Abstract
Summary Fungi isolated from mouthrinse specimens during episodes of acute pseudomembranous fungal stomatitis and deep-seated mycoses in patients with haematological malignancies were tested for susceptibility to seven antifungal agents. Topical treatment of stomatitis with clotrimazole or chlorhexidine did not induce any change in the susceptibility of oral Candida albicans. Treatment of deeper mycoses with 5-fluorocytosine, however, resulted in a significant increase in oral strains resistant to this agent. Of C. albicans strains isolated, 7% were resistant to 5-fluorocytosine ≫32 μg/ml. One patient died of disseminated mycosis during treatment with this drug; the resistant C. albicans was isolated from the mouth, liver, spleen and kidneys. Strains of Torulopsis glabrata and C. krusei resistant to 5-fluorocytosine were also found in some patients. Organisms resistant to 5-fluorocytosine were generally sensitive to polyenes and imidazoles.