Publications
| Title | Abstract | Year(sorted ascending) Filter | PMID Filter |
|---|
| significance of detection of porphyromonas gingivalis, bacteroides forsythus and treponema denticola in periodontal pockets. | the relationship between the detection of porphyromonas gingivalis, bacteroides forsythus and treponema denticola in subgingival plaque samples of periodontal pockets and periodontal status was evaluated using the polymerase chain reaction (pcr). a total of 165 sites in 60 periodontitis patients were examined, and the relationships between the detection of each of the three bacterial species and the pocket depth and bleeding on probing (bop) were analyzed. the detection ratios of p. gingivalis, ... | 2000 | 11212582 |
| oral chlamydia trachomatis in patients with established periodontitis. | periodontitis is considered a consequence of a pathogenic microbial infection at the periodontal site and host susceptibility factors. periodontal research supports the association of actinobacillus actinomycetemcomitans, porphyromonas gingivalis, prevotella intermedia, and bacteroides forsythus, and periodontitis; however, causality has not been demonstrated. in pursuit of the etiology of periodontitis, we hypothesized that the intracellular bacteria chlamydia trachomatis may play a role. as a ... | 2000 | 11218493 |
| mgla and mglb of treponema denticola; similarity to abc transport and spa genes. | the mgla and mglb genes (td-mgla and td-mglb) of the oral spirochete treponema denticola were sequenced. these two t. denticola genes are highly homologous to the e. coli and treponema pallidum mgla and mglb genes which are part of the three gene beta-methylgalactoside transport operon, mglbac. both td-mgla and td-mglb are also homologous to the high affinity abc-type transporters for ribose and arabinose, and surface presentation antigens (spa) locus, part of the type iii secretion systems in e ... | 2000 | 11328650 |
| cloning and dna sequence analysis of an immunogenic glucose-galactose mglb lipoprotein homologue from brachyspira pilosicoli, the agent of colonic spirochetosis. | colonic spirochetosis (cs) is a newly emerging infectious disease of humans and animals caused by the pathogenic spirochete brachyspira (formerly serpulina) pilosicoli. the purpose of this study was to characterize an antigen that was recognized by antibodies present in sera of challenge-exposed pigs. the gene encoding the antigen was identified by screening a plasmid library of human b. pilosicoli strain sp16 (atcc 49776) genomic dna with hyperimmune and convalescent swine sera. the predicted a ... | 2000 | 10899855 |
| "checkerboard" assessments of periodontal microbiota and serum antibody responses: a case-control study. | we explored the association between subgingival microbial profiles and serum igg responses to periodontal microbiota in relation to clinical periodontal status. | 2000 | 10914791 |
| metabolic pathways for cytotoxic end product formation from glutamate- and aspartate-containing peptides by porphyromonas gingivalis. | metabolic pathways involved in the formation of cytotoxic end products by porphyromonas gingivalis were studied. the washed cells of p. gingivalis atcc 33277 utilized peptides but not single amino acids. since glutamate and aspartate moieties in the peptides were consumed most intensively, a dipeptide of glutamate or aspartate was then tested as a metabolic substrate of p. gingivalis. p. gingivalis cells metabolized glutamylglutamate to butyrate, propionate, acetate, and ammonia, and they metabo ... | 2000 | 10940008 |
| molecular characterization of the gyrb region of the oral spirochete, treponema denticola. | the nucleotide (nt) sequence of the treponema denticola (td) dna gyrase beta-subunit gene (gyrb) has been determined. southern blot analysis of td chromosomal dna indicated that gyrb is present as a single copy. approximately 3.2kb of the nt sequence 5' and 0.7kb of nucleotide sequence 3' of gyrb were obtained. analysis of the deduced amino acid (aa) sequence revealed two complete open reading frames (orfs) (orf1 and orf3) and a truncated orf (orf4'). orf1 has no homology to sequences in the dat ... | 2000 | 10940564 |
| cytokine responses to treponema pectinovorum and treponema denticola in human gingival fibroblasts. | human gingival fibroblasts were challenged with treponema pectinovorum and treponema denticola to test three specific hypotheses: (i) these treponemes induce different cytokine profiles from the fibroblasts, (ii) differences in cytokine profiles are observed after challenge with live versus killed treponemes, and (iii) differences in cytokine profiles are noted from different gingival fibroblast cell lines when challenged with these treponemes. three normal gingival fibroblast cell cultures were ... | 2000 | 10948156 |
| identification of periodontal disease-associated bacteria in the "plaque-free zone". | subgingival plaque bacteria live within a biofilm covered with glycocalyx, and little is known of the bacterial species associated with biofilm formation at the bottom of human periodontal pockets, the so-called "plaque-free zone"(pfz). | 2000 | 10972648 |
| the effect of repeated professional supragingival plaque removal on the composition of the supra- and subgingival microbiota. | the purpose of the present investigation was to determine the effect of weekly professionally administered supragingival plaque removal on the composition of the supra and subgingival microbiota. | 2000 | 10983597 |
| comparison of the microbiota of supra- and subgingival plaque in health and periodontitis. | the purpose of the present investigation was to compare the microbial composition of supra and subgingival plaque in 22 periodontally healthy (mean age 32+/-16 years) and 23 adult periodontitis subjects (mean age 51+/-14 years). | 2000 | 10983598 |
| prevalence of periodontal pathogens in localized and generalized forms of early-onset periodontitis. | the primary objectives of this study were to investigate the prevalence of 8 putative periodontal pathogens in subjects with early-onset periodontitis (eop) and to evaluate the microbial differences between localized and generalized forms of this periodontal disease condition. thirty-one females and 11 males with a mean age of 30.3 (s.d. 4.0) years were examined. seventeen subjects had generalized (geop) and 25 had localized early-onset periodontitis (leop). subgingival plaque samples were assay ... | 2000 | 10983884 |
| borrelia burgdorferi periplasmic flagella have both skeletal and motility functions. | bacterial shape usually is dictated by the peptidoglycan layer of the cell wall. in this paper, we show that the morphology of the lyme disease spirochete borrelia burgdorferi is the result of a complex interaction between the cell cylinder and the internal periplasmic flagella. b. burgdorferi has a bundle of 7-11 helically shaped periplasmic flagella attached at each end of the cell cylinder and has a flat-wave cell morphology. backward moving, propagating waves enable these bacteria to swim in ... | 2000 | 10995478 |
