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Subgingival Biofilm (subgingival + biofilm)
Selected AbstractsGingival changes during pregnancy: II.JOURNAL OF CLINICAL PERIODONTOLOGY, Issue 3 2010Influence of hormonal variations on the subgingival biofilm Carrillo-de-Albornoz A, Figuero E, Herrera D, Bascones-Martínez A. Gingival changes during pregnancy: II. Influence of hormonal variations on the subgingival biofilm. J Clin Periodontol 2010; 37: 230,240. doi: 10.1111/j.1600-051X.2009.01514.x. Abstract Aim: To determine whether the exacerbated gingival inflammation that develops in pregnant women is related to a change in the subgingival biofilm induced by the increase in hormone levels during pregnancy. Material and Methods: This open cohort study included 48 pregnant and 28 non-pregnant women without periodontitis. Pregnant women were evaluated in the first, second and third trimester and at 3 months after delivery. Non-pregnant women were evaluated twice, with a 6-month interval, assessing microbiological, clinical and hormonal variables at each visit. Total anaerobic counts and frequency of detection and proportions were calculated. The Friedman test with the Bonferroni correction was used for intra-group comparisons and Mann,Whitney U -tests for inter-group assessment. Correlations were analysed by means of Spearman's rank correlation coefficient. Results: Proportions of the subgingival periodontal pathogens did not differ throughout pregnancy, although significant differences were found for all the pathogens after delivery. Porphyromonas gingivalis -positive patients presented an increase in gingival inflammation (p<0.001) that was not related to plaque. Correlations were found between maternal hormone levels and P. gingivalis and Prevotella intermedia. Conclusion: Qualitative differences in periodontal pathogens were found from pregnancy to post-partum. Patients harbouring P. gingivalis presented and increased gingival inflammatory status. [source] Methods of detection of Actinobacillus actinomycetemcomitans, Porphyromonas gingivalis and Tannerella forsythensis in periodontal microbiology, with special emphasis on advanced molecular techniques: a reviewJOURNAL OF CLINICAL PERIODONTOLOGY, Issue 12 2004Mariano Sanz Abstract Background: Certain specific bacterial species from the subgingival biofilm have demonstrated aetiological relevance in the initiation and progression of periodontitis. Among all the bacteria studied, three have shown the highest association with destructive periodontal diseases: Actinobacillus actinomycetemcomitans (Aa), Porphyromonas gingivalis (Pg) and Tannerella forsythensis (Tf). Therefore, the relevance of having accurate microbiological diagnostic techniques for their identification and quantification is clearly justified. Aim: To evaluate critically all scientific information on the currently available microbial diagnostic techniques aimed for the identification and quantification of Aa, Pg and Tf. Summary: Bacterial culturing has been the reference diagnostic technique for many years and, in fact, most of our current knowledge on periodontal microbiology derives from cultural data. However, the advent of new microbial diagnostics, mostly based on immune and molecular technologies, has not only highlighted some of the shortcomings of cultural techniques but has also allowed their introduction as easy and available adjunct diagnostic tools to be used in clinical research and practice. These technologies, mostly polymerase chain reaction (PCR), represent a field of continuous development; however, we still lack the ideal diagnostic to study the subgingival microflora. Qualitative PCR is still hampered by the limited information provided. Quantitative PCR is still in development; however, the promising early results reported are still hampered by the high cost and the equipment necessary for the processing. Conclusion: Quantitative PCR technology may have a major role in the near future as an adjunctive diagnostic tool in both epidemiological and clinical studies in periodontology. However, culture techniques still hold some inherent capabilities, which makes this diagnostic tool the current reference standard in periodontal microbiology. [source] Stress and the periodontal diseases: growth responses of periodontal bacteria to Escherichia coli stress-associated autoinducer and exogenous FeMOLECULAR ORAL MICROBIOLOGY, Issue 3 2005A. Roberts Psychological stress is known to increase the circulating levels of the catecholamine hormones noradrenaline and adrenaline, which have been shown to influence the growth of a large number of bacterial species by acting in a siderophore-like manner or by inducing the production of novel autoinducers of growth. As we have previously demonstrated that periodontal organisms display differing growth responses to noradrenaline and adrenaline, the aim of this study was to determine whether these growth effects were based upon either siderophore-like or autoinducer mechanisms. Initial inocula of 43 microbial organisms normally found within the subgingival biofilm were established under anaerobic conditions (35°C). Each strain was re-inoculated into a serum-based minimal medium and growth was assessed by optical density (OD600nm) with test and control cultures performed in triplicate. Test cultures were supplemented with either 50 ,m ferric nitrate or a previously described Escherichia coli autoinducer of growth. Significant growth effects for supplementation with ferric nitrate (13 species responding positively) and E. coli autoinducer (24 species responding positively) were observed, with differences in growth response within bacterial species and within microbial complexes. When data