Environmental Study of Azole-Resistant Aspergillus fumigatus and Other Aspergilli in Austria, Denmark, and Spain (original) (raw)
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Clinical microbiology and infection : the official publication of the European Society of Clinical Microbiology and Infectious Diseases, 2016
Azole resistant Aspergillus fumigatus originating from the environment as well as induced during therapy are continuously emerging in Danish clinical settings. We performed a laboratory based retrospective study (2010-2014) of azole resistance and genetic relationship of A. fumigatus at the national mycology reference laboratory of Denmark. 1162 clinical and 133 environmental A. fumigatus isolates were identified by morphology, thermotolerance and/or β-tubulin sequencing. Screening for azole resistance was carried out using azole-agar and resistant isolates were susceptibility tested by the EUCAST E.Def 9.2 reference method and CYP51A sequenced. Genotyping was performed for outbreak investigation and when appropriate using the Short Tandem Repeat Aspergillus fumigatus microsatellite assay. All 133 environmental A. fumigatus isolates were azole susceptible. However, from 2010-2014 there was an increasing prevalence of azole resistance (from 1.4% to 6% isolates (P<0.001) and 1.8% t...
The Journal of antimicrobial chemotherapy, 2018
The prevalence of azole resistance in Aspergillus fumigatus is uncertain in Australia. Azole exposure may select for resistance. We investigated the frequency of azole resistance in a large number of clinical and environmental isolates. A. fumigatus isolates [148 human, 21 animal and 185 environmental strains from air (n = 6) and azole-exposed (n = 64) or azole-naive (n = 115) environments] were screened for azole resistance using the VIPcheck™ system. MICs were determined using the Sensititre™ YeastOne YO10 assay. Sequencing of the Aspergillus cyp51A gene and promoter region was performed for azole-resistant isolates, and cyp51A homology protein modelling undertaken. Non-WT MICs/MICs at the epidemiological cut-off value of one or more azoles were observed for 3/148 (2%) human isolates but not amongst animal, or environmental, isolates. All three isolates grew on at least one azole-supplemented well based on VIPcheck™ screening. For isolates 9 and 32, the itraconazole and posaconazo...
Azole Resistance of Environmental and Clinical Aspergillus fumigatus Isolates from Switzerland
Antimicrobial agents and chemotherapy, 2018
is a ubiquitous opportunistic pathogen. This fungus can acquire resistance to azole antifungals due to mutations in the azole target (). Recently, mutations typical for environmental azole resistance acquisition (for example, TR/L98H) have been reported. These mutations can also be found in isolates recovered from patients. Environmental azole resistance acquisition has been reported on several continents. Here we describe, for the first time, the occurrence of azole-resistant isolates of environmental origin in Switzerland with mutations, and we show that these isolates can also be recovered from a few patients. While the TR/L98H mutation was dominant, a single azole-resistant isolate exhibited a mutation (G54R) that was reported only for clinical isolates. In conclusion, our study demonstrates that azole resistance with an environmental signature is present in environments and patients of Swiss origin and that mutations believed to be unique to clinical settings are now also obser...
Medical Laboratory Journal , 2020
Background and objectives: Aspergillosis is a widely distributed infectious disease, which is difficult to manage. According to recent studies, the prevalence of resistant Aspergillus fumigatus has increased from 3.3% to 6.6%. Acquired triazole resistance in Aspergillus species is an evolving global health challenge, which has made the control of diseases caused by Aspergillus a concern. This study was performed to investigate prevalence of azole resistance in Aspergillus isolates from environmental samples. Methods: In this study, 316 soil samples were collected from three hospitals and a university campus in Gorgan (Iran) from July to September 2017. Two grams of each sample were suspended in 5 ml of 0.2M NaCl with 1% Tween 20. Then, 100 µl of the suspension was plated on sabouraud dextrose agar (SDA) supplemented with chloramphenicol, SDA supplemented with chloramphenicol and voriconazole (VOR, 1 mg/L) and SDA supplemented with chloramphenicol and itraconazole (ITC, 4 mg/L). The plates were incubated at 37 °C and examined for growth after 24, 48 and 72 hours. Results: We detected Aspergillus fumigatus, Aspergillus flavus, Aspergillus niger and Aspergillus nidulans isolates in 187(59.2%), 84(26.6%), 147(46.5%) and 65(20.6%) samples, respectively. We found no VOR resistant isolate. However, 21 (25%) A. flavus and 16 (8.6%) A. fumigatus isolates were intermediate for VOR. In addition, seven (8.3%) A. flavus, 68 (36.4%) A. fumigatus, 41 (27.9%) A. niger and three (4.5%) A. nidulans isolates were resistant to ITC. Conclusion: We were able to detect A.fumigatus, A. flavus, A. niger from all four sampling sites in Gorgan, North of Iran. A. fumigatus is the most prevalent and most resistant isolate in the studied area. History of previous agriculture activity and use of pesticides in the proximity of sampling sites may have affected the rate of ITC resistance.
