[Show abstract][Hide abstract] ABSTRACT: To evaluate the in vitro growth inhibition of Candida albicans, the rate of chlorhexidine release and shore A hardness from resins-based denture soft lining materials modified by chlorhexidine diacetate (CDA) or chlorhexidine hydrochloride (CHC) incorporation.
Dental materials: official publication of the Academy of Dental Materials 06/2014; · 2.88 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Erratum to: Pediatr NephrolDOI:10.1007/s00467-013-2437-4DOI:10.1007/s00467-013-2436-5Erratum to: Lower dental caries prevalence associated to chronic kidney disease: a systematic review10.1007/s00467-013-2437-4Erratum to: Chronic kidney disease: a new look at pathogenetic mechanisms and treatment options10.1007/s00467-013-2436-5These articles were paginated incorrectly in Vol. 29, No. 5: the correct page numbers for article 467–2437 are 771–778 and for the article 467–2436, 779–792.The publisher apologizes for any inconvenience caused.
[Show abstract][Hide abstract] ABSTRACT: Candidiasis is a major opportunistic fungal infection in humans, and its incidence has increased steadily over the last two decades. Candida albicans has a large arsenal of virulence attributes such as dimorphism and biofilm formation. The microbial resistance and the side effects of traditional therapy have boosted efforts to improve the therapeutic arsenal with a newer range of drugs. In this study, a novel nerolidol rich essential oil derived from Piper claussenianum (Miq.) C. DC., Piperaceae, was tested on the growth, morphodifferentiation and biofilm formation of C. albicans. Inflorescence and leaf oils revealed a minimal inhibitory concentration of 0.9 and 0.2%, respectively. Leaf oil managed to downregulate the yeast to hyphal transition by 81%, and biofilm formation by about 30 and 50% after a 24 and 48 hour, respectively. These results demonstrate that this compound could be a promising agent, reinforcing the arsenal of therapeutic alternatives for candidiasis management.
Journal of Medical Microbiology 02/2014; · 2.30 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Objectives
To evaluate the in vitro growth inhibition of Candida albicans, the rate of chlorhexidine release and shore A hardness from resins-based denture soft lining materials modified by chlorhexidine diacetate (CDA) or chlorhexidine hydrochloride (CHC) incorporation.
Resin discs were prepared from soft denture liners based on poly (methyl methacrylate) (PMMA) or poly (ethyl methacrylate) (PEMA) containing 0.5, 1.0 and 2.0 wt.% of CDA or CHC. For antifungal activity resin discs were placed on agar plates inoculated with C. albicans, after 48 h at 37 °C the diameters of inhibition zones were measured. For the chlorhexidine release, discs were immersed into distilled water at 37 °C, and spectral measurements were made after 48 h. Shore A hardness was evaluated at the baseline, 2 and 7 days, using 6 mm thick rectangular specimens also immersed into distilled water at 37 °C. Data were statistically processed by SigmaStat software using ANOVA and all pairwise multiple comparison procedures was done using the Holm–Sidak method, with α = 0.05 (p < 0.001).
CDA added to PMMA soft liner and PEMA soft liner had a dose-related inhibitory effect on C. albicans and on chlorhexidine release rate (p < 0.001). The PMMA and PEMA hardness increased statistically by time but not for the different CDA concentrations. CHC had no inhibitory effect on C. albicans.
Chlorhexidine diacetate released from resins-based soft lining materials can be convenient to reduce the biofilm development on the material surface and treat denture stomatitis, without depending on patient compliance.
[Show abstract][Hide abstract] ABSTRACT: Objectives
the aim of this study was to evaluate the effect of SLPI on the growth and biological processes of Candida albicans.
Two C. albicans strains were used in this study, a clinical isolate resistant to fluconazole (PRI) and a reference strain ATCC 24433. The minimal inhibitory concentration (MIC) was determined according to the CLSI methodology. The influence of SLPI on secreted serine proteinase activities (SSP) was measured by the cleavage of specific substrate, and surface hydrophobicity was determined by the aqueous-hydrocarbon biphasic separation method. Flow cytometry was performed to investigate receptors for SLPI and variations in the cell wall mannoprotein expression. Interaction between yeast and epithelium was assessed using the MA-104 cells lineage. Ultrastructure was analyzed by transmission electron microscopy (TEM).
