Evaluation of five commercial Sabouraud gentamicin-chloramphenicol agar media

The diagnosis of fungal infections relies on the isolation of the causative agent by culture of clinical specimens. Among the different culture media, Sabouraud glucose agar remains the most widely used. The use of commercial culture media is highly recommended as good laboratory practice in clinical microbiology. Therefore, the comparative performance of five different Sabouraud gentamicin-chloramphenicol agar media, available commercially as plates, was investigated. A total of 124 strains encompassing 45 yeasts and 79 filamentous fungi were cultured. Colonies of the dermatophytes (28 strains) and some related keratinophilic fungi (6 strains) were of overall similar appearance or size on all five media. Conversely, all the Aspergillus strains tested (n=17) as well as a few other strains of Hyphomycetes (n=5/18) exhibited important differences in the colour of the colonies. Furthermore, growth of the members of Mucorace ae was also affected, with great differences in the diameter of the colonies observed. In addition, quantitative cultures of the yeasts revealed marked variations in the number of the colonies, or even no growth, for two Candida species, Cryptococcus species, and Trichosporon cutaneum. In conclusion, the only formulation that gave good results with all fungal types tested was the one from Becton Dickinson (France).