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Trypticase Soy Agar (trypticase + soy_agar)
Selected AbstractsAntibiotic resistance profile of the subgingival microbiota following systemic or local tetracycline therapyJOURNAL OF CLINICAL PERIODONTOLOGY, Issue 6 2004Rosa Maria J. Rodrigues Abstract Background: Tetracyclines have been extensively used as adjunctives to conventional periodontal therapy. Emergence of resistant strains, however, has been reported. This study evaluated longitudinally the tetracycline resistance patterns of the subgingival microbiota of periodontitis subjects treated with systemic or local tetracycline therapy+scaling and root planing (SRP). Methods: Thirty chronic periodontitis patients were randomly assigned to three groups: SRP+500 mg of systemic tetracycline twice/day for 14 days; SRP alone and SRP+tetracycline fibers (ActsiteŽ) at four selected sites for 10 days. Subgingival plaque samples were obtained from four sites with probing pocket depths (PPD)6 mm in each patient at baseline, 1 week, 3, 6 and 12 months post-therapy. Samples were dispersed and diluted in pre-reduced anaerobically sterilized Ringer's solution, plated on Trypticase Soy Agar (TSA)+5% blood with or without 4 ,g/ml of tetracycline and incubated anaerobically for 10 days. The percentage of resistant microorganisms were determined and the isolates identified by DNA probes and the checkerboard method. Significance of differences among and within groups over time was sought using the Kruskal,Wallis and Friedman tests, respectively. Results: The percentage of resistant microorganisms increased significantly at 1 week in the tetracycline groups, but dropped to baseline levels over time. The SRP+ActsiteŽ group presented the lowest proportions of resistant species at 6 and 12 months. No significant changes were observed in the SRP group. The predominant tetracycline-resistant species included Streptococcus spp., Veillonela parvula, Peptostreptococcus micros, Prevotella intermedia, Gemella morbillorum and Actinobacillus actinomycetemcomitans (Aa). A high percentage of sites with resistant Aa, Porphyromonas gingivalis and Tanerella forsythensis was observed in all groups at baseline. However, T. forsythensis was not detected in any group and P. gingivalis was not present in the SRP+ActsiteŽ group at 1 year post-therapy. Aa was still frequently detected in all groups after therapy. However, the greatest reduction was observed in the SRP+ActsiteŽ group. Conclusion: Local or systemically administered tetracycline results in transitory selection of subgingival species intrinsically resistant to this drug. Although the percentage of sites harboring periodontal pathogens resistant to tetracycline were quite elevated in this population, both therapies were effective in reducing their prevalence over time. [source] A novel approach to controlling bacterial contamination on toothbrushes: chlorhexidine coatingINTERNATIONAL JOURNAL OF DENTAL HYGIENE, Issue 4 2009LA Turner Abstract:, Purpose:, This project was conducted to determine the effectiveness of chlorhexidine-coated toothbrush filaments in reducing quantities of bacteria. Materials and methods:, An Institutional Review Board (IRB)-approved, two-group, double-blind, randomized, post-test only study was conducted. Sixty-four individuals utilized control and experimental toothbrushes, for 30 days. At the end of the study toothbrushes were returned and transported to the laboratory for analysis. Microorganisms were detached from the filaments by sonification and vortexing then plated on Mitis Salivarius (MS) (selective) and trypticase soy agar (TSA) 5% Sheep Blood (non-selective) media. Inoculated plates were incubated aerobically for 24 h at 37°C. After incubation, bacterial colony-forming units (CFU) were determined. Data were analysed using Wilcoxon and Kruskal,Wallis tests. Results:, Fifty-nine toothbrushes were returned for analysis; experimental (n = 31) and control (n = 28). Data from TSA media revealed a mean CFU for the control group of 5.41 × 105 compared with 6.28 × 105 for the experimental group. Data from MS agar resulted in a mean CFU for the control group of 4.32 × 105 compared with 4.20 × 105 for the experimental group. Conclusion:, Results revealed no statistically significant difference in the quantity of bacteria surviving on toothbrush filaments between control and experimental groups, on both selective and non-selective media, after 30 days. [source] Efficacy of sodium hypochlorite and peracetic acid in sanitizing green coconutsLETTERS IN APPLIED MICROBIOLOGY, Issue 3 2009E.H.M. Walter Abstract Aims:, To evaluate the efficacy of sanitizing green coconuts (Cocos nucifera L.) through the treatment applied by juice industries using sodium hypochlorite and peracetic acid. Methods and Results:, The surface of the fruits was inoculated with a mixture of five Listeria monocytogenes strains. The treatments consisted in immersing the fruits for 2 min at room temperature in sodium hypochlorite solution containing 200 mg l,1 residual chlorine at pH 6ˇ5, and 80 mg l,1 solution of peracetic acid or sterile water. Bacterial populations were quantified by culturing on trypticase soy agar supplemented with yeast extract and Oxford selective culture medium; however, recovery was higher on the nonselective medium. Immersion in water produced a reduction in the L. monocytogenes population of 1ˇ7 log10 CFU per fruit, while immersion in sodium hypochlorite and peracetic acid solutions resulted in population reductions of 2ˇ7 and 4ˇ7 log10 CFU per fruit respectively. Conclusions:, The treatments studied are efficient to green coconuts. Significance and Impact of the Study:, Sanitation of green coconut is one of the most important control measures to prevent the contamination of coconut water. This article provides information that shows the adequacy of sanitizing treatments applied by the juice industries. [source] Microbial flora of root canal,treated teeth associated with asymptomatic periapical radiolucent lesionsMOLECULAR ORAL MICROBIOLOGY, Issue 6 2001G. S. P. Cheung This study aimed to investigate the composition of microflora in endodontically treated teeth associated with asymptomatic periapical lesions in southern Chinese patients. Twenty-four teeth which had received nonsurgical root canal treatment more than 4 years previously, and which presents an acceptable coronal restoration with a periapical radiolucent area, were re-treated nonsurgically. Bacteriological samples were obtained after removal of the old root canal filling. The samples were inoculated on enriched trypticase soy agar and four selective media for incubation at 37°C in both a carbon dioxide-enriched atmosphere and anaerobically. Eighteen teeth that had received gutta-percha root canal fillings were grouped for analysis, 12 (66.7%) of which contained cultivable microorganisms. The total colony forming units per ml of transport medium ranged from 0 to 2.3×105. The number of bacterial genera recovered ranged between 0 and 6, with facultative gram-positive cocci being the most prevalent group of bacteria isolated. Facultative anaerobic bacteria were present in all, whereas strict anaerobic bacteria were found in 3 out of the 12 teeth with positive growth. The size of the periapical rarefaction did not show any relationship with the quantity of microorganisms recovered. Coagulase-negative staphylococci, streptococci and Pseudomonas aeruginosa were most frequently isolated in this group of patients. The possible origin of these organisms is discussed. [source] | ||||||||||