A simple medium for isolation and identification of Candida albicans directly from clinical specimens

Abstract

A simple and specific medium consisting of chitosan, trypticase, Tween-80 and agar is devised to isolate the organisms directly from the clinical specimens and to produce germ tubes and chlamydospores for rapid differentiation and identification of Candida albicans from other closely related Candida species. By manipulating the incubating conditions, the specific phase of the organism can be produced in liquid or on solid medium at different time intervals to study the physiology of the organism.

Many methods and media have been proposed in the past for identification of Candida albicans and to differentiate this from the closely related species of Candida (5–8, 15). Taschdjian, Burchall&Kozinn (15) showed that C. albicans produces germ tube within an hour or two when it is grown in human or animal serum or serum substitutes. The specificity of this germ tube test was later confirmed by various workers by using different media (3–5). The distinctive feature that differentiates C. albicans from other species is the production of chlamydospores (14). However, in all these studies three types of media were required to isolate the organisms from clinical specimens and to produce germ tubes and chlamydospores for identification. Recently studies have shown that a single medium can be employed to produce both structural components of the organism from the primary isolation medium but the preparation of the medium is more exhaustive (1) and time consuming (13) than the medium to be described here. The present investigation was therefore undertaken to develop a simple and specific medium to isolate the organism directly from the clinical specimens and to produce various morphological phases of Candida albicans to differentiate from other closely related Candida species for clinical diagnosis and to provide a medium to study the physiology and metabolism of the organism under in vitro conditions.