Examination of cyp51A and cyp51B expression level of the first Polish azole resistant clinical Aspergillus fumigatus isolate

Brillowska-Dąbrowska, Anna; Mroczyńska, Martyna; Nawrot, Urszula; Włodarczyk, Katarzyna; Kurzyk, Ewelina

doi:10.18388/abp.2015_1143

Cited by 22 publications

(12 citation statements)

References 26 publications

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“…This is despite the fact that most FSSC isolates show relatively low VRC susceptibilities with the majority (369 of 555; 66%) exhibiting a minimum growth inhibitory concentration for VRC (MIC VRC ) of ≥8 mg/l (Espinel-Ingroff et al, 2016). Unlike most other Ascomycetes that have only one CYP51 gene, moulds of the Pezizomycotina clade have two CYP51 paralogues (CYP51A and CYP51B) (Brillowska-Dabrowska et al, 2015;Ruan et al, 2017;Abastabar et al, 2019), and Fusarium and Neocosmospora species also have a third CYP51 paralogue, CYP51C (Liu et al, 2011;Fan et al, 2013). In A. fumigatus, modifications of CYP51A are major contributors to azole resistance (Chowdhary et al, 2017).…”

Section: Introductionmentioning

confidence: 99%

A 23 bp cyp51A Promoter Deletion Associated With Voriconazole Resistance in Clinical and Environmental Isolates of Neocosmospora keratoplastica

et al. 2020

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In the fungal pathogen Aspergillus fumigatus, resistance to azole antifungals is often linked to mutations in CYP51A, a gene that encodes the azole antifungal drug target lanosterol 14α-demethylase. The aim of this study was to investigate whether similar changes could be associated with azole resistance in a Malaysian Fusarium solani species complex (FSSC) isolate collection. Most (11 of 15) clinical FSSC isolates were Neocosmospora keratoplastica and the majority (6 of 10) of environmental isolates were Neocosmospora suttoniana strains. All 25 FSSC isolates had high minimum inhibitory concentrations (MICs) for itraconazole and posaconazole, low MICs for amphotericin B, and various (1 to >32 mg/l) voriconazole susceptibilities. There was a tight association between a 23 bp CYP51A promoter deletion and high (>32 mg/l) voriconazole MICs; of 19 FSSC strains sequenced, nine isolates had voriconazole MICs > 32 mg/l, and they all contained the 23 bp CYP51A promoter deletion, although it was absent in the ten remaining isolates with low (≤12 mg/l) voriconazole MICs. Surprisingly, this association between voriconazole resistance and the 23 bp CYP51A promoter deletion held true across species boundaries. It was randomly distributed within and across species boundaries and both types of FSSC isolates were found among environmental and clinical isolates. Three randomly selected N. keratoplastica isolates with low (≤8 mg/l) voriconazole MICs had significantly lower (1.3-7.5 times) CYP51A mRNA expression levels than three randomly selected N. keratoplastica isolates with high (>32 mg/l) voriconazole MICs. CYP51A expression levels, however, were equally strongly induced (∼6,500-fold) by voriconazole in two representative strains reaching levels, after 80 min of induction, that were comparable to those of CYP51B. Our results suggest that FSSC isolates with high voriconazole MICs have a 23 bp CYP51A promoter deletion that provides a potentially useful marker for voriconazole resistance in FSSC isolates. Early detection of possible voriconazole resistance is critical for choosing the correct treatment option for patients with invasive fusariosis.

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Section: Introductionmentioning

confidence: 99%

A 23 bp cyp51A Promoter Deletion Associated With Voriconazole Resistance in Clinical and Environmental Isolates of Neocosmospora keratoplastica

et al. 2020

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“…These data support the general rule described by Rodriguez-Tudela et al (2008), that currently known A. fumigatus susceptible to ITR do not show resistance to other triazoles, and that routine antifungal susceptibility tests should always include ITZ. On the other hand, the resistance to ITZ could be a result of other mechanisms, e.g., upregulation of efflux pumps and does not necessarily indicate cross-resistance (Rodriguez-Tudela et al, 2008;Shapiro et al, 2011;Brillowska-Dąbrowska et al, 2015). Another important observation described in the presented study is that the MIC values obtained in the Etest were often lower than in the reference methods and that an incubation time of 48hrs for the Etest improved detection of resistance.…”