| the le1 bacteriophage replicates as a plasmid within leptospira biflexa: construction of an l. biflexa-escherichia coli shuttle vector. | we have discovered that le1, one of the plaque-forming phages previously described as lytic for the leptospira biflexa saprophytic spirochete (i. saint girons, d. margarita, p. amouriaux, and g. baranton, res. microbiol. 141:1131-1138, 1990), was indeed temperate. le1 was found to be unusual, as southern blot analysis indicated that it is one of the few phages to replicate in the prophage state as a circular plasmid. the unavailability of such small endogenous replicons has hindered genetic expe ... | 2000 | 11004167 |
| metabolic engineering of an aerobic sulfate reduction pathway and its application to precipitation of cadmium on the cell surface. | the conversion of sulfate to an excess of free sulfide requires stringent reductive conditions. dissimilatory sulfate reduction is used in nature by sulfate-reducing bacteria for respiration and results in the conversion of sulfate to sulfide. however, this dissimilatory sulfate reduction pathway is inhibited by oxygen and is thus limited to anaerobic environments. as an alternative, we have metabolically engineered a novel aerobic sulfate reduction pathway for the secretion of sulfides. the ass ... | 2000 | 11010904 |
| hemolytic and hemoxidative activities in mycoplasma penetrans. | mycoplasma penetrans is a newly isolated mollicute from the urine of patients infected with human immunodeficiency virus that demonstrates the capacity to adhere to and invade human cells. a previous report, based on assays with mouse red blood cells (rbcs), indicated that m. penetrans lacked hemolytic activity. in our studies, we incubated different isolates of m. penetrans with various rbc species and observed hemolytic zones surrounding individual mycoplasma colonies. all m. penetrans strains ... | 2000 | 11035754 |
| microbiological parameters associated with il-1 gene polymorphisms in periodontitis patients. | polymorphisms in the cluster of il-1 genes have been significantly associated with the severity of adult periodontitis. the purpose of this study was to compare microbiological parameters in il-1 genotype negative and positive adult subjects with a range of periodontitis severities. | 2000 | 11073323 |
| the spirochete flaa periplasmic flagellar sheath protein impacts flagellar helicity. | spirochete periplasmic flagella (pfs), including those from brachyspira (serpulina), spirochaeta, treponema, and leptospira spp., have a unique structure. in most spirochete species, the periplasmic flagellar filaments consist of a core of at least three proteins (flab1, flab2, and flab3) and a sheath protein (flaa). each of these proteins is encoded by a separate gene. using brachyspira hyodysenteriae as a model system for analyzing pf function by allelic exchange mutagenesis, we analyzed purif ... | 2000 | 11073915 |
| antibiotic selective markers and spirochete genetics. | until very recently, the pathogenic spirochetes have been refractory to genetic manipulation. this has been due, in part, to difficulties with in vitro growth and the genetic distance that spirochetes are from typical gram-negative and gram-positive organisms. insertional mutagenesis and other genetic techniques are now possible in some of the pathogenic spirochetes such as borrelia burgdorferi, brachyspira (serpulina) hyodysenteriae, leptospira sp., and treponema denticola. however, organisms s ... | 2000 | 11075914 |
| dna exchange and insertional inactivation in spirochetes. | spirochetes have complex life cycles and are associated with a number of diseases in humans and animals. despite their significance as pathogens, spirochete genetics are in their early stages. however, gene inactivation has been achieved in borrelia burgdorferi, brachyspira hyodysenteriae, and treponema denticola. here, we review methods that have been used in spirochetes for gene inactivation and dna exchange, with a primary focus on b. burgdorferi. we also describe factors influencing electrot ... | 2000 | 11075915 |
| development of shuttle vectors for spirochetes. | constructions of escherichia coli-spirochete shuttle vectors are based on naturally occurring plasmids, broad host range plasmids or bacteriophages. this review primarily focuses on genetic tools for treponema denticola which is associated with periodontal diseases. the t. pallidum flaa protein, e. coli beta-galactosidase, and the green fluorescent protein were successfully expressed in t. denticola from a shuttle vector system. | 2000 | 11075916 |
| insertional inactivation of the prtp gene of treponema denticola confirms dentilisin's disruption of epithelial junctions. | the purified chymotrypsin-like protease of treponema denticola, designated dentilisin or prtp (ddbj accession no. d83264), can disrupt cell-cell junctions and impair the barrier function of epithelial monolayers in vitro. serine protease inhibitors block these effects. yet, the protease is apparently less significant in perturbing intracellular signaling pathways and cytoskeletal rearrangement in fibroblasts. the purpose of this study was to use a prtp-deficient mutant of t. denticola to confirm ... | 2000 | 11075935 |
| measurement of proteases in human subgingival dental plaque by fluorescence polarization. | fluorescence polarization (fp) was examined as a rapid quantitative method to assay the proteases in subgingival plaque. protease activity was measured by a decrease in fp at 0.5-min intervals over 5 min, using bodipy-alpha-casein, a protein substrate. to quantitate activity, the least absolute deviation (lad) slope for each assay was determined. protease activity increased with the quantity of plaque (r=0.416, p<0.001). of the 208 subgingival plaque samples, 87 contained detectable protease act ... | 2000 | 11084150 |
| intergeneric communication in dental plaque biofilms. | dental plaque is a complex biofilm that accretes in a series of discrete steps proceeding from a gram-positive streptococcus-rich biofilm to a structure rich in gram-negative anaerobes. this study investigated information flow between two unrelated plaque bacteria, streptococcus cristatus and porphyromonas gingivalis. a surface protein of s. cristatus caused repression of the p. gingivalis fimbrial gene (fima), as determined by a chromosomal fima promoter-lacz reporter construct and by reverse t ... | 2000 | 11092870 |
| the tprk gene is heterogeneous among treponema pallidum strains and has multiple alleles. | we have previously shown that the tprk antigen of t. pallidum, nichols strain, is predominantly expressed in treponemes obtained 10 days after infection and that the hydrophilic domain of tprk is a target of opsonic antibodies and confers significant protection against homologous challenge. the t. pallidum genome sequence reported the presence of a single copy of the tprk gene in the nichols strain. in the present study we demonstrate size heterogeneity in the central portions of the tprk hydrop ... | 2000 | 10639452 |
