Objectives: Azole resistance of aspergillosis etiologic agents is an emerging problem in Europe and other parts of the world. The aim of the study: to determine susceptibility to voriconazole of Aspergillus spp. strains isolated from patients with aspergillosis in Saint Petersburg, Russia.
Methods: Fungal species identification was done using morphological and molecular methods. A total of 230 strains of Aspergillus spp. isolated from biological samples of patients with different clinical forms of aspergillosis (invasive, chronic and allergic) in Saint Petersburg during 2014 – 2019 yrs. have been tested by standard disk diffusion method according to CLSI M51A Document. For 34 strains MICs of voriconazole have been determined according to EUCAST Document E Def 9.3.1.
Results: Species distribution among Aspergillus spp. isolates was as follows: A. fumigatus – 68%, A. niger – 16%, A. flavus – 13%, rare species – 3% (A. terreus – 4 strains, A. calidoustus – 2, A. ustus – 1, A. sydowii – 1). By disk diffusion method no voriconazole resistant isolates were found among common species: A. fumigatus , A. niger, A. flavus. Only 4 resistant strains were revealed among rare species: A. terreus – 1, A. calidoustus – 2, A. ustus – 1 (inhibition zone diameter < 17 mm). Voriconazole MICs for A. fumigatus, A. flavus, A. niger strains ranged from 0,125 to 0,5 mg/L. Only A. calidoustus showed high MIC – 4 mg/L.
Conclusion: Resistance to voriconazole among etiologic agents of aspergillosis in Saint Petersburg, Russia was found only among rare fungal species (A. calidoustus, A. ustus, A. terreus). Future surveillance is necessary to monitor antifungal resistance.
Full conference title:
- TIMM (2019)