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

Oral Candida species in healthy and HIV-infected subjects in Chennai, South India

Objective: Candidiasis is the most common fungal infection in human immunodeficiency virus (HIV) - infected individuals. As there is sparse data on the oral <I>Candida</I> species in HIV- infected individuals in India, we characterized <I>Candida</I> species from the oral cavity in two cohorts - with and without HIV infection and with presence or absence of clinical oral candidiasis, in Chennai, South India.<br>Methods: Saliva samples were collected from 147 consecutive study participants by the oral rinse technique. <I>Candidal</I> species were isolated by culturing specimens on Sabouraud‘s dextrose agar. The pure cultures so derived were speciated using the commercially available ID32C system, and the results were interpreted using APILAB plus software.<br>Results: In the HIV seropositive group, the most commonly isolated candida species was <I>C.albicans</I> (86%) followed by <I>C.tropicalis</I> (23%), <I>C.guilliermondi</I> (6%), <I>C.krusei</I> (5%) and others (4%). In the healthy cohort without clinical candidiasis, C.tropicalis was the most commonly isolated species.<br>Conclusion: There appears to be a marked variation in oral <I>Candida</I> species found in HIV-seropositive and seronegative individuals in India. To our knowledge, this is the first attempt to identify oral Candida species in a South Indian population.