| biochemical and chemical studies on strains designated prevotella intermedia and proposal of a new pigmented species, prevotella nigrescens sp. nov. | a total of 31 strains of prevotella intermedia were subjected to dna-dna hybridization and were characterized by performing physiological tests and by performing a multilocus enzyme analysis, using malate dehydrogenase and glutamate dehydrogenase. all of the strains assigned to p. intermedia fermented glucose and sucrose, hydrolyzed starch but not esculin, and produced indole, acetic, isobutyric, isovaleric, and succinic acids as metabolic end products. the results of dna reassociation experimen ... | 1992 | 1390107 |
| the tet(q) gene in bacteria isolated from patients with refractory periodontal disease. | twenty-two tetracycline-resistant (tetr) anaerobic and facultative anaerobic bacteria isolated from periodontal pockets of 12 patients with refractory periodontitis were examined for the presence of the tet q determinant by dna-dna hybridization. dot blots of bacterial dna were tested with an intragenic digoxigenin-labelled tet(q) probe consisting of a 1.45 kb ecori/pvuii fragment from plasmid pnfd13-2. southern blots of chromosomal dna digested with the restriction enzyme ecori were also examin ... | 1994 | 7478767 |
| oligonucleotide probes to the 16s ribosomal rna: implications of sequence homology and secondary structure with particular reference to the oral species prevotella intermedia and prevotella nigrescens. | eight oligonucleotides based upon regions of the small subunit 16s ribosomal rna gene sequences were analysed against a background of their position within the molecule and their two-dimensional structure to rationalise their use in recognising prevotella intermedia and prevotella nigrescens. the 41 clinical isolates from both oral and respiratory sites and two reference strains were subjected to dna-dna hybridisation and multilocus enzyme electrophoresis to confirm their identity. alignment of ... | 1995 | 7553378 |
| identification of a chromosomally encoded kanamycin acetylase in porphyromonas gingivalis. | sonic extracts from the test strains of porphyromonas gingivalis, prevotella intermedia and prevotella nigrescens were tested for the ability to inactivate kanamycin sulfate in the presence of atp or acetyl coenzyme a (acetyl-coa). residual kanamycin activity was determined by a bio-assay using escherichia coli jm109 as the assay organism. sonic extracts of all test strains of p. gingivalis inactivated kanamycin. all strains tested in this study required the presence of acetyl-coa for inactivati ... | 1995 | 7557341 |
| characterisation of black-pigmented anaerobes isolated from diseased and healthy periodontal sites. | prevotella intermedia has recently been re-defined and a new species, prevotella nigrescens has been proposed. however, there is little data available on the incidence of these new species in periodontal health or disease. black-pigmented anaerobes isolated from diseased and healthy subgingival sites were identified by serotyping, sds-page and physiological tests. in adult periodontitis subjects, 64% of active sites, 35.7% of inactive sites and 38.5% of healthy sites yielded black-pigmented anae ... | 1995 | 7562320 |
| heat shock proteins in the human periodontal disease process. | the production of hsp by periodontopathic gram-negative bacteria was examined by sds-page, two dimensional gel electrophoresis, and western blotting using monoclonal antibodies against hsps. strains of actinobacillus actinomycetemcomitans, eikenella corrodens, fusobacterium nucleatum, prevotella intermedia, prevotella nigrescens, prevotella melaninogenica, and treponema socranskii species produced hsp which reacted with anti-yersinia enterocolitica hsp 60 and/or mycobacterial 65-kda hsp monoclon ... | 1995 | 7565172 |
| characterization of immunoglobulin g-degrading proteases of prevotella intermedia and prevotella nigrescens. | degradation of immunoglobulins is thought to be an important factor in the causation of periodontal diseases by hindering local host defenses and by providing nutrients to the periodontal microflora. in this study, we characterized the proteolytic activity against human immunoglobulin g (igg) of 20 strains of prevotella intermedia and prevotella nigrescens isolated from periodontal pockets and oral abscesses. igg degradation was studied by sodium dodecyl sulphate-polyacrylamide gel electrophores ... | 1995 | 7567062 |
| a longitudinal study from prepuberty to puberty of gingivitis. correlation between the occurrence of prevotella intermedia and sex hormones. | a longitudinal study of 24 subjects progressing normally from prepuberty to puberty was undertaken to evaluate the effects of sex hormone levels on clinical and microbiologic parameters and on serum antibodies. during elementary school, at the beginning of the longitudinal monitoring, 2 groups, 12 subjects with gingivitis and 12 gingivitis-free subjects, were selected and observed through puberty. bone ages and self-assessment of secondary sex characteristics were used to confirm puberty. a stat ... | 1994 | 7852609 |
| characterization of prevotella intermedia and prevotella nigrescens isolates from periodontic and endodontic infections. | the occurrence and surface properties of prevotella intermedia and p. nigrescens in healthy sites and in periodontic and endodontic infections were studied among 73 strains, tentatively identified as p. intermedia. fifteen strains were from necrotic root canal infections, 41 were from periodontal samples, and 17 isolates were obtained from healthy gingival sites. identification of isolates as either p. intermedia or p. nigrescens was based on differences in malate and glutamate dehydrogenase ele ... | 1994 | 7907659 |
| species-specificity of monoclonal antibodies recognising prevotella intermedia and prevotella nigrescens. | prevotella intermedia and prevotella nigrescens are not easily distinguished, making it difficult to assess their roles in disease. this study examined the specificity of three monoclonal antibodies (mabs) for these species. differentiation between p. intermedia (13 isolates) and p. nigrescens (24 isolates) was by the electrophoretic mobility of their malate and glutamate dehydrogenase enzymes or by dna homology grouping. all p. intermedia reacted strongly with mab 40bi3.2.2 whereas p. nigrescen ... | 1994 | 8056301 |
| interdental supragingival plaque--a natural habitat of actinobacillus actinomycetemcomitans, bacteroides forsythus, campylobacter rectus, and prevotella nigrescens. | the aim of this study was to test the hypothesis that suspected periodontal pathogens form a minor component of the supragingival plaque of individuals without periodontal diseases. twenty-one dental hygienist trainees with a mean age of 23.5 years were twice sampled for interdental plaque between 1st and 2nd molars in all quadrants. the samples were assessed for actinobacillus actinomycetemcomitans, bacteroides forsythus, campylobacter rectus, porphyromonas gingivalis, and the prevotella interm ... | 1994 | 8083438 |
