were detected in either implant or tooth samples. When results of the periodontopathic bacteria from the implant and tooth samples of the same patient were compared, 18 patients (54%) showed the same results for both samples and 15 (45%) patients different results. The implant surface may be colonized with

  7. Comparison of the Oral Microbiomes of Canines and Their Owners Using Next-Generation Sequencing

    PubMed Central

    Oh, Changin; Lee, Kunkyu; Cheong, Yeotaek; Lee, Sang-Won; Park, Seung-Yong; Song, Chang-Seon; Choi, In-Soo; Lee, Joong-Bok

    2015-01-01

    The oral microbiome, which is closely associated with many diseases, and the resident pathogenic oral bacteria, which can be transferred by close physical contact, are important public health considerations. Although the dog is the most common companion animal, the composition of the canine oral microbiome, which may include human pathogenic bacteria, and its relationship with that of their owners are unclear. In this study, 16S rDNA pyrosequencing was used to compare the oral microbiomes of 10 dogs and their owners and to identify zoonotic pathogens. Pyrosequencing revealed 246 operational taxonomic units in the 10 samples, representing 57 genera from eight bacterial phyla. Firmicutes (57.6%), Proteobacteria (21.6%), Bacteroidetes (9.8%), Actinobacteria (7.1%), and Fusobacteria (3.9%) were the predominant phyla in the human oral samples, whereas Proteobacteria (25.7%), Actinobacteria (21%), Bacteroidetes (19.7%), Firmicutes (19.3%), and Fusobacteria (12.3%) were predominant in the canine oral samples. The predominant genera in the human samples were Streptococcus (43.9%), Neisseria (10.3%), Haemophilus (9.6%), Prevotella (8.4%), and Veillonella (8.1%), whereas the predominant genera in the canine samples were Actinomyces (17.2%), Unknown (16.8), Porphyromonas (14.8), Fusobacterium (11.8), and Neisseria (7.2%). The oral microbiomes of dogs and their owners were appreciably different, and similarity in the microbiomes of canines and their owners was not correlated with residing in the same household. Oral-to-oral transfer of Neisseria shayeganii, Porphyromonas canigingivalis, Tannerella forsythia, and Streptococcus minor from dogs to humans was suspected. The finding of potentially zoonotic and periodontopathic bacteria in the canine oral microbiome may be a public health concern. PMID:26134411

  8. Oral inflammation, tooth loss, risk factors, and association with progression of Alzheimer's disease.

    PubMed

    Singhrao, Sim K; Harding, Alice; Simmons, Tal; Robinson, Sarita; Kesavalu, Lakshmyya; Crean, StJohn

    2014-01-01

    Periodontitis is a polymicrobial chronic inflammatory disease of tooth-supporting tissues with bacterial etiology affecting all age groups, becoming chronic in a subgroup of older individuals. Periodontal pathogens Porphyromonas gingivalis, Tannerella forsythia, and Treponema denticola are implicated in the development of a number of inflammatory pathologies at remote organ sites, including Alzheimer's disease (AD). The initial inflammatory hypothesis proposed that AD hallmark proteins were the main contributors of central nervous system (CNS) inflammation. This hypothesis is expanding to include the role of infections, lifestyle, and genetic and environmental factors in the pathogenesis of AD. Periodontal disease (PD) typifies a condition that encompasses all of the above factors including pathogenic bacteria. These bacteria not only are the source of low-grade, chronic infection and inflammation that follow daily episodes of bacteremia arising from everyday tasks such as brushing, flossing teeth, chewing food, and during dental procedures, but they also disseminate into the brain from closely related anatomical pathways. The long-term effect of inflammatory mediators, pathogens, and/or their virulence factors, reaching the brain systemically or otherwise would, over time, prime the brain's own microglia in individuals who have inherent susceptibility traits. Such susceptibilities contribute to inadequate neutralization of invading agents, upon reaching the brain. This has the capacity to create a vicious cycle of sustained local inflammatory milieu resulting in the loss of cytoarchitectural integrity and vital neurons with subsequent loss of function (deterioration in memory). The possible pathways between PD and AD development are considered here, as well as environmental factors that may modulate/exacerbate AD symptoms.

  9. Microbial (Pathogen)/Recreational Water Quality Criteria

    EPA Pesticide Factsheets

    Documents pertaining to Recreational Human Health Ambient Water Quality Criteria for Microbial Organisms (Pathogens). These documents include safe levels for cyanotoxins microcystin and cylindrospermopsin, and Coliphage to protect human health.

  10. Anti-Immune Strategies of Pathogenic Fungi.

    PubMed

    Marcos, Caroline M; de Oliveira, Haroldo C; de Melo, Wanessa de Cássia M Antunes; da Silva, Julhiany de Fátima; Assato, Patrícia A; Scorzoni, Liliana; Rossi, Suélen A; de Paula E Silva, Ana C A; Mendes-Giannini, Maria J S; Fusco-Almeida, Ana M

    2016-01-01

    Pathogenic fungi have developed many strategies to evade the host immune system. Multiple escape mechanisms appear to function together to inhibit attack by the various stages of both the adaptive and the innate immune response. Thus, after entering the host, such pathogens fight to overcome the immune system to allow their survival, colonization and spread to different sites of infection. Consequently, the establishment of a successful infectious process is closely related to the ability of the pathogen to modulate attack by the immune system. Most strategies employed to subvert or exploit the immune system are shared among different species of fungi. In this review, we summarize the main strategies employed for immune evasion by some of the major pathogenic fungi.

  11. Whole genome plasticity in pathogenic bacteria.

    PubMed

    Dobrindt, U; Hacker, J

    2001-10-01

    The exploitation of bacterial genome sequences has so far provided a wealth of new general information about the genetic diversity of bacteria, such as that of many pathogens. Comparative genomics uncovered many genome variations in closely related bacteria and revealed basic principles involved in bacterial diversification, improving our knowledge of the evolution of bacterial pathogens. A correlation between metabolic versatility and genome size has become evident. The degenerated life styles of obligate intracellular pathogens correlate with significantly reduced genome sizes, a phenomenon that has been termed "evolution by reduction". These mechanisms can permanently alter bacterial genotypes and result in adaptation to their environment by genome optimization. In this review, we summarize the recent results of genome-wide approaches to studying the genetic diversity of pathogenic bacteria that indicate that the acquisition of DNA and the loss of genetic information are two important mechanisms that contribute to strain-specific differences in genome content.

  12. Calorie restriction and susceptibility to intact pathogens

    PubMed Central

    2008-01-01

    Long-term calorie restriction (CR) causes numerous physiological changes that ultimately increase mean and maximum lifespan of most species examined to date. One physiological change that occurs with CR is enhanced immune function, as tested using antigens and mitogens to stimulate an immune response. Fewer studies have used intact pathogen exposure to test whether the enhanced capacity of the immune response during CR actually decreases susceptibility of hosts to their pathogens. So far, studies using intact bacteria, virus, and helminth worm exposure indicate that, despite similar or enhanced immune system function, CR hosts are more susceptible to infection by intact pathogens than their fully fed counterparts. Long-term CR studies that examine susceptibility to a variety of parasite taxa will help determine if direct CR or CR mimetics will be beneficial to people living in pathogen-rich environments. PMID:19424864

  13. Speciation in fungal and oomycete plant pathogens.

    PubMed

    Restrepo, Silvia; Tabima, Javier F; Mideros, Maria F; Grünwald, Niklaus J; Matute, Daniel R

    2014-01-01

    The process of speciation, by definition, involves evolution of one or more reproductive isolating mechanisms that split a single species into two that can no longer interbreed. Determination of which processes are responsible for speciation is important yet challenging. Several studies have proposed that speciation in pathogens is heavily influenced by host-pathogen dynamics and that traits that mediate such interactions (e.g., host mobility, reproductive mode of the pathogen, complexity of the life cycle, and host specificity) must lead to reproductive isolation and ultimately affect speciation rates. In this review, we summarize the main evolutionary processes that lead to speciation of fungal and oomycete plant pathogens and provide an outline of how speciation can be studied rigorously, including novel genetic/genomic developments.

