| characterization of oral treponemes isolated from human periodontal pockets. | a total of 90 clinical strains of oral treponemes was isolated from subgingival plaque in patients with periodontal disease. they were characterized by biochemical means as well as cell enzyme, protein analysis using sodium dodecyl sulfate-polyacrylamide gel electrophoresis and dna dot blot hybridization. sixty strains were isolated on medium 10 (m10), which was fundamentally serum-free. the remainder were isolated on serum-containing media. isolates were divided into 6 groups according to their ... | 1995 | 8596668 |
| identity of 1:2:1 and 2:4:2 subgingival spirochetes by dna hybridization. | a group of 1:2:1 and 2:4:2 subgingival spirochetes, well characterized by transmission electron microscopy, biochemical tests, cellular fatty acid and carbohydrate analyses, and ribotyping, was recently suggested to represent new treponemal species. the present study used dna hybridization to examine this possibility. when dna of a representative strain (no. 16) of the 8 1:2:1 spirochetes examined was labeled by iodination, it showed, after s1 nuclease treatment, from 58 to 104% (average 76%) ho ... | 1995 | 8602347 |
| interbacterial binding among strains of pathogenic and commensal oral bacterial species. | strong interspecies adherence was demonstrated among the periodontal pathogens treponema denticola, bacteroides forsythus and porphyromonas gingivalis, and between these pathogens and the commensal plaque organism streptococcus crista. adherence showed specificity and demonstrated saturation binding kinetics. binding between b. forsythus and p. gingivalis appeared to be a unimodal protein-protein interaction. binding between the other organisms was at least bimodal involving interactions between ... | 1996 | 8604253 |
| bacteriological diagnosis of periodontal disease. | dental plaque bacteria cause virtually all the forms of inflammatory periodontal disease. periodontitis is caused by the specific periodontopathic bacteria, which induce destruction of connective tissue attachment and adjacent alveolar bone. examinations to identify the infections by porphyromonas gingivalis, actinobacillus actinomycetemcomitans, prevotella intermedia, campylobacter rectus, bacteroides forsythus, fusobacterium nucleatum, eikenella corrodens and treponema denticola have recently ... | 1994 | 8620588 |
| sequence analysis, expression, and binding activity of recombinant major outer sheath protein (msp) of treponema denticola. | the gene encoding the major outer sheath protein (msp) of the oral spirochete treponema denticola atcc 35405 was cloned, sequenced, and expressed in escherichia coli. preliminary sequence analysis showed that the 5' end of the msp gene was not present on the 5.5-kb cloned fragment described in a recent study (m. haapasalo, k. h. müller, v. j. uitto, w. k. leung, and b. c. mcbride, infect. immun. 60:2058-2065,1992). the 5' end of msp was obtained by pcr amplification from a t. denticola genomic l ... | 1996 | 8626313 |
| proline iminopeptidase from the outer cell envelope of the human oral spirochete treponema denticola atcc 35405. | certain periodontopathic organisms have been shown to exhibit high activity of proline iminopeptidase (pipase). the human oral spirochete treponema denticola atcc 35405 was found to contain an easily extractable, novel pipase (ec 3.4.11.5), which was purified to a sodium dodecyl sulfate- polyacrylamide gel electrophoresis-pure form by means of fast protein liquid chromatographic procedures. the range of the minimum monomeric molecular mass (280 amino acid residues) of the pipase, based on amino ... | 1996 | 8641769 |
| characterization of new periodontal and endodontic isolates of spirochetes. | gas chromatographic analysis of cellular fatty acids (cfa), biochemical reactions, electrophoresis of soluble cellular proteins, as well as immunodiffusion were used to discriminate between 16 fresh spirochete isolates from periodontal and endodontic infections. cfa patterns were compared by the hewlett packard midi library to all available reference strains, and results of the biochemical tests were compared to vpi's records for treponemal strains. the electrophoretograms of soluble proteins of ... | 1996 | 8653496 |
| gene inactivation in the oral spirochete treponema denticola: construction of an flge mutant. | treponema denticola is implicated in the etiology of periodontal diseases. we now report the construction of a specific flge mutant of t. denticola atcc 35405 following electroporation utilizing an erythromycin resistance cassette inserted into an flge dna fragment. the resulting mutant displays no visible motility and lacks periplasmic flagella as would be predicted from inactivation of the gene for the flagellar hook protein. | 1996 | 8655571 |
| coaggregation between porphyromonas gingivalis and treponema denticola. | to elucidate an ecological profile of several periodontopathogens, the authors examined the coaggregation between cells of porphyromonas gingivalis and oral bacterial strains including treponema denticola in vitro. coaggregation between cells of plaque bacteria was examined by visual assay and phase-contrast microscope. p. gingivalis cells coaggregated with strains of t. denticola and treponema socranskii subspecies socranskii, but did not coaggregate with t. socranskii subspecies buccale, t. so ... | 1994 | 8689730 |
| effect of initial therapy on dynamics of immunogloblin g levels to some periodontopathic bacteria in serum and gingival crevicular fluid. | using enzyme-linked immunosorbent assay, the igg antibody levels to specific gram-negative periodontopathic bacteria in serum of 21 adult periodontitis patients and the gingival crevicular fluid (gcf) from 42 sites with destructive lesions and 21 healthy sites were evaluated before and after initial preparation. porphyromonas gingivalis, bacteroides forsythus, prevotella intermedia, prevotella nigrescens, campylobacter rectus, treponema denticola and actinobacillus actinomycetemcomitans in subgi ... | 1994 | 8689734 |
| porphyromonas gingivalis, actinobacillus actinomycetemcomitans and treponema denticola detection in oral plaque samples using the polymerase chain reaction. | detection of putative pathogens is critical for delineating the etiology and progression of periodontitis. in the present study, we have used a polymerase chain reaction (pcr) assay utilizing primers specific for the lkt a gene of actinobacillus actinomycetemcomitans, the fimbrial gene of porphyromonas gingivalis, and tdp a gene of treponema denticola in order to determine the presence of these pathogens in subgingival plaque samples from periodontitis sites. these gene specific primers were als ... | 1996 | 8707980 |
| a role for bacteriophages in the evolution and transfer of bacterial virulence determinants. | a virulence-associated region in the genome of dichelobacter nodosus has been shown to contain an integrase gene which is highly related to the integrases of shigella flexneri phage sf6 and coliphages p4 and phi r73, together with open reading frames (vapb, c and d) related to genes borne on plasmids in neisseria gonorrhoeae, escherichia coli, actinobacillus actinomycetemcomitans and treponema denticola. similar to p4 and phi r73, the vap region is bracketed by putative bacteriophage att sites a ... | 1995 | 8709840 |
| aspects of adherence of oral spirochetes. | oral spirochetes are present in the oral cavity in various numbers and forms and have been strongly implicated as playing a role in the etiology of periodontal disease. because adherence to host tissues is a critical first step in establishing a bacterial infection, reports on the attachment of oral spirochetes to host tissues and matrix components were reviewed. the great bulk of the literature concerns treponema denticola; however, where there is information regarding other oral spirochete spe ... | 1996 | 8727103 |