| effect of therapy on periodontal infections. | periodontal disease progression requires the simultaneous presence of high numbers of pathogens, low numbers of compatible or beneficial species, a conductive local environment, and a susceptible host. effective therapy acts by altering one or more of these factors. data from an ongoing study were used to examine the biological basis of treatment success or failure. seventeen subjects showing disease progression were treated by widman flap surgery at deep sites, scaling at shallow sites, and 1 o ... | 1993 | 8410615 |
| proposal of a new species prevotella nigrescens sp. nov. among strains previously classified as pr. intermedia. | | 1993 | 8518765 |
| confirmation of the species prevotella intermedia and prevotella nigrescens. | the elevation of the two genotypes of prevotella intermedia to species rank as p. intermedia and prevotella nigrescens has increased the need for reliable differentiation between the two taxa. in this study, 53 strains, including strains whose species affiliations were known as well as fresh dental plaque isolates, were subjected to a multilocus enzyme electrophoretic analysis, dna analyses in which we used whole genomic dna, rrna sequences, and an oligonucleotide specific for the former p. inte ... | 1995 | 8590668 |
| lipopolysaccharide increases cell surface-associated fibronectin in fibroblasts in vitro. | this study assessed the fibronectin expression by fibroblasts derived from noninflamed and inflamed gingiva by measuring the amount of cell surface-associated fibronectin and fibronectin released into the medium. the effects of added lipopolysaccharide from porphyromonas gingivalis, prevotella nigrescens and escherichia coli on both types of fibroblasts were also studied. in the absence of lipopolysaccharide, the amounts of the two types of fibronectin were significantly larger in the fibroblast ... | 1996 | 8604252 |
| prevotella intermedia and prevotella nigrescens serotypes, ribotypes and binding characteristics. | type strains and 62 clinical isolates of prevotella intermedia and prevotella nigrescens were typed with the use of genomic dna fingerprints and rrna gene probes. the strains were further serotyped with monoclonal antibodies and characterized with sds-page, enzymatic activities, hemolysis and hemagglutination and coaggregation with streptococcus and actinomyces spp. p. intermedia and p. nigrescens were found to have distinct ribotype patterns which correspond to previously defined serotyupes i a ... | 1996 | 8674976 |
| 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 |
| collagen-binding activity of prevotella intermedia measured by a microtitre plate adherence assay. | the ability of prevotella intermedia to bind type i collagen was investigated. a simple method in which bacterial cells were allowed to attach to collagen-coated microtitre plate wells was used to characterize the activity. all strains of p. intermedia tested, as well as those of the closely related species prevotella nigrescens, showed a capacity to attach to the collagen film. exponential-phase cultures of p. intermedia demonstrated a greater binding capacity than older cells. attachment to th ... | 1996 | 8704994 |
| analytical performance of an immunologic-based periodontal bacterial test for simultaneous detection and differentiation of actinobacillus actinomycetemcomitans, porphyromonas gingivalis, and prevotella intermedia. | the analytical performance of a membrane-based immunoassay for the simultaneous detection and differentiation of actinobacillus actinomycetemcomitans, porphyromonas gingivalis, and prevotella intermedia (including prevotella nigrescens) was investigated. positive reactions were observed for 71 of 71 reference strains and recent oral isolates of a. actinomycetemcomitans, p. gingivalis, and p. intermedia. no cross-reactivity was observed with 39 other common oral and environmental species. the spe ... | 1996 | 8724708 |
| binding and degradation of lactoferrin by porphyromonas gingivalis, prevotella intermedia and prevotella nigrescens. | the ability of laboratory and clinical strains of porphyromonas gingivalis, prevotella intermedia and prevotella nigrescens to bind and to degrade lactoferrin (lf) has been assessed. lf bound readily to whole cells of each species apparently via high-affinity site and one or more low-affinity sites. p. gingivalis showed a lower affinity for lf than the other two species (p < 0.001). virtually all strains of p. gingivalis completely degraded lf under the conditions employed, whereas p. intermedia ... | 1996 | 8809549 |
| source of suspected periodontal pathogens re-emerging after periodontal treatment. | to clarify the source of re-emerging periodontal pathogens after treatment, we compared the ribotypes of actinobacillus actinomycetemcomitans, porphyromonas gingivalis, prevotella intermedia/prevotella nigrescens group and campylobacter rectus before and after treatment in 7 periodontitis patients and in 6 of the spouses. the patients harbored a. actinomycetemcomitans, p. gingivalis, p. intermedia/p. nigrescens group or c. rectus in their subgingival or salivary samples before treatment. the res ... | 1996 | 8811482 |
| clinical, microbiological and immunological profile of healthy, gingivitis and putative active periodontal subjects. | thirteen periodontally healthy subjects were monitored clinically for 6-12 months. clinical measurements at 6-weekly intervals included duplicate pd measurements, presence of plaque, redness, and bleeding on probing. baseline measurements consisted of 2 visits 1 wk apart. microbial samples were taken from 11 of the subjects who had completed at least 8 months of monitoring. levels of serum antibodies to 12 periodontal species were determined from 10 subjects. standard deviations of replicate pd ... | 1996 | 8814590 |
| effect of oxygen, inoculum composition and flow rate on development of mixed-culture oral biofilms. | the effect of aeration on the development of a defined biofilm consortium of oral bacteria was investigated in a two-stage chemostat system. an inoculum comprising 10 species, including both facultatively anaerobic and obligately anaerobic bacteria, and species associated with oral health and disease, was inoculated into an anaerobic first-stage chemostat vessel. the effluent from this chemostat was linked to an aerated [200 ml co2/air (5:95, v/v) min-1] second-stage vessel, in which removable h ... | 1996 | 8868437 |