  14. Polyglycine hydrolases secreted by pathogenic fungi

    USDA-ARS?s Scientific Manuscript database

    Pathogens are known to produce proteases that target host defense proteins. Here we describe polyglycine hydrolases, fungal proteases that selectively cleave glycine-glycine peptide bonds within the polyglycine interdomain linker of targeted plant defense chitinases. Polyglycine hydrolases were puri...

  15. Exposure Control--OSHA's Bloodborne Pathogens Standard.

    ERIC Educational Resources Information Center

    Granville, Mark F.

    1993-01-01

    Explains schools' responsibilities in complying with the Occupational Safety and Health Administration's (OSHA) Bloodborne Pathogens Standard. Describes exposure determination plan, protective equipment, housekeeping practices, labeling of waste, training employees, hepatitis B vaccinations, postexposure evaluation and medical follow-up, and…

  16. Biofilm formation by saprophytic and pathogenic leptospires.

    PubMed

    Ristow, Paula; Bourhy, Pascale; Kerneis, Sophie; Schmitt, Christine; Prevost, Marie-Christine; Lilenbaum, Walter; Picardeau, Mathieu

    2008-05-01

    Leptospires exist as saprophytic organisms that are aquatic or as pathogens that are able to survive in water. Leptospirosis is transmitted to humans through environmental surface waters contaminated by the urine of mammals, usually rodents, which are chronically infected by pathogenic strains. The ecology of Leptospira spp. prompted us to evaluate if these spirochaetes were able to form biofilms. This study investigated the characteristics of biofilm development by both saprophytic and pathogenic Leptospira species using microscopic examinations and a polystyrene plate model. Biofilms were formed preferentially on glass and polystyrene surfaces. Electron microscopic images showed cells embedded in an extracellular matrix. The formation of such a biofilm is consistent with the life of saprophytic strains in water and may help pathogenic strains to survive in environmental habitats and to colonize the host.

  17. Comparative genomics of the liberibacteral plant pathogens

    USDA-ARS?s Scientific Manuscript database

    Comparative analyses of multiple Liberibacter genomes provide significant insights into the evolutionary history, genetic diversity, and phylogenetic and metabolomic capacities among pathogenic bacteria that have caused tremendous economic losses to agricultural crops. In addition, genomic analyses ...

  18. Anti-Immune Strategies of Pathogenic Fungi

    PubMed Central

    Marcos, Caroline M.; de Oliveira, Haroldo C.; de Melo, Wanessa de Cássia M. Antunes; da Silva, Julhiany de Fátima; Assato, Patrícia A.; Scorzoni, Liliana; Rossi, Suélen A.; de Paula e Silva, Ana C. A.; Mendes-Giannini, Maria J. S.; Fusco-Almeida, Ana M.

    2016-01-01

    Pathogenic fungi have developed many strategies to evade the host immune system. Multiple escape mechanisms appear to function together to inhibit attack by the various stages of both the adaptive and the innate immune response. Thus, after entering the host, such pathogens fight to overcome the immune system to allow their survival, colonization and spread to different sites of infection. Consequently, the establishment of a successful infectious process is closely related to the ability of the pathogen to modulate attack by the immune system. Most strategies employed to subvert or exploit the immune system are shared among different species of fungi. In this review, we summarize the main strategies employed for immune evasion by some of the major pathogenic fungi. PMID:27896220

  19. Exposure Control--OSHA's Bloodborne Pathogens Standard.

    ERIC Educational Resources Information Center

    Granville, Mark F.

    1993-01-01

    Explains schools' responsibilities in complying with the Occupational Safety and Health Administration's (OSHA) Bloodborne Pathogens Standard. Describes exposure determination plan, protective equipment, housekeeping practices, labeling of waste, training employees, hepatitis B vaccinations, postexposure evaluation and medical follow-up, and…

  20. Microbial mito-pathogens: fact or fiction?

    PubMed

    Bongaerts, Ger P A; van den Heuvel, Lambert P

    2008-01-01

    Mitochondria are bacteria-like semi-autonomous intracellular organelles that function as the powerhouses of eukaryotic cells. Inactivation or destruction of these organelles may have far-reaching consequences regarding the viability of the cells and thus of tissues, organs and finally even the body. Since mitochondria resemble (degenerated) bacteria, we have extrapolated from both cytological and microbiological facts the existence of various (kinds of) mitochondrion-specific microbial pathogens, i.e., pathogenic micro-organisms that may damage or destroy the mitochondria from within. These mito-pathogens may include mitoviruses, mitoviroids and mitobacteria. Although these mito-pathogens have not yet been demonstrated in humans, their theoretical degenerative effect regarding energy production from energy-rich substrates, such as carbohydrates and fats, might explain diseases that have not yet been understood, such as prion diseases and post-traumatic muscle dystrophy. Therefore, these kinds of micro-organisms should be kept in mind.

  1. Phytochemicals as a preharvest pathogen reduction strategy

    USDA-ARS?s Scientific Manuscript database

    Phytochemicals are naturally occurring, non-nutritive chemicals produced by plants to limit pathogenic bacteria growth. Thousands of phytochemicals have been isolated from a variety of plants, and some have been documented to possess antimicrobial, antibacterial, and immunostimulatory properties. As...

  2. Comparative Pathogenicity of United Kingdom Isolates of the Emerging Pathogen Candida auris and Other Key Pathogenic Candida Species

    PubMed Central

    Szekely, Adrien; Johnson, Elizabeth M.

    2016-01-01

    ABSTRACT Candida auris, first described in 2009, has since emerged as an important, multidrug-resistant, nosocomial agent of candidemia, with large outbreaks reported worldwide and high mortality rates associated with therapeutic failure. The current study employed C. auris isolates from a variety of centers in the United Kingdom to evaluate the pathogenicity of this emerging pathogen compared to that of other common pathogenic yeast species in the invertebrate Galleria mellonella infection model. We showed that C. auris isolates differ in their growth characteristics in vitro, with a proportion of isolates failing to release daughter cells after budding, resulting in the formation of large aggregates of cells that cannot be physically disrupted. Our results also demonstrate strain-specific differences in the behavior of C. auris in G. mellonella, with the aggregate-forming isolates exhibiting significantly less pathogenicity than their nonaggregating counterparts. Importantly, the nonaggregating isolates exhibited pathogenicity comparable to that of C. albicans, which is currently accepted as the most pathogenic member of the genus, despite the fact that C. auris isolates do not produce hyphae and produce only rudimentary pseudohyphae either in vitro or in G. mellonella. IMPORTANCE The incidence of invasive candidiasis, which includes candidemia and deep tissue infections, continues to rise and is associated with considerable mortality rates. Candida albicans remains the most common cause of invasive candidiasis, although the prevalence of non-albicans species has increased over recent years. Since its first description in 2009, Candida auris has emerged as a serious nosocomial health risk, with widespread outbreaks in numerous hospitals worldwide. However, despite receiving considerable attention, little is known concerning the pathogenicity of this emerging fungal pathogen. Here, using the Galleria mellonella insect systemic infection model, we show

