Anti-biofilm properties of eucalyptol in combination with antifungals against Candida albicans isolates in patients with hematological malignancy

Oral candidiasis is a fungal infection caused mainly by Candida albicans and it is a major problem among hematologic malignancy patients. Biofilm formation is an attributable factor to both virulence and drug resistance of Candida species. The aim of the study was to evaluate the biofilm-producing ability of oral C. albicans isolates and to evaluate the inhibitory activity of eucalyptol on Candida biofilm, alone and in combination with antifungal agents. Samples were collected from the oral cavity of 106 patients with hematologic malignancy. The isolated yeasts were identified by PCR-sequencing. Then C. albicans isolates were analyzed for their biofilm-producing ability by crystal violet staining and MTT assay. The minimum biofilm inhibition concentrations (MBIC) of eucalyptol, amphotericin B, itraconazole, and nystatin and the in vitro interaction of eucalyptol with these drugs were tested according to CLSI-M-27-A3 protocol and checkerboard methods, respectively. From 106 patients, 50 (47.2%) were confirmed for oral candidiasis [mean ± SD age 39 ± 14 years; female 31 (62%) and male 19 (38%)]. C. albicans was isolated from 40 of 50 (80%) patients. From 40 C. albicans isolates, 24 (60%) and 16 (40%) were moderate and weak biofilm producer, respectively. The geometric mean MBIC of amphotericin B, itraconazole, nystatin and eucalyptol were 3.93 µg/mL, 12.55 µg/mL, 0.75 µg/mL and 798 µg/mL, respectively. Eucalyptol interacted synergistically with amphotericin B, itraconazole and nystatin against 12.5, 10, and 22.5% of isolates, respectively. Eucalyptol demonstrated promising activity against biofilm of C. albicans when tested alone or combined with antifungal drugs.

Enhancing of Wound Healing in Burn Patients through Candida albicans β-Glucan

The mortality and disability-adjusted life years (DALYs) of burn patients are decreasing over time. However, finding novel effective treatment approaches using natural agents is highly considered to reduce the burden of burn injuries. One of the recent agents used in wound healing is β-glucan, mainly extracted from fungi cell walls. This study aimed to evaluate the effect of 5% (m/m) of yeast β-glucan ointment on burn wound healing and to assess the impact of β-glucan on cytokines during the treatment. Thirty-three patients with second or third-degree burns were enrolled in this study. Two groups of twenty-three and ten patients used yeast 5% (m/m) β-glucan ointment (study group) and Stratamed ointment (control), respectively, on a daily basis, for a maximum of four weeks. The size of the burn wounds was measured before and at the end of the treatment. Blood samples of 14 and 10 patients in the β-glucan and control groups, respectively, were obtained before and after the treatment, and the enzyme-linked immunosorbent assay (ELISA) was performed to measure the serum concentration of the IL-4, IL-17, and IFN-γ cytokines. The log-binomial model was used to assess the efficacy of the β-glucan ointment on burn wound healing. ANOVA/ANCOVA was employed to assess the effects of β-glucan on the serum concentration of cytokines. After adjusting for potential confounders/covariates, patients receiving β-glucan had better wound healing (RR = 4.34; 95% CI: 0.73 to 25.67; p = 0.11). There was a significant difference in IL-4 secretion between the β-glucan and control groups after adjusting for potential confounders/covariates (MD = 77.27; 95% CI: 44.73 to 109.82; Cohen’s d = 2.21; 95% CI: 1.16 to 3.24; p = 0.0001). The results indicate that 5% (m/m) of β-glucan has efficacy in burn wound healing, and a significant difference was found in the level of IL-4 after receiving β-glucan. Further studies with a two-arm design and long-term use of ointment are needed to confirm the effect of β-glucan on wound healing and cytokine secretion.

Antifungal Activity of Capric Acid, Nystatin, and Fluconazole and Their In Vitro Interactions Against Candida Isolates from Neonatal Oral Thrush

Due to the increasing resistance of various Candida species to azole drugs, particularly fluconazole, it would be of significant importance to look for alternative therapies. The aim of this study was to investigate the antifungal activity of capric acid and its in vitro interactions with nystatin and fluconazole against Candida isolates. A total of 40 Candida isolates (C. albicans, 36; C. kefyr, 2; C. tropicalis, 1; C. glabrata, 1) collected from the oral cavity of neonates with oropharyngeal candidiasis and a reference strain of C. albicans (ATCC 10231) were used in this study. Antifungal activity of capric acid and two comparator antifungal drugs, namely fluconazole and nystatin, was tested according to CLSI M27-A3/M60 method. The in vitro interaction between capric acid with fluconazole and nystatin was determined following a checkerboard method and results were interpreted using fractional inhibitory concentration index. Nystatin had the lowest minimum inhibitory concentrations (range, 0.125-8 μg/mL; geometric mean [GM], 0.6229 μg/mL) followed by fluconazole (range, 0.5-16 μg/mL; GM, 1.9011 μg/mL) and capric acid (range, 128-2,048 μg/mL; GM, 835.9756 μg/mL). When tested in combination, capric acid with fluconazole demonstrated synergistic, indifferent, and antagonistic interactions in 3 (7.317%), 24 (58.536%), and 14 (34.146%) cases, respectively. For combination of capric acid with nystatin, synergistic, indifferent, and antagonistic interactions were observed in 1 (2.439%), 19 (46.341%), and 21 (51.219%) cases, respectively. All cases of synergistic interactions were against resistant or susceptible dose-dependent isolates. Fluconazole, nystatin, and capric acid seem to be more effective when they are used alone compared with their combination. However, their combination might be effective on resistant isolates.