In vitro susceptibilities of invasive fungi isolated from Austrian patients against echinocandins and commonly used azoles

B. Willinger, L. Sittenthaler, E. Steiner, A.M. Hirschl, C. Lass-Flörl

Author address: 

Vienna, Innsbruck, AT

Abstract: 

Objective: The aim of the study was to determine the in vitro susceptibilities of invasive fungal isolates collected since June 2008 by 20 different Austrian medical centres against commonly used azoles and the three available echinocandins. Methods: The clinical samples yielding the growth of fungi included blood cultures and other sterile specimens such as intravascular catheters, biopsies or aspirates, samples from the lower respiratory tract. Antifungal susceptibility for yeasts was assessed using a broth microdilution method following the Clinical Laboratory Standards Institute M27-A3 guidelines whereas moulds were tested as described by the European Committee on Antimicrobial Susceptibility Testing. For moulds also amphotericin B was tested. Results: So far 552 yeast isolates have been collected. C. albicans, followed by C. glabrata, C. parapsilosis and C. tropicalis were the most common isolated species. In addition we tested 35 strains of filamentous fungi including 26 strains of different Aspergillus species and 5 strains of zygomycetes. For Candida species, the MIC50 and MIC90 were 0.5 mg/l and 8 mg/l for fluconazole, 0.03 mg/l and 0.25 mg/l for voriconazole, 0.25 mg/l and 1.0 mg/l for caspofungin, 0.03 mg/l and 0.25 mg/l for anidulafungin, 0.25 mg/l and 0.5 mg/l for micafungin, respectively. Thus, the agent with the best in vitro activities for the azoles was voriconazole and for the echinocandins anidulafungin. Only 4.6% of Candida isolates were resistent to fluconazole, 2.0% to voriconazole, 0.5% to anidulafungin, 0.4% to caspofungin and 0.7% to micafungin respectively. 15.5% of C. glabrata strains were resistant to fluconazole, and 10.9% to voriconazole. Concerning the echinocandins elevated MICs were observed for C. glabrata, C. parapsilosis, C. guilliermondii and C. lusitaniae. For Aspergillus species, the MIC50 and MIC90 were 1.0 mg/l and 8 mg/l for amphotericin B, 0.5 mg/l and 2 mg/l for voriconazole, 0.5 mg/l and 1.0 mg/l for posaconzole. Concerning the echinocandins, only five strains showed MICs below 8 mg/l. For the zygomycetes, the MICs were within the expected range. Conclusion: Up to date our multicenter study reveals no evidence of emerging azole or echinocandin resistance among invasive clinical isolates of Candida spp. The MICs assessed for mould were within the expected range.
2010

abstract No: 

P836

Full conference title: 

20th European Congress of Clinical Microbiology and Infectious Diseases
    • ECCMID 20th (2010)