  3. Adaptive value of sex in microbial pathogens.

    PubMed

    Michod, Richard E; Bernstein, Harris; Nedelcu, Aurora M

    2008-05-01

    Explaining the adaptive value of sex is one of the great outstanding problems in biology. The challenge comes from the difficulty in identifying the benefits provided by sex, which must outweigh the substantial costs of sex. Here, we consider the adaptive value of sex in viruses, bacteria and fungi, and particularly the information available on the adaptive role of sex in pathogenic microorganisms. Our general theme is that the varied aspects of sex in pathogens illustrate the varied issues surrounding the evolution of sex generally. These include, the benefits of sex (in the short- and long-term), as well as the costs of sex (both to the host and to the pathogen). For the benefits of sex (that is, its adaptive value), we consider three hypotheses: (i) sex provides for effective and efficient recombinational repair of DNA damages, (ii) sex provides DNA for food, and (iii) sex produces variation and reduces genetic associations among alleles under selection. Although the evolution of sex in microbial pathogens illustrates these general issues, our paper is not a general review of theories for the evolution of sex in all organisms. Rather, we focus on the adaptive value of sex in microbial pathogens and conclude that in terms of short-term benefits, the DNA repair hypothesis has the most support and is the most generally applicable hypothesis in this group. In particular, recombinational repair of DNA damages may substantially benefit pathogens when challenged by the oxidative defenses of the host. However, in the long-term, sex may help get rid of mutations, increase the rate of adaptation of the population, and, in pathogens, may infrequently create new infective strains. An additional general issue about sex illustrated by pathogens is that some of the most interesting consequences of sex are not necessarily the reasons for which sex evolved. For example, antibiotic resistance may be transferred by bacterial sex, but this transfer is probably not the reason sex

  4. Plant antioxidant gene responses to fungal pathogens.

    PubMed

    Williamson, J D; Scandalios, J G

    1993-09-01

    Antioxidant defense systems are a prominent element in plant responses to environmental stress. Activated oxygen species have themselves been implicated as both a part of the plant's defense against pathogen attack as well as the phytotoxic component of photosensitizing fungal toxins. Molecular analyses are just beginning to define how plant oxidant and antioxidant genes might integrate with other defense responses to provide effective protection against pathogen attack.

  5. The cuticle and plant defense to pathogens.

    PubMed

    Serrano, Mario; Coluccia, Fania; Torres, Martha; L'Haridon, Floriane; Métraux, Jean-Pierre

    2014-01-01

    The cuticle provides a physical barrier against water loss and protects against irradiation, xenobiotics, and pathogens. Components of the cuticle are perceived by invading fungi and activate developmental processes during pathogenesis. In addition, cuticle alterations of various types induce a syndrome of reactions that often results in resistance to necrotrophs. This article reviews the current knowledge on the role of the cuticle in relation to the perception of pathogens and activation of defenses.

  6. MHC polymorphism under host-pathogen coevolution.

    PubMed

    Borghans, José A M; Beltman, Joost B; De Boer, Rob J

    2004-02-01

    The genes encoding major histocompatibility (MHC) molecules are among the most polymorphic genes known for vertebrates. Since MHC molecules play an important role in the induction of immune responses, the evolution of MHC polymorphism is often explained in terms of increased protection of hosts against pathogens. Two selective pressures that are thought to be involved are (1) selection favoring MHC heterozygous hosts, and (2) selection for rare MHC alleles by host-pathogen coevolution. We have developed a computer simulation of coevolving hosts and pathogens to study the relative impact of these two mechanisms on the evolution of MHC polymorphism. We found that heterozygote advantage per se is insufficient to explain the high degree of polymorphism at the MHC, even in very large host populations. Host-pathogen coevolution, on the other hand, can easily account for realistic polymorphisms of more than 50 alleles per MHC locus. Since evolving pathogens mainly evade presentation by the most common MHC alleles in the host population, they provide a selective pressure for a large variety of rare MHC alleles. Provided that the host population is sufficiently large, a large set of MHC alleles can persist over many host generations under host-pathogen coevolution, despite the fact that allele frequencies continuously change.

  7. Sexual Reproduction of Human Fungal Pathogens

    PubMed Central

    Heitman, Joseph; Carter, Dee A.; Dyer, Paul S.; Soll, David R.

    2014-01-01

    We review here recent advances in our understanding of sexual reproduction in fungal pathogens that commonly infect humans, including Candida albicans, Cryptococcus neoformans/gattii, and Aspergillus fumigatus. Where appropriate or relevant, we introduce findings on other species associated with human infections. In particular, we focus on rapid advances involving genetic, genomic, and population genetic approaches that have reshaped our view of how fungal pathogens evolve. Rather than being asexual, mitotic, and largely clonal, as was thought to be prevalent as recently as a decade ago, we now appreciate that the vast majority of pathogenic fungi have retained extant sexual, or parasexual, cycles. In some examples, sexual and parasexual unions of pathogenic fungi involve closely related individuals, generating diversity in the population but with more restricted recombination than expected from fertile, sexual, outcrossing and recombining populations. In other cases, species and isolates participate in global outcrossing populations with the capacity for considerable levels of gene flow. These findings illustrate general principles of eukaryotic pathogen emergence with relevance for other fungi, parasitic eukaryotic pathogens, and both unicellular and multicellular eukaryotic organisms. PMID:25085958

  8. Environmental Variation Generates Environmental Opportunist Pathogen Outbreaks.

    PubMed

    Anttila, Jani; Kaitala, Veijo; Laakso, Jouni; Ruokolainen, Lasse

    2015-01-01

    Many socio-economically important pathogens persist and grow in the outside host environment and opportunistically invade host individuals. The environmental growth and opportunistic nature of these pathogens has received only little attention in epidemiology. Environmental reservoirs are, however, an important source of novel diseases. Thus, attempts to control these diseases require different approaches than in traditional epidemiology focusing on obligatory parasites. Conditions in the outside-host environment are prone to fluctuate over time. This variation is a potentially important driver of epidemiological dynamics and affect the evolution of novel diseases. Using a modelling approach combining the traditional SIRS models to environmental opportunist pathogens and environmental variability, we show that epidemiological dynamics of opportunist diseases are profoundly driven by the quality of environmental variability, such as the long-term predictability and magnitude of fluctuations. When comparing periodic and stochastic environmental factors, for a given variance, stochastic variation is more likely to cause outbreaks than periodic variation. This is due to the extreme values being further away from the mean. Moreover, the effects of variability depend on the underlying biology of the epidemiological system, and which part of the system is being affected. Variation in host susceptibility leads to more severe pathogen outbreaks than variation in pathogen growth rate in the environment. Positive correlation in variation on both targets can cancel the effect of variation altogether. Moreover, the severity of outbreaks is significantly reduced by increase in the duration of immunity. Uncovering these issues helps in understanding and controlling diseases caused by environmental pathogens.

  9. Plant pathogen nanodiagnostic techniques: forthcoming changes?

    PubMed Central

    Khiyami, Mohammad A.; Almoammar, Hassan; Awad, Yasser M.; Alghuthaymi, Mousa A.; Abd-Elsalam, Kamel A.