MIC values were calculated as 18 and 18.9 μM for the PRI and ATCC 24433, respectively. SSP activity was reduced by 48.8% by 18 μM of SLPI and cell surface hydrophobicity increased by 11.1%. Flow cytometry suggest the existence of SLPI binding sites on the surface of the yeast. Results showed a reduction in the expression of mannoproteins in 20.8% by the cells treated with 80 μM of SLPI, and 18 μM reduced the adhesion of yeasts to mammalian cells in 60.1%. TEM revealed ultrastructural changes in cells treated with 80 μM of SLPI, such as the presence of membrane-like structures within the cytoplasm.
SLPI exerts a significant influence on C. albicans viability and biological processes. Considering its constitutive and physiologic features, SLPI may become a promising tool for the development of new methodologies for the treatment and control of candidiasis.
[Show abstract][Hide abstract] ABSTRACT: BACKGROUND: The aim of this systematic review was to determine whether there is any evidence in the literature referring to a lower prevalence of dental caries in children and adolescents with chronic kidney disease (CKD) compared to healthy individuals. METHODS: A search of the PubMed Medline, Ovid Medline and Cochrane Library databases was performed using the MeSH terms "dental caries" and "chronic renal failure". To be eligible for entry in our study, controlled observational studies had to present a decayed, missing and filled index for primary teeth (dmft) and/or for permanent teeth (DMFT) in children and adolescents with CKD. RESULTS: After evaluation of title, keywords and abstracts of the articles selected, six articles met the inclusion criteria. Three of these six articles included studies which showed susceptibility to bias and possible confounding factors. A subsequent assessment of the six studies revealed that the mean caries indices in both primary (dmf) and permanent (DMF) teeth were lower in the children and adolescents with CKD compared with healthy individuals. CONCLUSION: Data in the literature weakly support a lower prevalence of caries in children and adolescents with CKD than in their healthy counterparts. There is still a lack of well-designed studies that provide better scientific evidence in support of this conclusion.
[Show abstract][Hide abstract] ABSTRACT: Objective: Lactoferrin (LAC) is an important protein for the system innate host defense by preventing infections like oral candidiasis common in HIV-infected children. The objective was to compare the salivary lactoferrin (LAC) levels with the Candida spp. colonization and medical records in HIV+ children.
Method: Whole stimulated saliva was collected from 40 HIV-infected children (10.8 ± 2.6 years old) followed by assessment of orofacial manifestation. The salivary samples were cultured and the colonies were counted. After which they were identified by sugar assimilation and fermentation (API 20C, Biomrieux, France). The Human Lactoferrin ELISA kit (Bethyl, USA) was used to measure the salivary lactoferrin levels. All data regarding personal information of the patients, medical history and recent laboratorial exams (CD4% and viral load) and the use of antiretroviral therapy (HAART) were collected from their medical records. Data was analyzed using Chi-square and Mann–Whitney test.
Result: The mean LAC levels was 6.5 ± 1.0 µg/ml. No differences were observed in salivary LAC levels regarding orofacial manifestation (p>0.05), immunosuppression (p=0.078), viral load (p>0.05), antiretroviral therapy (p=0.1) and Candida spp. colonization (p>0.05). However, a statistically significant difference was evident with dentition type which the lowest levels was observed in deciduous dentition (5.55 ± 1.75 µg/ml; p=0.04).
Conclusion: The present data suggests that in our subjects, the salivary lactoferrin levels are not associated with medical condition in HIV children infection as well the oral Candida colonization.
