Multicenter comparison of Fungitest for susceptibility testing of Candida species

In four laboratories the reproducibility of Fungitest, a colorimetric breakpoint method for antifungal susceptibility testing, was examined. The interlaboratory agreement of test results from 50 Candida strains was dependent on the antifungal agents and ranged from 56% to 100%. Itraconazole showed the poorest, amphotericin B and flucytosine (100% and 96%, respectively) the highest concordance. When minor discrepancies were disregarded the agreement increased to 94% to 100% for all agents. In total, major discrepancies were only seen in 2.7%. The overall agreement between concordant results and the NCCLS standard method was high, ranging between 96.4% and 100%. Generally, sensitive strains showed a better agreement with Fungitest. Since the concordance in multisite studies with Fungitest will always depend on the isolates chosen, further studies with this test are necessary.