for all organisms were compared with published responses to catecholamines there were only weak correlations with Fe (r = 0.28) and E. coli autoinducer (r = 0.34) responses. However, large positive responses (> 25% increase) to free Fe and/or E. coli autoinducer were significantly more prevalent in the group of organisms (n = 12) known to exhibit similar responses to catecholamine hormones (P < 0.01; ,2 = 4.56). The results support the view that catecholamines may exert their effects on subgingival organisms by initiating autoinducer production, or simply by acting in a siderophore-like manner, scavenging bound iron from the local environment. It is possible that autoinducer mechanisms may play an important role in the response of oral microorganisms to stress hormones, thereby contributing to the clinical course of stress-associated periodontal diseases. [source] Tannerella forsythia infection-induced calvarial bone and soft tissue transcriptional profilesMOLECULAR ORAL MICROBIOLOGY, Issue 5 2010V. Bakthavatchalu Summary Tannerella forsythia is associated with subgingival biofilms in adult periodontitis, although the molecular mechanisms contributing to chronic inflammation and loss of periodontal bone remain unclear. We examined changes in the host transcriptional profiles during a T. forsythia infection using a murine calvarial model of inflammation and bone resorption. Tannerella forsythia was injected into the subcutaneous soft tissue over calvariae of BALB/c mice for 3 days, after which the soft tissues and calvarial bones were excised. RNA was isolated and Murine GeneChip® (Affymetrix, Santa Clara, CA) array analysis of transcript profiles showed that 3226 genes were differentially expressed in the infected soft tissues (P < 0.05) and 2586 genes were differentially transcribed in calvarial bones after infection. Quantitative real-time reverse transcription-polymerase chain reaction analysis of transcription levels of selected genes corresponded well with the microarray results. Biological pathways significantly impacted by T. forsythia infection in calvarial bone and soft tissue included leukocyte transendothelial migration, cell adhesion molecules (immune system), extracellular matrix,receptor interaction, adherens junction, and antigen processing and presentation. Histologic examination revealed intense inflammation and increased osteoclasts in calvariae compared with controls. In conclusion, localized T. forsythia infection differentially induces transcription of a broad array of host genes, and the profiles differ between inflamed soft tissues and calvarial bone. [source] Molecular characterization of Treponema denticola infection-induced bone and soft tissue transcriptional profilesMOLECULAR ORAL MICROBIOLOGY, Issue 4 2010V. Bakthavatchalu Summary Treponema denticola is associated with subgingival biofilms in adult periodontitis and with acute necrotizing ulcerative gingivitis. However, the molecular mechanisms by which T. denticola impacts periodontal inflammation and alveolar bone resorption remain unclear. Here, we examined changes in the host transcriptional profiles during a T. denticola infection using a murine calvarial model of inflammation and bone resorption. T. denticola was injected into the subcutaneous soft tissue over the calvaria of BALB/c mice for 3 days, after which the soft tissues and the calvarial bones were excised. RNA was isolated and analysed for transcript profiling using Murine GeneChip® arrays. Following T. denticola infection, 2905 and 1234 genes in the infected calvarial bones and soft tissues, respectively, were differentially expressed (P , 0.05). Biological pathways significantly impacted by T. denticola infection in calvarial bone and calvarial tissue included leukocyte transendothelial migration, cell adhesion (immune system) molecules, cell cycle, extracellular matrix,receptor interaction, focal adhesion, B-cell receptor signaling and transforming growth factor-, signaling pathways resulting in proinflammatory, chemotactic effects, and T-cell stimulation. In conclusion, localized T. denticola infection differentially induces transcription of a broad array of host genes, the profiles of which differed between inflamed calvarial bone and soft tissues. [source] Perpetuation of subgingival biofilms in an in vitro modelMOLECULAR ORAL MICROBIOLOGY, Issue 1 2010L.M. Shaddox Summary This study evaluated the reproducibility of in-vitro -grown biofilms, initiated with subgingival plaque from patients with periodontal disease, and continued through several cycles by re-inoculating new biofilms from previously grown biofilms. Subgingival plaque samples from bleeding pockets along with saliva samples were collected from three patients with chronic periodontitis and perpetuated through seven cycles. Calcium hydroxyapatite disks were coated with sterilized saliva inoculated with dispersed subgingival plaque. The biofilms were grown anaerobically at 37°C for 10 days, and at specific intervals total viable bacteria were enumerated and the species present were analysed by DNA,DNA checkerboard hybridization. All cycles of biofilm growth occurred at similar rates and reached steady-state at day 7. No statistically or microbially significant differences were found for viable counts or species present, at the same period of maturation, among the different cycles. This study demonstrated that growth of certain target subgingival periodontal species in this biofilm model was reproducible and could be perpetuated in vitro through several cycles. The model could be useful in future studies to characterize different periodontopathogenic properties and biofilm interactions, especially in recolonization studies. [source] | ||||||||||