Susceptibility to azoles and amphotericin B of isolates of Candida spp. Experience of a university health network, between 2004 and 2010

Objective: To describe antifungal susceptibility testing surveillance (December 2004-September 2010) in Candida spp., for amphotericin B, fluconazole and voriconazole, at the Laboratorio de Microbiologia, Pontificia Universidad Catolica de Chile. Method: The study was performed utilizing E test and included yeasts from invasive origin and isolates in which antifimgal susceptibility testing was asked for by the patient's physician. Results: The yeasts were mainly recovered from urine samples (n: 64), blood cultures (n: 51) and secretions (n: 24). Two hundred ninety three isolates were studied: C. albicans (38%), C. glabrata (30%), C. tropicalis (11%), C. parapsilosis (10%), C. krusei (4%) and others (7%). All Candida species were 100% susceptible to amphotericin B, except C. krusei (1/12). Fluconazole's global susceptibility in C. albicans was 91.8%, but 100% in isolates from blood cultures versus 76% in isolates from urine. C. tropicalis was 93.9% susceptible to fluconazole, C. parapsilosis, 90% and C. glabrata 30.3%. C. krusei had no susceptible isolates to fluconazole. Voriconazole resistance was mainly present in C. glabrata (11.5%). Conclusions: We recommend the study of antifungal susceptibility in isolates from invasive origin, selected urine strains and C. glabrata. Fluconazole remains effective in C. albicans from blood.