In vitro susceptibilities of Malaysian clinical isolates of Cryptococcus neoformans var. grubii and Cryptococcus gattii to five antifungal drugs

Abstract

The in vitro susceptibilities of Malaysian clinical isolates of Cryptococcus neoformans var. grubii and C . gattii to five antifungal drugs (amphotericin B, flucytosine, fluconazole, itraconazole and ketoconazole) were determined using the Etest method. None of the Malaysian isolates was resistant to amphotericin B and ketoconazole. Isolates resistant to flucytosine, fluconazole and itraconazole were observed in this study. Minimum inhibition concentrations (MICs) of > or = 32 microg ml(-1) against flucytosine, > or = 64 microg ml(-1) against fluconazole and > or = 1 microg ml(-1) against itraconazole were noted in four (8.3%), two (4.2%) and one (2.1%) isolates respectively. There was no significant difference in the MICs for both Cryptococcus species (P > 0.05), indicating that C. gattii was as susceptible as var. grubii to all the antifungal drugs tested. No significant difference in the MICs for both Cryptococcus species collected from 1980 to 1990 and 2002 to 2004 were observed (P > 0.05).

Results from the ARTEMIS DISK Global Antifungal Surveillance Study, 1997 to 2005: an 8.5-Year Analysis of Susceptibilities of Candida Species and Other Yeast Species to Fluconazole and Voriconazole Determined by CLSI Standardized Disk Diffusion Testing

“…This species has long been noted to be an important opportunistic pathogen in tropical and subtropical climates and has recently gained importance due to an outbreak of C. gattii on Vancouver Island, BC, Canada (10,15,39). The decreased susceptibility of this species of Cryptococcus to fluconazole is similar to that observed by other investigators (14,42,43), although a recent report from Africa found low MICs to fluconazole and other azoles (15). Both C. gattii and C. neoformans were very susceptible to voriconazole in the present study (Table 9).…”

In vitro antifungal susceptibility profiles and genotypes of 308 clinical and environmental isolates of Cryptococcus neoformans var. grubii and Cryptococcus gattii serotype B from north-western India

“…grubii, which agrees with several previous reports (Fernandes et al, 2003;Trilles et al, 2004;Khan et al, 2007Khan et al, , 2009Gomez-Lopez et al, 2008). However, there is divergence of results concerning the antifungal susceptibility patterns of the two species in some other studies, which reported no such difference (Chen et al, 2000;Calvo et al, 2001;Morgan et al, 2006;Tay et al, 2006;Thompson et al, 2009). This divergence in results may be due to a possible lack of uniformity in the methodologies of testing adopted by different investigators.…”

Molecular typing and in vitro antifungal susceptibility of Cryptococcus spp from patients in Midwest Brazil

“…Studies conducted in several parts of the world have shown low MIC 50 and MIC 90 values for fluconazole against C. neoformans VNI [43][44][45]. In this study, the MIC 50 and MIC 90 values for fluconazole were 4-8 mg/L; however, higher values (2-128 mg/L) have been reported for isolates of C. neoformans VNI [46].…”

“…High MIC values (≥ 64 mg/L) have been reported for fluconazole against C. gattii [44,47], in contrast to this study, which determined values ≤ 16 mg/L. Hagen et al [48] analyzed 350 isolates of C. gattii originating from clinical, environmental and animal sources and reported that MIC values for flucytosine and fluconazole were higher, i.e.…”