IADR/AADR/CADR General Session and Exhibition 2013; 03/2013
[Show abstract][Hide abstract] ABSTRACT: OBJECTIVE: The aim of this study was to analyze the effect of C. albicans on enamel microhardness in vitro. STUDY DESIGN: Candida albicans was isolated from the oral mucosa (M) and dentin carious lesion (D) of an HIV+ child. Three groups of 12 enamel blocks each were placed in Petri plates (yeast carbon base agar/1% bovine serum albumin): G1, exposed to biofilm formed by C. albicans from M; G2, exposed to biofilm formed by C. albicans from D; G3, no biofilm. Three enamel blocks from each group were removed on days 3, 5, 8, and 10 after biofilm formation to measure the cross-sectional Knoop microhardness (CSMH) of the enamel areas, exposed and not exposed to biofilm. RESULTS: CSMH decreased in G1 and G2: in G1 on day 5, and in G2 on day 3 (analysis of variance: P < .05; Mann-Whitney test: P < .05), with a similar mean percentage reduction for both groups. CONCLUSIONS: Candida albicans can reduce enamel microhardness in vitro.
Oral surgery, oral medicine, oral pathology and oral radiology. 02/2013;
[Show abstract][Hide abstract] ABSTRACT: Four actinomycete strains previously isolated from Brazilian soils were tested for their antimicrobial activity against Bacillus pumilus LF-4 and Desulfovibrio alaskensis NCIMB 13491, bacteria that are well known to be involved in biofilm formation and biocorrosion. Strain 235, belonging to the species Streptomyces lunalinharesii, inhibited the growth of both bacteria. The antimicrobial activity was seen over a wide range of pH, and after treatment with several chemicals and heat but not with proteinase K and trypsin. The antimicrobial substances present in the concentrated supernatant from growth media were partially characterized by SDS-PAGE and extracellular polypeptides were seen. Bands in the size range of 12 to 14.4 kDa caused antimicrobial activity. Transmission electron microscopy of D. alaskensis cells treated with the concentrated supernatant containing the antimicrobial substances revealed the formation of prominent bubbles, the spherical double-layered structures on the cell membrane, and the periplasmic space completely filled with electron-dense material. This is the first report on the production of antimicrobial substances by actinomycetes against bacteria involved in biocorrosion processes, and these findings may be of great relevance as an alternative source of biocides to those currently employed in the petroleum industry.
BioMed research international. 01/2013; 2013:309769.
[Show abstract][Hide abstract] ABSTRACT: Control of plant pathogen Sclerotinia sclerotiorum is an ongoing challenge because of its wide host range and the persistence of its sclerotia in soil. Fungicides are the most commonly used method to control this fungus but these can have ecotoxicity impacts. Chitinolytic Streptomyces strains isolated from Brazilian tropical soils were capable of inhibiting S. sclerotiorum growth in vitro, offering new possibilities for integrated pest management and biocontrol, with a new approach to dealing with an old problem. Strain Streptomyces sp. 80 was capable of irreversibly inhibiting fungal growth. Compared to other strains, its crude enzymes had the highest chitinolytic levels when measured at 25°C and strongly inhibited sclerotia from S. sclerotiorum. It produced four hydrolytic enzymes involved in fungal cell wall degradation when cultured in presence of the fungal mycelium. The best production, obtained after three days, was 0.75 U/ml for exochitinase, 0.9 U/ml for endochitinase, 0.16 U/ml for glucanase, and 1.78 U/ml for peptidase. Zymogram analysis confirmed two hydrolytic bands of chitinolytic activity with apparent molecular masses of 45.8 and 206.8 kDa. One glucanase activity with an apparent molecular mass of 55 kDa was also recorded, as well as seven bands of peptidase activity with apparent molecular masses ranging from 15.5 to 108.4 kDa. Differential interference contrast microscopy also showed alterations of hyphal morphology after co-culture. Streptomyces sp. 80 seems to be promising as a biocontrol agent against S. sclerotiorum, contributing to the development of new methods for controlling plant diseases and reducing the negative impact of using fungicides.
The Journal of Microbiology 10/2012; 50(5):798-806. · 1.28 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: The ability of 2 different approaches to supplement the antimicrobial effects of chemomechanical debridement in infected root canals was compared in vivo.
