Azole Resistance in Aspergillus fumigatus: A Five-Year Follow Up Experience in a Tertiary Hospital With a Special Focus on Cystic Fibrosis

Azole-resistant Aspergillus fumigatus (ARAf) has emerged worldwide during the last decades. Drug pressure after long term treatments of chronically infected patients and the propagation of environmental clones selected under the pressure of imidazoles fungicides used in agriculture and farming both account for this emergence. The objectives of this study were to determine the rate of azole resistance in Aspergillus fumigatus during a 5-year period, taking into account (i) differences between underlying diseases of the patients treated, (ii) cross-resistance between azoles, and (iii) focusing on the 5-year evolution of our center’s cystic fibrosis cohort. Overall, the rates of voriconazole (VRC)-resistant and itraconazole (ITC)-resistant A. fumigatus isolates were 4.1% (38/927) and 14.5% (95/656), respectively, corresponding to 21/426 (4.9%) and 44/308 (14.3%) patients, respectively. Regarding cross-resistance, among VRC-R isolates tested for ITC, nearly all were R (20/21;95%), compared to only 27% (20/74) of VRC-R among ITC-R isolates. The level of azole resistance remained somewhat stable over years but greatly varied according to the azole drug, patient origin, and clinical setting. Whereas azole resistance during invasive aspergillosis was very scarce, patients with cystic fibrosis were infected with multiple strains and presented the highest rate of resistance: 5% (27/539) isolates were VRC-R and 17.9% (78/436) were ITC-R. These results underline that the interpretation of the azole resistance level in Aspergilllus fumigatus in a routine setting may consider the huge variability depending on the azole drug, the clinical setting, the patient background and the type of infection.

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Characterization of Aspergillus fumigatus cross-resistance between clinical and DMI azole drugs

Applied and Environmental Microbiology ◽

10.1128/aem.02539-20 ◽

2020 ◽

pp. AEM.02539-20 ◽

Cited By ~ 1

Author(s):

Rocio Garcia-Rubio ◽

Irene Gonzalez-Jimenez ◽

Jose Lucio ◽

Emilia Mellado

Keyword(s):

Aspergillus Fumigatus ◽

Clinical Setting ◽

Opportunistic Infections ◽

Treatment Options ◽

Critical Role ◽

Crop Protection ◽

Public Health Problem ◽

Resistance Mechanisms ◽

Cross Resistance ◽

Azole Resistance

Drug resistance poses a serious threat to human health and agricultural production. Azole drugs are the largest group of 14-α sterol demethylation inhibitor fungicides that are used both in agriculture and in clinical practice. As plant pathogenic molds share their natural environment with fungi that cause opportunistic infections in humans, both are exposed to a strong and persistent pressure of demethylase inhibitor (DMI) fungicides, including imidazole and triazole drugs. As a result, a loss of efficacy has occurred for this drug class in several species. In the clinical setting, Aspergillus fumigatus azole resistance is a growing public health problem and finding the source of this resistance has gained much attention. It is urgent to determine if there is a direct link between the agricultural use of azole compounds and the different A. fumigatus resistance mechanisms described for clinical triazoles. In this work we have performed A. fumigatus susceptibility testing to clinical triazoles and crop protection DMIs using a collection of azole susceptible and resistant strains which harbor most of the described azole resistance mechanisms. Various DMI susceptibility profiles have been found in the different A. fumigatus populations groups based on their azole resistance mechanism and previous WGS analysis, which suggests that the different resistance mechanisms have different origins and are specifically associated to the local use of a particular DMI.Importance Due to the worldwide emergence of A. fumigatus azole resistance, this opportunistic pathogen poses a serious health threat and, therefore, it has been included in the Watch List of the CDC 2019 Antimicrobial Resistance Threats Report. Azoles play a critical role in the control and management of fungal diseases, not only in the clinical setting but also in agriculture. Thus, azole resistance leads to a limited therapeutic arsenal which reduces the treatment options for aspergillosis patients, increasing their mortality risk. Evidence is needed to understand whether A. fumigatus azole resistance is emerging from an agricultural source due to the extended use of demethylase inhibitors as fungicides, or whether it is coming from somewhere else such as the clinical setting. If the environmental route is demonstrated, the current use and management of azole antifungal compounds might be forced to change in the forthcoming years.