| antagonistic effect of oral bacteria towards treponema denticola. | this study was designed to isolate oral bacteria exhibiting antagonism towards treponema denticola and to characterize the inhibitory activity. eleven bacterial isolates obtained from subgingival sites and identified as either staphylococcus aureus or streptococcus mutans were found to inhibit the growth of t. denticola. when the activity spectra of these isolates were analyzed, two additional periodontopathogens (porphyromonas gingivalis and prevotella intermedia) were found to be affected, whe ... | 1996 | 8727911 |
| the major surface protein complex of treponema denticola depolarizes and induces ion channels in hela cell membranes. | the oral spirochete treponema denticola is closely associated with periodontal diseases in humans. the 53-kda major surface protein (msp) located in the outer membrane of t. denticola serovar a (atcc 35405) has both pore-forming activity and adhesin activity. we have used standard patch clamp recording methods to study the effects of a partially purified outer membrane complex containing msp on hela cells. the msp complex was free of the chymotrypsin-like proteinase also found in the outer membr ... | 1996 | 8757811 |
| treponema maltophilum sp. nov., a small oral spirochete isolated from human periodontal lesions. | a novel culture medium for cultivation of fastidious oral anaerobes is described. this medium, omiz-pat, consists of a rich chemically defined basal medium supplemented with asialofetuin, as well as yeast extract and neopeptone fractions. addition of 1 mg of rifampin per liter and 100 mg of fosfomycin per liter allowed routine isolation of spirochetes by a limit dilution method in 96-well plates containing liquid omiz-pat. in addition to members of the four previously recognized species of oral ... | 1996 | 8782684 |
| the peptidolytic capacity of the spirochete system. | relatively scant chemical information has been available on the proteinases and peptidases of spirochetes in spite of the association of spirochetes with several serious infections known to plague humans and other animal species. this situation has partly resulted from difficulties in growing some spirochetes under laboratory conditions. the cells of treponema denticola, a spirochete suggested to be associated with periodontal infections, have turned out to be a good source of new chemical infor ... | 1996 | 8803947 |
| characterization of tetracycline and erythromycin resistance determinants in treponema denticola. | treponema denticola isolates were evaluated for the presence of known tetracycline and erythromycin resistance determinants by southern blot hybridization of whole-cell dna and pcr assays. we examined all isolates available, which included 12 clinical and 4 american type culture collection isolates. two isolates carried the tet b determinant, five isolates carried both the tet b and erm f determinants, seven isolates carried the erm f determinant, and two did not carry any of the tet or erm dete ... | 1996 | 8807063 |
| a comparison of cysteine and serine proteinases in human gingival crevicular fluid with tissue, saliva and bacterial enzymes by analytical isoelectric focusing. | gingival crevicular fluid (gcf) contains several different proteinase activities and the study sought to clarify their sources. gingival tissue and gcf were collected from chronic periodontitis patients. gel-filtration chromatography of crude tissue extracts yielded cathepsin b and tryptase fractions sensitive to cysteine and serine proteinase inhibitors, respectively. cell sonicates of suspected periodontal pathogens were prepared from broth cultures of reference strains. of these, porphyromona ... | 1996 | 8809301 |
| an extracellular enzyme with hyaluronidase and chondroitinase activities from some oral anaerobic spirochaetes. | treponema denticola, treponema vincentii and treponema socranskii produce an enzyme that hydrolyses hyaluronic acid (ha) and chondroitin sulphate (cs). the secreted enzyme is specifically inhibited by gold sodium thiomalate and anti-bee-venom antibodies. the use of saturated substrate (ha or cs) transblots allowed the visualization of active enzyme directly from culture supernatants and is a useful tool in clarification of complex polysaccharide-degrading enzyme specificities. the affinity-purif ... | 1996 | 8828225 |
| evaluation of the long-term efficacy and safety of locally-applied minocycline in adult periodontitis patients. | the objectives of the present study were to establish in a long-term investigation the safety as well as the clinical and microbiological efficacy of scaling and rootplaning combined with local application of 2% minocycline hydrochloride-gel versus placebo-gel in patients with moderate to severe chronic adult periodontitis. this was an 18 months, randomized, double-blind, parallel, comparative study, in which 20 healthy patients with moderate to severe chronic periodontitis participated. at base ... | 1996 | 8877655 |
| iron acquisition by oral hemolytic spirochetes: isolation of a hemin-binding protein and identification of iron reductase activity. | oral anaerobic spirochetes (oas) have been implicated in the etiology of periodontal disease. to adapt to the environment of the subgingiva, oas must be able to acquire iron from limited sources. oas have previously been shown not to produce siderophores but are beta-hemolytic and can bind hemin via a proteinaceous 47-kda outer membrane sheath (oms) receptor. present studies show that [3h]hemin is not transported into the cytoplasm, that hemin and ferric ammonium citrate, as the sole iron source ... | 1996 | 8890484 |
| selling biotechnology in the dental medicine marketplace: the omnigene diagnostics dna probe tests for periodontal pathogens. | omnigene diagnostics, inc. has applied the principles of genetic engineering to develop species-specific dna probe tests for eight periodontal pathogens (porphyromonas gingivalis, prevotella intermedia, actinobacillus actinomycetem-comitans, fusobacterium nucleatum, eikenella corrodens, campylobacter rectus, bacteroides forsythus, and treponema denticola). the test requires minimal effort on the part of the clinician: subgingival plaque samples are collected from the patient and sent through the ... | 1996 | 8931245 |
| degradation of host protease inhibitors and activation of plasminogen by proteolytic enzymes from porphyromonas gingivalis and treponema denticola. | bacterial proteases may participate in the pathogenesis of periodontal diseases through their action on host proteins. in the present study, the ability of selected periodontopathogens, as well as two proteases isolated from porphyromonas gingivalis and treponema denticola, to degrade host protease inhibitors was evaluated. the activation of human plasminogen by the two bacterial proteases was also investigated. proteolytic breakdown of host protease inhibitors (alpha-1-antitrypsin, antichymotry ... | 1996 | 8936322 |
| proteolytic artifacts in sds-page analysis of selected periodontal pathogens. | the aim of the study was to examine whether proteolytic artifacts, which result in a loss and poor resolution of protein bands, occur during sodium dodecyl sulfate (sds)-polyacrylamide gel electrophoresis analysis of cellular proteins from selected proteolytic (porphyromonas gingivalis, prevotella nigrescens and treponema denticola) and non-proteolytic (fusobacterium nucleatum) bacteria. conditions to limit or prevent proteolysis were also investigated. bacterial cells were incubated in solubili ... | 1996 | 8941761 |
