In-Vitro Susceptibility Pattern of Candida isolated from Women with Vaginal Candidiasis to four Anti-fungal Agents in Dar es Salaam; Tanzania

Objective: To determine anti-fungal susceptibility pattern of Candida species (n = 272) isolated from women with vaginal candidiasis (VC) in Dar es Salaam; Tanzania against varying concentrations (0.05 to 12.8 g/ml) of miconazole; clotrimazole; ketoconazole and nystatin using agar dilution and broth macro-dilution methods. Test isolates and reference strains: Clinical isolates and reference strains; Candida albicans (ATCC 32354); Candida krusei (ATCC6258); Candida parapsilosis (ATCC22019) and Candida glabrata (ATCC2001).Methods: Determination of minimum inhibitory concentration ranges; and MIC50 and MIC90 (required to inhibit 50and 90of the isolates); respectively. MIC for nystatin was least concentration that prevented visible growth while for the azoles MIC was the concentration that caused 80growth inhibition compared with drug free control. Results: The MIC for Candida albicans; Candida famata; Candida krusei; Candida lusitaniae; Candida parapsilosis and Candida norvegensis were between 0.05 to 0.2 g/ml against all four anti-fungal drugs tested. Some Candida tropicalis and Candida glabrata isolates had moderately high (MIC =6.4) and high MICs (12.8 g/ml); especially with the azole anti-fungal drugs. The overall agreement between the results of the two methods were 88; and for individual antifungals the agreement was 90.8; 91.3; 80and 88for clotrimazole; ketoconazole; miconazole and nystatin; respectively. C. glabrata and C. parapsilosis gave low agreement (68- 75) for the azole antifungals. Conclusions: i) most of the clinical isolates had low MIC values to all the four anti-fungal drugs tested; indicating susceptibility; ii) some strains of C. tropicalis and C. glabrata had high MIC values; and; iii) there was a good overall agreement ( 88) between agar dilution and broth macro-dilution methods. There is a need for a follow-up in-vivo study to determine clinical response following treatment with the investigated anti-fungals