| an investigation into the use of sds-page of cell surface extracts and proteolytic activity to differentiate prevotella nigrescens and prevotella intermedia. | by comparison of the cell surface proteins derived from the outer membrane and fibrils from 14 prevotella intermedia and 19 prevotella nigrescens strains using sds and analysed by sds-page, it was possible to distinguish the two species. a polypeptide of approx. 21 kda distinguished p. intermedia strains, whereas two polypeptides of approx. 18 and 22 kda could be used to identify p. nigrescens strains. four other human oral black pigmented bacterial species (porphyromonas gingivalis, prevotella ... | 1996 | 8869494 |
| clonality of porphyromonas gingivalis, prevotella intermedia and prevotella nigrescens isolated from periodontally diseased and healthy sites. | black-pigmented anaerobes have been implicated as major pathogens in the aetiology of adult periodontitis but these organisms are also found in healthy sites. this study aimed to examine the relationship between genotypes of black-pigmented anaerobes and disease status of periodontal sites using restriction endonuclease analysis (rea) and ribotyping. the main black-pigmented species recovered from sites were porphyromonas gingivalis, prevotella intermedia and prevotella nigrescens. each of the 5 ... | 1996 | 8884636 |
| pcr reaction and dot-blot hybridization to monitor the distribution of oral pathogens within plaque samples of periodontally healthy individuals. | the purpose of this study was to determine the distribution of the putative periodontal pathogens prevotella intermedia, prevotella nigrescens, the three oral capnocytophaga species (c. ochracea, c. sputigena, c. gingivalis), as well as porphyromonas gingivalis and actinobacillus actinomycetemcomitans in plaque samples of periodontally healthy individuals. we chose a newly developed 16s rdna directed polymerase chain reaction (pcr) and a previously described dot-blot hybridization assay to detec ... | 1996 | 8910839 |
| 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 |
| distribution and genetic analysis of oral prevotella intermedia and prevotella nigrescens. | a total of 344 prevotella intermedia and nigrescens group isolates from 59 subjects were identified by hybridization with nonradioactively labeled species-specific oligonucleotide probes. identification of 20 p. intermedia and 46 p. nigrescens isolates was confirmed by analyzing the electrophoretic mobilities of malate and glutamate dehydrogenase enzymes. a total of 111 isolates (32%) were identified as p. intermedia and 233 isolates (68%) as p. nigrescens. identification performed with oligonuc ... | 1996 | 8941760 |
| 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 |
| characterization of prevotella intermedia and prevotella nigrescens by enzyme production, restriction endonuclease and ribosomal rna gene restriction analyses. | restriction endonuclease analysis, rrna gene restriction analysis (ribotyping), multilocus enzyme electrophoresis and lipase production were investigated for their potential to differentiate isolates belonging to the closely-related species prevotella intermedia and prevotella nigrescens. of 122 strains identified originally as p. intermedia, 52 were assigned to p. intermedia and 68 to p. nigrescens using multilocus enzyme electrophoresis. all 39 p. intermedia and 52 out of 53 p. nigrescens test ... | 1996 | 8941766 |
| degradation of lactoferrin by periodontitis-associated bacteria. | the degradation of human lactoferrin by putative periodontopathogenic bacteria was examined. fragments of lactoferrin were separated by sodium dodecyl sulfate-polyacrylamide gel electrophoresis, and measured by densitometry. the degradation of lactoferrin was more extensive by porphyromonas gingivalis and capnocytophaga sputigena, slow by capnocytophaga ochracea, actinobacillus actinomycetemcomitans and prevotella intermedia, and very slow or absent by prevotella nigrescens, campylobacter rectus ... | 1996 | 8961558 |
| extracts of periodontopathic microorganisms lack functional superantigenic activity for murine t cells. | products of periodontopathic bacteria exert immunomodulatory effects on various lymphoid cell populations, some of which have been implicated in the pathogenesis of periodontitis. it has recently been suggested that some of these bacterial products may possess superantigenic (sag) activity. sag bind simultaneously to the v beta chain of t cell receptors and to class ii major histocompatibility complex molecules, thereby activating as many as 35% of t cells to proliferate and produce cytokines. i ... | 1996 | 8971649 |
| 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 |
| electrophoresis of whole-cell soluble proteins of microorganisms isolated from bacteremias in endodontic therapy. | we have previously demonstrated that anaerobic bacteria are the microorganisms most frequently isolated from blood following endodontic therapy of teeth with apical periodontitis. phenotypic characterisation of the isolates suggested that the bacteria in the blood originated from the root canal. the present experiment using sodium dodecyl sulfate-polyacrylamide gel electrophoresis (sds-page) was carried out in an effort to verify these findings, and to further study the microorganisms involved i ... | 1996 | 9021323 |
| tetracycline resistance in prevotella isolates from periodontally diseased patients is due to the tet(q) gene. | tetracycline-resistance in gram-negative periodontal bacteria is often due to the presence of the tet(q) gene. in the present study the polymerase chain reaction (pcr) was used to examine 54 isolates of gram-negative anaerobic rods (prevotella intermedia, prevotella nigrescens and related or bacteroides-like species) for the presence of the tet(q) gene. the isolates were recovered from 42 patients with periodontal disease living in northern europe and north america. an 814 base-pair segment of t ... | 1996 | 9028255 |
| identification of a lactoferrin-binding protein in prevotella nigrescens. | a 40-kda lactoferrin-binding protein was identified in a strain of prevotella nigrescens isolated from a patient with periodontitis. the protein was purified by affinity column chromatography using a sepharose-lactoferrin column and detergent-solubilized membranes. the n-terminal sequence revealed no apparent similarities with any other sequenced bacterial protein. the native conformation of the 40-kda protein was a condition to bind either iron-free or iron-saturated lactoferrin. a possible fun ... | 1997 | 9163907 |