| associations between porphyromonas gingivalis and oral treponemes in subgingival plaque. | colonization and/or proliferation of treponema denticola may depend on the presence of porphyromonas gingivalis. the aims of this study were to confirm this synergistic relationship, to determine whether other oral bacteria were similarly associated with p. gingivalis and to relate coinfection to the periodontal status of plaque donors. subgingival plaque was collected from every tooth except third molars in 106 subjects who were grouped by their worst periodontal condition. in addition to p. gi ... | 1996 | 8941768 |
| hyaluronan, a possible ligand mediating treponema denticola binding to periodontal tissue. | binding of treponema denticola atcc 35405 to glycosaminoglycans, fibrinogen, type i collagen and porcine periodontal ligament epithelial cells was studied using an enzyme-linked immunosorbent assay. t. denticola bound to hyaluronan (hyaluronic acid) and its hexameric fragments. whereas little or no binding was detected to chondroitin-4-sulfate or dermatan sulfate proteoglycan. binding of t. denticola to hyaluronan gradually increased during the 2-h incubation time. in contrast, binding to fibrin ... | 1996 | 8941769 |
| development of a gene transfer system in treponema denticola by electroporation. | treponema denticola is strongly implicated in the etiology of periodontal diseases. however, genetic transformation of this organism has not been reported. we now demonstrate a gene transfer system in t. denticola by electroporation using a broad host plasmid pkt210 as a shuttle vector. plasmid extraction, southern blot hybridization as well as the polymerase chain reaction indicated the presence of the plasmid in t. denticola transformants. the restriction patterns of plasmid pkt210 rescued fro ... | 1996 | 8941770 |
| characterization of the treponema denticola prtp gene encoding a prolyl-phenylalanine-specific protease (dentilisin). | a chymotrypsin-like protease from treponema denticola atcc 35405 was purified by chromatographic techniques. the purified enzyme consisted of three polypeptides (38, 43, and 72 kda). the protease exhibited specificity for peptide bonds containing phenylalanine and proline at the p1 and p2 positions, respectively, and was classified as a serine protease on the basis of inhibition studies. naturally occurring protease inhibitors such as alpha1-antitrypsin and alpha1-antichymotrypsin had no effect ... | 1996 | 8945563 |
| bodipy-alpha-casein, a ph-independent protein substrate for protease assays using fluorescence polarization. | bodipy-alpha-casein is a new fluorescent protein substrate designed for fluorescence polarization studies to measure proteolytic activity at any ph over the range from ph 2 to 11. kinetic protease assays in real-time were performed in 1 to 5 min using an fpm-1 fluorescence polarization instrument. a purified enzyme or bacterial culture was mixed with the bodipy-alpha-casein in a buffer of an appropriate ph and the decrease in fluorescence polarization was automatically recorded at 0.5-min interv ... | 1996 | 8954519 |
| treponema medium sp. nov., isolated from human subgingival dental plaque. | a new treponema species, for which we propose the name treponema medium, was isolated from subgingival plaque from an adult with periodontal disease. the morphological characteristics, differential biochemical characteristics, and protein profiles on sodium dodecyl sulfate-polyacrylamide gel electrophoresis gels of this organism are described. the guanine-plus-cytosine content of the dna of t. medium is 51 mol%. the levels of dna-dna relatedness of the new species to other treponema species, inc ... | 1997 | 8995804 |
| polymerase chain reaction detection of 8 putative periodontal pathogens in subgingival plaque of gingivitis and advanced periodontitis lesions. | a 16s rrna-based polymerase chain reaction (pcr) detection method was used to determine the prevalence of actinobacillus actinomycetemcomitans, bacteroides forsythus, campylobacter rectus, eikenella corrodens, porphyromonas gingivalis, prevotella intermedia. prevotella nigrescens and treponema denticola in subgingival specimens of 50 advanced periodontitis, 50 adult gingivitis and 50 pediatric gingivitis subjects. the optimal pcr conditions were determined for each study species. agarose gel ele ... | 1996 | 9002880 |
| gamma-glutamyltransferase from the outer cell envelope of treponema denticola atcc 35405. | the human oral spirochete treponema denticola atcc 35405 was shown to exhibit relatively high enzyme activity toward the gamma-glutamyl amide bond present in n-gamma-l-glutamyl-4-nitroaniline. the enzyme responsible for this catalysis (gamma-glutamyltransferase [ggt]; ec 2.3.2.2) was purified by means of fast protein liquid chromatography to two sodium dodecyl sulfate-polyacrylamide gel electrophoresis (sds-page)-pure forms from a mild (0.1%) triton x-100 extract of washed cells. the ggt was stu ... | 1997 | 9009331 |
| conservation of msp, the gene encoding the major outer membrane protein of oral treponema spp. | the major surface protein (msp) of treponema denticola has been implicated as a mediator of the interaction between the spirochete and the gingival epithelium in periodontal diseases. previous studies showed that the msp of t. denticola atcc 35405 had porin activity, depolarized epithelial cell membranes, bound to extracellular matrix components of epithelial cells, and formed a regular hexagonal surface array in the treponemal outer membrane. the gene encoding msp in atcc 35405 was recently clo ... | 1997 | 9023187 |
| 3-hydroxy fatty acids in a lipopolysaccharide-like material from treponema denticola strain fm. | treponemes are associated with major oral diseases such as apical and marginal periodontitis. lipopolysaccharide (lps) is regarded as an important virulence factor in these diseases. it is unclear whether lps is present in oral treponemes. therefore, the present study was undertaken to examine if a common oral treponeme-treponema denticola-possesses lps. a modified westphal method (phenol water-ethanol-hexane extraction) was used to extract lps-like material from t. denticola, reference strain f ... | 1996 | 9028185 |
| occurrence of porphyromonas gingivalis, bacteroides forsythus, and treponema denticola in periodontally healthy and diseased subjects as determined by an elisa technique. | the aim of this study was to assess by means of an elisa technique, the occurrence of 3 putative periodontopathogens, porphyromonas gingivalis, bacteroides forsythus, and treponema denticola, in 3 clinically-defined adult periodontal conditions. thirty systemically-healthy subjects were selected and grouped into 3 categories according to their periodontal health: 1) 10 periodontitis subjects (ps), having moderate adult chronic periodontitis; 2) 10 untreated gingivitis subjects (ugs), exhibiting ... | 1997 | 9029447 |
| membrane components of treponema denticola trigger proteinase release from human polymorphonuclear leukocytes. | tissue destruction during periodontitis is believed to be primarily brought about by leukocyte proteinases. we postulate that oral spirochetes cause discharge of polymorphonuclear leukocyte (pmn) lysosomal enzymes. effects of treponema denticola 53-kda outer membrane protein, lipopolysaccharide (lps), and peptidoglycan on degranulation of matrix metalloproteinases (mmp)-8 (collagenase) and -9 (gelatinase), cathepsin g, and elastase by human peripheral blood pmns were studied by specific enzyme a ... | 1996 | 9033454 |
| relationship of treponema denticola periplasmic flagella to irregular cell morphology. | treponema denticola is an anaerobic, motile, oral spirochete associated with periodontal disease. we found that the periplasmic flagella (pfs), which are located between the outer membrane sheath and cell cylinder, influence its morphology in a unique manner. in addition, the protein composition of the pfs was found to be quite complex and similar to those of other spirochetes. dark-field microscopy revealed that most wild-type cells had an irregular twisted morphology, with both planar and heli ... | 1997 | 9045823 |