| the effect of scaling and root planing on the clinical and microbiological parameters of periodontal diseases: 12-month results. | previously, we reported that srp resulted in a decrease in mean pocket depth and attachment level and reduced prevalence and levels of bacteroidesforsythus, porphyromonas gingivalis, and treponema denticola at 3 and 6 months post-srp in 57 subjects with adult periodontitis. 32 of the 57 subjects were monitored at 9 and 12 months. thus, the purpose of the present investigation was to evaluate the microbial and clinical effects of srp in 32 (mean age 48+/-11) subjects over a 12-month period. | 2000 | 10674959 |
| epithelial cell response to challenge of bacterial lipoteichoic acids and lipopolysaccharides in vitro. | accumulating dental plaque at the gingival margin contains lipoteichoic acids (ltas) from the cell walls of gram-positive bacteria. in subgingival plaque associated with periodontal disease the amount of lipopolysaccharides (lpss) from gram-negative bacteria increases. as the gingival junctional epithelium (je) is an important structural and functional tissue, participating in the first line defence against apical advancement of dental plaque, this study examined the direct effects of ltas (from ... | 2000 | 10707944 |
| periodontopathic bacteria in children with down syndrome. | it is widely known that individuals with down syndrome (ds) often develop severe early-onset periodontal diseases. in this study, we examined the prevalence of periodontopathic bacteria in ds children to determine if specific pathogens are acquired in their childhood. | 2000 | 10711615 |
| identification of a treponema denticola oppa homologue that binds host proteins present in the subgingival environment. | proteins secreted or exported by treponema denticola have been implicated as mediators of specific interactions between the spirochete and subgingival tissues in periodontal diseases. however, limited information is available on the ability of this peptidolytic organism to bind or transport soluble peptides present in the subgingival environment. a prominent 70-kda protein was isolated from surface extracts of t. denticola atcc 35405. a clone expressing a portion of the protein was identified in ... | 2000 | 10722578 |
| induction of apoptotic cell death in peripheral blood mononuclear and polymorphonuclear cells by an oral bacterium, fusobacterium nucleatum. | it is largely unknown why a variety of bacteria present in the oral cavity are capable of establishing themselves in the periodontal pockets of nonimmunocompromised individuals in the presence of competent immune effector cells. in this paper we present evidence for the immunosuppressive role of fusobacterium nucleatum, a gram-negative oral bacterium which plays an important role in the generation of periodontal disease. our studies indicate that the immunosuppressive role of f. nucleatum is lar ... | 2000 | 10722579 |
| multiple alleles of treponema pallidum repeat gene d in treponema pallidum isolates. | two new tprd alleles have been identified in treponema pallidum: tprd2 is found in 7 of 12 t. pallidum subsp. pallidum isolates and 7 of 8 non-pallidum isolates, and tprd3 is found in one t. pallidum subsp. pertenue isolate. antibodies against tprd2 are found in persons with syphilis, demonstrating that tprd2 is expressed during infection. | 2000 | 10735882 |
| systemic diseases caused by oral infection. | recently, it has been recognized that oral infection, especially periodontitis, may affect the course and pathogenesis of a number of systemic diseases, such as cardiovascular disease, bacterial pneumonia, diabetes mellitus, and low birth weight. the purpose of this review is to evaluate the current status of oral infections, especially periodontitis, as a causal factor for systemic diseases. three mechanisms or pathways linking oral infections to secondary systemic effects have been proposed: ( ... | 2000 | 11023956 |
| electrophoretic mobility distributions of single-strain microbial populations. | 2001 | 11157207 | |
| heterogeneity of host immunological risk factors in patients with aggressive periodontitis. | the pathogenesis of early-onset periodontitis (eop) can be explained by various host risk factors. previous studies have focused on a single (among many possible) immunological risk factor and the association among the factors has not been assessed. we comprehensively investigated the associations among multiple host immunological risk factors in eop patients to further elucidate their role in the pathogenesis of eop. | 2001 | 11338294 |
| the tprk protein of treponema pallidum is periplasmic and is not a target of opsonic antibody or protective immunity. | the finding that treponema pallidum, the syphilis spirochete, contains 12 orthologs of the treponema denticola outer membrane major sheath protein has engendered speculation that members of this t. pallidum repeat (tpr) family may be similarly surface exposed. in this regard, the tprk protein was reported to be a target of opsonic antibody and protective immunity and subject to immunologically driven sequence variation. despite these findings, results from our previous analyses of treponemal out ... | 2001 | 11342586 |
| pcr detection of 5 putative periodontal pathogens in dental plaque samples from children 2 to 12 years of age. | the purpose of this study was to detect the presence of prevotella intermedia, p. nigrescens, bacteroides forsythus, treponema denticola, and campylobacter rectus in plaque samples from 119 children, collected from their toothbrushes using a polymerase chain reaction (pcr). | 2001 | 11350526 |
| effects of the oral spirochete treponema denticola on interleukin-8 expression from epithelial cells. | this communication demonstrates that the interaction of the oral spirochete treponema denticola 35405 with kb epithelial cells does not lead to the induction of interleukin-8 production as occurs with a variety of other bacteria. utilizing the dentilisin protease mutant k1 of t. denticola, this property was demonstrated to be primarily a function of the expression of the protease by strain 35405. | 2001 | 11358542 |
| bacterial diversity in human subgingival plaque. | the purpose of this study was to determine the bacterial diversity in the human subgingival plaque by using culture-independent molecular methods as part of an ongoing effort to obtain full 16s rrna sequences for all cultivable and not-yet-cultivated species of human oral bacteria. subgingival plaque was analyzed from healthy subjects and subjects with refractory periodontitis, adult periodontitis, human immunodeficiency virus periodontitis, and acute necrotizing ulcerative gingivitis. 16s ribos ... | 2001 | 11371542 |
