Persea americana Glycolic Extract: In Vitro Study of Antimicrobial Activity against Candida albicans Biofilm and Cytotoxicity Evaluation.

This study evaluated the antifungal activity of Persea americana extract on Candida albicans biofilm and its cytotoxicity in macrophage culture (RAW 264.7). To determine the minimum inhibitory concentration (MIC), microdilution in broth (CLSI M27-S4 protocol) was performed. Thereafter, the concentrations of 12.5, 25, 50, 100, and 200 mg/mL (n = 10) with 5 min exposure were analyzed on mature biofilm in microplate wells for 48 h. Saline was used as control (n = 10). After treatment, biofilm cells were scraped off and dilutions were plated on Sabouraud dextrose agar. After incubation (37°C/48 h), the values of colony forming units per milliliter (CFU/mL) were converted to log10 and analyzed (ANOVA and Tukey test, 5%). The cytotoxicity of the P. americana extract was evaluated on macrophages by MTT assay. The MIC of the extract was 6.25 mg/mL and with 12.5 mg/mL there was elimination of 100% of planktonic cultures. Regarding the biofilms, a significant reduction (P < 0.001) of the biofilm at concentrations of 50 (0.580 ± 0.209 log10), 100 (0.998 ± 0.508 log10), and 200 mg/mL (1.093 ± 0.462 log10) was observed. The concentrations of 200 and 100 mg/mL were cytotoxic for macrophages, while the concentrations of 50, 25, and 12.5 mg/mL showed viability higher than 55%.

Oral microbial colonization in patients with systemic lupus erythematous: correlation with treatment and disease activity.

Treating patients with systemic lupus erythematosus (SLE) with steroids and immunosuppressive drugs may interfere in the presence of potentially opportunistic microorganisms in the oral cavity. The aim of this study was to evaluate the presence of Candida spp., Staphylococcus spp., Enterobacteria and Pseudomonas spp. in the oral cavity of SLE patients, compared with healthy controls. A group of 40 patients who had received therapy for at least 60 days was selected (19-53 years). For the control group, 40 healthy individuals matched for age, gender and use of partial prosthesis were selected. Oral rinse samples were collected and plated on specific culture media. After incubation, the number of colony forming units (CFU) was obtained and the isolates were identified at species level. Microbial counts were compared between SLE and control by analysis of variance (ANOVA) and Mann-Whitney (p < 0.05 significant). Microorganism counts in patients with and without immunosuppressive drugs, as well with active and inactive disease (according to SLEDAI score) were also compared. No significant differences in CFU/mL between SLE and control patients were observed (yeasts, p = 0.55; Staphylococci, p = 0.24; Enterobacteria/Pseudomonas spp., p = 0.26). No differences in microbial counts were observed regarding clinical parameters tested. The most frequent species isolated in the SLE group were Candida albicans, Staphylococcus epidermidis and Klebsiella oxytoca. In conclusion, no differences in frequency and microorganism levels were found between SLE patients and healthy individuals.

Prevalence and antifungal resistance profile of Candida spp. oral isolates from patients with type 1 and 2 diabetes mellitus.

OBJECTIVE: The goal of the study was to measure the prevalence of Candida spp. in the oral cavity of patients with diabetes types 1 and 2 when compared to healthy individuals and to study antifungal resistance profile of the isolates. DESIGN: There were 162 subjects in the study: diabetes type 1 (n=39); control group 1 (n=50): healthy individuals matched in gender, age, and oral conditions to diabetes type 1 patients; diabetes type 2 (n=37); control group 2 (n=36) who were matched to each patient of the diabetes type 2 group. Stimulated saliva was collected and isolates were identified with phenotypic tests. The presence of C. dubliniensis was determined by multiplex PCR. RESULTS: There were no statistically significant differences in Candida spp. frequency between the diabetes 1 group and its control (p=0.443) nor between the diabetes 2 group and its control (p=0.429). C. albicans was the most frequently isolated yeast in all groups. In the diabetes groups, C. stellatoidea, C. parapsilosis, C. tropicalis, C. lipolytica, C. glabrata, and C. krusei were also identified. Additionally, in control groups, C. kefyr was also detected. None of the isolates were resistant to amphotericin B and flucytosine. A low percentage of the isolates were resistant to ketoconazole. CONCLUSIONS: No differences were detected in colonization of Candida spp. oral isolates from type 1 and type 2 diabetes when compared to matched controls. The antifungal resistance of Candida spp. isolates for ketoconazole from type 1 diabetes patients was significantly higher than that of its matched control.

Frequency of Candida spp. in the oral cavity of Brazilian HIV-positive patients and correlation with CD4 cell counts and viral load.

The aim of this study was to evaluate the prevalence of Candida spp., and particularly C. dubliniensis, among oral isolates from Brazilian HIV-positive patients correlating these results with CD4 cell counts and viral load. Forty-five individuals (23 female and 22 male) diagnosed as HIV-positive by ELISA and Western-blot, under anti-retroviral therapy for at least 1 year and without oral candidosis signals were included in the study. The control group was constituted by 45 healthy individuals, matched to the test group in relation to age, gender, and oral conditions. Oral rinses were collected and the identification was performed by phenotypic tests. The existence of C. dubliniensis among the isolates was analyzed using a validated multiplex PCR assay. Candida spp. were detected at significantly higher number in the oral cavity of HIV-positive patients in relation to the controls (P = 0.0008). C. albicans was the most frequently isolated species in both groups. In the HIV group, C. glabrata, C. lipolytica, C. krusei, C. guilliermondii, and C. parapsilosis were also identified. In the control group, we additionally identified C. tropicalis and C. dubliniensis. Two isolates (1.9%, 2/108) from control individuals were identified as C. dubliniensis and this species was not verified in the HIV group. Candida spp. counts were statistically lower (P = 0.0230) in the oral cavity of patients with low viral load (<400 copies/mm(3)). Candida spp. counts did not differ statistically among groups with different levels of CD4 cells counts (P = 0.1068).