| detection of peptidase activity from treponema denticola, porphyromonas forsythus, and bacteroides forsythus as a means of periodontal therapy evaluation. | we have previously reported that the periocheck test offers a rapid, simple periodontal diagnostic tool by detecting peptidase activity specifically attributed to treponema denticola, porphyromonas gingivalis, and bacteroides forsythus. relationships between the peptidase activity detected by the periocheck test and clinical measures were investigated. fifty-seven periocheck-positive sites selected from 27 patients with adult periodontitis were subjected to scaling and root planing. two weeks la ... | 1995 | 9055698 |
| partial identification of spirochaetes from two dairy cows with digital dermatitis by polymerase chain reaction analysis of the 16s ribosomal rna gene. | specimens taken postmortem from typical lesions of digital dermatitis in two dairy cows were tested by the polymerase chain reaction (pcr) for the presence of a spirochaetal 16s rrna gene. seven different assays detected the gene in the samples from both cows. two of the pcr products were sequenced and a comparison of the nucleotide sequences revealed that the spirochaete belonged to the genus treponema and was closely related to treponema denticola. a pcr specific for the detection of the digit ... | 1997 | 9080644 |
| relationship between peptidase activity from treponema denticola, porphyromonas gingivalis, and bacteroides forsythus and attachment loss. | as a diagnostic test, "periocheck" can detect the n-carbobenzoxyglycyl-glycy-arginyl peptidase that is produced by treponema denticola, porphyromonas gingivalis, and bacteroides forsythus. the aim of this study was to clarify the relationship between peptidase activity and attachment loss. after phase 1 and surgical therapy, a total of 111 sites from 47 adult periodontitis patients were divided into four groups according to peptidase activity (trypsin unit, tu): a, < 0.1 tu; b, 0.1-0.2 tu; c and ... | 1996 | 9116469 |
| release and activation of human neutrophil matrix metallo- and serine proteinases during phagocytosis of fusobacterium nucleatum, porphyromonas gingivalis and treponema denticola. | the phagocytic ingestion of reference strains and clinical isolates of fusobacterium nucleatum, porphyromonas gingivalis, and treponema denticola by polymorphonuclear leukocytes (pmns) and the concomitant release of pmn granule proteinases were studied by specific functional and immunological assays. pmns were incubated with the microorganisms anaerobically at 37 degrees c for indicated time periods. the suspensions and pellets were used for phagocytic ingestion assay and electron microscopic st ... | 1997 | 9144046 |
| genetic and transcriptional analysis of flgb flagellar operon constituents in the oral spirochete treponema denticola and their heterologous expression in enteric bacteria. | oral spirochetes possess many potential virulence factors, including the capacity for tissue invasion and persistence despite a vigorous host immune response. in an attempt to identify treponemal immunoreactive components, sera derived from individuals with advanced periodontal disease were used as a reagent to isolate recombinant bacteriophage lambda clones expressing antigens of the oral spirochete treponema denticola atcc 35405. nucleotide sequence analysis of a clone expressing three immunor ... | 1997 | 9169730 |
| in vitro effect of the sensonic toothbrush on treponema denticola. | the purpose of this in vitro study was to compare the effects of the sensonic. oral-b braun mechanical and oral-b manual toothbrushes upon the morphology and cellular integrity of treponema denticola. this spirochete was chosen because of its frequent isolation from active lesions of inflammatory periodontal disease and its pathogenic potential. t. denticola, strain atcc 33421, was grown in an anaerobic nitrogen rich atmosphere in enhanced 1186 mycoplasma broth. 160, 5-ml aliquots of cultured mi ... | 1997 | 9178111 |
| visualization of an extracellular mucoid layer of treponema denticola atcc 35405 and surface sugar lectin analysis of some treponema species. | slime layers and capsules are common amongst medically relevant bacteria. we herein report that treponema denticola, which has been associated with periodontitis, synthesizes or acquires an extracellular polysaccharide layer that we have observed through electron microscopy using the polysaccharide-specific dye alcian blue and phosphotungstate. we have also visualized this extracellular layer by dark-field microscopy of alcian blue-stained spirochete cells. a representative strain of each of the ... | 1997 | 9227137 |
| activation of the interleukin-1beta precursor by treponema denticola: a potential role in chronic inflammatory periodontal diseases. | there are several indications suggesting that interleukin-1beta (il-1beta) may play an important role in inflammatory periodontal diseases. we hypothesized that periodontal sites would represent a unique combination of both cellular sources of il-1beta precursor (pro-il-1beta) and microbial proteases and proposed that treponema denticola, a suspected periodontal pathogen, would play a critical role in the inflammatory nature of adult chronic periodontitis by activating pro-il-1beta. the aim of t ... | 1997 | 9234775 |
| cystalysin, a 46-kilodalton cysteine desulfhydrase from treponema denticola, with hemolytic and hemoxidative activities. | a 46-kda hemolytic protein, referred to as cystalysin, from treponema denticola atcc 35404 was overexpressed in escherichia coli lc-67. both the native and recombinant 46-kda proteins were purified to homogeneity. both proteins expressed identical biological and functional characteristics. in addition to its biological function of lysing erythrocytes and hemoxidizing the hemoglobin to methemoglobin, cystalysin was also capable of removing the sulfhydryl and amino groups from selected s-containin ... | 1997 | 9234780 |
| the relationship between gingivitis and the serum antibodies to the microbiota associated with periodontal disease in children with down's syndrome. | gingival inflammation in down's syndrome children (ds) develops earlier and is more rapid and extensive than in non-ds children. abnormalities in host response to the oral flora have been proposed as etiological factors of this gingival inflammation. however, the relationship between gingivitis and the host response to oral microorganisms in ds by age has not been determined. the objective of this study was to clarify this relationship. sera were obtained from 75 ds subjects (aged 2 to 18 years) ... | 1997 | 9249633 |
| subgingival microbiota in adult chinese: prevalence and relation to periodontal disease progression. | the "checkerboard" dna-dna hybridization technology was used to study the epidemiology of 18 microbial species associated with various states of periodontal health and disease, in a sample of 148 chinese subjects never exposed to systematic dental therapeutic intervention, aged 30 to 39 and 50 to 59 years. our aims were to: 1) describe the prevalence of these microorganisms; 2) correlate the microbiological and clinical profiles of the subjects; and 3) examine the association between the microbi ... | 1997 | 9249637 |
| lipoproteins of treponema denticola: their effect on human polymorphonuclear neutrophils. | the presence of lipoproteins and lipooligosaccharides in treponema denticola, an oral spirochaete associated with periodontal diseases, was investigated. t. denticola atcc 35404 and the clinical isolate gm-1 were metabolically labeled with [3h]-cis-9-octadecenoic acid and extracted with the non-ionic detergent triton x-114. the extract was phase separated, precipitated with acetone and delipidated to remove non-covalently bound lipid (dlpp). in t. denticola atcc 35404, sodium dodecyl sulfate pol ... | 1997 | 9266497 |
