In Vitro Activity of the New Azole Isavuconazole (BAL 4815) Compared with Six other Antifungal Agents against 155 Cryptococcus neoformans Isolates from Cuba

M.T. Illnait-Zaragozi, I. Curfs-Breuker, G.F. Martinez, C.M. Fernandez, T.Boekhout, J.F. Meis


Background: There are no data regarding the antifungal susceptibility of Cryptococcus neoformans (CN) isolates from Cuba. A collection of clinical and environmental isolates has been used for comparison of the in vitro activity of 7 antifungal agents.
Methods: 110 meningitis (80% AIDS patients) isolates and 45 environmental isolates were included. MICs were determined for amphotericin B (AmB), flucytocine (5FC), fluconazole (FLU), itraconazole (IT), voriconazole (VOR), posaconazole (POS) and Isavuconazole (ISA). Micro dilution testing was done in accordance with CLSI M27-A2 guidelines in RPMI 1640 MOPS broth with L-glutamine without bicarbonate. Plates were incubated at 35oC for 72 hrs. The MIC was determined visually and spectrophotometrically as the lowest concentration of drug showing absence of growth or ≥ 50% reduction of growth compared with that of the growth control for AMB and 5FC, and azoles, respectively.
Results: The MIC90 of the clinical isolates for AmB, 5FC, FLU, IT, VOR, POS and ISA were 0.25, 8, 4, 0.25, 0.125, 0.125 and 0.031 mg/L respectively. No significant differences between visual and spectrophotometric reading and between environmental and clinical isolates were observed.
Conclusions: Reported acquired drug resistance to AmB, 5FC, FLU, or IT in CN was not observed in this study with Cuban isolates. AmB, 5FC, IT, VOR, and POS are active antifungal agents. ISA, with the lowest MIC90 seems to be a promising alternative drug for treating cryptococcal infections.


abstract No: 

    • ICAAC 46th