Abstract

ANTIFUNGAL EFFICACY OF NATURAL STONES AGAINST CLINICAL ISOLATES OF CANDIDA SPECIES

Onyekachukwu Izuchukwu Udemezue* and Christie Amaechi Oyeka

ABSTRACT

The high prevalence of fungal infections particularly in immunocompromised patients, limited repertoire of antifungal drugs and development of resistance to the available drugs, have increased the demand for new and effective antifungal agents. The aim of this research was to determine the antifungal efficacy of natural stones (brimstone, black stone and blue stone) against clinical isolates of Candida species. Four hundred and fifty high vaginal swabs were collected from patients suspected of having vulvo-vaginal candidiasis. These were inoculated on Sabouraud dextrose agar supplemented with 50μg/ml chloramphenicol and incubated aerobically at 25oC for 24hours. The yeast isolates were identified based on their morphological, physiological, biochemical and molecular characteristics. Anticandidal activity of the natural stones was evaluated using the agar-well diffusion method. The Minimum inhibitory concentration (MIC) and Minimum fungicidal concentration (MFC) of the agents were determined using the broth dilution method. Forty-two percent (188) of the HVS were positive for Candida growth; Candida albicans (51%), C. tropicalis (28%), C. glabrata (15%) and C. parapsilosis (6%). Blue stone gave the best inhibition zone diameter (IZD) of 31.50±0.71mm against C. tropicalis, sulphur stone, 18.50±0.71mm against C. parapsilosis and Black stone, 0.00mm for all the isolates at 200mg/ml. The positive control, ketoconazole gave the IZD of 21.00±1.41mm against C. albicans, 21.50±0.71mm against C. tropicalis, 20.50±0.71mm against C. glabrata and 19.00±1.41mm against C. parapsilosis at 200mg/ml. The MIC and MFC of the test agents varied among the Candida isolates. For Candida albicans, Blue stone, MIC (50mg/ml), Sulphur stone (200mg/ml), Black stone (200mg/ml) and Ketoconazole (50mg/ml). Natural stones have shown to be effective in vitro, against clinical isolates of Candida species and could serve as potential antifungal drugs.

Keywords: Candida, Natural stones, Antifungal, Fungicidal, Candidiasis.