80 research outputs found
Exopolysaccharide Matrix Of Developed Candida Albicans Biofilms After Exposure To Antifungal Agents
No full textThis study aimed to evaluate the effects of fluconazole or nystatin exposure on developed Candida albicans biofilms regarding their exopolysaccharide matrix. The minimal inhibitory concentration (MIC) against fluconazole or nystatin was determined for C. albicans reference strain (ATCC 90028). Poly(methlymethacrylate) resin (PMMA) specimens were fabricated according to the manufacturer's instructions and had their surface roughness measured. Biofilms were developed on specimens surfaces for 48 h and after that were exposed during 24 h to fluconazole or nystatin prepared in a medium at MIC, 10 x MIC or 100 x MIC. Metabolic activity was evaluated using an XTT assay. Production of soluble and insoluble exopolysaccharide and intracellular polysaccharides was evaluated by the phenol-sulfuric method. Confocal laser scanning microscope was used to evaluate biofilm architecture and percentage of dead/live cells. Data were analyzed statistically by ANOVA and Tukey's test at 5% significance level. The presence of fluconazole or nystatin at concentrations higher than MIC results in a great reduction of metabolic activity (p0.05). The exposure to nystatin also did not alter the exopolysaccharide matrix at all the tested concentrations (p>0.05). Biofilm architecture was not affected by either of the antifungal agents (p>0.05). Nystatin promoted higher proportion of dead cells (p<0.05). It may be concluded that fluconazole and nystatin above the MIC concentration reduced the metabolic activity of C. albicans biofilms; however, they were not able to alter the exopolysaccharide matrix and biofilm architecture.236716722Gendreau, L., Loewy, Z.G., Epidemiology and etiology of denture stomatitis (2011) J Prosthodont, 20, pp. 251-260Tobudic, S., Kratzer, C., Lassnigg, A., Presterl, E., Antifungal susceptibility of Candida albicans in biofilms (2012) Mycoses, 55, pp. 199-204Chaffin, W.L., Candida albicans cell wall proteins (2008) Microbiol Mol Biol Rev, 72, pp. 495-544Seneviratne, C.J., Jin, L., Samaranayake, L.P., Biofilm lifestyle of Candida: A mini review (2008) Oral Dis, 14, pp. 582-590Ramage, G., Rajendran, R., Sherry, L., Williams, C., Fungal biofilm resistance (2012) Int J Microbiol, , 528-521Chandra, J., Kuhn, D.M., Mukherjee, P.K., Hoyer, L.L., McCormick, T., Ghannoum, M.A., Biofilm formation by the fungal pathogen Candida albicans: Development, architecture, and drug resistance (2001) J Bacteriol, 183, pp. 5385-5394Konopka, K., Dorocka-Bobkowska, B., Gebremedhin, S., Duzgunes, N., Susceptibility of Candida biofilms to histatin 5 and fluconazole (2010) Antonie Van Leeuwenhoek, 97, pp. 413-417Baillie, G.S., Douglas, L.J., Effect of growth rate on resistance of Candida albicans biofilms to antifungal agents (1998) Antimicrob Agents Chemother, 42, pp. 1900-1905Niimi, M., Firth, N.A., Cannon, R.D., Antifungal drug resistance of oral fungi (2010) Odontology, 98, pp. 15-25Ramage, G., Mowat, E., Jones, B., Williams, C., Lopez-Ribot, J., Our current understanding of fungal biofilms (2009) Crit Rev Microbiol, 35, pp. 340-355Baillie, G.S., Douglas, L.J., Matrix polymers of Candida biofilms and their possible role in biofilm resistance to antifungal agents (2000) J Antimicrob Chemother, 46, pp. 397-403Seneviratne, C.J., Jin, L.J., Samaranayake, Y.H., Samaranayake, L.P., Cell density and cell aging as factors modulating antifungal resistance of Candida albicans biofilms (2008) Antimicrob Agents Chemother, 52, pp. 3259-3266da Silva, W.J., Seneviratne, J., Samaranayake, L.P., Del Bel Cury, A.A., Bioactivity and architecture of Candida albicans biofilms developed on poly (methyl methacrylate) resin surface (2010) J Biomed Mater Res B Appl Biomater, 94, pp. 149-156(2008) Reference Method For Broth Dilution Antifungal Susceptibility Testing of Yeasts, Approved Standard, , CLSI, CLSI Document M27-A3, Wayne, PA:CLSIda Silva, W.J., Seneviratne, J., Parahitiyawa, N., Rosa, E.A., Samaranayake, L.P., Del Bel Cury, A.A., Improvement of XTT assay performance for studies involving Candida albicans biofilms (2008) Braz Dent J, 19, pp. 364-369Tenuta, L.M., Ricomini, F.A.P., Del Bel Cury, A.A., Cury, J.A., Effect of sucrose on the selection of mutans streptococci and lactobacilli in dental biofilm formed in situ (2006) Caries Res, 40, pp. 546-549Dubois, M., Gilles, K., Hamilton, J.K., Rebers, P.A., Smith, F., A colorimetric method for the determination of sugars (1951) Nature, 28, p. 167. , 168Heydorn, A., Nielsen, A.T., Hentzer, M., Sternberg, C., Givskov, M., Ersboll, B.K., Quantification of biofilm structures by the novel computer program COMSTAT (2000) Microbiology, 