title: In vitro susceptibility of respiratory isolates of Aspergillus species to itraconazole and amphotericin B. acquired resistance to itraconazole.
abstract: 122 Aspergillus strains were isolated from respiratory specimens from 80 patients. Aspergillus fumigatus was the most common species, constituting 88% of the isolates. Susceptibility testing by the NCCLS broth macrodilution procedure revealed that the minimal inhibitory concentration 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 itraconazole use in treatment of Aspergillus infection have been documented. We identified 3 patients infected with A. fumigatus strains that acquired in vitro resistance to itraconazole during prolonged therapy. This finding supports the importance of susceptibility testing.
authors.affiliation: Department of Laboratory Medicine, Karolinska Institute and Hospital, Stockholm, Sweden.
authors.forename: E
authors.initials: E
authors.lastname: Chryssanthou
mesh_terms: D000666:Amphotericin B / Q000494:pharmacology*; D000935:Antifungal Agents / Q000494:pharmacology*; D001228:Aspergillosis / Q000188:drug therapy; D001230:Aspergillus / Q000187:drug effects*; D004352:Drug Resistance, Microbial; D006801:Humans; D017964:Itraconazole / Q000494:pharmacology*; D008826:Microbial Sensitivity Tests; D012141:Respiratory Tract Infections / Q000188:drug therapy
chemical_list: D000935:Antifungal Agents; D017964:Itraconazole; D000666:Amphotericin B