Usefulness of Chromogenic Media in the Identification of Candida spp. Yeasts Compared to Mass Spectrometry

Yeasts of the <i>Candida</i> genus are part of the normal human microbiota but can cause infections (candidiasis) under certain conditions. While <i>Candida albicans</i> remains the most common etiological agent, the prevalence of non-albicans <i>Candida</i> species-such as <i>C. glabrata</i>, <i>C. tropicalis</i>, <i>C. krusei</i>, <i>C. parapsilosis</i>, <i>C. kefyr</i>, <i>C. lusitaniae</i>, and the emerging multidrug-resistant <i>C. auris</i>-has been increasing. Effective treatment of candidiasis requires rapid and accurate identification of the causative species, particularly due to species-specific antifungal agent resistance patterns. The aim of this study was to evaluate the usefulness of five chromogenic media for the differentiation of <i>Candida</i> species: BD CHROMagar Candida (Becton Dickinson), CHROM ID Candida (<i>bio</i>Mérieux), CHROMAgar Candida Plus (CHROMAgar France, Biomaxima), CHROMAgar Candida Plus (GRASO Biotech), and Brilliance Candida Agar (OXOID). A total of 175 strains from the following species were tested: <i>C. albicans</i>, <i>C. parapsilosis</i>, <i>C. dubliniensis</i>, <i>C. lusitaniae</i>, <i>C. tropicalis</i>, <i>C. glabrata</i>, <i>C. kefyr</i>, <i>C. krusei</i>, and <i>C. auris</i>. Species identification was confirmed by MALDI-TOF mass spectrometry using the MALDI Biotyper system (Bruker). Colony morphology, especially color characteristics, was assessed on each medium. The morphological features of most <i>Candida</i> species were consistent with the manufacturer's descriptions and allowed for presumptive species-level identification. However, some species showed reproducible but previously undescribed morphological traits, including variations in colony shade. Notably, <i>C. auris</i> could not be reliably identified using BD, <i>bio</i>Mérieux, or OXOID media. In conclusion, while chromogenic media are a helpful preliminary diagnostic tool, subtle differences in colony coloration can complicate interpretation. Diagnostic caution is recommended, and confirmatory methods such as MALDI-TOF remain essential for reliable identification, especially for emerging or less common <i>Candida</i> species.