| hydrolytic and depolymerising enzyme activity of prevotella intermedia and prevotella nigrescens. | prevotella intermedia has been reported to be associated with periodontal disease whilst p. nigrescens has predominantly been isolated from more specific conditions and healthy sites. the aim of the present study was to compare the enzyme activity of these species. | 1996 | 9171510 |
| protein degradation by prevotella intermedia and actinomyces meyeri supports the growth of non-protein-cleaving oral bacteria in serum. | the proteolytic activities of oral bacteria are thought to play an important role in the aetiology of dental abscesses. bacteria-derived proteases may contribute to tissue destruction, and are likely to impair host defence by degrading immunoglobulins and complement. degraded periodontal tissue and tissue fluid are likely to constitute essential sources of nutrients in the abscess. tissue fluid, which is derived from serum, is rich in protein and poor in carbohydrate, suggesting that breakdown o ... | 1997 | 9178115 |
| pcr-dna probe assays for identification and detection of prevotella intermedia sensu stricto and prevotella nigrescens. | the purpose of this study was to construct pcr-dna probe assays specific for prevotella intermedia sensu stricto and prevotella nigrescens based on the ability of randomly amplified polymorphic dna (rapd) fingerprinting to generate species-specific markers. the strategy included four steps: (i) construction of first-generation dna probes from a 850-bp rapd marker for p. intermedia sensu stricto and a 1,300-bp rapd marker for p. nigrescens, (ii) cloning and sequencing of each rapd marker, (iii) d ... | 1997 | 9196214 |
| intra-familial transmission and distribution of prevotella intermedia and prevotella nigrescens. | the periodontal bacteria prevotella intermedia and prevotella nigrescens have been recently separated from each other. the purpose of this study was to investigate the distribution and routes of transmission of these bacteria among family members. seven patients with moderate to severe periodontitis were selected. these probands, their spouses and 14 of their children were investigated. the presence of pr. intermedia and pr. nigrescens was determined by culture techniques in pooled subgingival p ... | 1997 | 9210087 |
| optimized oligonucleotides for the differentiation of prevotella intermedia and prevotella nigrescens. | the gram-negative, anaerobic bacterium prevotella intermedia plays an important role in the progression of periodontitis, whereas the etiological role of the closely related but phenotypically indistinguishable species prevotella nigrescens is controversial. to differentiate between these species properly, 16s rdna/rna directed, computer-optimized oligonucleotides were designed and tested with 26 p. intermedia, 26 p. nigrescens and a number of closely and more distantly related strains. the olig ... | 1997 | 9227136 |
| role of porphyromonas gingivalis, prevotella intermedia, and prevotella nigrescens in extraoral and some odontogenic infections. | porphyromonas gingivalis, prevotella intermedia, and prevotella nigrescens were isolated from 138 subjects with various infections (intraabdominal, skin and soft-tissue, head and neck, pleuropulmonary, and odontogenic infections and bacteremia). the phenotypic identification of 173 isolates was completed by molecular methods. arbitrarily primed polymerase chain reaction (ap pcr) analysis was used to determine the genetic similarity of intraindividual p. intermedia/p. nigrescens group isolates re ... | 1997 | 9310676 |
| beta-lactamase production by oral pigmented prevotella species isolated from young children. | the frequency of beta-lactamase production by oral pigmented prevotella species isolated from 23 healthy young children and the minimal inhibitory concentrations (mics) for 186 available beta-lactamase-positive isolates were examined by using the chromogenic cephalosporin disk test (ab biodisk, solna, sweden) and the etest (ab biodisk) and/or the agar dilution method of the national committee for clinical laboratory standards (villanova, pa, usa), respectively. beta-lactamase-positive prevotella ... | 1997 | 9310704 |
| fermentation product analysis in the identification of black-pigmented bacteria from periodontitis. | a quantitative procedure is described for the analysis of fermentation products of eight representative black-pigmented gram-negative anaerobic bacterial strains (porphyromonas gingivalis 381, porphyromonas gingivalis atcc 33277, prevotella intermedia atcc 25611, prevotella nigrescens atcc 33563, prevotella melaninogenica atcc 25845, prevotella denticola atcc 33185, and prevotella loescheii atcc 15930) from oral sites in humans, using gas-liquid chromatography. this procedure for the identificat ... | 1997 | 9345789 |
| characterization of the lactoferrin-dependent inhibition of the adhesion of actinobacillus actinomycetemcomitans, prevotella intermedia and prevotella nigrescens to fibroblasts and to a reconstituted basement membrane. | lactoferrin was previously shown to inhibit the adhesion of a. actinomycetemcomitans, p. intermedia and p. nigrescens to human cells. lactoferrin was also shown to competitively inhibit the binding of these bacteria to the basement membrane protein laminin. the present study aimed to determine the type of interactions inhibited by lactoferrin. lactoferrin binds to fibroblast monolayers and matrigel, a reconstituted basement membrane, through ionic interactions. the adhesion of a. actinomycetemco ... | 1997 | 9350211 |
| "checkerboard" versus culture: a comparison between two methods for identification of subgingival microbiota. | the present study compared the "checkerboard" dna-dna hybridization methodology with culture techniques for the analysis of the composition of the subgingival microbiota. 70 subjects, presenting with a variety of periodontal conditions, contributed with a total of 283 subgingival plaque samples analyzed with respect to the following species: porphyromonas gingivalis, prevotella intermedia/prevotella nigrescens, fusobacterium nucleatum, campylobacter rectus, eikenella corrodens, bacteroides forsy ... | 1997 | 9395099 |
| reduced serum igg reactivities with bacteria from dental plaque in hiv-infected persons with periodontitis. | serum samples were obtained from 44 hiv-seropositive (hiv+) and 37 hiv-seronegative (hiv-) persons that were grouped according to periodontal status. serum igg and iga reactivities towards streptococcus mutans, actinobacillus actinomycetemcomitans, porphyromonas gingivalis. prevotella intermedia, prevotella nigrescens and fusobacterium nucleatum were measured by means of elisa. hiv+ persons with chronic marginal periodontitis showed significantly lower igg reactivities to the periodontal pathoge ... | 1997 | 9402504 |
