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. 2022 Feb;65(2):178-185.
doi: 10.1111/myc.13400. Epub 2021 Nov 29.

An expanded agar-based screening method for azole-resistant Aspergillus fumigatus

Jose Lucio  1 , Irene Gonzalez-Jimenez  1 , Rocio Garcia-Rubio  1 , Maria Soledad Cuetara  2 , Emilia Mellado  1   3
Affiliations

An expanded agar-based screening method for azole-resistant Aspergillus fumigatus

Jose Lucio et al. Mycoses. 2022 Feb.

Abstract

Antifungal susceptibility testing is an essential tool for guiding antifungal therapy. Reference methods are complex and usually only available in specialised laboratories. We have designed an expanded agar-based screening method for the detection of azole-resistant Aspergillus fumigatus isolates. Normally, identification of resistance mechanisms is obtained only after sequencing the cyp51A gene and promoter. However, our screening method provides azole resistance detection and presumptive resistance mechanisms identification. A previous agar-based method consisting of four wells containing voriconazole, itraconazole, posaconazole and a growth control, detected azole resistance to clinical azoles. Here, we have modified the concentrations of voriconazole and posaconazole to adapt to the updated EUCAST breakpoints against A. fumigatus. We have also expanded the method to include environmental azoles to assess azole resistance and the azole resistance mechanism involved. We used a collection of A. fumigatus including 54 azole-resistant isolates with Cyp51A modifications (G54, M220, G448S, TR53 , TR34 /L98H, TR46 /Y121F/T289A, TR34 /L98H/S297T/F495I), and 50 azole susceptible isolates with wild-type Cyp51A. The screening method detects azole-resistant A. fumigatus isolates when there is growth in any of the azole-containing wells after 48h. The growth pattern in the seven azoles tested helps determine the underlying azole resistance mechanism. This approach is designed for surveillance screening of A. fumigatus azole-resistant isolates and can be useful for the clinical management of patients prior to antifungal susceptibility testing confirmation.

Keywords: Aspergillus fumigatus; Cyp51A mutations; azole resistance; screening method; surveillance studies.

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References

REFERENCES

    1. Latgé J-P, Chamilos G. Aspergillus fumigatus and Aspergillosis in 2019. Clin Microbiol Rev. 2019;2019:33. 10.1128/CMR.00140-18
    1. Low CY, Rotstein C. Emerging fungal infections in immunocompromised patients. F1000 Med Rep. 2011;3:1-8. 10.3410/M3-14
    1. Nivoix Y, Velten M, Letscher-Bru V, et al. Factors associated with overall and attributable mortality in invasive aspergillosis. Clin Infect Dis. 2008;47:1176-1184. 10.1086/592255
    1. Taccone FS, Van den Abeele AM, Bulpa P, et al. Epidemiology of invasive aspergillosis in critically ill patients: clinical presentation, underlying conditions, and outcomes. Crit Care. 2015;19:1-15. 10.1186/s13054-014-0722-7
    1. Patterson TF, Thompson GR, Denning DW, et al. Practice guidelines for the diagnosis and management of aspergillosis: 2016 update by the infectious diseases society of America. Clin Infect Dis. 2016;63:e1-e60. 10.1093/cid/ciw326

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