Discrete proteolysis of focal contact and adherens junction components in Porphyromonas gingivalis-infected oral keratinocytes: a strategy for cell adhesion and migration disabling.
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Adhesive interactions of cells are critical to tissue integrity. We show that infection with Porphyromonas gingivalis, a major pathogen in the periodontal disease periodontitis, interferes with both cell-matrix and cell-cell adhesion in the oral keratinocyte cell line HOK-16. Thus, infected cells showed reduced adhesion to extracellular matrix, changes in morphology from spread to rounded, and impaired motility on purified matrices in Transwell migration assays and scratch assays. Western blot analysis of P. gingivalis-challenged HOK-16 cells revealed proteolysis of focal contact components (e.g., focal adhesion kinase), adherens junction proteins (e.g., catenins), and adhesion signaling molecules (e.g., the tyrosine kinase SRC). Proteolysis was selective, since important components of adherens junctions (E-cadherin) or signaling molecules (extracellular signal-regulated kinases ERK1/2) were not degraded. The virulence factors gingipains, cysteine proteinases expressed by P. gingivalis, are likely responsible for this proteolytic attack, since they directly digested specific proteins in pull-down experiments, and their proteolytic activity was blocked by the cysteine proteinase inhibitor N-alpha-p-tosyl-L-lysine chloromethyl ketone and also by a caspase inhibitor. Proteolysis was strain dependent, such that ATCC 33277 and 381 had high proteolytic potential, whereas W50 showed almost no proteolytic activity. These findings may help explain the formation of gingival pockets between cementum and periodontal epithelium, a hallmark of periodontitis. Furthermore, they illustrate a new pathogenetic paradigm of infection whereby bacteria may disrupt the integrity of epithelia. (+info)
Evaluation of antibacterial activity of Mangifera indica on anaerobic dental microglora based on in vivo studies.
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The present study was carried out to compare the subgingival plaque microflora in mango leaf users. Fifty subjects of both sexes, 25 of them used tooth brush and 25 used mango leaf as their home care hygiene device were included in the study. The microbiological evaluation for specific bacterial counts of Actinobacillus actinomycetemcomitans, Prevotella intermedia, Porphyromonas gingivalis, Fusobacterium nucleatum and Peptostreptococcus micros were carried out for all subject. Specific microbial evaluation revealed significant decrease in the proportion of P. intermedia and P. gingivalis in mango leaf users compared to tooth brush users. It shows that mangiferin possesses antibacterial activity in vivo against specific periodontal pathogens such as P. intermedia and P. gingivalis. Use of mango leaf in conjunction with a tooth brush will be a good home care device for maintenance of oral hygiene. (+info)
Superinfecting microorganisms in patients under treatment with cyclosporin-A and its correlation to gingival overgrowth.
(3/15)
The aim of this study was to identify the presence of superinfecting microorganisms (Gram-negative enteric rods and Candida sp.) in heart transplant patients and correlate this with gingival overgrowth. Thirty patients (10 females, 20 males--mean age 45 years) were examined. All were under cyclosporin-A (CsA) therapy. Patients who had taken any antibiotics 3 months prior the study or had been submitted to periodontal therapy were not enrolled. Patients were required to have at least 6 teeth. The plaque index (PI), gingival index (GI), pocket depth (PD) and clinical attachment level (CAL) were recorded. Microbiological samples were taken from sulcus/pocket (s/p) and from stimulated saliva (ss) and submitted to analysis. Patients were divided into two groups: the ones with gingival overgrowth (GO) and those without gingival overgrowth (WGO). After statistical analysis (chi-square test, Student's t-test, Fisher test, p < or = 0.05), we concluded that there was no statistical difference between groups in the parameters of gender, CsA dosage, time since transplantation, PI, GI, PD and CAL. Gram-negative rods from either the sulcus/pocket or saliva samples were not found. Candida sp. was detected (s/p-30% and ss-30%). Stimulated saliva samples analysis determined that the presence of Candida sp. was associated with patients without gingival overgrowth. (+info)
Evaluation of the marginal gingival health using laser Doppler flowmetry.
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The purposes of this study were to compare the gingival blood flow (GBF) in test sites (teeth retaining fixed partial dentures) and control sites (contralateral natural teeth) and investigate whether there is any relationship between clinical indices and GBF values. Twelve healthy subjects (6 females and 6 males) aged 20 to 54 years were enrolled this study. The GBF was measured from the middle point of the marginal gingiva in the test and control sites using laser Doppler flowmetry (LDF). Additionally, plaque index, gingival index and probing depth measurements were recorded. Statistically significant difference (p<0.05) was found between the test and control sites for marginal GBF. In contrast, no significant difference (p>0.05) was found between test and control sites with respect to the clinical indices, except for plaque index. The findings of this study suggest that there is a significant relation between resin-bonded fixed partial dentures with margins located subgingivally and marginal GBF. Clinical indices are helpful to collect information about the clinical health status of gingival tissues, but GBF is a good tool to measure gingival tissue blood flow and assess periodontal health. In conclusion, laser Doppler flowmetry can be used together with clinical indices to evaluate the marginal gingival health. (+info)
Osteocalcin in serum, saliva and gingival crevicular fluid: their relation with periodontal treatment outcome in postmenopausal women.