| periodontitis patient and the spouse: periodontal bacteria before and after treatment. | suspected periodontal pathogens can be transmitted between spouses. the treatment response may be unsuccessful in periodontitis patients, if the spouse harbors these bacteria. the aim of the present 6-month follow-up study was to clarify whether the microbiological treatment outcome of periodontitis patients is related to the detection of suspected periodontal pathogens in the saliva of the spouse. 10 patients with advanced periodontitis and their spouses were included in the study. the patients ... | 1997 | 9442426 |
| 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 |
| similarity of salivary and subgingival prevotella intermedia and prevotella nigrescens isolates by arbitrarily primed polymerase chain reaction. | the distribution and the genetic similarity of prevotella intermedia and prevotella nigrescens in saliva and in subgingival samples recovered from the same subject were studied in 16 subjects with different periodontal status. the isolates (4 salivary and 4 subgingival p. intermedia/nigrescens group isolates per subject) were identified to species level by hybridization with species-specific oligonucleotide probes, and the clonal analysis was performed using arbitrarily primed polymerase chain r ... | 1996 | 9467372 |
| pathogenicity of prevotella intermedia and prevotella nigrescens isolates in a wound chamber model in rabbits. | the pathogenicity of 14 isolates identified as prevotella intermedia or prevotella nigrescens by serogrouping using monoclonal antibodies was compared in a tissue cage model in rabbits. seven strains from periodontal abscesses, 5 strains from deep periodontal pockets and 2 strains from gingivitis were tested in the animal model comprising 6 teflon tissue cages implanted on the back each of 34 rabbits. a total of 10(5)-10(8) cells of p. intermedia or p. nigrescens strains were inoculated alone or ... | 1997 | 9467400 |
| salivary iga responses to bacteria in dental plaque as related to periodontal and hiv infection status. | levels of total iga and specific iga reactive with streptococcus mutans, actinobacillus actinomycetemcomitans, porphyromonas gingivalis, prevotella intermedia, prevotella nigrescens and fusobacterium nucleatum were measured by elisa in parotid saliva from hiv+ and hiv- persons with healthy gingiva (hg), chronic gingivitis, chronic marginal periodontitis (cmp), or necrotizing ulcerative periodontitis (nup). when the hiv+ group was compared with the hiv- group regardless of periodontal status, tot ... | 1997 | 9469606 |
| 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 |
| biochemical and genetic characterization of a prevotella intermedia/nigrescens-like organism. | thirty-three previously non-typable faintly pigmented gram-negative anaerobic bacterial isolates, biochemically most closely related to prevotella intermedia and prevotella nigrescens, were analysed for enzymic reactions, cellular fatty acid (cfa) composition, electrophoretic mobility of malate and glutamate dehydrogenases, hybridization with p. intermedia and p. nigrescens species-specific oligonucleotide probes and, for genetic heterogeneity, by arbitrarily primed pcr (ap-pcr). p. intermedia a ... | 1998 | 9542074 |
| phylogenetic characterization and proposal of a new pigmented species to the genus prevotella: prevotella pallens sp. nov. | complete 16s rrna gene sequences of three representative strains of anaerobic, gram-negative, pigmented, moderately saccharolytic, indole-positive bacteria isolated from the oral cavity of humans were determined. according to comparative analyses of the rrna sequence data, this organism represents a previously unknown species within the genus prevotella. in addition, 22 representative strains and 21 reference strains (including 11 prevotella intermedia and 10 prevotella nigrescens strains) were ... | 1998 | 9542075 |
| supernatant cytotoxicity and proteolytic activity of selected oral bacteria against human gingival fibroblasts in vitro. | the purpose of this study was to determine if endodontic bacterial act in vitro on human gingival fibroblast functions via extracellular products. the bacteria used were prevotella nigrescens, capnocytophaga ochracea, peptostreptoccocus micros and actinobacillus actinomycetemcomitans. supernatants were collected from bacterial cultures at the beginning of the stationary phase when their density was similar. toxins that inhibited fibroblast proliferation were found in all culture supernatants of ... | 1998 | 9569986 |
| beta-lactamase-producing strains in the species prevotella intermedia and prevotella nigrescens. | a total of 96 strains were collected that included laboratory strains and clinical isolates classified prevotella intermedia sensu lato and the type strains of the species p. intermedia sensu stricto and prevotella nigrescens. susceptibility to amoxicillin and amoxicillin-clavulanic acid was determined by the etest. pcr-dna probe assays were used to speciate each strain as p. intermedia sensu stricto or p. nigrescens. by etest, 71 strains (74%) were susceptible to both amoxicillin and amoxicilli ... | 1998 | 9573820 |
| occurrence of prevotella nigrescens and prevotella intermedia in infections of endodontic origin. | the occurrence of prevotella intermedia and prevotella nigrescens in endodontic infections was studied using sodium dodecyl sulfate polyacrylamide gel electrophoresis (sds-page) of whole cell protein to distinguish between the species. previous studies have shown an association between black-pigmented bacteria (bpb) and endodontic infections and that prevotella intermedia (previously known as bacteroides intermedius) was the most commonly isolated bpb. recently, however, strains identified as p. ... | 1997 | 9587274 |
| black-pigmented bacteria in coronal and apical segments of infected root canals. | black-pigmented bacteria (bpb) have been associated with infections of endodontic origin. the purpose of this study was to culture and identify bpb from the apical and coronal segments of infected root canals to understand better their ecological relationships. teeth with a periapical radiolucency were extracted and immediately placed in reduced transport fluid for transport to an anaerobic chamber. of 18 sampled roots, 12 were positive for the growth of bpb. eight of the 12 roots with bpb had a ... | 1998 | 9641113 |
| in vitro adhesion of two strains of prevotella nigrescens to the dentin of the root canal: the part played by different irrigation solutions. | blocks of bovine incisor dentin, on the root canal surface of which a smear layer had been formed, were inoculated in vitro with two strains of prevotella nigrescens, a wild sampled strain and a reference one (nctc 9336). half the blocks were pretreated with irrigating solutions: 6% citric acid for 5 min + 6.25% sodium hypochlorite for 10 min. they were compared with the other blocks simply rinsed in distilled water (i.e. the control samples). the bacteria adhering to the dentin surface after an ... | 1998 | 9641142 |
