C-214. Comparison of HardyCHROMTM Candida with the Vitek Yeast Biochemical Card Identification System for the Identification of Common Yeast Pathogens

W. Phillips1, M. Sarina2, T. Zumwalt2, R. Clasen1, J. Hardy1;
1Hardy Diagnostics, Santa Maria, CA, 2Central Coast Pathology Consultants, San Luis Obispo, CA.

Candida species are common human commensals that are capable of causing a wide variety of diseases. In the past, invasive candidiasis was most commonly associated with Candida albicans, but recently other species, such as C. glabrata, have become common causative agents for this type of infection. In the last few years candidiasis has been steadily increasing in the United States, and is now considered to be the fourth most common cause of nosocomial septicemia. Since these types of infections have an estimated fifty percent mortality rate, early detection is vital to ensure proper diagnosis and treatment. In an effort to expedite clinical identification and to save labor and supply costs a study was performed by Central Coast Pathology to assess the effectiveness of HardyCHROMTM Candida for species identification. HardyCHROMTM Candida contains chromogenic substrates that interact with the unique enzymes produced by the most common strains of pathogenic Candida spp., which allows for species identification based solely on colony morphology and color. Strains of C. albicans, C. tropicalis, and C. krusei can be identified within 48 hours without further additional testing, while strains of C. glabrata can be presumptively identified. In this study a total of 101 clinical isolates were identified with both HardyCHROMTM Candida and the Vitek Yeast Biochemical Card identification system. Out of the 101 isolates tested, HardyCHROMTM Candida was found to have a 99% specificity rate when compared to the Vitek Yeast Biochemical Card identification system. The few isolates that were not easily identified on this media were unusual clinical strains such as C. kefyr, C. guilliermondii, and C. parapsilosis. Overall this study suggests that the chromogenic medium, HardyCHROMTM Candida is an accurate and cost effective way to differentiate and identify commonly isolated clinical Candida strains.