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In VitroSusceptibility of Aspergillus fumigatus to Isavuconazole: Correlation with Itraconazole, Voriconazole, and Posaconazole

Antimicrobial Agents and Chemotherapy ◽

10.1128/aac.01141-13 ◽

2013 ◽

Vol 57 (11) ◽

pp. 5778-5780 ◽

Cited By ~ 50

Author(s):

Lea Gregson ◽

Joanne Goodwin ◽

Adam Johnson ◽

Laura McEntee ◽

Caroline B. Moore ◽

...

Keyword(s):

Aspergillus Fumigatus ◽

Amphotericin B ◽

Clinical Isolates ◽

Cross Resistance ◽

Azole Resistance ◽

First Line ◽

Content Type

ABSTRACTTriazoles are first-line agents for treating aspergillosis. The prevalence of azole resistance inAspergillus fumigatusis increasing, and cross-resistance is a growing concern. In this study, the susceptibilities of 40A. fumigatusclinical isolates were tested by using the CLSI method with amphotericin B, itraconazole, voriconazole, posaconazole, and the new triazole isavuconazole. Isavuconazole MICs were higher in strains with reduced susceptibilities to other triazoles, mirroring changes in voriconazole susceptibility. Isavuconazole MICs differed depending on the Cyp51A substitution.

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Azole Resistance in Aspergillus fumigatus in Patients with Cystic Fibrosis: A Matter of Concern?

Mycopathologia ◽

10.1007/s11046-017-0162-4 ◽

2017 ◽

Vol 183 (1) ◽

pp. 151-160 ◽

Cited By ~ 21

Author(s):

A. Hamprecht ◽

F. Morio ◽

O. Bader ◽

P. Le Pape ◽

J. Steinmann ◽

...

Keyword(s):

Cystic Fibrosis ◽

Aspergillus Fumigatus ◽

Azole Resistance

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Revision of EUCAST breakpoints: consequences for susceptibility of contemporary Danish mould isolates to isavuconazole and comparators

Journal of Antimicrobial Chemotherapy ◽

10.1093/jac/dkaa212 ◽

2020 ◽

Vol 75 (9) ◽

pp. 2573-2581

Author(s):

Karin Meinike Jørgensen ◽

Jesus Guinea ◽

Joseph Meletiadis ◽

Rasmus Krøger Hare ◽

Maiken Cavling Arendrup

Keyword(s):

Aspergillus Niger ◽

Aspergillus Fumigatus ◽

Aspergillus Flavus ◽

Aspergillus Terreus ◽

Cross Resistance ◽

Azole Resistance ◽

Resistance Screening ◽

Resistant Mutants ◽

Definition Of ◽

Resistance Rates

Abstract Background EUCAST recently revised the definition of the ‘I’ category from ‘intermediate’ to ‘susceptible, increased exposure’. Consequently, all current antifungal breakpoints have been reviewed and revised breakpoints (v 10.0) have been released. Objectives We investigated isavuconazole and comparator MICs (mg/L) against contemporary moulds and the consequences of the breakpoint revision for susceptibility classification. Methods Six hundred and ninety-six Aspergillus and 46 other moulds were included. EUCAST E.Def 10.1 azole resistance screening was performed for Aspergillus fumigatus and E.Def 9.3.1 testing of non-susceptible A. fumigatus and other moulds. Most non-wildtype/resistant isolates underwent cyp51A sequencing. Results Isavuconazole MIC50/MIC90s were ≤1/≤2 mg/L for Aspergillus flavus, A. fumigatus and Aspergillus nidulans versus 2/4 mg/L for Aspergillus niger and 2/16 mg/L for Aspergillus terreus. For the remaining moulds, MICs were highest for Fusarium (16 to >16 mg/L), lowest for dermatophytes (0.06–0.5 mg/L) and in between for Mucorales and others (1 to >16 mg/L). A very strong isavuconazole–voriconazole MIC correlation was found for A. fumigatus (Pearson r = 0.888) and itraconazole–posaconazole correlation for A. fumigatus (r = 0.905) and A. terreus (r = 0.848). For A. fumigatus, the revised breakpoints lowered isavuconazole resistance (22.6% to 7.7%, P < 0.0001) and increased voriconazole resistance (3.8% to 6.7%, P = 0.025), resulting in similar resistance rates across the four azoles (range: 6.7%–7.7%). For A. terreus, isavuconazole resistance remained unchanged (81.3%) and higher than itraconazole (43.8%, P = 0.004) and posaconazole (53.1%, P = 0.03) resistance. Azole cross-resistance was found in 24/24, 13/20 and 4/90 isolates, and Cyp51A alterations in 16/18, 1/7 and 2/4 sequenced isolates with isavuconazole MICs of >4, 4 and 2 mg/L, respectively. Conclusions Isavuconazole displays broad anti-mould activity. The revised breakpoints result in fewer misclassifications of wildtype isolates without compromising detection of resistant mutants.