| assessment of pretreatment orthodontic patients using the bana test. n-benzoyl-dl-arginine-naphthylamide. | ninety-two subjects were tested before orthodontic mechanotherapy for the presence of three putative periodontopathogens-porphyromonas gingivalis, treponema denticola, and bacteroides forsythus-with the bana test (perioscan oral-b). the sample ranged from 9 to 16 years, with a mean age of 13.1 years, and consisted of 51% girls and 49% boys; 48% african american, 46% white, 4% asian, and 2% hispanic. unlike other bana studies that examined children and adolescents with a 15-minute incubation time ... | 1997 | 9267226 |
| characterization of a methyl-accepting chemotaxis protein gene, dmca, from the oral spirochete treponema denticola. | a gene, dmca, expressing a methyl-accepting chemotaxis protein (mcp) from the oral spirochete treponema denticola has been characterized. the gene was initially identified as an open reading frame immediately upstream from the previously characterized prtb protease gene of strain atcc 35405. nucleotide sequencing of the dmca gene revealed a potential 57-kda protein product with extensive homology with the signaling regions of mcps from a variety of bacteria. the protein expressed in escherichia ... | 1997 | 9317000 |
| identification, isolation, and characterization of the 42-kilodalton major outer membrane protein (mompa) from treponema pectinovorum atcc 33768. | the major protein present in the isolated outer membrane of treponema pectinovorum atcc 33768, mompa, was identified, purified, and characterized. immuno-gold electron microscopy, using anti-mompa serum, and cell fractionation experiments confirmed the localization of mompa to the outer membrane. mompa was determined by sodium dodecyl sulfate-polyacrylamide gel electrophoresis to have a molecular mass of 42 kda when heat denatured, whereas native mompa formed a number of detergent-stable forms w ... | 1997 | 9335294 |
| cross-infection from periodontitis sites to failing implant sites in the same mouth. | twenty-five tooth and implant sites in nine patients were investigated for the presence of putative periodontopathic organisms, using specific dna probes for actinobacillus actinomycetemcomitans, porphromonas gingivalis, prevotella intermedia, eikenella corrodens, fusobacterium nucleatum, treponema denticola, and campylobacter recta. five of nine patients showed a likelihood of transmission from tooth to implant sites. these patients also showed a high number of putative periodontopathic organis ... | 1997 | 9337029 |
| the optimization of the bana test as a screening instrument for gingivitis among subjects seeking dental treatment. | porphyromonas gingivalis, treponema denticola and bacteroides forsythus have been implicated in periodontal disease and each possesses an enzyme capable of hydrolyzing the synthetic trypsin substrate, bana. we have used a chairside test for bana hydrolysis to diagnose an anaerobic periodontal infection in patients with advanced forms of clinical disease using a 15-min/55 degrees c incubation protocol. however, the bana test performance is dependent upon the length and temperature of incubation. ... | 1997 | 9350555 |
| clinical and microbiological features of subjects with adult periodontitis who responded poorly to scaling and root planing. | in a previous report, it was shown that scaling and root planing (srp) decreased mean pocket depth and attachment level in subjects with adult periodontitis, as well as the levels and prevalence of bacteroides forsythus, porphyromonas gingivalis and treponema denticola. however, a subset of subjects in that study exhibited mean loss of attachment following srp. the purpose of the present investigation was to seek clinical and microbiological differences between subjects who responded well or poo ... | 1997 | 9350562 |
| putative periodontal pathogens in subgingival plaque of young adults with and without early-onset periodontitis. | this study assessed the associations between putative periodontal pathogens and early-onset periodontitis (eop) in a population of 248 subjects, 13 to 19 years of age at baseline, derived from a representative sample of u.s. young adults. the subjects were selected based on the presence or absence of attachment loss at baseline. the attachment level was assessed clinically at baseline and at a 6-year follow-up examination, and the presence of 7 bacterial species was assessed at follow-up using d ... | 1997 | 9358364 |
| differential attachment of oral treponemes to monolayers of epithelial cells. | this in vitro study describes the attachment properties of several oral treponemes to monolayers of epithelial cells and the effect of epithelial cell confluence on treponeme attachment. four serotypes of treponema denticola, treponema scoliodontum, three subspecies of treponema socranskii, and treponema vincentii were tested with monolayers of epithelial cells of human and canine origin. attachment of oral treponemes were compared to attachment by t. pallidum subsp. pallidum, and by the non-pat ... | 1997 | 9358369 |
| spirochaetes and other bacterial species associated with bovine digital dermatitis. | the 16s rrna genes from spirochaetes associated with digital dermatitis of british cattle were amplified by polymerase chain reaction from digital dermatitis lesion biopsies using one universal and one treponeme-specific primer. two treponemal sequences were identified both of which shared a high degree of homology with the oral pathogen treponema denticola (98%). two further 16s rrna gene sequences were obtained and shared similarity to bacteroides levii (99%) and mycoplasma hyopharyngis (98%). ... | 1997 | 9368358 |
| virulence characteristics of oral treponemes in a murine model. | this study was designed to investigate the virulence characteristics of treponema denticola, t. socranskii, t. pectinovorum, and t. vincentii following challenge infection of mice. these microorganisms induced well-demarcated, dose-dependent, raised subcutaneous (s.c.) abscesses which were similar in time of onset, lesion progression, and duration of healing. only viable cells were capable of inducing these characteristic s.c. abscesses. histological examination of the skin lesion 3 and 5 days p ... | 1997 | 9393801 |
| identification, sequence, and expression of treponema denticola mcpa, a putative chemoreceptor gene. | the nucleotide sequence of a methyl-accepting chemotaxis protein gene, mcpa, from treponema denticola has been determined. the mcpa gene encodes a 729-amino acid protein whose deduced amino acid sequence has significant homology with several bacterial mcps. t. denticola mcpa contains two n-terminal transmembrane regions and two c-terminal putative methylation sequences that are separated by a highly conserved signaling domain. the organization of these structural features is characteristic of mc ... | 1997 | 9435104 |
| oral food consumption and subgingival microorganisms: subgingival microbiota of gastrostomy tube-fed children and healthy controls. | this study examined the effect of oral food consumption on the prevalence and levels of subgingival bacteria and yeasts in 20 gastrostomy tube-fed children and 24 healthy controls. microbial identification was carried out using anaerobic culture and 16s rrna-based pcr identification methods. streptococcal and actinomyces species were recovered from 100% and 76% of all subjects and averaged 66% and 11% of total cultivable organisms, respectively. in decreasing order of prevalence, fusobacterium, ... | 1997 | 9444590 |