    2014-01-01

    Plant diseases are among the major factors limiting crop productivity. A first step towards managing a plant disease under greenhouse and field conditions is to correctly identify the pathogen. Current technologies, such as quantitative polymerase chain reaction (Q-PCR), require a relatively large amount of target tissue and rely on multiple assays to accurately identify distinct plant pathogens. The common disadvantage of the traditional diagnostic methods is that they are time consuming and lack high sensitivity. Consequently, developing low-cost methods to improve the accuracy and rapidity of plant pathogens diagnosis is needed. Nanotechnology, nano particles and quantum dots (QDs) have emerged as essential tools for fast detection of a particular biological marker with extreme accuracy. Biosensor, QDs, nanostructured platforms, nanoimaging and nanopore DNA sequencing tools have the potential to raise sensitivity, specificity and speed of the pathogen detection, facilitate high-throughput analysis, and to be used for high-quality monitoring and crop protection. Furthermore, nanodiagnostic kit equipment can easily and quickly detect potential serious plant pathogens, allowing experts to help farmers in the prevention of epidemic diseases. The current review deals with the application of nanotechnology for quicker, more cost-effective and precise diagnostic procedures of plant diseases. Such an accurate technology may help to design a proper integrated disease management system which may modify crop environments to adversely affect crop pathogens. PMID:26740775

  10. Plant and pathogen nutrient acquisition strategies

    PubMed Central

    Fatima, Urooj; Senthil-Kumar, Muthappa

    2015-01-01

    Nutrients are indispensable elements required for the growth of all living organisms including plants and pathogens. Phyllosphere, rhizosphere, apoplast, phloem, xylem, and cell organelles are the nutrient niches in plants that are the target of bacterial pathogens. Depending upon nutrients availability, the pathogen adapts various acquisition strategies and inhabits the specific niche. In this review, we discuss the nutrient composition of different niches in plants, the mechanisms involved in the recognition of nutrient niche and the sophisticated strategies used by the bacterial pathogens for acquiring nutrients. We provide insight into various nutrient acquisition strategies used by necrotrophic, biotrophic, and hemibiotrophic bacteria. Specifically we discuss both modulation of bacterial machinery and manipulation of host machinery. In addition, we highlight the current status of our understanding about the nutrient acquisition strategies used by bacterial pathogens, namely targeting the sugar transporters that are dedicated for the plant’s growth and development. Bacterial strategies for altering the plant cell membrane permeability to enhance the release of nutrients are also enumerated along with in-depth analysis of molecular mechanisms behind these strategies. The information presented in this review will be useful to understand the plant–pathogen interaction in nutrient perspective. PMID:26442063

  11. Antibody-mediated resistance against plant pathogens.

    PubMed

    Safarnejad, Mohammad Reza; Jouzani, Gholamreza Salehi; Tabatabaei, Meisam; Tabatabaie, Meisam; Twyman, Richard M; Schillberg, Stefan

    2011-01-01

    Plant diseases have a significant impact on the yield and quality of crops. Many strategies have been developed to combat plant diseases, including the transfer of resistance genes to crops by conventional breeding. However, resistance genes can only be introgressed from sexually-compatible species, so breeders need alternative measures to introduce resistance traits from more distant sources. In this context, genetic engineering provides an opportunity to exploit diverse and novel forms of resistance, e.g. the use of recombinant antibodies targeting plant pathogens. Native antibodies, as a part of the vertebrate adaptive immune system, can bind to foreign antigens and eliminate them from the body. The ectopic expression of antibodies in plants can also interfere with pathogen activity to confer disease resistance. With sufficient knowledge of the pathogen life cycle, it is possible to counter any disease by designing expression constructs so that pathogen-specific antibodies accumulate at high levels in appropriate sub-cellular compartments. Although first developed to tackle plant viruses and still used predominantly for this purpose, antibodies have been targeted against a diverse range of pathogens as well as proteins involved in plant-pathogen interactions. Here we comprehensively review the development and implementation of antibody-mediated disease resistance in plants.

  12. Plant pathogen nanodiagnostic techniques: forthcoming changes?

    PubMed

    Khiyami, Mohammad A; Almoammar, Hassan; Awad, Yasser M; Alghuthaymi, Mousa A; Abd-Elsalam, Kamel A

    2014-09-03

    Plant diseases are among the major factors limiting crop productivity. A first step towards managing a plant disease under greenhouse and field conditions is to correctly identify the pathogen. Current technologies, such as quantitative polymerase chain reaction (Q-PCR), require a relatively large amount of target tissue and rely on multiple assays to accurately identify distinct plant pathogens. The common disadvantage of the traditional diagnostic methods is that they are time consuming and lack high sensitivity. Consequently, developing low-cost methods to improve the accuracy and rapidity of plant pathogens diagnosis is needed. Nanotechnology, nano particles and quantum dots (QDs) have emerged as essential tools for fast detection of a particular biological marker with extreme accuracy. Biosensor, QDs, nanostructured platforms, nanoimaging and nanopore DNA sequencing tools have the potential to raise sensitivity, specificity and speed of the pathogen detection, facilitate high-throughput analysis, and to be used for high-quality monitoring and crop protection. Furthermore, nanodiagnostic kit equipment can easily and quickly detect potential serious plant pathogens, allowing experts to help farmers in the prevention of epidemic diseases. The current review deals with the application of nanotechnology for quicker, more cost-effective and precise diagnostic procedures of plant diseases. Such an accurate technology may help to design a proper integrated disease management system which may modify crop environments to adversely affect crop pathogens.

  13. Adenoid reservoir for pathogenic biofilm bacteria.

    PubMed

    Nistico, L; Kreft, R; Gieseke, A; Coticchia, J M; Burrows, A; Khampang, P; Liu, Y; Kerschner, J E; Post, J C; Lonergan, S; Sampath, R; Hu, F Z; Ehrlich, G D; Stoodley, P; Hall-Stoodley, L

    2011-04-01

    Biofilms of pathogenic bacteria are present on the middle ear mucosa of children with chronic otitis media (COM) and may contribute to the persistence of pathogens and the recalcitrance of COM to antibiotic treatment. Controlled studies indicate that adenoidectomy is effective in the treatment of COM, suggesting that the adenoids may act as a reservoir for COM pathogens. To investigate the bacterial community in the adenoid, samples were obtained from 35 children undergoing adenoidectomy for chronic OM or obstructive sleep apnea. We used a novel, culture-independent molecular diagnostic methodology, followed by confocal microscopy, to investigate the in situ distribution and organization of pathogens in the adenoids to determine whether pathogenic bacteria exhibited criteria characteristic of biofilms. The Ibis T5000 Universal Biosensor System was used to interrogate the extent of the microbial diversity within adenoid biopsy specimens. Using a suite of 16 broad-range bacterial primers, we demonstrated that adenoids from both diagnostic groups were colonized with polymicrobial biofilms. Haemophilus influenzae was present in more adenoids from the COM group (P = 0.005), but there was no significant difference between the two patient groups for Streptococcus pneumoniae or Staphylococcus aureus. Fluorescence in situ hybridization, lectin binding, and the use of antibodies specific for host epithelial cells demonstrated that pathogens were aggregated, surrounded by a carbohydrate matrix, and localized on and within the epithelial cell surface, which is consistent with criteria for bacterial biofilms.

  14. Pathogenic bacteria and timing of laying

    PubMed Central

    Møller, Anders Pape; Soler, Juan J; Nielsen, Jan Tøttrup; Galván, Ismael

    2015-01-01

    Pathogenic bacteria constitute a serious threat to viability of many organisms. Because growth of most bacteria is favored by humid and warm environmental conditions, earlier reproducers in seasonal environments should suffer less from the negative consequences of pathogenic bacteria. These relationships, and the effects on reproductive success, should be particularly prominent in predators because they are frequently exposed to pathogenic microorganisms from sick prey. Here, we presented and tested this hypothesis by sampling bacteria on adult and nestling goshawks Accipiter gentilis. We predicted that early breeders and their offspring should have fewer bacteria than those reproducing later during the breeding season. Adult goshawks with a high abundance of Staphylococcus on their beak and claws were easier to capture and their laying date was delayed. Moreover, goshawks that laid their eggs later had offspring with more Staphylococcus on their beaks and claws. The strength of the association between laying date and bacterial density of nestlings was stronger during the warm spring of 2013, when nestlings suffered from a higher abundance of pathogenic bacteria. Hatching failure and fledging failure were more common in nests with a higher abundance of Staphylococcus independently of the number of years occupied, laying date, and age of the female nest owner. These findings imply that timing of reproduction may be under the influence of pathogenic bacteria. Because early breeding goshawks produce more recruits than later breeders, our results suggest a role for pathogenic bacteria in the optimal timing of reproduction. PMID:25937910

