Susceptibility of Medical Fungal Isolates to Commonly used Antifungal Agents

The susceptibility of fungal isolates associated with indoor air of medical institutions to commonly used antifungal agents were investigated using the open plate technique on Sabouraud Dextrose Agar plates. The well in agar diffusion technique was used in determining the antifungal susceptibility. The antifungal agents used were fluconazole and ketoconazole and these drugs were prepared into four concentrations. Result showed reduced antifungal activity as the concentration decreased. Results of fluconazole against the fungal isolates showed that Aspergillus flavus, Aspergillus niger, Candida sp, and Mucor sp were all sensitive at 5 mg/ml, 2.5 mg/ml, and 1.25 mg/ml while Rhizopus sp was only sensitive at the 5mg/ml concentration. Antifungal activity of ketoconazole showed that Aspergillus flavus, Candida sp, Mucor sp and Rhizopus sp were all sensitive at the 5, 2.5, 1.25 and 0.63 mg/ml concentrations while A. niger was susceptible to ketoconazole at 5 and 2.5 mg/ml concentrations. The MIC of Ketoconazole against Candida sp, Aspergillus flavus, Mucor sp and Rhizopus sp was 0.63 mg/ml. while the MIC of Aspergillus niger was at 2.5 mg/ml. There was highly significant difference (P≤0.05) in the response of the fungal isolates to fluconazole and ketoconazole in all concentrations of the drugs. Result also showed that both drugs were more effective against Candida sp and because of the effectiveness of ketoconazole on other isolates, it is recommended for use in treating mycoses caused by these fungi from this site.