| tetracycline antibiotics: mode of action, applications, molecular biology, and epidemiology of bacterial resistance. | tetracyclines were discovered in the 1940s and exhibited activity against a wide range of microorganisms including gram-positive and gram-negative bacteria, chlamydiae, mycoplasmas, rickettsiae, and protozoan parasites. they are inexpensive antibiotics, which have been used extensively in the prophlylaxis and therapy of human and animal infections and also at subtherapeutic levels in animal feed as growth promoters. the first tetracycline-resistant bacterium, shigella dysenteriae, was isolated i ... | 2001 | 11381101 |
| cloning and expression of two novel hemin binding protein genes from treponema denticola. | treponema denticola does not appear to produce siderophores, so it must acquire iron by other pathways. indeed, t. denticola has been shown to have an iron-regulated 44-kda outer membrane protein (hbpa) with hemin binding ability. to characterize the hbpa protein, its gene was cloned from genomic dna libraries of t. denticola. sequence analysis of the hbpa open reading frame indicated that it encoded a 42.8-kda protein with a 23-amino-acid signal peptide. hbpa has no significant homology to any ... | 2001 | 11401987 |
| development of a gene inactivation system for bacteroides forsythus: construction and characterization of a bspa mutant. | bacteroides forsythus is a gram-negative anaerobic bacterium associated with periodontitis. the bspa gene encoding a cell surface associated leucine-rich repeat protein (bspa) involved in adhesion to fibronectin and fibrinogen was recently cloned from this bacterium in our laboratory. we now describe the construction of a bspa-defective mutant of b. forsythus. this is the first report describing the generation of a specific gene knockout mutant of b. forsythus, and this procedure should be usefu ... | 2001 | 11402017 |
| sodium ion-driven serine/threonine transport in porphyromonas gingivalis. | porphyromonas gingivalis is an asaccharolytic, gram-negative bacterium that relies on the fermentation of amino acids for metabolic energy. when grown in continuous culture in complex medium containing 4 mm (each) free serine, threonine, and arginine, p. gingivalis assimilated mainly glutamate/glutamine, serine, threonine, aspartate/asparagine, and leucine in free and/or peptide form. serine and threonine were assimilated in approximately equal amounts in free and peptide form. we characterized ... | 2001 | 11418553 |
| characterization of an aminoacylase from the hyperthermophilic archaeon pyrococcus furiosus. | aminoacylase was identified in cell extracts of the hyperthermophilic archaeon pyrococcus furiosus by its ability to hydrolyze n-acetyl-l-methionine and was purified by multistep chromatography. the enzyme is a homotetramer (42.06 kda per subunit) and, as purified, contains 1.0 +/- 0.48 g-atoms of zinc per subunit. treatment of the purified enzyme with edta resulted in complete loss of activity. this was restored to 86% of the original value (200 u/mg) by treatment with zncl(2) (and to 74% by th ... | 2001 | 11418567 |
| change in subgingival microbial profiles in adult periodontitis subjects receiving either systemically-administered amoxicillin or metronidazole. | the current investigation evaluated changes in levels and proportions of 40 bacterial species in subgingival plaque samples during, immediately after and up to 1 year after metronidazole or amoxicillin therapy combined with srp. | 2001 | 11422580 |
| detection of treponema denticola in atherosclerotic lesions. | we examined 26 atherosclerotic lesions and 14 nondiseased aorta specimens to detect the periodontopathogenic part of the bacterial 16s rrna locus by pcr. treponema denticola sequence of the 16s rrna locus was found in 6 out of 26 dna samples (23.1%) from the formalin-fixed, paraffin-embeded atherosclerotic lesions obtained during surgery but not in any of the 14 nondiseased aorta samples from deceased persons. utilizing immunofluorescence microscopy, we observed aggregated antigenic particles re ... | 2001 | 11230436 |
| detection of putative periodontal pathogens in non-insulin-dependent diabetes mellitus and non-diabetes mellitus by polymerase chain reaction. | it has been assumed that there is a relationship between periodontal diseases and diabetes mellitus, however the putative periodontal microorganisms in non-diabetes mellitus (non-dm) individuals and non-insulin-dependent diabetes mellitus (niddm) patients have not been well studied. in this study, the detection rates of 5 putative periodontal pathogens: actinobacillus actinomycetemcomitans, porphyromonas gingivalis, eikenella corrodens, treponema denticola, and candida albicans by polymerase cha ... | 2001 | 11246700 |
| borrelia burgdorferi and treponema pallidum: a comparison of functional genomics, environmental adaptations, and pathogenic mechanisms. | 2001 | 11254661 | |
| rapid detection and quantification of five periodontopathic bacteria by real-time pcr. | the quantity of periodontopathic bacteria in plaque samples is an important determinant for understanding the etiologic role of bacteria. the real-time pcr method was used to detect and quantify periodontopathic bacteria, such as actinobacillus actinomycetemcomitans, bacteroides forsythus, porphyromonas gingivalis, treponema denticola, and treponema socranskii, in saliva and subgingival plaque samples. there was good agreement between the results of conventional pcr and real-time pcr methods. us ... | 2001 | 11270605 |
| characterization of the yersinia pestis yfu abc inorganic iron transport system. | in yersinia pestis, the causative agent of plague, two inorganic iron transport systems have been partially characterized. the yersiniabactin (ybt) system is a siderophore-dependent transport system required for full virulence. yfe is an abc transport system that accumulates both iron and manganese. we have identified and cloned a y. pestis yfuabc operon. the yfuabc system is a member of the cluster of bacterial abc iron transporters that include sfu of serratia, hit of haemophilus, and yfu of y ... | 2001 | 11292695 |
| periodontal pathogens produce quorum sensing signal molecules. | different species of bacteria important in the composition of dental plaque were tested for production of extracellular autoinducer-like activities that stimulate the expression of the luminescence genes in vibrio harveyi. several strains of prevotella intermedia, fusobacterium nucleatum, and porphyromonas gingivalis were found to produce such activities. interestingly, these bacteria belong to the same phylogenetic group, and they are periodontal pathogens important in the development of period ... | 2001 | 11292769 |
| a spirochete surface protein uncouples store-operated calcium channels in fibroblasts: a novel cytotoxic mechanism. | the cytotoxicity of infectious agents can be mediated by disruption of calcium signaling in target cells. outer membrane proteins of the spirochete treponema denticola, a periodontal pathogen, inhibit agonist-induced ca(2+) release from internal stores in gingival fibroblasts, but the mechanism is not defined. we determined here that the major surface protein (msp) of t. denticola perturbs calcium signaling in human fibroblasts by uncoupling store-operated channels. msp localized in complexes on ... | 2001 | 11312269 |