Samples from necrotic root canals of teeth with apical periodontitis were taken at the baseline (S1), after preparation with rotary nickel-titanium BioRaCe instruments and 2.5% NaOCl irrigation (S2), and then after either passive ultrasonic irrigation (PUI) for activation of NaOCl (n = 13) or a final rinse with 2% chlorhexidine (CHX) (n = 14) (S3). The incidence of positive culture for bacteria and fungi as well as positive broad-range polymerase chain reaction (PCR) results for bacteria, fungi, and archaea was determined.
All S1 samples were positive for bacteria in all methods. Fungi were not detected, and archaea occurred in only one S1 sample. Treatment procedures were significantly effective in reducing the incidence of positive culture and PCR results. Although both supplementary approaches reduced the incidence of positive bacteriologic results when compared with postinstrumentation samples, reduction was not statistically significant (P > .05). There was no significant difference for intergroup comparisons either (P > .05).
Although supplementary disinfection with either PUI or a final rinse with CHX can reduce the number of cases with positive culture and PCR results for bacteria, many cases still remain with detectable bacteria in the main root canal. Research on alternative or supplementary antimicrobial methods or substances should be encouraged.
Journal of endodontics 09/2012; 38(9):1202-6. · 2.95 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Objective: The aim of this study was to evaluate the kinetics of chlorhexidine release in a long term analysis, as well as the cellular cytotoxicity and the in vitro biofilm inhibition of Candida albicans of resins-based denture soft lining materials containing chlorhexidine diacetate (CDA).
Method: Resin discs were prepared from Coesoft® and Trusoft®, containing 0.5, 1.0 and 2.0 wt.% of CDA. In order to evaluate the chlorhexidine release, each disc was immersed in 1 mL of distilled water at 37°C, and spectral measurements were made to follow change in optical densities of storage solution, after each 48 hours during, 40 days, changing the storage solution. To evaluate the cytotoxicity in fibroblastic L929 cells, the neutral red dye-uptake technique was used, until the 28th day. For antifungal activity on C. albicans (ATCC 10231), the biofilm was allowed to develop over the resin discs surface and the bioactivity of the biofilms was measured by the MTT reduction assay after each 48 hours, during 22 days. Data were statistically processed by SigmaStat software using ANOVA and all pairwise multiple comparison procedures was done using the Holm-Sidak method, with overall significance level=0.05. (p<0.001).
Result: The CDA added to both resins-based denture soft lining materials had a dose-related chlorhexidine release rate and inhibitory effect on the growth of C. albicans (p< 0.001). It was observed slight to moderate additional cytotoxic effect from CDA added incorporated discs for both tested materials for the first analyzed days.
Conclusion: Chlorhexidine had a dose-related inhibitory effect on the growth of C. albicans and was also released from both resins-based denture soft lining materials. The cytotoxcity probably do not exceed the clinically tolerable level.
[Show abstract][Hide abstract] ABSTRACT: Objective: This study aimed to compare in vitro the efficacy of five different intracanal medicaments (IM) for primary human single-rooted teeth, against a biofilm composed by Candida albicans and Enterococcus faecalis.
Method: Thirty primary anterior teeth avulsed and/or indicated for extraction were collected and were standardized till K files 45 sizes. During instrumentation, the canal was irrigated with 5 ml of 0.9% saline solution (SS) between each endodontic file exchange. The samples were sterilized individually by etilenic oxide and contaminated with C. albicans and E. faecalis to form the biofilm. The teeth were divided randomly into six groups: control group (no medicament), Camphorated paramonochlorophenol (CMCP), Calen® paste (CH), Calen-CMCP® paste (CH-CMCP), CleanForm® Clorhexidine 2% Gel (CHX), and Guedes-Pinto® paste (iodoform, Rifocort® and camphorated paramonochlorophenol in equal parts) (GP). The following collections were made with sterilized paper cones to measurement the biofilm formation before the IM insert - initial quantification; after 7 days with the IM - final quantification; and 7 days after the removed the IM - residual quantification. The IM were removed by irrigation of 10 ml of SS, under constant aspiration. The data of colonies-forming unit (CFU) were submitted to the analysis of variance (ANOVA, a parametric Tukey test) with a significance level of 2.5%. It was also submitted to the analyses paired (X2 test).
