Antifungal evaluation of multidrug-resistant nondermatophytic moulds of bovine origin

Abstract

Background and aim: Fungi are eukaryotic, non- chlorophyllous saprophytic organisms that are ubiquitous in nature. They are observed  to cause infections called mycosis, especially in animals for which antifungals are usually recommended. Though, unproductive treatment  kept increasing, it leads to drug resistance or tolerance. In this study, the antifungal activities of four oxoid brand conventional  antifungal drugs were evaluated for multi drug resistance on some selected fungal isolates recovered from bovine sources. 

Methods: Fungal isolates were recovered from bovine and cultured using standard techniques, identified by direct microscopy  and molecular techniques. Susceptibility test was evaluated using disc diffusion method. The oxoid brand discs of Ketoconazole 10 µg/ml,  Fluconazole 25 µg/ml, Voriconazole 1 µg/ml and Amphotericin B 20 µg/ml were used for the analysis, incubated at 28 °C and zone of  inhibition measured after 3-5 days.

Results: Seven fungal genera were identified from the bovine skin samples, out of which eleven  species were used for susceptibility test. Ketoconazole was highly effective against some fungal isolates such as Penicillium citrinum, Fusarium succisae, Cladosporium tenussimum, Curvularia kusanol, Fusarium solani, Voriconazole could not clear the moulds tested  completely and were tagged to be resistant mutant, all moulds tested were resistant to Fluconazole while Amphotericin B showed  minimal inhibitory zones on the moulds.

Conclusion: This study has shown that several fungal isolates respond differently to antifungal  drugs. The different non-dermatophytic moulds tested were highly susceptible to Ketoconazole when compared with other antifungals employed in this study and as such may be best recommended for the treatment of infections caused by these moulds.