Cryptococcus neoformans, the etiological agent of cryptococcosis, is yeast, which causes life-threatening infections. Among 143 samples of C. neoformans, eighty-three samples were isolated from 38 AIDS patients, in different time, from several areas of Sao Paulo between 1994 to 1997. The remaining sequential isolates came from 35 patients. The sampling from Rio de Janeiro was composed by sixty samples isolated at intervals from 20 AIDS patients between 1995 to 2000. All the patients had at least one sequential isolates. Susceptibility to antifungals was tested in accordance with NCCLS (M-27A). The molecular typing was analyzed by PCR-based random amplified polymorphic DNA assay (RAPD). Seventy-nine isolates from Sao Paulo were C. neoformans var. neoformans and four C. neoformans var. gattii. C. neoformans var. neoformans was the predominant species isolated in Rio de Janeiro. The minimum inhibitory concentration (MIC) varied in a range of 0.5 to 16.0 µg/ml for fluconazole; 0.0313 to 1.0 µg/ml for itraconazole; 2.0 to 16.0 µg/ml for 5-flucytosine, and 0.0313 to 1.0 µg/ml for amphotericin B. Six patients presented one isolate with a MIC for fluconazole 2 and 3 dilutions higher than the other isolates; 5 for 5-FC, 4 for ITR and 2 for AMB. Analysis of our findings showed that the majority isolates from Sao Paulo and Rio de Janeiro included in this study had 80 to 100 % similarity, and that despite this genetic similarity, they could be identified different genotypes with our primer. Serial isolates had been investigated to answer the question if a single patient is infected by one or more strains and also if a recurrent infection is caused by the same or a new strain.
Full conference title:
The 15 th Congress of the International Society for Human and Animal Mycology
- ISHAM 15th (2003)