Dynamics of biofilm formation and the interaction between candida albicans and methicillin-susceptible (MSSA) and -resistant staphylococcus aureus (MRSA)

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

In vivo evaluation of photodynamic inactivation using Photodithazine (R) against Candida albicans

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Experimental Autoimmune Encephalomyelitis Development Is Aggravated by Candida albicans Infection

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Lactobacillus acidophilus ATCC 4356 inhibits biofilm formation by C. albicans and attenuates the experimental candidiasis in Galleria mellonella

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Evaluation of gene expression SAP5, LIP9, and PLB2 of candida albicans biofilms after photodynamic inactivation

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Inactivation of candida albicans by cold atmospheric pressure plasma jet

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Competitive interactions between C. albicans, C. glabrata and C. krusei during biofilm formation and development of experimental Candidiasis

In this study, we evaluated the interactions between Candida albicans, Candida krusei and Candida glabrata in mixed infections. Initially, these interactions were studied in biofilms formed in vitro. CFU/mL values of C. albicans were lower in mixed biofilms when compared to the single biofilms, verifying 77% and 89% of C. albicans reduction when this species was associated with C. glabrata and C. krusei, respectively. After that, we expanded this study for in vivo host models of experimental candidiasis. G. mellonella larvae were inoculated with monotypic and heterotypic Candida suspensions for analysis of survival rate and quantification of fungal cells in the haemolymph. In the groups with single infections, 100% of the larvae died within 18 h after infection with C. albicans. However, interaction groups achieved 100% mortality after 72 h of infection by C. albicans-C. glabrata and 96 h of infection by C. albicans-C. krusei. C. albicans CFU/mL values from larvae hemolymph were lower in the interacting groups compared with the monoespecies group after 12 h of infection. In addition, immunosuppressed mice were also inoculated with monotypic and heterotypic microbial suspensions to induce oral candidiasis. C. albicans CFU/mL values recovered from oral cavity of mice were higher in the group with single infection by C. albicans than the groups with mixed infections by C. albicans-C. glabrata and C. albicans-C. krusei. Moreover, the group with single infection by C. albicans had a higher degree of hyphae and epithelial changes in the tongue dorsum than the groups with mixed infections. We concluded that single infections by C. albicans were more harmful for animal models than mixed infections with non-albicans species, suggesting that C. albicans establish competitive interactions with C. krusei and C. glabrata during biofilm formation and development of experimental candidiasis.

Nanostructured lipid system as a strategy to improve the anti-Candida albicans activity of Astronium sp

The genus Astronium (Anacardiaceae) includes species, such as Astronium fraxinifolium, Astronium graveolens, and Astronium urundeuva, which possess anti-inflammatory, anti-ulcerogenic, healing, and antimicrobial properties. Nanostructured lipid systems are able to potentiate the action of plant extracts, reducing the required dose and side effects and improving antimicrobial activity. This work aims to evaluate a nanostructured lipid system that was developed as a strategy to improve the anti-Candida albicans activity of hydroethanolic extracts of stems and leaves from Astronium sp. The antifungal activity against C. albicans (ATCC 18804) was evaluated in vitro by a microdilution technique. In addition to the in vitro assays, the Astronium sp. that showed the best antifungal activity and selectivity index was submitted to an in vivo assay using a model of vulvovaginal candidiasis infection. In these assays, the extracts were either used alone or were incorporated into the nanostructured lipid system (comprising 10% oil phase, 10% surfactant, and 80% aqueous phase). The results indicated a minimal inhibitory concentration of 125.00 µg/mL before incorporation into the nanostructured system; this activity was even more enhanced when this extract presented a minimal inhibitory concentration of 15.62 µg/mL after its incorporation. In vivo assay dates showed that the nanostructure-incorporated extract of A. urundeuva leaves was more effective than both the unincorporated extract and the antifungal positive control (amphotericin B). These results suggest that this nanostructured lipid system can be used in a strategy to improve the in vitro and in vivo anti-C. albicans activity of hydroethanolic extracts of Astronium sp.

Effect of tyrosol on adhesion of Candida albicans and Candida glabrata to acrylic surfaces

The prevention of adhesion of Candida cells to acrylic surfaces can be regarded as an alternative to prevent denture stomatitis. The use of quorum sensing molecules, such as tyrosol, could potentially interfere with the adhesion process. Therefore, the aim of this study was to assess the effect of tyrosol on adhesion of single and mixed cultures of Candida albicans and Candida glabrata to acrylic resin surfaces. Tyrosol was diluted in each yeast inoculum (10(7) cells/ml in artificial saliva) at 25, 50, 100, and 200 mM. Then, each dilution was added to wells of 24-well plates containing the acrylic specimens, and the plates were incubated at 37°C for 2 h. After, the effect of tyrosol was determined by total biomass quantification, metabolic activity of the cells and colony-forming unit counting. Chlorhexidine gluconate (CHG) was used as a positive control. Data were analyzed using analysis of variance (ANOVA) and the Holm-Sidak post hoc test (α = 0.05). The results of total biomass quantification and metabolic activity revealed that the tyrosol promoted significant reductions (ranging from 22.32 to 86.16%) on single C. albicans and mixed cultures. Moreover, tyrosol at 200 mM and CHG significantly reduced (p < 0.05) the number of adhered cells to the acrylic surface for single and mixed cultures of both species, with reductions ranging from 1.74 to 3.64-log10. In conclusion, tyrosol has an inhibitory effect on Candida adhesion to acrylic resin, and further investigations are warranted to clarify its potential against Candida infections.