  15. Sexual reproduction of human fungal pathogens.

    PubMed

    Heitman, Joseph; Carter, Dee A; Dyer, Paul S; Soll, David R

    2014-08-01

    We review here recent advances in our understanding of sexual reproduction in fungal pathogens that commonly infect humans, including Candida albicans, Cryptococcus neoformans/gattii, and Aspergillus fumigatus. Where appropriate or relevant, we introduce findings on other species associated with human infections. In particular, we focus on rapid advances involving genetic, genomic, and population genetic approaches that have reshaped our view of how fungal pathogens evolve. Rather than being asexual, mitotic, and largely clonal, as was thought to be prevalent as recently as a decade ago, we now appreciate that the vast majority of pathogenic fungi have retained extant sexual, or parasexual, cycles. In some examples, sexual and parasexual unions of pathogenic fungi involve closely related individuals, generating diversity in the population but with more restricted recombination than expected from fertile, sexual, outcrossing and recombining populations. In other cases, species and isolates participate in global outcrossing populations with the capacity for considerable levels of gene flow. These findings illustrate general principles of eukaryotic pathogen emergence with relevance for other fungi, parasitic eukaryotic pathogens, and both unicellular and multicellular eukaryotic organisms.

  16. Hydrologic modeling of pathogen fate and transport.

    PubMed

    Dorner, Sarah M; Anderson, William B; Slawson, Robin M; Kouwen, Nicholas; Huck, Peter M

    2006-08-01

    A watershed-scale fate and transport model has been developed for Escherichia coli and several waterborne pathogens: Cryptosporidiumspp., Giardiaspp., Campylobacter spp, and E. coli O157:H7. The objectives were to determine the primary sources of pathogenic contamination in a watershed used for drinking water supply and to gain a greater understanding of the factors that most influence their survival and transport. To predict the levels of indicator bacteria and pathogens in surface water, an existing hydrologic model, WATFLOOD, was augmented for pathogen transport and tested on a watershed in Southwestern Ontario, Canada. The pathogen model considered transport as a result of overland flow, subsurface flow to tile drainage systems, and in-stream routing. The model predicted that most microorganisms entering the stream from land-based sources enter the stream from tile drainage systems rather than overland transport. Although the model predicted overland transport to be rare, when it occurred, it corresponded to the highest observed and modeled microbial concentrations. Furthermore, rapid increases in measured E. coli concentrations during storm events suggested that the resuspension of microorganisms from stream sediments may be of equal or greater importance than land-based sources of pathogens.

  17. Genome dynamics in major bacterial pathogens

    PubMed Central

    Ambur, Ole Herman; Davidsen, Tonje; Frye, Stephan A; Balasingham, Seetha V; Lagesen, Karin; Rognes, Torbjørn; Tønjum, Tone

    2009-01-01

    Pathogenic bacteria continuously encounter multiple forms of stress in their hostile environments, which leads to DNA damage. With the new insight into biology offered by genome sequences, the elucidation of the gene content encoding proteins provides clues toward understanding the microbial lifestyle related to habitat and niche. Campylobacter jejuni, Haemophilus influenzae, Helicobacter pylori, Mycobacterium tuberculosis, the pathogenic Neisseria, Streptococcus pneumoniae, Streptococcus pyogenes and Staphylococcus aureus are major human pathogens causing detrimental morbidity and mortality at a global scale. An algorithm for the clustering of orthologs was established in order to identify whether orthologs of selected genes were present or absent in the genomes of the pathogenic bacteria under study. Based on the known genes for the various functions and their orthologs in selected pathogenic bacteria, an overview of the presence of the different types of genes was created. In this context, we focus on selected processes enabling genome dynamics in these particular pathogens, namely DNA repair, recombination and horizontal gene transfer. An understanding of the precise molecular functions of the enzymes participating in DNA metabolism and their importance in the maintenance of bacterial genome integrity has also, in recent years, indicated a future role for these enzymes as targets for therapeutic intervention. PMID:19396949

  18. Adenoid Reservoir for Pathogenic Biofilm Bacteria▿

    PubMed Central

    Nistico, L.; Kreft, R.; Gieseke, A.; Coticchia, J. M.; Burrows, A.; Khampang, P.; Liu, Y.; Kerschner, J. E.; Post, J. C.; Lonergan, S.; Sampath, R.; Hu, F. Z.; Ehrlich, G. D.; Stoodley, P.; Hall-Stoodley, L.

    2011-01-01

    Biofilms of pathogenic bacteria are present on the middle ear mucosa of children with chronic otitis media (COM) and may contribute to the persistence of pathogens and the recalcitrance of COM to antibiotic treatment. Controlled studies indicate that adenoidectomy is effective in the treatment of COM, suggesting that the adenoids may act as a reservoir for COM pathogens. To investigate the bacterial community in the adenoid, samples were obtained from 35 children undergoing adenoidectomy for chronic OM or obstructive sleep apnea. We used a novel, culture-independent molecular diagnostic methodology, followed by confocal microscopy, to investigate the in situ distribution and organization of pathogens in the adenoids to determine whether pathogenic bacteria exhibited criteria characteristic of biofilms. The Ibis T5000 Universal Biosensor System was used to interrogate the extent of the microbial diversity within adenoid biopsy specimens. Using a suite of 16 broad-range bacterial primers, we demonstrated that adenoids from both diagnostic groups were colonized with polymicrobial biofilms. Haemophilus influenzae was present in more adenoids from the COM group (P = 0.005), but there was no significant difference between the two patient groups for Streptococcus pneumoniae or Staphylococcus aureus. Fluorescence in situ hybridization, lectin binding, and the use of antibodies specific for host epithelial cells demonstrated that pathogens were aggregated, surrounded by a carbohydrate matrix, and localized on and within the epithelial cell surface, which is consistent with criteria for bacterial biofilms. PMID:21307211

  19. Intracellular lifestyle of Brucella spp. Common genes with other animal pathogens, plant pathogens, and endosymbionts.

    PubMed

    Ugalde, R A

    1999-12-01

    Brucella spp. are intracellular pathogens that belong, like Agrobacterium, Rhizobium and Rickettsia, to the alpha-2-subgroup of proteobacteria. The genome organization of most Brucella spp. is characterized by the presence of two chromosomes. The intracellular lifestyle of Brucella, as well as the possible genes involved in pathogenesis and host cell signaling, are discussed, including the presence of genes with high similarity to those from other animal pathogens, plant pathogens and endosymbionts.

  20. Risk factors for drug-resistant pathogens in immunocompetent patients with pneumonia: Evaluation of PES pathogens.

    PubMed

    Ishida, Tadashi; Ito, Akihiro; Washio, Yasuyoshi; Yamazaki, Akio; Noyama, Maki; Tokioka, Fumiaki; Arita, Machiko

    2017-01-01

    The new acronym, PES pathogens (Pseudomonas aeruginosa, Enterobacteriaceae extended-spectrum beta-lactamase-positive, and methicillin-resistant Staphylococcus aureus), was recently proposed to identify drug-resistant pathogens associated with community-acquired pneumonia. To evaluate the risk factors for antimicrobial-resistant pathogens in immunocompetent patients with pneumonia and to validate the role of PES pathogens. A retrospective analysis of a prospective observational study of immunocompetent patients with pneumonia between March 2009 and June 2015 was conducted. We clarified the risk factors for PES pathogens. Of the total 1559 patients, an etiological diagnosis was made in 705 (45.2%) patients. PES pathogens were identified in 51 (7.2%) patients, with 53 PES pathogens (P. aeruginosa, 34; ESBL-positive Enterobacteriaceae, 6; and MRSA, 13). Patients with PES pathogens had tendencies toward initial treatment failure, readmission within 30 days, and a prolonged hospital stay. Using multivariate analysis, female sex (adjusted odds ratio [AOR] 1.998, 95% confidence interval [CI] 1.047-3.810), admission within 90 days (AOR 2.827, 95% CI 1.250-6.397), poor performance status (AOR 2.380, 95% CI 1.047-5.413), and enteral feeding (AOR 5.808, 95% CI 1.813-18.613) were independent risk factors for infection with PES pathogens. The area under the receiver operating characteristics curve for the risk factors was 0.66 (95% CI 0.577-0.744). We believe the definition of PES pathogens is an appropriate description of drug-resistant pathogens associated with pneumonia in immunocompetent patients. The frequency of PES pathogens is quite low. However, recognition is critical because they can cause refractory pneumonia and different antimicrobial treatment is required. Copyright © 2016 The Author(s). Published by Elsevier Ltd.. All rights reserved.

