Evaluation of the New Chromogenic Medium Candida ID 2 for Isolation and Identification of Candida albicans and Other Medically Important Candida Species

Abstract

The usefulness of Candida ID 2 (CAID2) reformulated medium (bioMérieux, France) has been compared with that of the former Candida ID (CAID; bioMérieux), Albicans ID 2 (ALB2; bioMérieux), and CHROMagar Candida (CAC; Chromagar, France) chromogenic media for the isolation and presumptive identification of clinically relevant yeasts. Three hundred forty-five stock strains from culture collections, and 103 fresh isolates from different clinical specimens were evaluated. CAID2 permitted differentiation based on colony color between Candida albicans (cobalt blue; sensitivity, 91.7%; specificity, 97.2%) and Candida dubliniensis (turquoise blue; sensitivity, 97.9%; specificity, 96.6%). Candida tropicalis gave distinguishable pink-bluish colonies in 97.4% of the strains in CAID2 (sensitivity, 97.4%; specificity, 100%); the same proportion was reached in CAC, where colonies were blue-gray (sensitivity, 97.4%; specificity, 98.7%). CAC and CAID2 showed 100% sensitivity values for the identification of Candida krusei. However, with CAID2, experience is required to differentiate the downy aspect of the white colonies of C. krusei from other white-colony-forming species. The new CAID2 medium is a good candidate to replace CAID and ALB2, and it compares well to CAC for culture and presumptive identification of clinically relevant Candida species. CAID2 showed better results than CAC in some aspects, such as quicker growth and color development of colonies from clinical specimens, detection of mixed cultures, and presumptive differentiation between C. albicans and C. dubliniensis.

Identification and characterization of nine atypical Candida dubliniensis clinical isolates

“…In our hands, group I isolates showed different shades of green colour that hindered their positive identification as C. albicans or C. dubliniensis. Our results for this group of strains are consistent with other reports in the literature (Eraso et al, 2006a;Pincus et al, 1999;Tintelnot et al, 2000). The remaining uncommon isolates (group II) developed pink colonies, which is inconsistent with either C. albicans or C. dubliniensis.…”

Characterization and Susceptibility Pattern of Candida Isolates From Hiv - Seropositive Patients in a Tertiary Care Hospital

“…A major advantage is the ability to detection of mixed cultures of yeast in clinical specimens. Hence CHROM agar Candida would be a useful, cost effective tool for rapid identification of various Candida species directly from clinical samples 2,5,9,21 .…”

Strengths and Limitations of different Chromogenic Media for the Identification of <i>Candida</i> Species

“…An appropriate primary cu lture med iu m that assists in the recovery and differentiation of colonies which are phenotypically similar is a vital requirement for the laboratory detection of mixed fungal clinical specimens. Traditional methods for identification of yeast pathogens involves several days and specific mycology media wh ile chromogenic med ia contains chromogenic substrates which react with enzy mes secreted by the organisms to give colour reactions for d ifferent species [9] thus complementing traditional methods of identification [11]. CHROMagar™ Candida is the most well-known and widely used chromogenic mediu m for the identificat ion of different Candida species and is the most expensive of the five chromogenic media .…”

“…To ma ke a precise differentiation between the two species requires PCR-based tests, but due to the high quantities of throughput samples at diagnostic laboratories, this is not feasible and thus PCR-based tests are mostly used in research laboratories [7]. Looking at the phenotypic characteristics is much mo re inexpensive than that of the genotypic characteristics, and scientists have therefore demonstrated the use of selective and differential media for the presumptive identificat ion of Candida species with good sensitivity and specificity [8], thereby reducing the time used for isolation, identification and detection in mixed cultures [9].…”