RESUMO
Thirty Candida isolates obtained from the oropharynxes of three AIDS patients were genotypically characterized. In vitro fluconazole MIC determination revealed increasing fluconazole resistances during treatment, thereby confirming the in vivo situation. Pulsed-field gel electrophoresis karyotyping, randomly amplified polymorphic DNA analysis, and hybridizations with Candida albicans repetitive element 2 were used to determine possible genotypic changes. The isolates from two patients showed genetic homogeneity, suggesting the selection for resistant variants. One patient experienced a strain switch to Candida krusei. Horizontal spread of identical strains between the patients could be excluded. However, the molecular methods used might not be sufficient to detect the underlying genetic basis of resistance to fluconazole.
Assuntos
Infecções Oportunistas Relacionadas com a AIDS/microbiologia , Candida/genética , Fluconazol/farmacologia , Sequência de Bases , Candida/efeitos dos fármacos , Candida/isolamento & purificação , Candida albicans/genética , Estudos de Coortes , Resistência Microbiana a Medicamentos , Eletroforese em Gel de Campo Pulsado , Feminino , Genótipo , Humanos , Cariotipagem , Masculino , Testes de Sensibilidade Microbiana , Dados de Sequência Molecular , Família Multigênica , Hibridização de Ácido Nucleico , Reação em Cadeia da PolimeraseRESUMO
After repeated use of fluconazole for therapy of oropharyngeal candidosis, the emergence of in vitro fluconazole-resistant Candida albicans isolates (MIC, > or = 25 micrograms/ml) together with oral candidosis unresponsive to oral dosages of up to 400 mg of fluconazole were observed in patients with human immunodeficiency virus (HIV) infection. Antifungal susceptibility testing was done by broth microdilution and agar dilution techniques on C. albicans isolates recovered from a cohort of patients with symptomatic HIV infection who were treated repeatedly with fluconazole for oropharyngeal candidosis. In vitro findings did show a gradual increase in the MICs for C. albicans isolates recovered from selected patients with repeated episodes of oropharyngeal candidosis. Primary resistance of C. albicans to fluconazole was not seen. Cross-resistance in vitro occurred between fluconazole and other azoles (ketoconazole, itraconazole), but to a lesser extent. The results of the study suggest that the development of clinical resistance to fluconazole could be clearly correlated to in vitro resistance to fluconazole. Itraconazole may still serve as an effective antifungal agent in patients with HIV infection and oropharyngeal candidosis nonresponsive to fluconazole.
Assuntos
Infecções Oportunistas Relacionadas com a AIDS/microbiologia , Candida albicans/efeitos dos fármacos , Candidíase Bucal/microbiologia , Fluconazol/farmacologia , Infecções Oportunistas Relacionadas com a AIDS/tratamento farmacológico , Antifúngicos/farmacologia , Candida albicans/genética , Candida albicans/isolamento & purificação , Candidíase Bucal/tratamento farmacológico , Estudos de Coortes , Resistência Microbiana a Medicamentos , Evolução Fatal , Feminino , Humanos , Masculino , Testes de Sensibilidade MicrobianaRESUMO
In patients with AIDS and recurrent oropharyngeal candidosis results of biotyping and serotyping were compared with antifungal susceptibility testing. Biotype B1 was found predominantly with 44.3% from 169 C. albicans isolates. Serotype A was seen in 150/169 C. albicans isolates. No close correlation between high MIC values (> or = 25 micrograms/ml) for C. albicans isolates against fluconazole nor a change to a particular biotype or serotype has been observed in recurrences of oral candidosis.