In vitro adhesion of oral candida dubliniensis isolates to acrylic denture surfaces following brief exposure to sub-cidal concentrations of polyenes, azoles and chlorhexidine

We aimed to investigate the effect of brief exposure to sub-cidal concentrations of nystatin, amphotericin B, ketoconazole, fluconazole and chlorhexidine gluconate on the adhesion of oral Candida dubliniensis isolates to the surface of acrylic dentures. After determining the minimum inhibitory concentration of each drug, 20 oral isolates of C. dubliniensis were exposed to sub-cidal concentrations of the drugs for 1 h. The drugs were then removed by dilution, and the adhesion of the isolates to denture acrylic strips was assessed by an in vitro adhesion assay. Compared to the controls, exposure to nystatin, amphotericin B, ketoconazole, fluconazole and chlorhexidine gluconate suppressed the ability of C. dubliniensis isolates to adhere to acrylic denture surfaces with a reduction of 74.68, 74.27, 57.31, 44.57 and 56.53% [p <0.001 for all drugs], respectively. Brief exposure to sub-cidal concentrations of anti-mycotics suppressed the adhesion of C. dubliniensis oral isolates to acrylic denture surfaces

Impact of brief and sequential exposure to nystatin on the germ tube formation and cell surface hydrophobicity of oral candida albicans isolates from human immunodeficiency virus-infected patients

To evaluate the impact of brief and sequential exposure to nystatin on the germ tube formation and cell surface hydrophobicity of oral isolates of Candida albicans obtained from patients infected with human immunodeficiency virus [HIV]. After determining the minimum inhibitory concentration of nystatin, 10 oral isolates of C. albicans from 10 different HIV-infected patients were briefly [1 h] and sequentially [10 days] exposed to subtherapeutic concentrations of nystatin. Following a subsequent drug removal, the germ tube formation and cell surface hydrophobicity of these isolates were determined via a germ tube induction assay and an aqueous hydrocarbon assay, respectively. The data obtained from these assays for the control [unexposed to nystatin] and nystatin-exposed isolates were analyzed using Student's t tests.The mean percentage reduction in the germ tube formation and cell surface hydrophobicity of the nystatin-exposed isolates compared to the controls was 30.12 +/- 1.99 [p < 0.001] and 29.65 +/- 2.33 [p < 0.001], respectively. These data elucidate the possible pharmacodynamic mechanisms by which nystatin might operate in vivo in the modulation of candidal virulence

Effects of Subtherapeutic concentrations of chlorhexidine gluconate on germ tube formation of oral candida

The main objective of this study was to investigate the effect of brief exposure to subtherapeutic concentrations of chlorhexidine gluconate on germ tube formation of Candida albicans isolates obtained from smokers, diabetics, asthmatics using steroid inhalers and healthy individuals. Forty isolates of C. albicans were used in this study. All these isolates were quantified for germ tube formation without exposure to the drug and were used as the control group for data analysis. Isolates were also exposed to three subtherapeutic concentrations of chlorhexidine gluconate [0.00125, 0.0025 and 0.005%] for 30 min [limited exposure]; the antiseptic was then removed and germ tube formation of these isolates was quantified microscopically following incubation in a germ tube-inducing medium. Compared with the unexposed controls, brief exposure to all concentrations of chlorhexidine gluconate suppressed the ability of the C. albicans isolates to form germ tubes in increasing order by 13.72% [p < 0.001 to p = 0.02], 46.16% [p < 0.001] and 72.46% [p <0.001]. These findings show that brief exposure to subtherapeutic concentrations of chlorhexidine gluconate may modulate germ tube formation of C. albicans isolates, thereby suppressing their pathogenicity, and further elucidate the pharmacodynamic mechanisms by which chlorhexidine gluconate may operate in vivo

comparison of the antifungal activity of herbal toothpastes against other brands of toothpastes on clinical isolates of candida albicans and candida dubliniensis

To evaluate the anti-Candida activity on Candida albicans and Candida dubliniensis species of 2 herbal and 7 other brands of toothpastes commonly used in Kuwait. Antifungal activity was determined by agar diffusion test on 65 isolates of C. albicans and 21 isolates of C. dubliniensis for each toothpaste. A uniform quantity of toothpaste was filled into wells punched into Sabouraud dextrose agar medium plates inoculated with the test isolates, incubated at 37°C; inhibition zone diameters were read after 24 h. The mean inhibition zone diameters ranged between 12 and 23 mm for C. albicans and between 12 and 27 mm for C. dubliniensis. A herbal toothpaste brand manufactured in the Middle Eastern region [United Arab Emirates] consisting of many herbal ingredients compared to other brands was found to be the most active [p < 0.001] against both Candida species tested, which also demonstrated higher inhibitory activity against C. dubliniensis isolates compared to C. albicans. The herbal toothpaste brand presented significant anticandidal activity over conventional toothpastes and may be useful in reducing the pathogenic potential of Candida species

Prevalence of Candida dubliniensis among oral Candida isolates in patients attending the Kuwait University Dental Clinic

The aim of this study was to determine the oral candidal carriage of patients seeking dental treatment at the Kuwait University Dental Clinic and to ascertain the Candida species composition among them. 370 oral rinse samples were collected from patients. The germ tube test, CHROMagar Candida medium and VITEK 2 yeast identification system were used for species identification. C. dubliniensis isolates were confirmed by the production of rough colonies with hyphal fringes and chlamydospores on simplified sunflower seed agar. Of the 370 samples investigated, 160 [43.24%] showed Candida in culture. The isolation of Candida was significantly higher in individuals who were smokers or were under medication for either diabetics or asthma [99 [62%]] compared to healthy individuals [61 [38%]]. Of the 210 samples which did not yield Candida, 131 [62.38%] were healthy and 79 [37.62%] were associated with smoking or with usage of drugs for aforementioned conditions. Species isolated were C. albicans [102 [63.7%]], C. dubliniensis [23[14.3%]], C. krusei [13 [8.1%]], C. tropicalis [12 [7.5%]] and C. glabrata [10 [6.2%]].Candida species were more prevalent in patients having predisposing factors implicated in oral candidosis, such as in smokers, diabetic patients and asthmatic patients using inhalation steroids. C. albicans was the most prevalent species isolated, followed by C. dubliniensis