| "red complex" (bacteroides forsythus, porphyromonas gingivalis, and treponema denticola) in endodontic infections: a molecular approach. | the "red complex," composed of bacteroides forsythus, porphyromonas gingivalis, and treponema denticola, is implicated in severe forms of periodontal diseases. the purpose of this study was to assess the occurrence of the red complex in root canal infections through the use of a sensitive technique-the 16s rdna-directed polymerase chain reaction (pcr). | 2001 | 11312465 |
| brachyspira (serpulina) hyodysenteriae gyrb mutants and interstrain transfer of coumermycin a(1) resistance. | to further develop genetic techniques for the enteropathogen brachyspira hyodysenteriae, the gyrb gene of this spirochete was isolated from a lambdazapii library of strain b204 genomic dna and sequenced. the putative protein encoded by this gene exhibited up to 55% amino acid sequence identity with gyrb proteins of various bacterial species, including other spirochetes. b. hyodysenteriae coumermycin a(1)-resistant (cn(r)) mutant strains, both spontaneous and uv induced, were isolated by plating ... | 2001 | 11319078 |
| new tests for syphilis: rational design of a pcr method for detection of treponema pallidum in clinical specimens using unique regions of the dna polymerase i gene. | a sensitive and specific pcr method to detect treponema pallidum in clinical specimens was developed. pcr primers were designed based on two unique features of the dna polymerase i gene (pola). the first distinctive characteristic is that the region codes for a high cysteine content and has low homology with similar regions of dna polymerase i gene from known microorganisms. the second unique feature is the presence of four insertions in the gene. pcr tests using primers designed on the basis th ... | 2001 | 11326018 |
| relationship of periodontopathic bacteria with early-onset periodontitis in down's syndrome. | down's syndrome (ds) patients often develop severe early-onset marginal periodontitis in early adulthood; however, there is little information available on the microbiology of ds periodontitis. | 2001 | 11327065 |
| coiling phagocytosis of borrelia burgdorferi by primary human macrophages is controlled by cdc42hs and rac1 and involves recruitment of wiskott-aldrich syndrome protein and arp2/3 complex. | lyme borreliosis is a multisystemic disorder primarily affecting the skin, nervous system, and joints. it is caused by the spirochete borrelia burgdorferi sensu lato and is transmitted via ticks of the ixodidae family. persistence of borreliae within macrophages has been implicated in the often chronic history of borreliosis. the uptake of b. burgdorferi by professional phagocytes occurs predominantly by coiling phagocytosis, a host cell-driven process in which single pseudopods wrap around and ... | 2001 | 11179351 |
| cytoplasmic filament-deficient mutant of treponema denticola has pleiotropic defects. | in treponema denticola, a ribbon-like structure of cytoplasmic filaments spans the cytoplasm at all stages of the cell division process. insertional inactivation was used as a first step to determine the function of the cytoplasmic filaments. a suicide plasmid was constructed that contained part of cfpa and a nonpolar erythromycin resistance cassette (ermf and ermam) inserted near the beginning of the gene. the plasmid was electroporated into t. denticola, and double-crossover recombinants which ... | 2001 | 11208807 |
| selenium-dependent growth of treponema denticola: evidence for a clostridial-type glycine reductase. | assessment of the nutritional requirements of treponema denticola disclosed a strict growth dependence on selenium. in vivo labeling of cells of this organism with (75)se and electrophoretic analysis revealed three labeled bands, two of which were selenoproteins correlating in size with subunits a and b of glycine reductase. antibodies directed against glycine- or betaine-reductase subunits of eubacterium acidaminophilum specifically also reacted with proteins from cell lysates of t. denticola. ... | 2001 | 11797052 |
| maternal periodontitis and prematurity. part ii: maternal infection and fetal exposure. | clinical data from the first 812 deliveries from a cohort study of pregnant mothers entitled oral conditions and pregnancy (ocap) demonstrate that both antepartum maternal periodontal disease and incidence/progression of periodontal disease are associated with preterm birth and growth restriction after adjusting for traditional obstetric risk factors. in the current study we present measures of maternal periodontal infection using whole chromosomal dna probes to identify 15 periodontal organisms ... | 2001 | 11887461 |
| molecular characterization of the treponema denticola fliq region. | a treponema denticola 4.2 kb dna region containing four complete genes (orfl, fliq, flir, and flhb) and a truncated gene (flha') was sequenced and analyzed. the deduced amino acid sequences of fliq, flir, flhb and flha' have significant homology with bacterial proteins associated with the flagellar export apparatus, whereas the deduced amino acid sequence of orf1 has homology with an e. coli alcohol dehydrogenase. a putative sigma70-like promoter was identified upstream of fliq. rt-pcr analysis ... | 2001 | 11913797 |
| [pathogenesis of surface component from treponema denticola]. | 2001 | 11431928 | |
| polymerase chain reaction detection of treponema denticola in endodontic infections within root canals. | a 16s rdna-based polymerase chain reaction (pcr) method was used to detect the occurrence of treponema denticola in root canals. | 2001 | 11482139 |
| detection of putative oral pathogens in acute periradicular abscesses by 16s rdna-directed polymerase chain reaction. | a 16s rdna-directed polymerase chain reaction method was used to assess the occurrence of four black-pigmented anaerobic rods, treponema denticola, and actinobacillus actinomycetemcomitans in acute periradicular abscesses. pus was collected by aspiration from 10 cases diagnosed as acute abscesses of endodontic origin. dna was extracted from the samples and analyzed using a polymerase chain reaction-based identification assay. the method allowed detecting black-pigmented anaerobes in 80% of the e ... | 2001 | 11487143 |
| clinical periodontal findings and microflora profiles in children with chronic neutropenia under supervised oral hygiene. | this is the first known case report that used a polymerase chain reaction (pcr)-based method to help identify the oral microflora in patients with chronic neutropenia. in this study, we report clinical periodontal findings and microflora profiles of 2 children, 1 with severe congenital neutropenia (scn, kostmann type) and 1 with cyclic neutropenia (cn). | 2001 | 11495144 |