| evaluation of the antimicrobial effect of lactoferrin on porphyromonas gingivalis, prevotella intermedia and prevotella nigrescens. | the antimicrobial effect of lactoferrin (apolf) on the oral, black-pigmented anaerobes porphyromonas gingivalis, prevotella intermedia and p. nitrescens has been studied. apolf did not kill any of these species but it did inhibit the growth of p. gingivalis, while iron-saturated lf (felf) had no effect. the other two species were unaffected by apolf. this growth inhibitory effect of apolf could not be explained on the basis of chelation of inorganic iron, since growth of p. gingivalis occurred i ... | 1998 | 9657318 |
| citrate promotes attachment of prevotella nigrescens (intermedia) atcc 25261 to hydroxyapatite. | large quantities of prevotella nigrescens (intermedia) atcc 25261 (p. nigrescens) cells adhere to hydroxyapatite (ha) treated with citrate, but do not adhere experimental pellicle prepared from human whole saliva. to determine the nature of the citrate responsible for promoting p. nigrescens cell adhesion, the duration and frequency of citrate treatment of ha and the inhibitory effect of other carboxylates were tested. the citrate rapidly adhered to ha beads in less than 15 min. with a lower con ... | 1998 | 9680763 |
| 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 |
| analysis of ph-driven disruption of oral microbial communities in vitro. | previously, a mixed culture chemostat system was used to demonstrate that the ph generated from carbohydrate metabolism, rather than carbohydrate availability per se, was responsible for the shifts observed in the oral microflora which are associated with high carbohydrate diets and the development of dental caries. the aim of this study was to determine more accurately the microbially generated ph at which such shifts occurred. nine oral bacteria were grown in three independent chemostats, and ... | 1998 | 9745120 |
| role of fusobacterium nucleatum and coaggregation in anaerobe survival in planktonic and biofilm oral microbial communities during aeration. | coaggregation is a well-characterized phenomenon by which specific pairs of oral bacteria interact physically. the aim of this study was to examine the patterns of coaggregation between obligately anaerobic and oxygen-tolerant species that coexist in a model oral microbial community. obligate anaerobes other than fusobacterium nucleatum coaggregated only poorly with oxygen-tolerant species. in contrast, f. nucleatum was able to coaggregate not only with both oxygen-tolerant and other obligately ... | 1998 | 9746571 |
| purification and functional analysis of the dnak homologue from prevotella intermedia omz 326. | this study examined heat shock proteins (hsps) of the periodontal pathogen prevotella intermedia and the closely related species, prevotella nigrescens and prevotella corporis. after heat shock at 45 degrees c for 5 min, cell-free extracts were analysed by sds-page and western blotting with polyclonal antibodies against escherichia coli hsps. p. intermedia, p. nigrescens and p. corporis all expressed a dnak homologue. the p. nigrescens dnak was of a similar molecular mass to e. coli dnak (70 kda ... | 1998 | 9785453 |
| antimicrobial susceptibilities of porphyromonas gingivalis, prevotella intermedia, and prevotella nigrescens spp. isolated in spain. | the susceptibilities of 143 porphyromonas gingivalis, prevotella intermedia, and prevotella nigrescens isolates to 18 antimicrobial agents were tested. all p. gingivalis isolates were susceptible. in contrast, some prevotella spp. (17%) were resistant to beta-lactams, erythromycin, clindamycin, or tetracycline and carried resistance genes, ermf or tetq, or beta-lactamases. | 1998 | 9797247 |
| incidence of prevotella intermedia and prevotella nigrescens in periodontal health and disease. | the incidence of black-pigmented rods (bprs), especially prevotella intermedia and prevotella nigrescens, in periodontal health and disease were examined. furthermore, the degradative enzyme activities of p. intermedia were compared among the strains from periodontal health and disease. microbiological specimens were collected from subgingival crevice or periodontal pocket by paper point. the bprs were found in 71.1% of periodontally healthy subjects (n=45), and in 47.1% of healthy sites (n=34) ... | 1998 | 9802558 |
| risk indicators for harboring periodontal pathogens. | the risk for harboring 6 putative periodontal pathogens in 4 selected periodontal pockets, in whole saliva, or in either site (i.e., orally) was determined in 52 caucasians, 49 african-americans, 48 asian-americans, and 50 hispanics living in los angeles. 16s rrna pcr analysis assessed the presence of actinobacillus actinomycetemcomitans, bacteroides forsythus, porphyromonas gingivalis, prevotella intermedia, prevotella nigrescens, and treponema denticola. step-wise regression analysis determine ... | 1998 | 9802709 |
| pathogenicity of facultative and obligate anaerobic bacteria in monoculture and combined with either prevotella intermedia or prevotella nigrescens. | the pathogenicity of obligate and facultative anaerobic bacteria commonly found in endodontic infections was tested using a mouse model. the capacity of inducing abscesses was evaluated seven days after subcutaneous injection of the bacteria in pure culture and in combinations with either prevotella intermedia or prevotella nigrescens. nine of the fifteen bacterial strains tested were pathogenic in pure culture. no statistically significant differences were detected between these strains in pure ... | 1998 | 9872113 |
| binding and utilization of human transferrin by prevotella nigrescens. | to survive and multiply within their hosts, pathogens must possess efficient iron-scavenging mechanisms. in the present study, we investigate the capacity of prevotella nigrescens and prevotella intermedia to use various sources of iron for growth and characterize the transferrin-binding activity of p. nigrescens. iron-saturated human transferrin and lactoferrin, but not ferric chloride and the iron-free form of transferrin, could be used as sources of iron by p. nigrescens and p. intermedia. ne ... | 1999 | 9916061 |
| use of pcr and sodium dodecyl sulfate-polyacrylamide gel electrophoresis techniques for differentiation of prevotella intermedia sensu stricto and prevotella nigrescens. | primers were designed from 16s rrna sequences of prevotella intermedia sensu stricto and prevotella nigrescens and were used to discriminate these two species by pcr. the results were compared with those from the pcr technique using primers designed from arbitrarily primed pcr products by guillot and mouton (e. guillot and c. mouton, j. clin. microbiol. 35:1876-1882, 1997). the specificities of both assays were studied by using p. intermedia atcc 25611, p. nigrescens atcc 33563, 174 clinical iso ... | 1999 | 10074526 |