146, pp. 2395-2407Force, R.W., Nahata, M.C., Salivary concentrations of ketoconazole and fluconazole: Implications for drug efficacy in oropharyngeal and esophageal candidiasis (1995) Ann Pharmacother, 29, pp. 10-15Gomes, P.N., da Silva, W.J., Pousa, C.C., Narvaes, E.A., Del Bel Cury, A.A., Bioactivity and cellular structure of Candida albicans and Candida glabrata biofilms grown in the presence of fluconazole (2011) Arch Oral Biol, 56, pp. 1274-1281Ellepola, A.N., Samaranayake, L.P., Oral candidal infections and antimycotics (2000) Crit Rev Oral Biol Med, 11, pp. 172-198Ellepola, A.N., Samaranayake, L.P., The postantifungal effect (PAFE) of antimycotics on oral C. albicans isolates and its impact on candidal adhesion (1998) Oral Dis, 4, pp. 260-267Nett, J.E., Sanchez, H., Cain, M.T., Andes, D.R., Genetic basis of Candida biofilm resistance due to drug-sequestering matrix glucan (2010) J Infect Dis, 202, pp. 171-175Mores, A.U., Souza, R.D., Cavalca, L., de Paula e Carvalho, A., Gursky, L.C., Rosa, R.T., Enhancement of secretory aspartyl protease production in biofilms of Candida albicans exposed to subinhibitory concentrations of fluconazole (2011) Mycoses, 54, pp. 195-201Goncalves, L.M., Del Bel Cury, A.A., Sartoratto, A., Garcia, R.V.L., Silva, W.J., Effects of undecylenic acid released from denture liner on Candida biofilms (2012) J Dent Res, 91, pp. 985-98
Levorotatory carbohydrates and xylitol subdue Streptococcus mutans and Candida albicans adhesion and biofilm formation
No full textDietary carbohydrates and polyols affect the microbial colonization of oral surfaces by modulating adhesion and biofilm formation. The aim of this study was to evaluate the influence of a select group of l-carbohydrates and polyols on either Streptococcus mutans or Candida albicans adhesion and biofilm formation in vitro. S. mutans or C. albicans suspensions were inoculated on polystyrene substrata in the presence of Tryptic soy broth containing 5% of the following compounds: d-glucose, d-mannose, l-glucose, l-mannose, d- and l-glucose (raceme), d- and l-mannose (raceme), l-glucose and l-mannose, sorbitol, mannitol, and xylitol. Microbial adhesion (2h) and biofilm formation (24h) were evaluated using MTT-test and Scanning Electron Microscopy (SEM). Xylitol and l-carbohydrates induced the lowest adhesion and biofilm formation in both the tested species, while sorbitol and mannitol did not promote C. albicans biofilm formation. Higher adhesion and biofilm formation was noted in both organisms in the presence of d-carbohydrates relative to their l-carbohydrate counterparts. These results elucidate, hitherto undescribed, interactions of the individually tested strains with l- and d-carbohydrates, and how they impact fungal and bacterial colonization. In translational terms, our data raise the possibility of using l-form of carbohydrates and xylitol for dietary control of oral plaque biofilms
Fungal species in endodontic infections : A systematic review and meta-analysis
No full textFungal infections are common on oral mucosae, but their role in other oral sites is ill defined. Over the last few decades, numerous studies have reported the presence of fungi, particularly Candida species in endodontic infections, albeit in relatively small numbers in comparison to its predominant anaerobic bacteriome. Here, we review the fungal biome of primary and secondary endodontic infections, with particular reference to the prevalence and behavior of Candida species. Meta-analysis of the available data from a total of 39 studies fitting the inclusion criteria, indicate the overall weighted mean prevalence (WMP) of fungal species in endodontic infections to be 9.11% (from a cumulative total of 2003 samples), with 9.0% in primary (n = 1341), and 9.3% in secondary infections (n = 662). Nevertheless, WMP for fungi in primary and secondary infections which were 6.3% and 7.5% for culture-based studies, increased to 12.5% and 16.0% in molecular studies, respectively. The most prevalent fungal species was Candida spp. The high heterogeneity in the reported fungal prevalence suggests the need for standardized sampling, and speciation methods. The advent of the new molecular biological analytical platforms, such as the next generation sequencing (NGS), and matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF), that enables identification and quantitation of a broad spectrum of hitherto unknown organisms in endodontic infections should radically alter our understanding of the endodontic mycobiome in the future. Candida spp. appear to be co-pathogens with bacteria in approximately one in ten patients with endodontic infections. Hence, clinicians should comprehend the importance and the role of fungi in endodontic infections and be cognizant of the need to eradicate both bacteria and fungi for successful therapy