| borrelia burgdorferi reva antigen is a surface-exposed outer membrane protein whose expression is regulated in response to environmental temperature and ph. | borrelia burgdorferi, the causative agent of lyme disease, produces reva protein during the early stages of mammalian infection. b. burgdorferi apparently uses temperature as a cue to its location, producing proteins required for infection of warm-blooded animals at temperatures corresponding to host body temperature, but does not produce such virulence factors at cooler, ambient temperatures. we have observed that b. burgdorferi regulates expression of reva in response to temperature, with the ... | 2001 | 11500397 |
| roles of fructosyltransferase and levanase-sucrase of actinomyces naeslundii in fructan and sucrose metabolism. | the ability of actinomyces naeslundii to convert sucrose to extracellular homopolymers of fructose and to catabolize these types of polymers is suspected to be a virulence trait that contributes to the initiation and progression of dental caries and periodontal diseases. previously, we reported on the isolation and characterization of the gene, ftf, encoding the fructosyltransferase (ftf) of a. naeslundii wvu45. allelic exchange mutagenesis was used to inactivate ftf, revealing that ftf-deficien ... | 2001 | 11500409 |
| humoral immune response in early-onset periodontitis: influence of smoking. | sixty-five patients with generalised early-onset periodontitis (g-eop) (age range 16-42 years, 32 smokers and 33 non-smokers) were assessed for antibody titres and avidity to a panel of five suspected periodontal pathogens (porphyromonas gingivalis, actinobacillus actinomycetemcomitans, prevotella intermedia, treponema denticola and bacteroides forsythus). thirty-four of these patients were untreated (17 smokers and 17 non-smokers), and thirty-one were in the maintenance phase of periodontal the ... | 2001 | 11519695 |
| sodium ion cycle in bacterial pathogens: evidence from cross-genome comparisons. | analysis of the bacterial genome sequences shows that many human and animal pathogens encode primary membrane na+ pumps, na+-transporting dicarboxylate decarboxylases or na+ translocating nadh:ubiquinone oxidoreductase, and a number of na+ -dependent permeases. this indicates that these bacteria can utilize na+ as a coupling ion instead of or in addition to the h+ cycle. this capability to use a na+ cycle might be an important virulence factor for such pathogens as vibrio cholerae, neisseria men ... | 2001 | 11528000 |
| mtnk, methylthioribose kinase, is a starvation-induced protein in bacillus subtilis. | methylthioadenosine, the main by-product of spermidine synthesis, is degraded in bacillus subtilis as adenine and methylthioribose. the latter is an excellent sulfur source and the precursor of quorum-sensing signalling molecules. nothing was known about methylthioribose recycling in this organism. | 2001 | 11545674 |
| aerobic sulfide production and cadmium precipitation by escherichia coli expressing the treponema denticola cysteine desulfhydrase gene. | the cysteine desulfhydrase gene of treponema denticola was over-expressed in escherichia coli to produce sulfide under aerobic conditions and to precipitate metal sulfide complexes on the cell wall. when grown in a defined salts medium supplemented with cadmium and cysteine, e. coli producing cysteine desulfhydrase secreted sulfide and removed nearly all of the cadmium from solution after 48 h. a control strain produced significantly less sulfide and removed significantly less cadmium. measureme ... | 2001 | 11549014 |
| identification of oral spirochetes at the species level and their association with other bacteria in endodontic infections. | recent molecular approaches have revealed that fastidious organisms such as bacteroides forsythus and oral treponemes were frequently found in root canals with apical periodontitis. the purpose of this study was to identify the isolates of oral spirochetes at the species level in endodontic infections and to determine their association with b forsythus and porphyromonas gingivalis. | 2001 | 11552154 |
| the opdb locus encodes the trypsin-like peptidase activity of treponema denticola. | high levels of treponema denticola in subgingival dental plaque are associated with severe periodontal disease. t. denticola, along with porphyromonas gingivalis and bacteroides forsythus, are the only cultivatable oral microorganisms that produce significant amounts of "trypsin-like" peptidase activity. the ability of subgingival plaque to hydrolyze n-alpha-benzoyl-dl-arginine-2-naphthylamide (bana) is associated with high levels of one or more of these organisms. the purpose of this study was ... | 2001 | 11553560 |
| motility and chemotaxis in tissue penetration of oral epithelial cell layers by treponema denticola. | the ability to penetrate tissue is an important virulence factor for pathogenic spirochetes. previous studies have recognized the role of motility in allowing pathogenic spirochetes to invade tissues and migrate to sites favorable for bacterial proliferation. however, the nature of the movements, whether they are random or controlled by chemotaxis systems, has yet to be established. in this study, we addressed the role of motility and chemotaxis in tissue penetration by the periodontal disease-a ... | 2001 | 11553571 |
| periodontal disease as a specific, albeit chronic, infection: diagnosis and treatment. | periodontal disease is perhaps the most common chronic infection in adults. evidence has been accumulating for the past 30 years which indicates that almost all forms of periodontal disease are chronic but specific bacterial infections due to the overgrowth in the dental plaque of a finite number of mostly anaerobic species such as porphyromonas gingivalis, bacteroides forsythus, and treponema denticola. the success of traditional debridement procedures and/or antimicrobial agents in improving p ... | 2001 | 11585783 |
| molecular detection of antimicrobial resistance. | the determination of antimicrobial susceptibility of a clinical isolate, especially with increasing resistance, is often crucial for the optimal antimicrobial therapy of infected patients. nucleic acid-based assays for the detection of resistance may offer advantages over phenotypic assays. examples are the detection of the methicillin resistance-encoding meca gene in staphylococci, rifampin resistance in mycobacterium tuberculosis, and the spread of resistance determinants across the globe. how ... | 2001 | 11585788 |
| chemotaxis of oral treponemes toward sera and albumin of rabbit. | the motility and chemotaxis of human oral spirochetes treponema denticola atcc 35404, t. medium atcc 700293, and t. vincentii atcc 35580 were examined by a capillary assay method. of five sera three human oral treponemes were dominantly chemoattractant to the rabbit serum. the checkerboard analysis of chemotaxis toward rabbit serum clearly showed that the motile t. denticola cells swam toward the culture media containing higher concentrations of the rabbit serum. t. denticola chemotaxis to the r ... | 2001 | 11592631 |