| microbiota of successful osseointegrated dental implants. | the long-term survival of dental implants depends, in part, on control of bacterial infection in the peri-implant region. periodontal pathogens colonized implants symptomatic through infection, whereas the microbiota of successful implants was similar to that of periodontal health. this study examined the impact on the peri-implant microbiota of crown restorations; implant type; length of time of loading; history of implant or periodontal infections; and whether implants replaced single or multi ... | 1999 | 10102550 |
| modulation of antibacterial peptide activity by products of porphyromonas gingivalis and prevotella spp. | this study investigated the ability of anaerobic periodontal bacteria to inactivate and resist killing by antimicrobial peptides through production of extracellular proteases. antibacterial activities of peptides were assessed in a double-layer agarose diffusion assay, and mics and mbcs were determined in broth microdilution assays. culture supernates of porphyromonas gingivalis and prevotella spp. inactivated mastoparan, magainin ii and cecropin b whilst gram-positive oral supragingival bacteri ... | 1999 | 10220176 |
| relationship between herpesviruses and adult periodontitis and periodontopathic bacteria. | various mammalian viruses and specific bacteria seem to play important roles in the pathogenesis of human periodontitis. this study examined the relationship between subgingival herpesviruses and periodontal disease and potential periodontopathic bacteria in 140 adults exhibiting either periodontitis or gingivitis. | 1999 | 10368051 |
| oral microflora in subjects with reduced salivary secretion. | it is generally assumed that a decreased salivary secretion rate will promote plaque accumulation and increase the risk for caries, gingival inflammation, and mucosal infections. in this study, the effect of hyposalivation on the oral microflora was examined. the following micro-organisms were analyzed in rinsing samples from 14 subjects with hyposalivation: the total number of anaerobically growing micro-organisms, alpha-hemolytic streptococci, mutans streptococci, lactobacilli, fusobacterium n ... | 1999 | 10439028 |
| microbiological features of papillon-lefèvre syndrome periodontitis. | papillon-lefevre syndrome patients exhibit hyperkeratosis palmo-plantaris and severe periodontitis. the syndrome is an autosomal recessive trait, but the mechanism of periodontal destruction is not known. this report presents the clinical and microbiological features of an 11-year old girl with papillon-lefèvre syndrome. clinical examination included conventional periodontal measurements and radiographic analysis. in samples from 3 deep periodontal lesions, the occurrence of major suspected peri ... | 1999 | 10487314 |
| incidence of prevotella intermedia and prevotella nigrescens carriage among family members with subclinical periodontal disease. | we established a typing system for prevotella intermedia and prevotella nigrescens using the combination of pcr ribotyping and arbitrarily primed pcr (ap-pcr) fingerprinting and applied this system to the study of intrafamilial incidence of these species in the oral cavity. pcr ribotyping followed by subtyping by ap-pcr fingerprinting was applied to each type strain of p. intermedia and p. nigrescens and 54 isolates (32 isolates of p. intermedia and 24 isolates of p. nigrescens) from extraoral i ... | 1999 | 10488167 |
| identical clonal types of porphyromonas gingivalis or prevotella nigrescens recovered from infected root canals and subgingival plaque. | clinical samples from 10 infected root canals and from subgingival plaque in 10 patients were screened by anaerobic culture for black-pigmented anaerobes. a total of 17 porphyromonas gingivalis and 9 prevotella nigrescens were obtained from four patients and were identified by species-specific polymerase chain reaction (pcr) amplification. the arbitrarily primed pcr reaction used to examine the genetic diversity of the isolates revealed that the p. gingivalis or p. nigrescens simultaneously pres ... | 1999 | 10495716 |
| hemolytic and hemagglutinating activities of prevotella intermedia and prevotella nigrescens. | a total of 91 isolates of prevotella intermedia or prevotella nigrescens from subgingival sites were identified by pcr using primers specific for sequences of 16s rrna. the hemolytic and hemagglutinating activities of the p. intermedia isolates exhibited significantly higher levels compared to those of the p. nigrescens isolates by quantitative analysis. the hemagglutinin gene (phg) was found in 23 of 26 p. intermedia isolates (88.5%), whereas it was found in only two of 44 isolates (4.5%) of p. ... | 1999 | 10499279 |
| beta-lactamase production in prevotella intermedia, prevotella nigrescens, and prevotella pallens genotypes and in vitro susceptibilities to selected antimicrobial agents. | the present study investigated the beta-lactamase production of 73 prevotella intermedia, 84 prevotella nigrescens, and 14 prevotella pallens isolates and their in vitro susceptibilities to six antimicrobial agents. the p. intermedia and p. nigrescens isolates were recovered from oral and extraoral samples obtained from subjects in two geographic locations from 1985 to 1995. the clonality of the beta-lactamase-positive and beta-lactamase-negative isolates and the clustering of the genotypes were ... | 1999 | 10508011 |
| black-pigmented anaerobic rods in closed periapical lesions. | this study determined the frequency of porphyromonas endodontalis, porphyromonas gingivalis, prevotella intermedia and prevotella nigrescens in 20 closed periapical lesions associated with symptomatic and asymptomatic refractory endodontic disease. | 1999 | 10530208 |
| association of black-pigmented bacteria with endodontic infections. | black-pigmented bacteria (bpb) have been associated with endodontic infections. the purpose of this study was to evaluate further the presence of bpb with the clinical signs and symptoms associated with endodontic infections. microbial samples were collected from the root canals of 40 intact teeth with necrotic pulps and apical periodontitis. conventional laboratory methods were used for identification of the strains of bpb isolated in pure culture. in addition, the polymerase chain reaction and ... | 1999 | 10530240 |