Low-temperature plasma: an effective approach against Candida albicans biofilm

This study evaluated the antifungal potential of low-temperature plasma (LTP) on a 72-hour Candida albicans biofilm. A growth inhibition zone test was conducted with agar plates inoculated with C. albicans and submitted to LTP and argon application at 3 and 10 mm for 10, 30, 60, 90, and 120 seconds. The groups for biofilm assays were 60 seconds of LTP application with a tip-to-sample distance of 3 mm (LTP-3) and 10 mm (LTP-10); –application of only argon gas for 60 seconds with a tip-to-sample distance of 3 mm (Ar-3) and 10 mm (Ar-10); and no treatment. The C. albicans biofilm was grown on saliva-coated discs. The medium was replaced every 24 hours. Confocal laser scanning microscopy revealed the proportion of live and dead cells, and variable pressure scanning electron microscopy (VPSEM) showed biofilm/cell structure. No inhibition zone was observed for control and either Ar groups. For the LTP groups, a progressively increasing of inhibition zone diameter was observed for different treatment durations. The LTP-3 and LTP-10 groups presented higher proportions of dead cells compared with the Ar-3 and Ar-10 groups. VPSEM revealed cell perforations in the LTP-3 and LTP-10 groups. A short period of LTP exposure demonstrated an antifungal effect on C. albicans biofilm.

Genetic evaluation and activity of antifungal against clinical isolate Candida albicans biofilms

Candida yeasts are common in the oral cavity and can cause candidosis in the presence of predisposing factors, especially diabetes. The manifestation of the disease is related to this set of local factors such as the presence of dental prostheses, salivary pH, salivary flow and tobacco and the ability to form biofilms. Biofilms are specific and organized communities of cells under the control of signaling molecules rather than random accumulations of cells resulting from cell division and frequently are drugs resistance. Aim: The objectives of this study were to determine the genetic patterns of these C. albicans isolates and to evaluate the in vitro activity amphotericin B and caspofungin against C. albicans biofilms. Methods: Microbial samples were collected from subgingival sites and seeded in CHROMagar for subsequent identification of C. albicans by PCR. Genotypes were defined based on the identification of the transposable introns in the 25S rDNA by PCR. Results: In this study, 6 strains were identified as C. albicans and of these, 3 strains were genotype A and 3 were genotype B. The results showed that both amphotericin B and caspofungin exhibited strong antifungal activities against C. albicans biofilm formation and inhibiting the biofilm formation ranging from 70.8 – 95.3% and 77.7 - 88.7%, respectively. The antifungals studied had low inhibitory effect on preformed biofims, ranging from 39.5 - 50.8% for amphotericin B and from 23.1 - 36.9% for caspofungin at the same concentration. The activity of the two drugs was most effective in inhibit biofilm formation.

In vitro antifungal susceptibility of candida albicans isolates from patients with chronic periodontitis and diabetes

Alterations that lead to deficiency of the immune system, such as diabetes mellitus, may promote proliferation of Candida albicans and selection of strains which have greater ability to adhere and to penetrate the host tissues. Recent studies indicate an increase of the antifungal resistance of C. albicans isolates in periodontal pockets, suggesting that the oral cavity could be a reservoir of resistant yeast to antifungal agents. Moreover, oral cavity can act as a reservoir of certain pathogens that may cause systemic infections. The periodontal pocket is an ecological niche suitable to host microorganisms that could act as opportunistic pathogens. The aim of this study is to contribute to the understanding of resistance to conventional antifungal against C. albicans isolates from patients with periodontitis and diabetes. The determination of the minimal inhibitory concentrations (MIC) was evaluated according to M27S3 of the CLSI (2008), with modifications. The results showed that 48.8% of the studied strains were resistant to one or more antifungals and 6.6% were resistant to fluconazole and voriconazole. These results suggest an increasing resistance to conventional antifungal agents among Candida species, suggesting that the oral cavity could host pathogen fungi.

Atividade da fração enriquecida em fenólicos de Buchenavia tomentosa e de algumas substâncias isoladas antes e após encapsulação com beta-ciclodextrina em Candida albicans

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Estudo de genes de Candida albicans com função desconhecida quanto à formação de biofilme, características biológicas e interação patógeno- hospedeiro

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Influência de Lactobacillus rhamnosus na patogenicidade e na expressão de genes de virulência de Candida albicans: estudo in vitro e in vivo

Pós-graduação em Biopatologia Bucal - ICT