IN-VITRO SUSCEPTIBILITY OF RESPIRATORY ISOLATES OF ASPERGILLUS SPECIES TO ITRACONAZOLE AND AMPHOTERICIN-B - ACQUIRED-RESISTANCE TO ITRACONAZOLE

122 Aspergillus strains were isolated from respiratory specimens from 80 patients, Aspergillus fumigatus was the most common species, consti tuting 88% of the isolates, Susceptibility testing by the NCCLS broth macrodilution procedure revealed that the minimal inhibitory concentra tion for 50% of the strains (MIC50) was 0.25 mg/l for itraconazole and 0.5 mg/l for amphotericin B. The MIC90 was 1 mg/l for both drugs, To our knowledge, no cases of in vitro resistance during long-term itraco nazole use in treatment of Aspergillus infection have been documented. We identified 3 patients infected with A. fumigatus strains that acqu ired in vitro resistance to itraconazole during prolonged therapy. Thi s finding supports the importance of susceptibility testing.