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One year prospective survey of azole resistance in Aspergillus fumigatus at a French cystic fibrosis reference centre: prevalence and mechanisms of resistance

Journal of Antimicrobial Chemotherapy ◽

10.1093/jac/dkz144 ◽

2019 ◽

Vol 74 (7) ◽

pp. 1884-1889 ◽

Cited By ~ 7

Author(s):

R -A Lavergne ◽

F Morio ◽

I Danner-Boucher ◽

D Horeau-Langlard ◽

V David ◽

...

Keyword(s):

Cystic Fibrosis ◽

Aspergillus Fumigatus ◽

Azole Resistance ◽

Mechanisms Of Resistance ◽

Prospective Survey ◽

Reference Centre ◽

One Year

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Relevance of heterokaryosis for adaptation and azole-resistance development in Aspergillus fumigatus

Proceedings of The Royal Society B Biological Sciences ◽

10.1098/rspb.2018.2886 ◽

2019 ◽

Vol 286 (1896) ◽

pp. 20182886 ◽

Cited By ~ 3

Author(s):

Jianhua Zhang ◽

Eveline E. Snelders ◽

Bas J. Zwaan ◽

Sijmen E. Schoustra ◽

Ed J. Kuijper ◽

...

Keyword(s):

Aspergillus Fumigatus ◽

Human Lung ◽

Spontaneous Mutation ◽

Acquired Resistance ◽

Fungal Mycelium ◽

Azole Resistance ◽

Resistance Level ◽

Resistance Development ◽

Genetic Changes ◽

Lung Colonization

Aspergillus fumigatus causes a range of diseases in humans, some of which are characterized by fungal persistence. Aspergillus fumigatus , being a generalist saprotroph, may initially establish lung colonization due to its physiological versatility and subsequently adapt through genetic changes to the human lung environment and antifungal treatments. Human lung-adapted genotypes can arise by spontaneous mutation and/or recombination and subsequent selection of the fittest genotypes. Sexual and asexual spores are considered crucial contributors to the genetic diversity and adaptive potential of aspergilli by recombination and mutation supply, respectively. However, in certain Aspergillus diseases, such as cystic fibrosis and chronic pulmonary aspergillosis, A. fumigatus may not sporulate but persist as a network of fungal mycelium. During azole therapy, such mycelia may develop patient-acquired resistance and become heterokaryotic by mutations in one of the nuclei. We investigated the relevance of heterokaryosis for azole-resistance development in A. fumigatus. We found evidence for heterokaryosis of A. fumigatus in patients with chronic Aspergillus diseases. Mycelium from patient-tissue biopsies segregated different homokaryons, from which heterokaryons could be reconstructed. Whereas all variant homokaryons recovered from the same patient were capable of forming a heterokaryon, those from different patients were heterokaryon-incompatible. We furthermore compared heterokaryons and heterozygous diploids constructed from environmental isolates with different levels of azole resistance. When exposed to azole, the heterokaryons revealed remarkable shifts in their nuclear ratio, and the resistance level of heterokaryons exceeded that of the corresponding heterozygous diploids.

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First Description of Azole-Resistant Aspergillus fumigatus Due to TR46/Y121F/T289A Mutation in France

Antimicrobial Agents and Chemotherapy ◽

10.1128/aac.00127-15 ◽

2015 ◽

Vol 59 (7) ◽

pp. 4331-4335 ◽

Cited By ~ 42

Author(s):

Rose-Anne Lavergne ◽

Florent Morio ◽

Loïc Favennec ◽

Stéphane Dominique ◽

Jacques F. Meis ◽

...

Keyword(s):

Public Health ◽

Cystic Fibrosis ◽

Aspergillus Fumigatus ◽

Environmental Samples ◽

Health Concern ◽

Azole Resistance ◽

Public Health Concern ◽

Content Type ◽

High Level ◽

Level Resistance

ABSTRACTAzole resistance inAspergillus fumigatusis an emerging public health concern. Recently, a novel fungicide-driven mutation in thecyp51Agene and its promoter, TR46/Y121F/T289A, leading to high-level resistance to voriconazole has been identified in The Netherlands, Belgium, Germany, Denmark, Tanzania, and India in both clinical and environmental samples. Here we report the first description ofA. fumigatuscarrying this mutation in France, in a cystic fibrosis patient, underlining the need for extensive monitoring ofAspergillusresistance.

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