TABLE 1.

In vitro activities of voriconazole and isavuconazole against Aspergillus spp. by the CLSI M38-A procedurea

Isolate group (n)Voriconazole MICIsavuconazole activity
MICMFC
GM90%50%RangeGM90%50%RangeGM90%50%Range
A. fumigatus (602)0.47710.50.125-20.822110.125-40.834110.125-4
A. flavus (34)0.652110.125-20.752110.25-20.799110.5-2
A. niger (32)0.771110.25-21.189210.25-41.215210.25-4
A. terreus (25)0.624110.25-10.660110.125-10.753110.25-2
Other Aspergillus spp.b (9)0.125-80.25-40.25-16
Environmental strains (302)0.54210.50.125-80.859110.25-40.893110.25-16
Clinical strains (400)0.42710.50.125-20.82710.50.125-20.818110.125-2
Overall (702)0.47310.50.125-80.827110.125-40.850110.125-16
  • a Activities are given for the most clinically relevant species and overall. All MICs and MFCs are expressed in micrograms per milliliter. GM, geometric mean. For the two azoles against Aspergillus spp., the MIC end point was defined as the lowest concentration that produced complete inhibition of growth (MIC-0) after 48 h of incubation.

  • b Due to the limited number of strains, antifungal activity is expressed only as a range of concentrations.