Background: Effective treatment options for invasive filamentous fungal infections are needed. Echinocandins and the new triazoles may hold promise for these difficult infections. We compared the in vitro activity of caspofungin (CASP), posaconazole (POSA), voriconazole (VORI), ravuconazole (RAVU) itraconazole (ITRA) and amphotericin B (AMB) against a large collection of clinical mould isolates. Methods: 462 clinical isolates of filamentous fungi (including 257 A. fumigatus, 30 A. flavus, 29 A. niger, 21 A. versicolor, 16 A. terreus, 37 Penicillium spp., and 11 Fusarium spp.) were collected during 2000-2001 from 15 centers in the US and Canada. Minimum inhibitory concentrations (MICs) were determined according to the NCCLS M38-P method. The endpoint for reading CASP was the minimum effective concentration (MEC). The % inhibited at 61603; 1 µg/ml and the MIC/MEC 90s were compared. Results: Among the triazoles, POSA was most active, inhibiting 95% of isolates at 61603; 1 µg/ml, followed by VORI (92%), RAVU (91%), and ITRA (79%). CASP and AMB inhibited 93% and 89% of isolates at 61603; 1 µg/ml, respectively, with CASP demonstrating an MEC 90 of 0.12 µg/ml. All 3 new triazoles and CASP inhibited >95% of Aspergillus spp. at 61603; 1 µg/ml, compared to 83% for ITRA and 91% for AMB. AMB inhibited only 38% of A. terreus isolates at 61603; 1 µg/ml, while the 3 new triazoles and CASP inhibited all A. terreus at 61603; 0.5 µg/ml. No agent had good in vitro activity against Fusarium (MIC/MEC 90s >8µg/ml for all tested agents except AMB (MIC 90, 2 µg/ml)). RAVU and CASP were the most active agents against Penicillium spp.(>97% inhibited at 61603; 1 µg/ml). Conclusions: The new triazoles and CASP have excellent in vitro activity against a very large collection of recent clinical isolates of Aspergillus spp., and some in vitro activity against selected other filamentous fungi.
Full conference title:
- ICAAC 42nd