CHROMagar as a primary isolation medium for rapid identification of Candida and its role in mixed Candida infection in sputum samples

Abstract

Introduction: Candida species occurs as commensal organisms but in immunocompromised patients and those on long term antibiotics, these unrecognized opportunistic fungi may become fatal. Although C. albicans is the most frequently isolated pathogen, the incidence of infections due to non-albicans Candida are on the increase especially with fluconazole resistant strains. Identification of Candida to species level therefore becomes important for selecting the appropriate antifungal agents. The need for rapid identification and the difficulty in detecting mixed cultures on the traditional Sabouraud’s dextrose agar (SDA) have led to the development of chromogenic media. Aim: This study was done to evaluate the usefulness of CHROMagar Candida for rapid identification of Candida species and to identify mixed Candida infection from sputum samples. Materials and methods: A total of 126 sputum samples were inoculated on CHROMagar Candida. The plates were incubated at 37?C for 48 hrs and the growth identified based on the colour of the colony. Results: Single yeast infection was observed in 113 samples (89.7%) and 11 samples showed mixed infection (8.7%). In our study, C.albicans (61.5%) was the predominant species and among the non-albicans Candida, C. tropicalis (18.5%) was the commonest species. Conclusion: Certainly CHROMagar Candida will be useful as a primary culture medium for identifying the yeast infections directly from the clinical specimens and also for the detection of mixed yeast infections which cannot be done on conventional SDA. Hence it helps us in selecting the appropriate antifungal agents for therapy and prophylaxis. Keywords: Candida albicans, Non-albicans Candida, CHROMagar, Mixed yeast infections, Antifungal agents