  1. Comparison of innate immune responses to pathogenic and putative non-pathogenic hantaviruses in vitro.

    PubMed

    Shim, So Hee; Park, Man-Seong; Moon, Sungsil; Park, Kwang Sook; Song, Jin-Won; Song, Ki-Joon; Baek, Luck Ju

    2011-09-01

    Hantaviruses are human pathogens that cause hemorrhagic fever with renal syndrome or hantavirus cardiopulmonary syndrome. The mechanisms accounting for the differences in virulence between pathogenic and non-pathogenic hantaviruses are not well known. We have examined the pathogenesis of different hantavirus groups by comparing the innate immune responses induced in the host cell following infection by pathogenic (Sin Nombre, Hantaan, and Seoul virus) and putative non-pathogenic (Prospect Hill, Tula, and Thottapalayam virus) hantaviruses. Pathogenic hantaviruses were found to replicate more efficiently in interferon-competent A549 cells than putative non-pathogenic hantaviruses. The former also suppressed the expression of the interferon-β and myxovirus resistance protein genes, while the transcription level of both genes increased rapidly within 24 h post-infection in the latter. In addition, the induction level of interferon correlated with the activation level of interferon regulatory factor-3. Taken together, these results suggest that the observed differences are correlated with viral pathogenesis and further indicate that pathogenic and putative non-pathogenic hantaviruses differ in terms of early interferon induction via activation of the interferon regulatory factor-3 in infected host cells.

  2. A large, mobile pathogenicity island confers plant pathogenicity on Streptomyces species.

    PubMed

    Kers, Johan A; Cameron, Kimberly D; Joshi, Madhumita V; Bukhalid, Raghida A; Morello, Joanne E; Wach, Michael J; Gibson, Donna M; Loria, Rosemary

    2005-02-01

    Potato scab is a globally important disease caused by polyphyletic plant pathogenic Streptomyces species. Streptomyces acidiscabies, Streptomyces scabies and Streptomyces turgidiscabies possess a conserved biosynthetic pathway for the nitrated dipeptide phytotoxin thaxtomin. These pathogens also possess the nec1 gene which encodes a necrogenic protein that is an independent virulence factor. In this article we describe a large (325-660 kb) pathogenicity island (PAI) conserved among these three plant pathogenic Streptomyces species. A partial DNA sequence of this PAI revealed the thaxtomin biosynthetic pathway, nec1, a putative tomatinase gene, and many mobile genetic elements. In addition, the PAI from S. turgidiscabies contains a plant fasciation (fas) operon homologous to and colinear with the fas operon in the plant pathogen Rhodococcus fascians. The PAI was mobilized during mating from S. turgidiscabies to the non-pathogens Streptomyces coelicolor and Streptomyces diastatochromogenes on a 660 kb DNA element and integrated site-specifically into a putative integral membrane lipid kinase. Acquisition of the PAI conferred a pathogenic phenotype on S. diastatochromogenes but not on S. coelicolor. This PAI is the first to be described in a Gram-positive plant pathogenic bacterium and is responsible for the emergence of new plant pathogenic Streptomyces species in agricultural systems.

  3. Global Expression Studies of Yersinia Pestis Pathogenicity

    SciTech Connect

    Garcia, E; Motin, V; Brubaker, R; Fitch, P

    2002-10-15

    The aim of these studies continues to be the investigation into the molecular mechanisms that underlie the virulence process in Yersinia pestis. In particular, the focus of this work centers on the identification of novel genes and pathways responsible for the pathogenic properties of this organism. In spite of more than four decades of intense investigation in this field, the dilemma as to what makes Y. pestis such a virulent and lethal pathogen remains unanswered. The method being employed makes use microarray technology (DNA chip) that enables the examination of the global activities of the whole complement of genes in this pathogen. Two primary resources available to the investigators (one directly obtained from a separate CBNP-funded project) make these studies possible: (1) Whole genome comparisons of the genes in Y. pestis and its near neighbors with attenuated or non pathogenic characteristics, and (2) the ability to duplicate in vitro, conditions that mimic the infection process of this pathogen. This year we have extended our studies from the original work of characterizing the global transcriptional regulation in Y. pestis triggered during temperature transition from 26 C to 37 C (roughly conditions found in the flea vector and the mammalian host, respectively) to studies of regulation encountered during shift between growth from conditions of neutral pH to acidic pH (the latter conditions, those mimic the environment found inside macrophages, a likely environment found by these cells during infection.). For this work, DNA arrays containing some 5,000 genes (the entire genome of Y. pestis plus those genes found uniquely in the enteropathogen, and near neighbor, Y. pseudotuberculosis) are used to monitor the simultaneous expression levels of each gene of known and unknown function in Y. pestis. Those genes that are up-regulate under the experimental conditions represent genes potentially involved in the pathogenic process. The ultimate role in

  4. Mental Health Disorders Associated with Foodborne Pathogens.

    PubMed

    Bolton, Declan J; Robertson, Lucy J

    2016-11-01

    Human infections with foodborne pathogenic organisms are relatively well described in terms of their overt physical symptoms, such as diarrhea, abdominal cramps, vomiting, fever, and associated sequelae. Indeed, some of these are key for diagnosis and treatment, although it should be noted that, for some foodborne pathogens, the physical symptoms might be more diffuse, particularly those associated with some of the foodborne parasites. In contrast, the impact of these pathogens on mental health is less well described, and symptoms such as depression, anxiety, and general malaise are usually ignored when foodborne infections are recorded. Despite this, it is generally accepted that there are several psychiatric disorders of unknown etiology that may be associated with microbial pathogens. Depression, autism, hypochondriasis and anxiety, schizophrenia, and Tourette syndrome probably have multiple contributing causes, among which foodborne pathogens may play a decisive or contributory role, possibly sharing pathophysiological pathways with other environmental triggers. This review focuses on foodborne parasites and bacterial pathogens. Some foodborne parasites, such as metacestodes of Taenia solium and tissue cysts (bradyzoites) of Toxoplasma gondii , may affect mental health by directly infecting the brain. In contrast, bacterial infections and other parasitic infections may contribute to mental illness via the immune system and/or by influencing neurotransmission pathways. Thus, cytokines, for example, have been associated with depression and schizophrenia. However, infectious disease models for psychiatry require a more complete understanding of the relationship between psychiatric disorders and microbial triggers. This article reviews the current state of knowledge on the role of foodborne parasitic and bacterial pathogens in mental illness and identifies some of the gaps that should be addressed to improve diagnosis and treatment of mental health issues that are