| association of oral spirochetes from sites of periodontal health with development of periodontitis. | the purpose of this investigation was to determine whether the presence of disease-associated bacteria in health-associated plaque correlated with susceptibility to periodontitis over time. sites of periodontal health were identified in 65 adults. six months later (recall 1), plaque was collected from sites that remained in periodontal health, and specific bacteria were detected using monoclonal antibodies in a microscopic assay. the spirochete morphogroup was identified by phase contrast micros ... | 1997 | 9444597 |
| coiling phagocytosis discriminates between different spirochetes and is enhanced by phorbol myristate acetate and granulocyte-macrophage colony-stimulating factor. | the mechanisms involved in coiling phagocytosis are not yet known, and it is not even clear whether this phenomenon is either an incidental event or a specific response. therefore, the phagocytic uptake of borrelia burgdorferi and other spirochetes by human monocytes in vitro was used to investigate the involvement of both sides--microbes and phagocytes--in coiling phagocytosis. as seen with electron microscopy, morphologically similar borrelia, leptospira and treponema strains induced markedly ... | 1998 | 9453619 |
| proteolytic activation of the interleukin-1beta precursor by candida albicans. | chronic inflammation rather than invasion is characteristic of some forms of superficial candidiasis such as denture stomatitis. we hypothesized that candida albicans may play a critical role in the pathogenesis of inflammatory lesions observed in chronic candidiasis by activating the proinflammatory cytokine interleukin-1beta (il-1beta) from epithelial stores of the precursor. the aim of this study was therefore to demonstrate the proteolytic cleavage and activation of the inactive precursor of ... | 1998 | 9453626 |
| filamentous actin disruption and diminished inositol phosphate response in gingival fibroblasts caused by treponema denticola. | previous reports have shown that treponema denticola causes rearrangement of filamentous actin (f-actin) in human gingival fibroblasts (hgf). the purpose of this investigation was to determine the effect of t. denticola on the generation of inositol phosphates (ips) in relation to a time course for f-actin disruption in hgf. cultured hgf were exposed to washed cells of t. denticola atcc 35405 for 140 min. changes in the fluorescence intensity of rhodamine-phalloidin-labeled f-actin in serial opt ... | 1998 | 9453629 |
| treponema denticola outer membrane inhibits calcium flux in gingival fibroblasts. | treponema denticola is a cultivable oral spirochete which perturbs the cytoskeleton in cultured cells of oral origin, but intracellular signalling pathways by which it affects actin assembly are largely unknown. as the outer membrane (om) of treponema denticola disrupts actin-dependent processes that normally require precise control of intracellular calcium, we studied the effects of an om extract on internal calcium release, ligand-gated and calcium release-activated calcium channels, and relat ... | 1998 | 9453630 |
| induction of a gradual, reversible morphogenesis of its host's epithelial brush border by vibrio fischeri. | bacteria exert a variety of influences on the morphology and physiology of animal cells whether they are pathogens or cooperative partners. the association between the luminous bacterium vibrio fischeri and the sepiolid squid euprymna scolopes provides an experimental model for the study of the influence of extracellular bacteria on the development of host epithelia. in this study, we analyzed bacterium-induced changes in the brush borders of the light organ crypt epithelia during the initial ho ... | 1998 | 9453641 |
| characterization of protease activities in capnocytophaga spp., porphyromonas gingivalis, prevotella spp., treponema denticola and actinobacillus actinomycetemcomitans. | protease activities in cell sonicates of defined bacterial strains were examined using peptide substrates and class-specific inhibitors. capnocytophaga spp. all produced serine dipeptidyl peptidase activity and arginine/lysine, elastase- and chymotrypsin-like enzymes with some metalloprotease characteristics. the elastase-like activity was strongest in capnocytophaga sputigena, but the others were greatest in capnocytophaga gingivalis. the latter also had a separate arginine-specific enzyme whic ... | 1997 | 9467394 |
| environmental effects on the growth and proteolysis of treponema denticola atcc 33520. | the effect of ph, redox potential, o2 and h2 on the growth and proteolytic activity of treponema denticola atcc 33520 was studied in a chemostat at different growth rates. the peptidase and protease activities were estimated using different amido-methyl coumarin derivatives and azocasein. the maximum growth rate of t. denticola atcc 33520 was 0.14 h-1. reduction of the growth rate of t. denticola by 50-60% gave: an increase in cell mass of 150-200%, a higher acetogenesis and a shift of the ph op ... | 1997 | 9467395 |
| genetic characterization of an oral treponeme isolated from human subgingival plaque. | we examined the genetic characteristics of a human oral treponeme isolated from subgingival plaque of a patient with periodontal disease that could not be assigned to any of the previously described oral treponema species. the guanine-plus-cytosine content of its dna was 51 mole%. the levels of dna-dna relatedness of the organism to other treponema species, including treponema denticola, treponema vincentii, treponema socranskii, treponema pallidum and treponema phagedenis, were less than 30%. t ... | 1997 | 9467407 |
| the effects of a pulsed nd:yag laser on subgingival bacterial flora and on cementum: an in vivo study. | the purpose of this study was to compare the effects of scaling and nd:yag laser treatments with that of scaling alone on cementum and levels of actinobacillus actinomycetemcomitans, bacteroides forsythus, porphyromonas gingivalis, and treponema denticola. study samples consisted of 14 patients, age 30 to 75 years, 8 females and 6 males, with a total of 150 periodontally involved sites with probing depth > or = 5 mm. group a consisted of 100 pockets that were subdivided into 4 equal groups that ... | 1996 | 9484091 |
| isolation and characterization of the outer membrane of borrelia hermsii. | the outer membrane of borrelia hermsii has been shown by freeze-fracture analysis to contain a low density of membrane-spanning outer membrane proteins which have not yet been isolated or identified. in this study, we report the purification of outer membrane vesicles (omv) from b. hermsii hs-1 and the subsequent identification of their constituent outer membrane proteins. the b. hermsii outer membranes were released by vigorous vortexing of whole organisms in low-ph, hypotonic citrate buffer an ... | 1998 | 9488399 |
| adherence of human oral spirochetes by collagen-binding proteins. | the ability of spirochetes to adhere to collagens was compared among three species of human oral treponemes. immunoblot analysis demonstrated that type i-, iv-, and v-collagen-binding polypeptides (cbps) were detected in the heated and unheated preparations from both treponema denticola atcc 33520 and t. socranskii subsp. buccale atcc 35534. few cbps, however, were detected in the heated and unheated preparations from a recently characterized isolate, t. medium strain g7201. immunoelectron micro ... | 1997 | 9492176 |
| microbial complexes in subgingival plaque. | it has been recognized for some time that bacterial species exist in complexes in subgingival plaque. the purpose of the present investigation was to attempt to define such communities using data from large numbers of plaque samples and different clustering and ordination techniques. subgingival plaque samples were taken from the mesial aspect of each tooth in 185 subjects (mean age 51 +/- 16 years) with (n = 160) or without (n = 25) periodontitis. the presence and levels of 40 subgingival taxa ... | 1998 | 9495612 |
