In Vitro Amphotericin B Resistance in Clinical Isolates of Aspergillus terreus, with a Head-to-Head Comparison to Voriconazole.

D.A. SUTTON, S.E. SANCHE, S.G. REVANKAR, and M.G. RINALDI

Abstract: 

Arnphotericin B (AMB) therapy continues to be the gold standard in the treatment of invasive aspergillosis in the immunocompromised host. Although Aspergillus fumigatus (AF) and Aspergillus flavus (AF) constitute the major species, several reports have documented invasive pulmonary or disseminated disease due to the less common agent, Aspergillus terreus (AT). Despite high dose AMB, clinical outcomes with AT in this setting are dismal. We therefore sought to determine the in vitro susceptibility of a substantial number of clinical isolates of AT against AMB (101 isolates), and to evaluate the activity of a less toxic, potentially useful investigational triazole, voriconazole (VOR1) (68 isolates). Clinical isolates submitted to the Fungus Testing Laboratory from 1990 to 1998 were evaluated by a macro broth dilution method based on the National Committee for Clinical Laboratory Standards document M27-A, modified to accomodate mould testing. Testing parameters included an incubation temperature of 35°C, a final inoculum of 1 x 104} cfu/ml as determined by hemacytometer count, Antibiotic Medium 3 for AMB, and RPMI 1640 for VORI. Geometric means far AMB 48 hr MICs and MLCs were 3.37 and 9.89micro g/ml, respectively, with only 1.98% of the 48 hr MICs appearing susceptible (an MIC of
1998

abstract No: 

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Full conference title: 

38th Interscience Conference on Antimicrobial Agents and Chemotherapy
    • ICAAC 38th