In vitro susceptibility to antifungal agents of clinical and environmental Cryptococcus neoformans isolated in southern of Brazil

Abstract

Comparou-se a suscetibilidade de 69 amostras de C. neoformans isoladas de pacientes com SIDA com 13 amostras de C. neoformans isoladas do meio ambiente, frente a quatro agentes antifúngicos. Com base na metodologia preconizada pelo NCCLS (M27-A) as concentrações inibitórias mínimas (CIMs) obtidas para a anfotericina B, itraconazol e cetoconazol foram muito semelhantes nos dois grupos estudados. Todavia, frente ao fluconazol, os isolados clínicos evidenciaram menor sensibilidade do que os provenientes do meio ambiente. Alguns aspectos envolvendo a importância e dificuldades dos testes de suscetibilidade com Cryptococcus neoformans são também discutidos pelos autores.

The purpose of the present study was to compare the susceptibility to four antifungal agents of 69 Cryptococcus neoformans strains isolated from AIDS patients with that of 13 C. neoformans strains isolated from the environment. Based on the NCCLS M27- A methodology the Minimal Inhibitory Concentrations (MICs) obtained for amphotericin B, itraconazole and ketoconazole were very similar for clinical and environmental isolates. Clinical isolates were less susceptible to fluconazole than environmental isolates. The significance of these findings and aspects concerning the importance, role and difficulties of C. neoformans susceptibility testing are also discussed.