| clinical and microbiological features of refractory periodontitis subjects. | the purpose of this investigation was to compare the clinical parameters and the site prevalence and levels of 40 subgingival species in successfully treated and refractory periodontitis subjects. 94 subjects received scaling and root planing and if needed, periodontal surgery and systemically administered tetracycline. 28 refractory subjects showed mean full mouth attachment loss and/or > 3 sites showing attachment loss > 2.5 mm within 1 year post-therapy. 66 successfully treated subjects showe ... | 1998 | 9495617 |
| detection of pathogen-related oral spirochetes, treponema denticola, and treponema socranskii in dental plaque from dogs. | spirochetes have been observed in dental plaque from dogs, but specific spirochetes have not been identified. in particular, it is not known whether treponemes associated with periodontal diseases in humans also occur in dogs, and whether, like in humans, detection of specific treponemes correlates with periodontal status of dogs. forty-two dogs were grouped according to the worst periodontal condition in the mouth, as determined by overt signs of inflammation and pocket probing depths. a repres ... | 1996 | 9520788 |
| in vitro models that support adhesion specificity in biofilms of oral bacteria. | adhesion to adsorbed pellicles and interspecies co-adhesion to form plaque biofilms involve selective interactions of bacterial adhesins with specific receptors. our laboratory has devised in vitro assays for co-adhesion between actinomyces naeslundii and streptococcus oralis or porphyromonas gingivalis on saliva-coated mineral and hexadecane droplet substrata. p. gingivalis structures significant for co-adhesion with a. naeslundii include surface vesicles and fimbriae. a family of arginine-spec ... | 1997 | 9524440 |
| characterization of a 4.2-kb plasmid isolated from periodontopathic spirochetes. | oral anaerobic treponemes are assoicated with active periodontal disease and may comprise up to 57% of the microbiota in periodontal pockets. four treponeme strains (designated u2a, u2b, u9b, and u9c) isolated from clincial cases were found to harbor a new 4.2-kb plasmid when plasmid dna was extracted and purified employing the qiagen plasmid kit. this plasmid differs from the smaller plasmids (2.0-, 2.6-, and 2.7-kb) reported previously by others in treponema denticola. the newly discovered 4.2 ... | 1996 | 9556407 |
| cytopathic effects of the major surface protein and the chymotrypsinlike protease of treponema denticola. | prominent antigens of treponema denticola have been suggested to be mediators of the cytopathic effects typically seen in periodontal disease. in the present study of the t. denticola major surface protein (msp) and the surface-expressed chymotrypsinlike protease complex (ctlp), we characterized the ability of these proteins to adhere to and lyse epithelial cells. msp and ctlp were closely associated in spirochete outer membranes. purified msp, both native and recombinant, and ctlp bound to glut ... | 1998 | 9573063 |
| function of protonatable residues in the flagellar motor of escherichia coli: a critical role for asp 32 of motb. | rotation of the bacterial flagellar motor is powered by a transmembrane gradient of protons or, in some species, sodium ions. the molecular mechanism of coupling between ion flow and motor rotation is not understood. the proteins most closely involved in motor rotation are mota, motb, and flig. mota and motb are transmembrane proteins that function in transmembrane proton conduction and that are believed to form the stator. flig is a soluble protein located on the cytoplasmic face of the rotor. ... | 1998 | 9573160 |
| structure and expression of the flaa periplasmic flagellar protein of borrelia burgdorferi. | the spirochete which causes lyme disease, borrelia burgdorferi, has many features common to other spirochete species. outermost is a membrane sheath, and within this sheath are the cell cylinder and periplasmic flagella (pfs). the pfs are subterminally attached to the cell cylinder and overlap in the center of the cell. most descriptions of the b. burgdorferi flagellar filaments indicate that these organelles consist of only one flagellin protein (flab). in contrast, the pfs from other spirochet ... | 1998 | 9573194 |
| an inexpensive solid medium for obtaining colony-forming units of oral spirochetes. | a method for the enumeration of colony-forming units of oral anaerobic spirochetes in new oral spirochete agarose (nos-a) medium was described recently. however, the high cost of agarose limits the extent to which large assays can be carried out. accordingly, a search for an inexpensive gelling agent that remains molten at 37 degrees c and gels at 25 degrees c was undertaken. varying amounts of noble agar or bacto agar (0.5 to 1.5%, w/v) were mixed with varying amounts of gelatin (0.5 to 1.0%, w ... | 1997 | 9573813 |
| molecular epidemiology of oral treponemes associated with periodontal disease. | periodontitis, a disease responsible for tooth loss worldwide, is characterized by chronic inflammation of the periodontium, eventually leading to destruction of periodontal ligaments and supporting alveolar bone. spirochetes, identified by dark-field microscopy as being the most predominant bacteria in advanced lesions, are thought to play a causative role. various spirochetal morphotypes were observed, but most of these morphotypes are as yet uncultivable. to assess the role of these organisms ... | 1998 | 9574713 |
| similarities of periodontal clinical and microbiological parameters in mother-child pairs. | the aim of this study was to verify the association between children and their mothers (n = 28) for periodontal clinical and microbiological measures. periodontal clinical parameters (probing depth and bleeding on probing) were obtained from six reference teeth from each mother-child pair. in addition, subgingival plaque samples taken from the same reference teeth were collected and placed on the perioscan test for the detection of treponema denticola, porphyromonas gingivalis and bacteroides fo ... | 1997 | 9590933 |
| molecular characterization of treponema pallidum mcp2, a putative chemotaxis protein gene. | the nucleotide sequence of the treponema pallidum mcp2 gene was determined. mcp2 encodes a 45.8-kda protein whose deduced amino acid sequence has significant homology with the c-terminal region of bacterial methyl-accepting chemotaxis proteins (mcps). the mcp2 n terminus lacks the hydrophobic transmembrane regions present in most mcps. an mcp2 fusion protein was strongly reactive with antibody (hc23) to the highly conserved domain of mcps and with rabbit syphilitic serum. antibody hc23 reacted w ... | 1998 | 9596781 |
| association of oral spirochetes from periodontally healthy sites with development of gingivitis. | the purpose of this investigation was to determine whether the presence of selected disease-associated bacteria in health-associated plaque correlated with future gingivitis. sites of periodontal health were identified in 65 adults. six months later (recall 1) plaque was collected from sites that remained in periodontal health, and 5 species of specific bacteria and pathogen-related oral spirochetes were detected using monoclonal antibodies in a microscopic assay. members of the spirochete morph ... | 1998 | 9609381 |
| evidence for a new type of outer membrane lipid in oral spirochete treponema denticola. functioning permeation barrier without lipopolysaccharides. | a new class of outer membrane lipid (oml) was isolated from the oral spirochete treponema denticola strain atcc 33521 using a phenol/chloroform/light petroleum procedure normally applied for lipopolysaccharide extraction. in addition to chemical analysis, fourier transform infrared (ftir) spectroscopy was applied to compare the biophysical properties of oml with lipopolysaccharides (lps) and lipoteichoic acids (lta). isolated oml fractions represent 1.4% of the total dry cell weight, are about 4 ... | 1998 | 9624160 |