  5. Antibiotic resistance in ocular bacterial pathogens.

    PubMed

    Sharma, S

    2011-01-01

    Bacterial infections of the eye are common and ophthalmologists are spoilt for choice with a variety of antibiotics available in the market. Antibiotics can be administered in the eye by a number of routes; topical, subconjunctival, subtenon and intraocular. Apart from a gamut of eye drops available, ophthalmologists also have the option of preparing fortified eye drops from parenteral formulations, thereby, achieving high concentrations; often much above the minimum inhibitory concentration (MIC), of antibiotics in ocular tissues during therapy. Antibiotic resistance among ocular pathogens is increasing in parallel with the increase seen over the years in bacteria associated with systemic infections. Although it is believed that the rise in resistant ocular bacterial isolates is linked to the rise in resistant systemic pathogens, recent evidence has correlated the emergence of resistant bacteria in the eye to prior topical antibiotic therapy. One would like to believe that either of these contributes to the emergence of resistance to antibiotics among ocular pathogens. Until recently, ocular pathogens resistant to fluoroquinolones have been minimal but the pattern is currently alarming. The new 8-fluoroquinolone on the scene-besifloxacin, is developed exclusively for ophthalmic use and it is hoped that it will escape the selective pressure for resistance because of lack of systemic use. In addition to development of new antibacterial agents, the strategies to halt or control further development of resistant ocular pathogens should always include judicious use of antibiotics in the treatment of human, animal or plant diseases.

  6. Regulatory Proteolysis in Arabidopsis-Pathogen Interactions.

    PubMed

    Pogány, Miklós; Dankó, Tamás; Kámán-Tóth, Evelin; Schwarczinger, Ildikó; Bozsó, Zoltán

    2015-09-24

    Approximately two and a half percent of protein coding genes in Arabidopsis encode enzymes with known or putative proteolytic activity. Proteases possess not only common housekeeping functions by recycling nonfunctional proteins. By irreversibly cleaving other proteins, they regulate crucial developmental processes and control responses to environmental changes. Regulatory proteolysis is also indispensable in interactions between plants and their microbial pathogens. Proteolytic cleavage is simultaneously used both by plant cells, to recognize and inactivate invading pathogens, and by microbes, to overcome the immune system of the plant and successfully colonize host cells. In this review, we present available results on the group of proteases in the model plant Arabidopsis thaliana whose functions in microbial pathogenesis were confirmed. Pathogen-derived proteolytic factors are also discussed when they are involved in the cleavage of host metabolites. Considering the wealth of review papers available in the field of the ubiquitin-26S proteasome system results on the ubiquitin cascade are not presented. Arabidopsis and its pathogens are conferred with abundant sets of proteases. This review compiles a list of those that are apparently involved in an interaction between the plant and its pathogens, also presenting their molecular partners when available.

  7. Enteric pathogens and soil: a short review.

    PubMed

    Santamaría, Johanna; Toranzos, Gary A

    2003-03-01

    It is known that soil is a recipient of solid wastes able to contain enteric pathogens in high concentrations. Although the role of soil as a reservoir of certain bacterial pathogens is not in question, recent findings show that soil may have a larger role in the transmission of enteric diseases than previously thought. Many of the diseases caused by agents from soil have been well characterized, although enteric diseases and their link to soil have not been so well studied. Gastrointestinal infections are the most common diseases caused by enteric bacteria. Some examples are salmonellosis ( Salmonella sp.), cholera ( Vibrio cholerae), dysentery ( Shigella sp.) and other infections caused by Campylobacter jejuni, Yersinia sp. and Escherichia coli O157:H7 and many other strains. Viruses are the most hazardous and have some of the lowest infectious doses of any of the enteric pathogens. Hepatitis A, hepatitis E, enteric adenoviruses, poliovirus types 1 and 2, multiple strains of echoviruses and coxsackievirus are enteric viruses associated with human wastewater. Among the most commonly detected protozoa in sewage are Entamoeba histolytica, Giardia intestinalis and Cryptosporidium parvum. This article reviews the existing literature of more than two decades on waste disposal practices that favor the entry of enteric pathogens to soil and the possible consequent role of the soil as a vector and reservoir of enteric pathogens.

  8. Host immune responses accelerate pathogen evolution

    PubMed Central

    Trivedi, Pankaj; Wang, Nian

    2014-01-01

    Pathogens face a hostile and often novel environment when infecting a new host, and adaptation is likely to be an important determinant of the success in colonization and establishment. We hypothesized that resistant hosts will impose stronger selection on pathogens than susceptible hosts, which should accelerate pathogen evolution through selection biased toward effector genes. To test this hypothesis, we conducted an experimental evolution study on Xanthomonas citri subsp. citri (Xcc) in a susceptible plant species and a resistant plant species. We performed 55 rounds of repeated reinoculation of Xcc through susceptible host grapefruit (isolates G1, G2, G3) and resistant host kumquat (isolates K1, K2, K3). Consequently, only K1 and K3 isolates lost their ability to elicit a hypersensitive response (HR) in kumquat. Illumina sequencing of the parental and descendant strains P, G1, G2, G3, K1, K2 and K3 revealed that fixed mutations were biased toward type three secretion system effectors in isolates K1 and K3. Parallel evolution was observed in the K1 and K3 strains, suggesting that the mutations result from selection rather than by random drift. Our results support our hypothesis and suggest that repeated infection of resistant hosts by pathogens should be prevented to avoid selecting for adaptive pathogens. PMID:24304673

  9. Pathogenicity island mobility and gene content.

    SciTech Connect

    Williams, Kelly Porter

    2013-10-01

    Key goals towards national biosecurity include methods for analyzing pathogens, predicting their emergence, and developing countermeasures. These goals are served by studying bacterial genes that promote pathogenicity and the pathogenicity islands that mobilize them. Cyberinfrastructure promoting an island database advances this field and enables deeper bioinformatic analysis that may identify novel pathogenicity genes. New automated methods and rich visualizations were developed for identifying pathogenicity islands, based on the principle that islands occur sporadically among closely related strains. The chromosomally-ordered pan-genome organizes all genes from a clade of strains; gaps in this visualization indicate islands, and decorations of the gene matrix facilitate exploration of island gene functions. A %E2%80%9Clearned phyloblocks%E2%80%9D method was developed for automated island identification, that trains on the phylogenetic patterns of islands identified by other methods. Learned phyloblocks better defined termini of previously identified islands in multidrug-resistant Klebsiella pneumoniae ATCC BAA-2146, and found its only antibiotic resistance island.

  10. Genomic Transition to Pathogenicity in Chytrid Fungi

    PubMed Central

    Joneson, Suzanne; Stajich, Jason E.; Shiu, Shin-Han; Rosenblum, Erica Bree

    2011-01-01

    Understanding the molecular mechanisms of pathogen emergence is central to mitigating the impacts of novel infectious disease agents. The chytrid fungus Batrachochytrium dendrobatidis (Bd) is an emerging pathogen of amphibians that has been implicated in amphibian declines worldwide. Bd is the only member of its clade known to attack vertebrates. However, little is known about the molecular determinants of - or evolutionary transition to - pathogenicity in Bd. Here we sequence the genome of Bd's closest known relative - a non-pathogenic chytrid Homolaphlyctis polyrhiza (Hp). We first describe the genome of Hp, which is comparable to other chytrid genomes in size and number of predicted proteins. We then compare the genomes of Hp, Bd, and 19 additional fungal genomes to identify unique or recent evolutionary elements in the Bd genome. We identified 1,974 Bd-specific genes, a gene set that is enriched for protease, lipase, and microbial effector Gene Ontology terms. We describe significant lineage-specific expansions in three Bd protease families (metallo-, serine-type, and aspartyl proteases). We show that these protease gene family expansions occurred after the divergence of Bd and Hp from their common ancestor and thus are localized to the Bd branch. Finally, we demonstrate that the timing of the protease gene family expansions predates the emergence of Bd as a globally important amphibian pathogen. PMID:22072962

  11. Mast cell-orchestrated immunity to pathogens

    PubMed Central

    Abraham, Soman N.; St John, Ashley L.

