APPEARANCE OF COLONIES OF PROTOTHECA ON CHROMAGAR CANDIDA-MEDIUM

The microorganisms capable of producing opportunist infections include the yeast-like organisms of the genus Candida, and the unicellular al gae of the genus Prototheca, which share common features and can, ther efore, lead to confusion. Their colonies are almost identical and they grow in the same culture media used routinely in mycology. CHROMagar Candida is a new chromogenic differential isolation medium that facili tates the presumptive differentiation of some of the most clinically i mportant yeast-like organisms. To our knowledge, the use of CHROMagar Candida with Prototheca spp. has not been reported in the literature. This report describes the growth of 151 strains of Prototheca on CHROM agar Candida compared to the growth of a total of 326 well-characteriz ed yeast organisms of the genera Candida, Cryptococcus, Trichosporon, Geotrichum, and Saccharomyces. It is clinically relevant to note that algae of the genus Prototheca (P. wickerhamii, P. zopfii, and P. stagn ora) and of the genus Candida parapsilosis produced similar cream-colo red colonies on CHROMagar Candida medium. Based on their growth CHROMa gar, a new species of Candida is described, C. zeylanoides, which has blue-green colonies. The colonies of two species of Trichosporon are a lso differentiated: the blue-green colonies of T. beigelii and the pin k colonies of T. capitatium.