Azole resistance in Aspergillus isolates from animals or their direct environment, 2013 ─ 2023: a systematic review

Lucía Dieste-Pérez ^* Manon M.C. Holstege Judith E. de Jong Annet Heuvelink ^*

• Royal GD, Deventer, Netherlands

Resistance of Aspergillus species to azoles in human medicine is getting more attention, and the role that animals and agricultural play here is becoming an important source of concern. In order to get better insights into the occurrence of azole resistance in Aspergillus spp. isolates from animals, a systematic literature review was carried out. Searches were performed in PubMed and Scopus databases for articles dealing with azole resistance in Aspergillus spp. isolates from both animals and their direct environment, published from 2013 until 2024. Descriptive clinical cases were analysed apart from articles providing in-vitro susceptibility test results. MIC50 and MIC90 values as well as the number of non-wild type (NWT) isolates were either directly extracted from the article or calculated based on published results of individual isolates or MIC distributions. Seventy-three out of 2042 articles were finally included in the analysis. Articles reporting clinical cases only included horses, dogs, cats, and zoo animals & wildlife, most of them occurring outside Europe. In general, successful clinical remission or recovery followed long and continuous fungicide azole treatments, regardless the azole -Aspergillus spp. -animal category combination. Itraconazole was the most common treatment described in clinical cases in companion animals (dogs and cats) and horses. The weighted geometric mean of the MIC50 values of itraconazole was lowest for A. fumigatus isolates for the animal category companion animals. Zoo animals & wildlife were treated often with voriconazole, and the weighted geometric mean of the MIC50 values of this and other azoles were equal to or somewhat lower than those calculated for A. fumigatus isolates from other animal categories. NWT A. fumigatus isolates were reported for both zoo animals & wildlife, horses, companion animals, and poultry, for several azoles, both occurring in Europe as well as outside Europe, and in healthy and sick animals. In conclusion, zoo animals & wildlife, horses and poultry, represent a higher concern regarding the occurrence of A. fumigatus and A. flavus NWT isolates than other animal categories. Lacking data did not allow for conclusions specifically concerning the situation in Europe and more systematic and comparable data is therefore required.