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BACKGROUND: Osteocalcin levels have been postulated as a marker of inhibition of bone formation. The aim of the present study was to assess plasma, saliva and GCF levels of osteocalcin and correlate them with periodontal treatment outcome in postmenopausal women. METHODS: Thirty-nine postmenopausal women (57.8 -/+8.5 years old) were recruited for the study. Periodontal examination of all women was carried out and plaque, bleeding on probing, probing depth (PD), and clinical attachment level (CAL) were recorded. Serum, saliva and gingival crevicular fluid osteocalcin were measured. Then, periodontal treatment was carried out. Six months after the first appointment a second periodontal examination was carried out. RESULTS: Mean PD and mean CAL decreased significantly at second appointment in the group with serum osteocalcin concentration <10 ng/ml (15.8 -/+15.8% and 15.3 -/+ 21.2% respectively; p < 0.05). Mean PD decreased significantly at second appointment in the groups with saliva osteocalcin concentration < 3 ng/ml (17.1 -/+ 15.9%; p < 0.05) and 3-7 ng/ml (16.2 -/+18.1%; p < 0.05). CONCLUSIONS: Low serum osteocalcin concentration is associated to a significantly higher percentage of decrease in PD and CAL after periodontal treatment in postmenopausal women. Low saliva osteocalcin concentrations are significantly associated to a higher percentage of decrease in PD. (+info)
Lactobacillus uli sp. nov. and Lactobacillus rimae sp. nov. from the human gingival crevice and emended descriptions of lactobacillus minutus and Streptococcus parvulus.
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Lactobacillus uli sp. nov. and Lactobacillus rimae sp. nov. are described. These organisms are short, gram-positive, strictly anaerobic, rod-shaped bacteria that have DNA G+C contents of 53 and 45 mol%, respectively, produce major amounts of lactic acid, and have been isolated from human gingival crevices and periodontal pockets. The major cellular fatty acid derivatives for both species are C18:1 cis-9 fatty acid methyl ester and C18:1 cis-9 dimethylacetyl. The type strain of L. uli is strain VPI D76D-27C (= ATCC 49627), and the type strain of L. rimae is strain D140H-11A (= ATCC 49626). Emended descriptions of Lactobacillus minutus (based on selected strains) and Streptococcus parvulus (based on many additional strains) also are given. (+info)
Subgingival microbiota in squirrel monkeys with naturally occurring periodontal diseases.
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The squirrel monkey (Saimiri sciureus) has been proposed as an in vivo model for the study of subgingival colonization by suspected periodontopathogens, such as black-pigmented porphyromonads and prevotellas (BP/P). However, the indigenous microbiota of the squirrel monkey has not been well described. Therefore, in order to more fully characterize the oral microbiota of these animals, we studied two groups of squirrel monkeys from widely different sources. Group I consisted of 50 breeding colony monkeys ranging in age from 9 months to over 6 years which had been raised in captivity; group II consisted of 16 young sexually mature monkeys recently captured in the wild in Guyana. Group I animals in captivity had developed moderate to severe gingivitis, with a mean gingival index (GI) of 2.6; 52% of the sites bled, 26% had detectable calculus, and 83% had detectable BP/P. A group I subset (six animals), for which predominant cultivable microbiota was described, had a mean GI of 2.4. Colony morphology enumeration revealed that five of the six subset animals were detectably colonized with BP/P (range, 0 to 16.9%) and Actinobacillus actinomycetemcomitans (range, 0 to 3.9%); all subset animals were colonized with Fusobacterium species (range, 0.8 to 3.6%), Actinomyces species (range, 2.3 to 11%), and gram-positive cocci (range, 1.4 to 21.4%). Predominant cultivable microbiota results revealed the presence of many bacterial species commonly found in the human gingival sulcus. At baseline, group II animals were clinically healthy and had a mean GI of 1.4; 67% of the sites bled and 2.1% had calculus, and none of the animals had detectable BP/P. Neisseriae were very common in noninflamed sites. Subsequently, when inflamed sites were compared with noninflamed sites in group II animals after they had been maintained in captivity for 6 months, inflamed sites exhibited a more complex microbiota and increased proportions of gram-negative rods and asaccharolytic bacteria. (+info)