Result: Except for CMCP, all drugs reduced the C. albicans CFU number (CH: p = 0.022; CH-CMCP: p = 0,002; CHX: p = 0.003; GP: p = 0.000). But, only CHX (p = 0.000) and GP (p = 0.007) were effective against E. faecalis. In the residual activity, no statistical significance was presented for microorganism’s reduction.
Conclusion: In vitro CHX and GP were more effective to reduce C. albicans and E. faecalis biofilm in primary human single-rooted teeth.
[Show abstract][Hide abstract] ABSTRACT: Objective: The choice of the material to protect the screw is an important issue for implant-supported prostheses, however the most common materials suggested for this are cotton, gutta-percha and polytetrafluoroethylene (PTFE) tape, based on their ease of insertion and/or removal. The aim of this study is evaluate these materials based on the total amount of in vitro Candida albicans biofilm formation over their surface in order to establish another parameter that contributes to the choice of which material should be used clinically.
Method: Titanium UCLA abutments with their respectively screw and analogs were used and filled with cotton, gutta-percha or PTFE. Specimens were separately immersed into brain heart infusion medium with standardized C. albicans suspension (3x106 cells/ml - ATCC 10231) and stored aerobically at 37°C with gentle agitation. A new yeast suspension was added after each 48 hours. Following 15 days the materials were carefully removed from the UCLA abutments and the biofilm quantification was performed by MTT reduction assay using a microplate reader at 490 nm. All experiments were carried out in triplicate. The values were expressed in optical density. Data were statistically processed by SigmaStat software using ANOVA and all pairwise multiple comparison procedures was done using the Holm-Sidak method, with overall significance level=0.05. (p<0.001).
Result: Significant difference was observed between the cotton and gutta-percha groups (p<0.05) and cotton and PTFE groups (p<0.05), however no significant difference were observed between gutta-percha and PTFE (p>0.05), although PTFE presented higher values.
Conclusion: Gutta-percha and PTFE tape presented lower biofilm formation if compared to cotton, being more suitable for clinical use, with no statistically significant difference between then.
[Show abstract][Hide abstract] ABSTRACT: Objective: Chronic kidney failure (CKF) is a progressive decline in renal function. Changes associated with the disease and its treatment can affect the oral cavity. This study aims to evaluate the prevalence of Candida spp. in children and adolescents with CKF undergoing hemodialysis, and its relation with hemodialysis duration.
Method: For the cross-sectional study, a group of Brazilian children and adolescents were recruited from 3 Pediatric Nephrology Services. After the approval of the Local Ethics Committee, demographics data and treatment duration were collected. For isolation of Candida species, oral samples were obtained from the dorsum of the tongue with a sterile swab which was put into a sterile test tube containing 1mL of sterile saline solution (0.85% NaCl). Within 2 hours the swabs were transported on ice to the laboratory. The samples were inoculated into CHROMagar Candida® (CHROMagar Microbiology, Paris, France) and incubated at 37°C (48 to 72 hours). The identification of Candida spp. was characterized by substrate assimilation profiles using the API 20C system (bioMrieux Vitek, Halzelowood, MO, USA). The duration of hemodialysis was categorized as ≤ 1 or > 1 year. Chi-square test was used for statistics analysis.
Result: A total of 51 patients were studied, 26 (51%) males and 25 (49%) females, with a mean age of 12.9 (SD 3.44). Frequency of Candida spp. was 37.3%. The majority of isolates were C. parapsilosis (36.8%) Other species encountered were C. guillhermondii (15.8%) and C. albicans (10.5%). No statistical significant differences were found related to the duration of the therapy and the frequency of isolates (p>0.05).
Conclusion: The results showed that the oral cavity of 37.3% of the children and adolescents with CKF undergoing hemodialysis were colonized by Candida species, but its presence was not related to the duration of hemodialysis.