    2015-01-01

    Although mast cells were discovered more than a century ago, their functions beyond their role in allergic responses remained elusive until recently. However, there is a growing appreciation that an important physiological function of these cells is the recognition of pathogens and modulation of appropriate immune responses. Because of their ability to instantly release several pro-inflammatory mediators from intracellular stores and their location at the host–environment interface, mast cells have been shown to be crucial for optimal immune responses during infection. Mast cells seem to exert these effects by altering the inflammatory environment after detection of a pathogen and by mobilizing various immune cells to the site of infection and to draining lymph nodes. Interestingly, the character and timing of these responses can vary depending on the type of pathogen stimulus, location of pathogen recognition and sensitization state of the responding mast cells. Recent studies using mast cell activators as effective vaccine adjuvants show the potential of harnessing these cells to confer protective immunity against microbial pathogens. PMID:20498670

  12. PIML: the Pathogen Information Markup Language.

    PubMed

    He, Yongqun; Vines, Richard R; Wattam, Alice R; Abramochkin, Georgiy V; Dickerman, Allan W; Eckart, J Dana; Sobral, Bruno W S

    2005-01-01

    A vast amount of information about human, animal and plant pathogens has been acquired, stored and displayed in varied formats through different resources, both electronically and otherwise. However, there is no community standard format for organizing this information or agreement on machine-readable format(s) for data exchange, thereby hampering interoperation efforts across information systems harboring such infectious disease data. The Pathogen Information Markup Language (PIML) is a free, open, XML-based format for representing pathogen information. XSLT-based visual presentations of valid PIML documents were developed and can be accessed through the PathInfo website or as part of the interoperable web services federation known as ToolBus/PathPort. Currently, detailed PIML documents are available for 21 pathogens deemed of high priority with regard to public health and national biological defense. A dynamic query system allows simple queries as well as comparisons among these pathogens. Continuing efforts are being taken to include other groups' supporting PIML and to develop more PIML documents. All the PIML-related information is accessible from http://www.vbi.vt.edu/pathport/pathinfo/

  13. Susceptibility of pathogenic and nonpathogenic Naegleria ssp

    SciTech Connect

    Whiteman, L.Y.

    1988-01-01

    The susceptibility of four species of Naegleria amoebae to complement-mediated lysis was determined. The amoebicidal activity of normal human serum (NHS) and normal guinea pig serum (NGPS) for Naegleria amoebae was measured by an in vitro cytotoxicity assay. Release of radioactivity from amoebae labeled with {sup 3}H-uridine and visual observation with a compound microscope were used as indices of lysis. Susceptibility or resistance to complement-mediated lysis in vitro correlated with the in vivo pathogenic potential. Nonpathogenic Naegleria amoebae were lysed at a faster rate and at higher cell concentrations than were pathogenic amoebae. Electrophoretic analysis of NHS incubated with pathogenic or nonpathogenic Naegleria spp. demonstrated that amoebae activate the complement cascade resulting in the production of C3 and C5 complement cleavage products. Treatment with papain or trypsin for 1 h, but not with sialidase, increase the susceptibility of highly pathogenic, mouse-passaged N. fowleri to lysis. Treatment with actinomycin D, cycloheximide or various protease inhibitors for 4 h did not increase susceptibility to lysis. Neither a repair process involving de novo protein synthesis nor a complement-inactivating protease appear to account for the increase resistance of N. fowleri amoebae to complement-mediated lysis. A binding study with {sup 125}I radiolabeled C9 indicated that the terminal complement component does not remain stably bound to the membrane of pathogenic amoebae.

  14. Current Interventions for Controlling Pathogenic Escherichia coli.

    PubMed

    Kim, Nam Hee; Cho, Tae Jin; Rhee, Min Suk

    2017-01-01

    This review examined scientific reports and articles published from 2007 to 2016 regarding the major environmental sources of pathogenic Escherichia coli and the routes by which they enter the human gastrointestinal tract. The literature describes novel techniques used to combat pathogenic E. coli transmitted to humans from livestock and agricultural products, food-contact surfaces in processing environments, and food products themselves. Although prevention before contamination is always the best "intervention," many studies aim to identify novel chemical, physical, and biological techniques that inactivate or eliminate pathogenic E. coli cells from breeding livestock, growing crops, and manufactured food products. Such intervention strategies target each stage of the food chain from the perspective of "Farm to Table food safety" and aim to manage major reservoirs of pathogenic E. coli throughout the entire process. Issues related to, and recent trends in, food production must address not only the safety of the food itself but also the safety of those who consume it. Thus, research aims to discover new "natural" antimicrobial agents and to develop "multiple hurdle technology" or other novel technologies that preserve food quality. In addition, this review examines the practical application of recent technologies from the perspective of product quality and safety. It provides comprehensive insight into intervention measures used to ensure food safety, specifically those aimed at pathogenic E. coli. Copyright © 2017 Elsevier Inc. All rights reserved.

  15. Hemagglutination, autoagglutination and pathogenicity of Moraxella bovis strains.

    PubMed Central

    Gil-Turnes, C

    1983-01-01

    Three isolates of Moraxella bovis, recovered from cattle with signs of infectious bovine keratoconjunctivitis, were tested for autoagglutinating activity, hemagglutinating activity and pathogenicity in young calves. Only the autoagglutinating and hemagglutinating isolates were pathogenic in calves. Treatment of the pathogenic isolates with magnesium chloride eliminated their pathogenic effects. PMID:6667436

  16. Contamination of produce with human pathogens: sources and solutions

    USDA-ARS?s Scientific Manuscript database

    Outbreaks of foodborne illnesses associated with the presence of human pathogens have led to increased concern about the prevalence of pathogens in the environment and the vulnerability of fresh produce to contamination by these pathogens. As the FDA strives to mandate treatments to reduce pathogen...

  17. Pathogenicity of two Egyptian H5N1 highly pathogenic avian influenza viruses in domestic ducks

    USDA-ARS?s Scientific Manuscript database

    Domestic ducks have been implicated in the dissemination and evolution of H5N1 highly pathogenic avian influenza (HPAI) viruses. Interestingly, the pathogenicity of H5N1 HPAI viruses in domestic ducks has increased over time with some viruses producing 100% mortality in ducks. These changes in vir...

  18. Pathogenicity of reassortant H5N1 highly pathogenic avian influenza viruses in domestic ducks

    USDA-ARS?s Scientific Manuscript database

    The pathogenicity of H5N1 highly pathogenic avian influenza (HPAI) viruses in domestic ducks has increased over time. These changes in virulence have been reported with viruses from countries with high population of domestic ducks, including Egypt. In order to understand which viral genes are contri...

  19. Host-pathogen interactions and genome evolution in two generalist and specialist microsporidian pathogens of mosquitoes

    USDA-ARS?s Scientific Manuscript database

    The adaptation of two distantly related microsporidia to their mosquito hosts was investigated. Edhazardia aedis is a specialist pathogen that infects Aedes aegypti, the main vector of dengue and yellow fever arboviruses. Vavraia culicis is a generalist pathogen of several insects including Anophele...

  20. Fusarium graminearum: an pathogen of maize in Nepal, pathogenic variability and mycotoxins

    USDA-ARS?s Scientific Manuscript database

    Fusarium graminearum is an important pathogen of maize in hills of Nepal. It predominantly occurs on maize grown in cool and humid environment of high hills. The pathogen is also known to infect other cereal crops including wheat and rice causing important diseases. The incidence of ear rot is hi...