| the esat-6 gene cluster of mycobacterium tuberculosis and other high g+c gram-positive bacteria. | the genome of mycobacterium tuberculosis h37rv has five copies of a cluster of genes known as the esat-6 loci. these clusters contain members of the cfp-10 (lhp) and esat-6 (esat-6) gene families (encoding secreted t-cell antigens that lack detectable secretion signals) as well as genes encoding secreted, cell-wall-associated subtilisin-like serine proteases, putative abc transporters, atp-binding proteins and other membrane-associated proteins. these membrane-associated and energy-providing pro ... | 2001 | 11597336 |
| complementation of a nonmotile flab mutant of borrelia burgdorferi by chromosomal integration of a plasmid containing a wild-type flab allele. | with the recent identification of antibiotic resistance phenotypes, the use of reporter genes, the isolation of null mutants by insertional inactivation, and the development of extrachromosomal cloning vectors, genetic analysis of borrelia burgdorferi is becoming a reality. a previously described nonmotile, rod-shaped, kanamycin-resistant b. burgdorferi flab::km null mutant was complemented by electroporation with the erythromycin resistance plasmid ped3 (a pgk12 derivative) containing the wild- ... | 2001 | 11673425 |
| integron integrases possess a unique additional domain necessary for activity. | integrons are genetic elements capable of integrating genes by a site-specific recombination system catalyzed by an integrase. integron integrases are members of the tyrosine recombinase family and possess the four invariant residues (rhry) and conserved motifs (boxes i and ii and patches i, ii, and iii). an alignment of integron integrases compared to other tyrosine recombinases shows an additional group of residues around the patch iii motif. we have analyzed the dna binding and recombination ... | 2001 | 11673443 |
| efficacy of manual and powered toothbrushes (ii). effect on microbiological parameters. | the purpose of the present investigation was to determine the effect of self-performed supragingival plaque removal using either manual (crest complete) or power (braun 3d plaque remover) toothbrushing on supra and subgingival plaque composition. | 2001 | 11686813 |
| treponema socranskii, treponema denticola, and porphyromonas gingivalis are associated with severity of periodontal tissue destruction. | the aim of the present study was to identify treponema socranskii in addition to treponema denticola and porphyromonas gingivalis by polymerase chain reaction (pcr), and to clarify the relationship between the presence of these microorganisms and the severity of clinical periodontal parameters. | 2001 | 11699477 |
| potential role for extracellular glutathione-dependent ferric reductase in utilization of environmental and host ferric compounds by histoplasma capsulatum. | the mammalian host specifically limits iron during histoplasma capsulatum infection, and fungal acquisition of iron is essential for productive infection. h. capsulatum expresses several iron acquisition mechanisms under iron-limited conditions in vitro. these components include hydroxamate siderophores, extracellular glutathione-dependent ferric reductase enzyme, extracellular nonproteinaceous ferric reductant(s), and cell surface ferric reducing agent(s). we examined the relationship between t ... | 2001 | 11705947 |
| the localization of periodontal-disease-associated bacteria in human periodontal pockets. | some gram-negative anaerobes are associated with the incidence and progression of periodontal disease. in periodontal pockets, however, the localization of those bacteria is unknown. we investigated the localization of 5 bacterial species in human periodontal pockets. fifteen teeth with a part of periodontal pockets from 10 adult periodontitis patients were obtained, and the localization of bacteria was examined immunohistochemically. positive reactions with anti-prevotella nigrescens antibody w ... | 2001 | 11706954 |
| sulfate-reducing bacteria in relation with other potential periodontal pathogens. | oral sulfate-reducing bacteria are involved in several clinical categories of periodontitis. the aim of this cross-sectional study was to compare the presence of sulfate-reducing bacteria (srb) with other putative pathogens including spirochetes, actinobacillus actinomycetemcomitans, bacteroides forsythus, porphyromonas gingivalis, and treponema denticola in periodontal lesions. | 2001 | 11737513 |
| borrelia spirochetes upregulate release and activation of matrix metalloproteinase gelatinase b (mmp-9) and collagenase 1 (mmp-1) in human cells. | borrelia burgdorferi, the spirochetal agent of lyme disease, stimulated human peripheral blood monocytes to release pro-matrix metalloproteinase-9 (gelatinase b; pro-mmp-9) and active matrix metalloproteinase-1 (collagenase-1; mmp-1). human neutrophils also released pro-mmp-9 and a 130-kda protein with gelatinolytic activity in response to live b. burgdorferi. in addition, u937 cells and human keratinocyte cells were also stimulated to release pro-mmp-9 under the same conditions. however, human ... | 2001 | 11119537 |
| role of treponema denticola in periodontal diseases. | among periodontal anaerobic pathogens, the oral spirochetes, and especially treponema denticola, have been associated with periodontal diseases such as early-onset periodontitis, necrotizing ulcerative gingivitis, and acute pericoronitis. basic research as well as clinical evidence suggest that the prevalence of t denticola, together with other proteolytic gram-negative bacteria in high numbers in periodontal pockets, may play an important role in the progression of periodontal disease. the accu ... | 2001 | 12002822 |
| construction and characterization of a chea mutant of treponema denticola. | the treponema denticola chea gene, encoding the central kinase of the general chemotaxis pathway, was analyzed for its role in chemotaxis and tissue penetration. the chea gene was interrupted by insertion of an ermf-ermam gene cassette. reverse transcription-pcr confirmed that the other downstream chemotaxis genes within the same operon (chew, chex, and chey) were still expressed in the chea mutant strain. lack of chea resulted in decreased swarming on soft-agar swarm plates and failure to respo ... | 2002 | 12003957 |
| substrate recognition properties of oligopeptidase b from salmonella enterica serovar typhimurium. | oligopeptidase b (opdb) is a serine peptidase broadly distributed among unicellular eukaryotes, gram-negative bacteria, and spirochetes which has emerged as an important virulence factor and potential therapeutic target in infectious diseases. we report here the cloning and expression of the opdb homologue from salmonella enterica serovar typhimurium and demonstrate that it exhibits amidolytic activity exclusively against substrates with basic residues in p(1). while similar to its eukaryotic ho ... | 2002 | 12029050 |