Azole resistance in Aspergillus fumigatus: a side-effect of environmental fungicide use?
The Lancet Infectious Diseases, 2009
Invasive aspergillosis due to multi-azole-resistant Aspergillus fumigatus has emerged in the Netherlands since 1999, with 6·0-12·8% of patients harbouring resistant isolates. The presence of a single resistance mechanism (denoted by TR/L98H), which consists of a substitution at codon 98 of cyp51A and a 34-bp tandem repeat in the gene-promoter region, was found in over 90% of clinical A fumigatus isolates. This is consistent with a route of resistance development through exposure to azole compounds in the environment. Indeed, TR/L98H A fumigatus isolates were cultured from soil and compost, were shown to be cross-resistant to azole fungicides, and genetically related to clinical resistant isolates. Azoles are abundantly used in the environment and the presence of A fumigatus resistant to medical triazoles is a major challenge because of the possibility of worldwide spread of resistant isolates. Reports of TR/L98H in other European countries indicate that resistance might already be spreading.
Prospective evaluation of azole resistance in Aspergillus fumigatus clinical isolates in France
Objectives: Several studies, especially in Europe, have recently reported the emerging phenomenon of azole resistance in Aspergillus fumigatus, but very few data are available in France. Our study aimed to determine the resistance prevalence in A. fumigatus isolates recovered from clinical samples over a 1-year period in two university hospital centers. Methods: All A. fumigatus isolates were screened for azole resistance using RPMI agar plates supplemented with itraconazole and voriconazole. Resistance was then confirmed by the EUCAST method. A part of the beta-tubulin gene was amplified for resistant isolates to confirm the A. fumigatus species, and the Cyp51A gene and its promoter were afterward sequenced to detect mutations potentially responsible for this resistance. Results: One hundred sixty-five A. fumigatus isolates were recovered from 134 patients. Three isolates recovered from three patients were found resistant with MICs of >8 mg/l, 4 mg/l, and 1 mg/l for itraconazole, voriconazole, and posaconazole, respectively. The TR 34 /L98H mutation, previously and largely described in other countries, was detected in the three isolates. Conclusion: Our study demonstrated the occurrence of azole resistance among unselected A. fumigatus clinical isolates, with an overall prevalence of 1.8%.
PLOS Pathogens, 2021
Aspergillus fumigatus is an opportunistic human pathogen that causes aspergillosis, a spectrum of environmentally acquired respiratory illnesses. It has a cosmopolitan distribution and exists in the environment as a saprotroph on decaying plant matter. Azoles, which target Cyp51A in the ergosterol synthesis pathway, are the primary class of drugs used to treat aspergillosis. Azoles are also used to combat plant pathogenic fungi. Recently, an increasing number of azole-naive patients have presented with pan-azole–resistant strains of A. fumigatus. The TR34/L98H and TR46/Y121F/T289A alleles in the cyp51A gene are the most common ones conferring pan-azole resistance. There is evidence that these mutations arose in agricultural settings; therefore, numerous studies have been conducted to identify azole resistance in environmental A. fumigatus and to determine where resistance is developing in the environment. Here, we summarize the global occurrence of azole-resistant A. fumigatus in th...
Antimicrobial Agents and Chemotherapy, 2019
To understand the characterizations of azole resistance in A. fumigatus from potting soil samples in the hospital, a total of 58 samples were collected. Among 106 A. fumigatus obtained, five isolates from 4 soil samples located in the gerontology department were identified as azole resistant A. fumigatus (ARAF). Four ARAF harbored TR34/L98H allele and the other one had no mutation in cyp51A gene. Among 174 A. fumigatus selected for genotyping, TRESPERG typing obtained a close discriminatory power [DI=0.9941, 95% CI (0.9913,0.9968)] compared with the STR typing [DI=0.9997, 95% CI (0.9976,1.0000)]. Genotyping showed that the TR34/L98H isolates in the hospital had a close genetic relationship with ARAF isolates from China and many other countries. In conclusion, this study indicated the presence of ARAF in potting soil samples from hospital, which might pose a risk of acquiring ARAF infection for patients.