Comparative Analysis of In-House and Commercially Available Media for Determining the Antifungal Susceptibility Profile of Candida Species

Background The emergence of treatment-resistant <i>Candida</i> species has highlighted the importance of antifungal susceptibility testing as it is difficult to determine therapeutics solely based on species identification. However, as compared to bacterial pathogens, antimicrobial susceptibility testing in fungi still remains underutilized in most clinical diagnostic microbiological services. The disc diffusion (DD) technique is reported to be easy and cost-effective and therefore can be easily incorporated as a routine method. However, the selection of media remains the most crucial factor for antifungal susceptibility testing using the DD method. In the present study, in-house prepared and commercially available Mueller-Hinton agar with 2% glucose and 0.5 μg/ml methylene blue dye (MH-GMB) for determining the antifungal susceptibility profile of <i>Candida</i> species. Method The study involved 165 strains of eight different <i>Candida</i> species obtained from various clinical specimens. MH-GMB was the media used for antifungal susceptibility testing of <i>Candida</i> strains, and the efficacy of in-house and commercially available MH-GMB was compared. Results All <i>Candida</i> isolates showed sufficient growth on readymade MH-GMB procured from commercial sources. The frequency of trailing phenomenon was very low in MH-GMB procured from commercial sources. The visualization of zone margins was more enhanced with commercially procured MH-GMB compared to in-house media. Conclusion As per the available literature, the present study is the first to report the comparative account of in-house prepared and commercially procured MH-GMB for antifungal susceptibility testing of <i>Candida</i> spp. Commercially procured MH-GMB appears to be more advantageous over in-house prepared media as there is rapid growth, infrequent appearance trailing phenomenon, and more clear zone diameters. It is easy to weigh and prepare. Since it is pre-formulated, there is no chance of preparation error.