Analysis of the secondary endodontic lesions focusing on the extraradicular microorganisms : an overview
No full textThe present study aimed at reviewing the literature on extraradicular infections of endodontically treated teeth, summarizing the main hypotheses on etiopathogenesis and describing the most suitable techniques to identify the composition of pathogenic extraradicular microorganisms. Medline database was searched using the keywords “Apical biofilm,” “extraradicular infection,” “secondary endodontic lesion,” “endodontic retreatment,” “biofilm” either alone or combined with AND. A further hand search was performed on the main endodontic journals. The most frequent bacterial species identified in different studies and with different techniques may vary considerably. Although the presence of some species of microorganisms seems to be determinant, the true origin of extraradicular infection is still undetermined. The literature analysis showed marked differences in methodology, materials, aims, and techniques adopted, which led to highly heterogeneous outcomes. The picture emerging from this review is that extraradicular infection is likely a multifactorial disease that requires further systematic investigation using standardized technique
Severe Acute Respiratory Syndrome (SARS): An interim information paper for dental health care workers
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Adhesion of oral Candida albicans isolates to denture acrylic following limited exposure to antifungal agents
No full textCandidal adherence to denture acrylic surfaces is implicated as the first step in the pathogenesis of Candida-associated denture stomatitis, the most prevalent form of oral candidosis in the West. This condition is treated by topically administered antifungal agents, mainly belonging to the polyenes and azoles. As the intraoral concentrations of antifungals fluctuate considerably due to the dynamics of the oral environment, the effect of short exposure to sublethal concentrations of antifungals on the adhesion of Candida albicans to denture acrylic surfaces was investigated. Seven oral C. albicans isolates were exposed to four-eight times minimum inhibitory concentrations (MIC) of five antifungal drugs, nystatin, amphotericin B, 5- fluorocytosine, ketoconazole and fluconazole, for 1 h. After removing the drug (by repeated washing) the adhesion of these isolates to acrylic strips was assessed by an in vitro adhesion assay. Exposure to antifungal agents significantly reduced the adherence of all seven C. albicans isolates to denture acrylic. The mean percentage reductions of adhesion after limited exposure to nystatin, amphotericin B, 5-fluorocytosine, ketoconazole and fluconazole were 86.48, 90.85, 66.72, 65.88 and 47.42%, respectively. These findings indicate that subtherapeutic doses of antifungals may modulate oral candidal colonization. Further, these results may have an important bearing on dosage regimens currently employed in treating oral candidosis.link_to_subscribed_fulltex
Factors affecting the adherence of Candida albicans to human buccal epithelial cells in human immunodeficiency virus infection
No full textAdherence to host surfaces is an essential prerequisite for colonization and infection. We compared the adherence of 15 oral isolates of Candida albicans harvested from human immunodeficiency virus (HIV)-infected individuals and 12 isolates from HIV-free individuals to buccal epithelial cells (BECs) from HIV-free individuals, and the adherence of a reference strain of C. albicans to BECs from HIV-infected as well as HIV-free individuals. C. albicans from HIV-infected individuals showed adherence values similar to those from HIV-free individuals. The clinical and laboratory parameters of the subjects from whom the Candida were isolated did not correlate with adherence. A reference strain of C. albicans (GDH 1957), however, adhered more readily to BECs from HIV-infected individuals than to cells from an HIV-free cohort. Several variables were found to be associated with the adherence of C. albicans to BECs from HIV-infected individuals: use of zidovudine, antibacterials and antiparasitics was associated with increased adhesion, while haemophilia, heterosexuality, bisexuality, increased age, decreased CD4 + count and use of folate were associated with a decreased candidal adhesion (all P < 0.05). Our data suggest that the quality of BECs including their receptivity to Candida may play an important part in increasing the oral yeast carriage in HIV infection.link_to_subscribed_fulltex
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