Evaluation of the morphological characteristics of Candida species on chromogenic agar medium and media for chlamydospore production

Abstract

Background: Candida is a widespread pathogen with various clinical forms. By testing chlamydospore production and culturing on chromogenic agar, C. albicans and some species of C. non-albicans could be identified. Objectives: 1. To study the morphological characteristics of Candida species on Brilliance Candida agar and chlamydospore production media; 2. To evaluate the Candida species identification value of Brilliance Candida agar and chlamydospore production media. Materials and methods: 75 Candida isolates belonging to five species were identified by MALDI-TOF MS and stored. These isolates were cultured on Brilliance Candida agar and chlamydospore production media. Results: On Brilliance Candida agar: 100% of C. albicans isolates grew well and had green colonies after 24 hours, 100% of C. tropicalis isolates grew well and had blue color colonies after 48 hours; isolates of C. krusei, C. parapsilosis, and C. glabrata had different coloured colonies after 12 - 48 hours. In addition, C. krusei colonies were dry and wrinkled, compared to the other species’colonies, which were creamy, soft, and convex. 83-100% of C. albicans isolates produced chlamydospores after 3 days. The specificity of the Brilliance Candida agar culture and chlamydospore production test was 100% in identifying C. albicans. The sensitivity of Chromogenic Agar was 100% for C. albicans identification and 83%-100% for chlamydospore production after 3 days. The specificity and sensitivity of Chromogenic Agar in identifying C. tropicalis was 100% after 48 hours. Conclusions: Brilliance Candida agar had high specificity and sensitivity in identifying C. albicans after 24 hours and C. tropicalis after 48 hours. Chlamydospore production test had high specificity and sensitivity in identifying C. albicans at 3 days Key words: Candida, chromogenic agar, chlamydospore