TABLE 4.

Correlation between inhibition zone diameters (in millimeters) obtained by the disk diffusion method and reference M38-A MICs (amphotericin B and triazoles) and MECs (caspofungin) for 483 mold isolates at three of the five centersa

Antifungal agent and incubation time (h)bCorrelation coefficient (R value)c for:
MHMGM
Itra
    240.79ND
    480.750.58
    720.740.67
Posa
    240.77ND
    480.710.65
    720.710.71
Vori-1
    240.85ND
    480.830.87
    720.820.53
Vori-10
    240.83ND
    480.800.85
    720.830.58
Cas-BBL
    240.92ND
    480.880.96
    720.900.87
Cas-Oxoid
    240.93ND
    480.890.88
    720.900.87
Amb
    240.68ND
    480.430.32
    720.310.54
  • a MICs were read at 24 h (zygomycetes), 72 h (Scedosporium sp.), and 48 h (other species) as recommended in the CLSI M38-A document. Caspofungin MECs were read at 24 h (all species except for Scedosporium sp., which were read at 48 h). Each MIC or MEC was plotted against inhibition zone diameters in millimeters obtained on both MH and MGM agars at each of the three incubation times; results from three centers were combined for linear regression analysis.

  • b Itra, itraconazole 10-μg disk; Posa, posaconazole 5-μg disk; Cas-BBL and Cas-Oxoid, caspofungin 5-μg disks from two sources; Vori-1 and Vori-10, voriconazole 1-μg and 10-μg disks, respectively; Amb, amphotericin B 10-μg disk.

  • c ND, not determined. The 48-h results for MGM medium encompassed 24- and 48-h zones of inhibition; 71% of the 24-h results were reported as no growth.