TABLE 2.

In vitro activities of voriconazole and isavuconazole against Fusarium spp., Scedosporium spp., and Zygomycetes by the CLSI M38-A procedurea

Isolate group (n)Voriconazole MIC-0, MIC-1Isavuconazole activity
MIC-0, MIC-1MFC
GM90%50%RangeGM90%50%Range90%50%Range
Zygomycetesb
    Mucor (21)>16, >16>16, 162->16, 2->1616, 82, 11->16, 0.25-16>1682->16
    Rhizopus (12)>16, >168, 88->16, 4->1616, 41, 0.51-16, 0.5-4>1641->16
    Absidia (6)16->16, 4->161-16, 0.5-84->16
    Cunninghamella (4)16->16, 8-162-16, 0.5-816->16
    Syncephalastrum (2)4->16, 2-160.25-8, 0.125-41-16
    Overall (45)>16, >16>16, 162->16, 2->163.364, 1.50616, 82, 10.25->16, 0.125-16>1641->16
S. apiospermum (16)1, 0.50.5, 0.250.25-8, 0.125-44, 24, 10.5-8, 0.06-8>1682->16
S. prolificans (6)16->16, 4-8>16, 4-16>16
Overall (22)1.438, 0.571>16, 80.5, 0.250.25->16, 0.125-85.040, 1.257>16, 84, 10.5->16, 0.06-16>16>162->16
Fusarium spp. (20)7.727, 3.60516, 84, 41->16, 1-816.564, 11.314>16, >1616, 161->16, 2->16>16>164->16
  • a Activities are given for the most clinically relevant genera of Zygomycetes and overall. All values are expressed as micrograms per milliliter. GM, geometric mean. For the two azoles against Fusarium spp., Scedosporium spp., and Zygomycetes, the MIC end point was defined as the lowest concentration that produced complete inhibition of growth (MIC-0). We also calculated MIC-1, defined as the lowest concentration that produced slight growth or approximately 25% of that of the growth control.

  • b MICs for Zygomycetes were read after 24 h of incubation.