| the frequent detection of a treponeme in bovine digital dermatitis by immunocytochemistry and polymerase chain reaction. | a study was carried out to determine whether spirochaetes are frequently associated with digital dermatitis in united kingdom (uk) dairy cattle. histopathological examination of lesions using a silver stain showed a large number of unidentified spirochaete-like organisms present in digital dermatitis hoof skin tissue in all examined biopsies. immunocytochemical staining demonstrated that spirochaetes in skin lesions were identified by polyclonal antisera to borrelia burgdorferi, treponema dentic ... | 1998 | 9646459 |
| subgingival microbiota in healthy, well-maintained elder and periodontitis subjects. | this investigation compared the site prevalence of 40 subgingival species in 30 periodontally healthy (mean age 36+/-9 years), 35 elders with a well-maintained periodontium (mean age 77+/-5) and 138 adult periodontitis subjects (mean age 46+/-11). subgingival plaque samples were taken from the mesial aspect of each tooth (up to 28 samples) in the 203 subjects at baseline. the presence and levels of 40 subgingival taxa were determined in 5003 plaque samples using whole genomic dna probes and chec ... | 1998 | 9650869 |
| the central, surface-exposed region of the flagellar hook protein flge of campylobacter jejuni shows hypervariability among strains. | in a previous study, we observed that monoclonal antibodies raised against the hook protein flge of campylobacter jejuni lio 36, isolate 5226, bound exclusively to this strain. the aim of this study was to elucidate the molecular basis for these binding specificities. the hook protein-encoding gene flge of c. jejuni was cloned in escherichia coli and sequenced. the flge genes of four additional c. jejuni strains were amplified by pcr and also sequenced. comparison of the deduced amino acid seque ... | 1998 | 9658019 |
| mutagenesis of outer membrane virulence determinants of the oral spirochete treponema denticola. | the pore-forming major surface protein (msp) and the chymotrypsin-like protease (ctlp) of treponema denticola atcc 35405 have been implicated in periodontal pathogenicity. allelic replacement mutations were constructed at two sites in the msp gene and at one site in the ctlp locus. all mutant strains lacked the msp hexagonal array outer membrane ultrastructure. strain cke, in which the locus encoding ctlp was disrupted, produced no ctlp and had aberrant msp expression. the msp mutant mhe lacked ... | 1998 | 9673024 |
| cloning and expression of the moraxella catarrhalis lactoferrin receptor genes. | the lactoferrin receptor genes from two strains of moraxella catarrhalis have been cloned and sequenced. the lfr genes are arranged as lbpb followed by lbpa, a gene arrangement found in lactoferrin and transferrin receptor operons from several bacterial species. in addition, a third open reading frame, orf3, is located one nucleotide downstream of lbpa. the deduced lactoferrin binding protein a (lbpa) sequences from the two strains were found to be 99% identical, the lbpb sequences were 92% iden ... | 1998 | 9673246 |
| regulation of sucrose-6-phosphate hydrolase activity in streptococcus mutans: characterization of the scrr gene. | previous results have implicated an important role for the enzyme iiscr, the sucrose-specific permease, in the transport of sucrose by cariogenic streptococcus mutans. the product of the scrb gene, sucrose-6-phosphate hydrolase (suc-6ph), is required for the metabolism of phosphorylated sucrose. the results from the utilization of scrb::lacz fusions in s. mutans gs-5 have suggested that sucrose-grown cells have higher levels of scrb gene expression than do cells grown with glucose or fructose. n ... | 1998 | 9673256 |
| dentilisin activity affects the organization of the outer sheath of treponema denticola. | prolyl-phenylalanine-specific serine protease (dentilisin) is a major extracellular protease produced by treponema denticola. the gene, prtp, coding for the protease was recently cloned and sequenced (k. ishihara, t. miura, h. k. kuramitsu, and k. okuda, infect. immun. 64:5178-5186, 1996). in order to determine the role of this protease in the physiology and virulence of t. denticola, a dentilisin-deficient mutant, k1, was constructed following electroporation with a prtp-inactivated dna fragmen ... | 1998 | 9683480 |
| the utility of whole saliva to detect the oral presence of periodontopathic bacteria. | this study compared the presence of 6 periodontopathic bacteria in whole saliva and subgingival plaque of 202 subjects. the test bacteria were identified using a 16s rrna-based pcr detection method. each study subject contributed a whole saliva sample and a paper point sample pooled from the deepest periodontal pocket in each quadrant of the dentition. the kappa test revealed a fair agreement between the presence of porphyromonas gingivalis, prevotella intermedia, and treponema denticola in whol ... | 1998 | 9706862 |
| expression of the peptide antibiotic human beta-defensin 1 in cultured gingival epithelial cells and gingival tissue. | human beta-defensin-1 (hbd-1) is a member of the family of small cationic antimicrobial peptides that have been identified in several mucosal epithelia. because human gingival epithelium is a site that is constantly challenged by oral microorganisms, we examined the expression of hbd-1 in human gingival epithelial and fibroblast cell cultures and tissue samples. cell cultures were challenged with cell wall extracts of porphyromonas gingivalis or fusobacterium nucleatum, escherichia coli lipopoly ... | 1998 | 9712771 |
| crevicular fluid level of beta-glucuronidase in relation to clinical periodontal parameters and putative periodontal pathogens in early-onset periodontitis. | analysis of beta-glucuronidase (betag) in the gingival crevicular fluid (gcf) provides an indication of neutrophil influx into the crevicular environment. the aim of this study was to test the hypotheses that: (1) betag is significantly elevated in individuals with early-onset periodontitis (eop) and that betag activity correlates with disease severity; and (2) betag level may reflect the local bacterial challenge in the gingival crevice. the study subjects consisted of a sub-sample of individua ... | 1998 | 9722267 |
| potential pathogenic mechanisms of periodontitis associated pregnancy complications. | during normal pregnancy, maternal hormones and locally acting cytokines play a key role in regulating the onset of labor, cervical ripening, uterine contraction, and delivery. maternal infections during pregnancy have been demonstrated to perturb this normal cytokine and hormone-regulated gestation, sometimes resulting in preterm labor, preterm premature rupture of membranes, and preterm low birth weight (plbw), i.e., < 2,500 g and < 37 weeks of gestation. our research focus has been to determin ... | 1998 | 9722707 |
| early-onset periodontitis associated with down's syndrome--clinical interventional study. | individuals with down's syndrome (ds) have an increased prevalence of periodontal disease compared with otherwise normal, age-matched control groups and other mentally handicapped patients of similar age distribution. the exaggerated immune-inflammatory response of the tissues cannot be explained by poor oral hygiene alone and might be the result of an impaired cell-mediated and humoral immunity and a deficient phagocytic system. as far as the progression and severity of destruction, the oral ma ... | 1998 | 9722720 |