Evaluation of Vitek 2 System and Chromagar for Identification of Yeasts in Clinical Laboratory

Abstract

BACKGROUNDSuccessfully identifying the species of Candida is important in the treatment and management of disease as resistance acquired by some species of Candida may avoid prescription of antifungal drugs that may not be available to species. AIMWe evaluated the performance of VITEK 2 system and CHROMagar in identification of Candida species against the conventional culture method. SETTINGS AND DESIGNThe study was conducted in a tertiary care hospital of Gujarat. METHODS AND MATERIALThe study was conducted over a period of 14 months. Candida species isolated from various clinical specimen were identified by conventional method as well as by VITEK 2 system and CHROMagar. The sensitivity and specificity of VITEK 2 system and CHROMagar was determined keeping conventional method as a gold standard method. RESULTSA total of 48 Candida species were identified by conventional method. Candida tropicalis (n=26) and Candida albicans (n=10) were most common isolates. VITEK 2 system was able to identify 36 (75%) isolates whereas CHROMagar was able to identify 45 (93.75%) isolates of Candida to species level. The sensitivity and specificity of CHROMagar for most common Candida species i.e. Candida albicans was 100% and 97.3% respectively whereas for Candida tropicalis was 100% and 95% respectively. The sensitivity and specificity of VITEK 2 system for Candida albicans was 100% whereas for Candida tropicalis was 76.92% and 100% respectively. CONCLUSIONSWe concluded that CHROMagar could be routinely used for identification of commonly isolated Candida species whereas VITEK 2 system could be used for determining MICs of antifungal agents.