Determination of azole fungal residues in soils and detection of Aspergillus fumigatus-resistant strains in market gardens of Eastern France

Abstract

Medical azole antifungals are major compounds used to prevent and to treat invasive aspergillosis (IA). Azole fungicides, called DMI (14-alpha demethylase inhibitors), are also widely used for crop protection and have been reported to be linked to azole-resistant A. fumigatus (aR-Af) development in the environment. The aim of this study was to determine whether or not market gardens that spray DMIs in Eastern France are also affected by the presence of aR-Af. Forty aR-Afs were detected in soils in only two of the four market gardens using DMIs, with 23% (7/30) and 10% (3/30) of soils containing aR-Af. A total of 87.5% of these isolates had the TR34/L98H mutation and 22.5% the TR46/Y121F/T289A mutation on the cyp51A gene. Analyses of residual azole concentrations in soils showed the presence of difenoconazole for up to 2 years after spraying, but only in soils of market gardens where aR-Af was detected. It is very important to identify professional activities that could lead to aR-Af development and to develop preventive measures for at-risk patients living near professional activities using DMIs. We have to better understand why, in some cases, the use of DMI is not linked to aR-Af. Measures should be taken to avoid the use of DMI conferring cross-resistance to preserve the efficiency of human therapeutics.

First azole‐resistant Aspergillus fumigatus isolates with the environmental TR46/Y121F/T289A mutation in Iran

“…We report the presence of TR 46 /Y121F/T289A now also from Iran, where until now only TR 34 /L98H had been isolated . This mutation, conferring voriconazole resistance, has been reported from both environmental (China, Taiwan, United Kingdom, Colombia, France, Germany, India, the Netherlands and Tanzania) and clinical sources (Spain, United Kingdom, France, Portugal, Argentina, Taiwan, Germany, China, Japan, United States, Denmark, Belgium and the Netherlands) (Table 1). All previous studies conducted in Iran for monitoring the mechanism of resistance among azole‐resistant A fumigatus in both clinical and environmental samples showed that the TR 34 /L98H mutation was reported with increasing frequency from 3.3% in 2013 to 6.6% in 2016 .…”

“…These mutations lead to high‐level resistance to triazole antifungals of A fumigatus isolates from both azole‐naive and azole‐treated patients . Furthermore, several institutions report a rise in resistant strains found in environmental niches such as soil samples, paddy fields, aerial samples of hospitals and compost . Compost (decaying plant waste material) is an important source of A fumigatus .…”

Investigation and Validation of Detection of Storage Stability of Difenoconazole Residue in Mango

“…Gas/liquid chromatography (GC/LC) and gas/liquid chromatography-mass spectrometry (GC/LC-MS) methods are mainly used for determination of difenoconazole [10][11][12][13]. Besides being accurate, these methods are timeconsuming due to complex processes involved, and thus, a large number of samples need to be stored for analysis.…”

Molecular Epidemiology of Azole-Resistant Aspergillus fumigatus in Sawmills of Eastern France by Microsatellite Genotyping

“…STR Af analysis was then performed using RStudio software (version 3.2.2, Boston, MA, USA). Microsatellite genotype distances were calculated using Bruvo’s distance (cutoff value = 0.2) and a minimum spanning network was calculated via the bruvo.msn function on the poppr library [ 17 ]. Finally, allelic diversity was calculated for the nine STR Af loci for AR Af and AS Af isolates by using the Simpson index of diversity ( D ).…”