[Show abstract][Hide abstract] ABSTRACT: The Control of plant pathogen Sclerotinia sclerotiorum is an on-going challenge because of its wide host range and the per-sistence of its sclerotia in soil. Fungicides are the most com-monly used method to control this fungus but these can have ecotoxicity impacts. Chitinolytic Streptomyces strains isolated from Brazilian tropical soils were capable of inhibit-ing S. sclerotiorum growth in vitro, offering new possibilities for integrated pest management and biocontrol, with a new approach to dealing with an old problem. Strain Streptomyces sp. 80 was capable of irreversibly inhibiting fungal growth. Compared to other strains, its crude enzymes had the high-est chitinolytic levels when measured at 25°C and strongly inhibited sclerotia from S. sclerotiorum. It produced four hydrolytic enzymes involved in fungal cell wall degradation when cultured in presence of the fungal mycelium. The best production, obtained after three days, was 0.75 U/ml for exochitinase, 0.9 U/ml for endochitinase, 0.16 U/ml for glucanase, and 1.78 U/ml for peptidase. Zymogram analysis confirmed two hydrolytic bands of chitinolytic activity with apparent molecular masses of 45.8 and 206.8 kDa. One glu-canase activity with an apparent molecular mass of 55 kDa was also recorded, as well as seven bands of peptidase activity with apparent molecular masses ranging from 15.5 to 108.4 kDa. Differential interference contrast microscopy also showed alterations of hyphal morphology after co-culture. Strepto-myces sp. 80 seems to be promising as a biocontrol agent against S. sclerotiorum, contributing to the development of new methods for controlling plant diseases and reducing the negative impact of using fungicides.
The Journal of Microbiology 06/2012; 50:798-806. · 1.28 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: The aim of this study was to compare type I collagen degradation by Candida albicans isolated from oral mucosa (M) and cavitated active dentinal caries (CAD) of HIV-infected children.
To verify the proteolytic activity, the specimens were cultivated in brain-heart infusion medium and the supernatants were incubated in the presence or absence of type I collagen at 37°C for 12 hours and analyzed using 10% sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Intensity of the bands on the gels was assessed by densitometric analysis using a scanner and images analyzed with software from Kodak Digital Science EDAS 120.
Supernatants of all the C. albicans degraded type I collagen: that from M, on average, by 38.3% (SD 21.67) and that from CAD by 54% (SD 25.94; Wilcoxon test: P < .05). Predisposing factors had no association with the percentage of type I collagen degradation (Mann-Whitney test: P > .05).
Candida albicans from different sites of the oral cavity of HIV-infected children has proteolytic activity for type I collagen.
[Show abstract][Hide abstract] ABSTRACT: Leishmaniasis and trypanosomiasis are two neglected and potentially lethal diseases that affect mostly the poor and marginal populations of developing countries around the world and consequently have an important impact on public health. Clinical manifestations such as cutaneous, mucocutaneous, and visceral disorders are the most frequent forms of leishmaniasis, a group of diseases caused by several Leishmania spp. American trypanosomiasis, or Chagas disease, is caused by Trypanosoma cruzi, a parasite that causes progressive damage to different organs, particularly the heart, esophagus, and lower intestine. African trypanosomiasis, or sleeping sickness, is caused by Trypanosoma brucei and is characterized by first presenting as an acute form that affects blood clotting and then becoming a chronic meningoencephalitis. The limited number, low efficacy, and side effects of conventional anti-leishmania and anti-trypanosomal drugs and the resistance developed by parasites are the major factors responsible for the growth in mortality rates. Recent research focused on plants has shown an ingenious way to obtain a solid and potentially rich source of drug candidates against various infectious diseases. Bioactive phytocompounds present in the crude extracts and essential oils of medicinal plants are components of an important strategy linked to the discovery of new medicines. These compounds have proven to be a good source of therapeutic agents for the treatment of leishmaniasis and trypanosomiasis. This work highlights some chemotherapeutic agents while emphasizing the importance of plants as a source of new and powerful drugs against these widespread diseases.
Frontiers in Microbiology 01/2012; 3:283. · 3.90 Impact Factor