| asymmetrical flagellar rotation in borrelia burgdorferi nonchemotactic mutants. | the lyme disease spirochete borrelia burgdorferi has bundles of periplasmic flagella subpolarly located at each cell end. these bundles rotate in opposite directions during translational motility. when not translating, they rotate in the same direction, and the cells flex. here, we present evidence that asymmetrical rotation of the bundles during translation does not depend upon the chemotaxis signal transduction system. the histidine kinase chea is known to be an essential component in the sign ... | 2002 | 11983908 |
| effect of fusobacterium nucleatum on the t and b cell responses to porphyromonas gingivalis in a mouse model. | t cell cytokine profiles and specific serum antibody levels in five groups of balb/c mice immunized with saline alone, viable fusobacterium nucleatum atcc 25586, viable porphyromonas gingivalis atcc 33277, f. nucleatum followed by p. gingivalis and p. gingivalis followed by f. nucleatum were determined. splenic cd4 and cd8 cells were examined for intracytoplasmic interleukin (il)-4, interferon (ifn)-gamma and il-10 by dual colour flow cytometry and the levels of serum anti-f. nucleatum and anti- ... | 2002 | 11985513 |
| the buccale puzzle: the symbiotic nature of endogenous infections of the oral cavity. | the indigenous, 'normal', microflora causes the majority of localized infectious diseases of the oral cavity (eg, dental caries, alveolar abscesses, periodontal diseases and candidiasis). the same microflora also protects the host from exogenous pathogens by stimulating a vigorous immune response and provides colonization resistance. how can a microflora that supports health also cause endogenous oral disease? this paradoxical host-symbiont relationship will be discussed within the dynamic of sy ... | 2002 | 18159372 |
| biological characterization of lipopolysaccharide from treponema pectinovorum. | this study investigated the endotoxic and biological properties of purified lipopolysaccharide (lps) isolated from an oral spirochete, treponema pectinovorum. endotoxicity, measured by limulus amoebocyte lysate kinetic assay, showed that the lps contained 1.28 endotoxin units per microg of purified lps, which was approximately 4,000 times less than escherichia coli o55:b5 lps. to determine in vivo endotoxicity, lps responder mice were administered lps following galactosamine (galn) sensitization ... | 2002 | 11748185 |
| periodontopathic bacteria in young healthy subjects of different ethnic backgrounds in los angeles. | the present study determined risk indicators for oral colonization by actinobacillus actinomycetemcomitans, porphyromonas gingivalis, bacteroides forsythus, and treponema denticola in 150 children and adolescents, 4 to 16 years of age, living in los angeles, california. | 2002 | 11922257 |
| genetic exchange between treponema denticola and streptococcus gordonii in biofilms. | some gram-positive oral bacteria such as streptococcus gordonii are naturally transformable. we investigated the possibility of genetic exchange among oral bacteria using an erythromycin-resistant (erm(r)) shuttle plasmid, pkmr4pe, as an indicator. s. gordonii challis cells were co-cultivated with purified pkmr4pe or with trepomena denticola harboring pkmr4pe either in broth or in artificial biofilms. transformation of s. gordonii occurred both in broth and in biofilms with pkmr4pe or t. dentico ... | 2002 | 11929558 |
| selenoprotein r is a zinc-containing stereo-specific methionine sulfoxide reductase. | selenoprotein r (selr) is a mammalian selenocysteine-containing protein with no known function. here we report that cysteine homologs of selr are present in all organisms except certain parasites and hyperthermophiles, and this pattern of occurrence closely matches that of only one protein, peptide methionine sulfoxide reductase (msra). moreover, in several genomes, selr and msra genes are fused or clustered, and their expression patterns suggest a role of both proteins in protection against oxi ... | 2002 | 11929995 |
| clinical, genetic and microbiological findings in a brazilian family with aggressive periodontitis. | aggressive periodontitis comprises a group of rapidly progressive forms of periodontitis. besides bacteria, a high level of subject susceptibility must be involved in the expression of disease. in the present study, we report the clinical, microbiological and genetic profile of a 14-individual family with aggressive periodontitis. | 2002 | 11940143 |
| genetic complementation in apicomplexan parasites. | a robust forward genetic model for apicomplexa could greatly enhance functional analysis of genes in these important protozoan pathogens. we have developed and successfully tested a genetic complementation strategy based on genomic insertion in toxoplasma gondii. adapting recombination cloning to genomic dna, we show that complementing sequences can be shuttled between parasite genome and bacterial plasmid, providing an efficient tool for the recovery and functional assessment of candidate genes ... | 2002 | 11959921 |
| genome sequence and analysis of the oral bacterium fusobacterium nucleatum strain atcc 25586. | we present a complete dna sequence and metabolic analysis of the dominant oral bacterium fusobacterium nucleatum. although not considered a major dental pathogen on its own, this anaerobe facilitates the aggregation and establishment of several other species including the dental pathogens porphyromonas gingivalis and bacteroides forsythus. the f. nucleatum strain atcc 25586 genome was assembled from shotgun sequences and analyzed using the ergo bioinformatics suite (http://www.integratedgenomics ... | 2002 | 11889109 |
| purification and characterization of arginine carboxypeptidase produced by porphyromonas gingivalis. | arginine carboxypeptidase was isolated from the cytoplasm of porphyromonas gingivalis 381 and purified by deae-sephacel column chromatography, followed by high-performance liquid chromatography on deae-5pw and tsk g2000sw(xl). sodium dodecyl sulfate-polyacrylamide gel electrophoresis of the purified enzyme revealed the presence of three major bands at 42, 33, and 32 kda with identical n-terminal sequences. by western blotting analysis and immunoelectron microscopy, the arginine carboxypeptidase ... | 2002 | 11895942 |
| complementation of a treponema denticola flge mutant with a novel coumermycin a1-resistant t. denticola shuttle vector system. | by using the mutated gyrb gene from a spontaneous coumermycin a1-resistant treponema denticola, an escherichia coli-t. denticola shuttle vector that renders t. denticola resistant to coumermycin was constructed. the complete t. denticola flge gene was cloned into the shuttle vector pkmcou, and the vector was transformed into the t. denticola atcc 33520 flge erythromycin-resistant knockout mutant hl210. the coumermycin-resistant transformants were motile and restored flge activity. this complemen ... | 2002 | 11895994 |