Development of simultaneous resistance to fluconazole in Candida albicans and Candida dubliniensis in a patient with AIDS.

In this report, we describe a patient with recurrent episodes of oral candidosis who finally suffered from fluconazole-refractory oral and oesophageal candidosis. The patient was monitored for 4 years until his death from AIDS. During the observation period, persistent colonization with both Candida albicans and Candida dubliniensis was observed. From the appearance of the first episode of oral candidosis, the patient was treated with fluconazole for 18 months. The infection became unresponsive to fluconazole 400 mg/day. In vitro susceptibility testing revealed the development of resistance to fluconazole in C. albicans and C. dubliniensis. Molecular typing confirmed the persistence of the same C. albicans and C. dubliniensis strains which developed resistance after up to 3 years of asymptomatic colonization. This observation demonstrates that Candida spp. other than C. albicans may develop resistance to fluconazole in a patient who is repeatedly exposed to the drug.