[Isolation, identification, and typing of yeasts from HIV-positive patients with oral candidiasis].

A study of oral candidiasis was conducted among 25 HIV-positive and AIDS patients. The predominant clinical form of presentation was the pseudomembranous one, whereas the most frequently yeast species found in the isolations were: Candida albicans (54.1%), Candida tropicalis (8.1%), and Torulopsis glabrata (8.1%). It was demonstrated that patients with recurrent infections have colonization of the oral cavity by multiple strains and/or yeast species more often (30.8%) than those through their first episode of oral candiadisis (12.5%). Of the 3 culture media used for the initial isolation, the combination of the potatodextrose agar (PDA) with Sabouraud triphenytletrazolium agar (STA) allowed to obtain the maximum isolation and differentiation among strains. The Sabouraud agar (SA), the most used medium to these ends at the international level, proved to be less useful than the previous ones. The STA was very efficient in the studies of phenotypic typing of most of the isolated yeast species and specially of C. albicans, which will make possible to approach epidemiological studies.