Azole-resistant environmental aspergilli and Aspergillus terreus in Denmark, Austria and Spain

Abstract number: O344

Mortensen K., Mellado E., Lass-Flörl C., Tudela J.L., Arendrup M.

Objectives: To investigate if azole resistant aspergilli and A. terreus are present in the environment and in commercial compost in Denmark (DK), Austria (A) and Spain (ES).

Methods: Soil samples were collected from the surroundings of the main hospitals in Copenhagen (CPH) (27), Innsbruck (25) and Madrid (31), flowerbeds in an amusement park in the centre of Copenhagen (23) and finally from compost bags purchased in DK (26), A (25) and ES (28).

Two grams of soil/compost were suspended in 5 ml 0.2 M NaCl-1% Tween and 100 ml plated on Sabouraud agar and 50 ml on each of 4 RPMI-1640–2% glucose agars containing itraconazole (4 mg/l), voriconazole (1 mg/l), posaconazole (0.5 mg/l) and no antifungal, respectively, and incubated at 37°C. Identification of aspergilli was based on standard micro- and macro-morphological criteria. Aspergillus isolates which grew on the azole containing agars underwent susceptibility testing using EUCAST E.DEF 9.1 microdilution method for itraconazole, posaconazole and voriconazole and b-tubulin sequencing unless they were able to grow at 48°C. The promoter and entire coding sequence of the cyp51A gene were sequenced for azole resistant isolates.

Results: From a total of 185 samples A. fumigatus was recovered in 139 (DK: 50/76, 66%; A: 49/50, 98%; ES: 40/59, 68%), A. niger in 36 (DK: 4/76, 5%; A: 5/50, 10%; ES: 27/59, 46%), A. terreus in seven (DK: 0/76; A: 7/50, 14%; ES: 0/59), A. nidulans in four (DK: 1/76, 1%; A: 0/50; ES: 3/59, 5%), A. flavus in three (DK: 2/76, 3%; A: 0/50; ES: 1/59, 2%), A. lentulus (ES: 1) and A. spp (ES: 2, molecular identification pending). A total of four A. fumigatus isolates (three from the amusement park in CPH and one from surroundings of CPH University Hospital (CPHUH)) displayed elevated MICs to itraconazole (>4 mg/l), posaconazole (0.5–4 mg/l) and voriconazole (4– >4 mg/l). All harboured the TR-L98H resistance mechanism. Additionally, one A. nidulans and one A. niger with elevated itraconazole MICs of 4 mg/l and 2 mg/l, respectively, were recovered from CPHUH.

Conclusion: Multi-azole resistant A. fumigatus is present in the environment in DK. The resistance mechanism is identical to that of environmental isolates in the Netherlands. In ES and A only Aspergillus species with intrinsic resistance to either azoles or amphotericin B were found. No link to commercial compost could be detected. Resistant aspergilli should be considered in aspergillosis, even in antifungal drug-naïve patients.

Session Details

Date: 10/04/2010
Time: 00:00-00:00
Session name: Abstracts 20th European Congress of Clinical Microbiology and Infectious Diseases
Location: Vienna, Austria, 10 - 13 April 2010
Presentation type:
Back to top