Evaluation of CandiSelect4, a new chromogenic medium for isolation and presumptive identification of Candida species from clinical specimens

Abstract In clinical laboratories, isolation of Candida species is generally based on the culture of specimens on Sabouraud dextrose agar. This strategy does not allow species identification on primary culture and makes it difficult to detect mixed cultures. Chromogenic media contain substrates that react specifically with different Candida species, and partly overcome these difficulties. Objectives The aim of this study was to compare two chromogenic media: (i) CandiSelect4 (C4), a new medium developed for direct identification of C. albicans and presumptive identification of C. krusei , C. tropicalis and C. glabrata (ii) CHROMagar Candida (CH), a medium licensed for direct identification of C. albicans , and presumptive identification of C. tropicalis and C. krusei , and employed in our laboratory since 2002. Materials and methods Altogether, 533 clinical specimens were seeded on both media. Identification on C4 was compared to that achieved on CH, API 32 C test or an in-house C. glabrata rapid identification test. Results Discrepant positive cultures occurred in 16 samples and were shared equally between C4 and CH. The ability of both media to detect associations was equivalent, with 34 associations identified with C4 and CH. No discrepancy was observed with respect to identification of C. albicans . C4 identified six of six C. krusei , but false-negative identification of C. tropicalis occurred in 2/11 cases and false-positive identification of C. glabrata occurred in 2/34 cases. Conclusions The overall performance of C4 and CH appeared almost identical during a two-month comparison in the clinical mycology setting.