| sodium dodecyl sulfate-polyacrylamide gel electrophoresis and polymerase chain reaction for differentiation of prevotella intermedia and prevotella nigrescens. | isolates previously thought to be prevotella intermedia have been shown to be a closely related species now known as prevotella nigrescens. the purpose of this study was to determine the efficacy of sodium dodecyl sulfate-polyacrylamide gel electrophoresis (sds-page) and polymerase chain reaction (pcr) to differentiate endodontic isolates of p. nigrescens from p. intermedia. fifty-six strains of black-pigmented bacteria isolated from endodontic infections and conventionally identified as p. inte ... | 1999 | 10530254 |
| microbial findings at failing implants. | the aim of this study was to evaluate qualitative differences in the subgingival microbiota at titanium implants, ad modum brånemark, demonstrating clinical and radiographic signs of loss of supporting tissues (peri-implantitis) as compared to implants surrounded by healthy tissues. a total of 37 patients demonstrating 1 or more implants with bone loss > or = 3 threads, bleeding on probing and/or suppuration and 51 patients with clinically healthy mucosa and no bone loss were recruited for the s ... | 1999 | 10551058 |
| possible potentiation of toxins from prevotella intermedia, prevotella nigrescens, and porphyromonas gingivalis by cotinine. | smoking is a recognized risk factor for the initiation and progression of periodontitis. however, the mechanism by which smoking induces its negative effects on the periodontium is not clear. this study aimed to test the hypothesis that synergy may occur between cotinine and bacterial products isolated from 3 putative periodontopathogens. | 1999 | 10588489 |
| survey for collagenase gene prtc in porphyromonas gingivalis and porphyromonas endodontalis isolated from endodontic infections. | collagenase is a potential virulence factor shown to be expressed by porphyromonas gingivalis associated with periodontal disease. the purpose of this study was to use the polymerase chain reaction (pcr) to detect the presence of the collagenase gene (prtc) in 21 strains of porphyromonas species isolated from endodontic infections. type strains for p. gingivalis (atcc 33277), p. endodontalis (atcc 35406), prevotella intermedia (atcc 25611), and prevotella nigrescens (atcc 33563) were used as con ... | 1999 | 10635221 |
| herpesviruses in human periodontal disease. | recent studies have identified various herpesviruses in human periodontal disease. epstein-barr virus type 1 (ebv-1) infects periodontal b-lymphocytes and human cytomegalovirus (hcmv) infects periodontal monocytes/ macrophages and t-lymphocytes. ebv-1, hcmv and other herpesviruses are present more frequently in periodontitis lesions and acute necrotizing ulcerative gingivitis-lesions than in gingivitis or periodontally healthy sites. reactivation of hcmv in periodontitis lesions tends to be asso ... | 2000 | 10791704 |
| "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 |
| 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 |
| 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 |
| coptidis rhizoma inhibits growth and proteases of oral bacteria. | the aim of this study was to investigate the antibacterial effect of coptidis rhizoma (cr), a traditional medicinal plant, on oral bacteria. | 2000 | 11002412 |
| microbial composition of supra- and subgingival plaque in subjects with adult periodontitis. | the purpose of the present study was to compare and relate the microbial composition of supra and subgingival plaque in 23 adult periodontitis subjects (mean age 51 +/- 14 years). | 2000 | 11034118 |
| the formation of mixed culture biofilms of oral species along a gradient of shear stress. | a chemostat mixed culture system was used to produce two distinct ecological states, state-1 (caries-like microcosm) and state-2 (periodontal-like microcosm). eleven bacterial species (streptococcus gordonii, strep. mitis i, strep. mutans, strep. oralis, actinomyces naeslundii, lactobacillus casei, neisseria subflava, fusobacterium nucleatum, porphyromonas gingivalis, prevotella nigrescens, veillonella dispar) were used to inoculate the planktonic system. a flow cell, designed to produce converg ... | 2000 | 11054158 |
| 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 |
| inhibitory effect of lactoferrin on the adhesion of prevotella nigrescens atcc 25261 to hydroxyapatite. | prevotella nigrescens atcc 25261 (p. nigrescens) cells adhere well to hydroxyapatite treated with citrate (cha), but the attachment is drastically inhibited by lactoferrin (lf). to determine the nature of the iron-free lf responsible for inhibiting p. nigrescens cell attachment, this study tested the duration and frequency of lf treatment of cha and the effects of divalent and trivalent ferric ions. the inhibitory effect on the attachment of p. nigrescens was somewhat higher with bovine lf than ... | 2000 | 11111322 |
| the prevotella intermedia group organisms in young children and their mothers as related to maternal periodontal status. | currently, the prevotella intermedia group includes three biochemically and phylogenetically related species: prevotella intermedia, prevotella nigrescens, and the newly described prevotella pallens. the two first-named species are mentioned with varying emphasis in connection with periodontal diseases, while such a connection of p. pallens is not known. mothers serve as a plausible source of bacteria to their children, and conceivably, a mother with periodontitis as a recurrent reservoir of per ... | 2000 | 11144405 |
| glucose metabolism by prevotella intermedia and prevotella nigrescens. | glucose metabolism by prevotella intermedia and prevotella nigrescens were investigated. glucose increased the anaerobic growth of these bacteria and promoted the accumulation of intracellular polysaccharide. the polysaccharide was confirmed to be glycogen-like glucan by the absorption spectrum of iodinepolysaccharide complex and the sugar composition. the washed cells consumed glucose anaerobically and converted a part of glucose into the metabolic end-products acetate, formate and succinate. t ... | 2000 | 11154402 |
| inhibition of actinobacillus actinomycetemcomitans leukotoxicity by bacteria from the subgingival flora. | actinobacillus actinomycetemcomitans produces a pore-forming leukotoxin that lyses human polymorphonuclear leukocytes and monocytes. certain proteolytic bacteria may coexist with a. actinomycetemcomitans in periodontal pockets. we aimed therefore to examine whether oral bacteria can modify the leukotoxicity of a. actinomycetemcomitans. a total of 55 strains representing 45 bacterial species of the subgingival flora were tested. each strain was incubated with the highly toxic strain of a. actinom ... | 2000 | 11154406 |