Section: Discussionmentioning

confidence: 57%

Relation of the polymorphism of cyp51A sequence and the susceptibility of Aspergillus fumigatus isolates to triazoles determined by commercial gradient test (Etest) and by reference methods

et al. 2017

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The aim of this study was to evaluate the accuracy of commercial gradient test (Etest) in the detection of triazole resistant Aspergillus fumigatus isolates using reference microdilution methods and the analysis of sequences of the cyp 51A gene. The study was performed on twenty clinical isolates which were identified as Aspergillus fumigatus based on the DNA sequences of the ITS1-2 fragment of ribosomal DNA and the β-tubulin gene, out of them seventeen isolates showed wild-type cyp51A sequence and three were positive for the mutation TR34/L98H. All isolates were tested for the susceptibility to itraconazole (ITZ), voriconazole (VOR) and posaconasole (POS) using microdilution methods, according to EUCAST and CLSI protocols, as well as using Etest. The results of microdilution and Etests were analysed separately according to clinical breakpoints (CBP) defined by EUCAST version 7.0 and epidemiological cut off values (ECV). Etest as well as reference methods excellently recognised the WT isolates, which were susceptible to all tested triazoles, regardless of the method and CBP or ECV criteria used. The Etest recognized three non-WT isolates as resistant or intermediately sensitive to ITZ and POS and one as resistant to VOR. The categorical concordance between Etests and EUCAST and Etests and the CLSI method ranged from 90 to 100%. The interpretation of the results obtained from routine A. fumigatus Etests requires great caution. The use of the confirmative examinations with reference AST methods as well as with molecular tests is recommended.

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“…The minimal inhibitory concentration (MIC) value of isolates that are described Table 1 are listed in Tables S1-S4 (Supplementary Materials). Some of these isolates have been described previously [22,23].…”

Section: A Fumigatus Isolatesmentioning

confidence: 99%

“…Two triazole resistant and two triazole susceptible isolates were randomly selected for quantitative analysis of expression of cyp51A, cyp51B, mdr1 (Afu5g06070), mdr2 (Afu4g10000), mdr3 (Afu3g03500), atrF (Afu6g04360) and β-tubulin (Afu7g00250) genes [22,24,25]. The list of primer sequences used in this study is present in Table 2.…”

Section: Gene Expression Analysismentioning

confidence: 99%

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The Effect of Posaconazole, Itraconazole and Voriconazole in the Culture Medium on Aspergillus fumigatus Triazole Resistance

et al. 2020

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Triazoles are the only compounds used as antibiotics in both medicine and agriculture. The presence of triazoles in the environment can contribute to the acquisition of azole resistance among isolates of Aspergillus fumigatus. The objective of this study was to investigate the effect of A. fumigatus exposure to triazoles on susceptibility to these compounds. Seventeen triazole-resistant and 21 triazole-sensitive A. fumigatus isolates were examined. The isolates were transferred 20 times on the Sabouraud medium supplemented with posaconazole, itraconazole or voriconazole, followed by five times on the medium not supplemented. The minimum inhibitory concentrations of antimycotics were examined according to the EUCAST broth microdilution method after the 20th transfer and also the 25th transfer. In addition, the expression levels of genes mdr1, mdr2, mdr3, atrF, cyp51A and cyp51B were determined. Cultivation of A. fumigatus on media supplemented with posaconazole, itraconazole and voriconazole resulted in the acquisition of resistance to the tested triazoles of all examined isolates. After recultivation on Sabouraud without azoles, most of the isolates lost their acquired resistance. The long-term use of triazole compounds in agriculture may result in the occurrence of triazole resistant A. fumigatus isolates in the environment, not only by induction or selection of mutations in the cyp51A gene, but also by contribution to changes in the gene expression.

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Examination of cyp51A and cyp51B expression level of the first Polish azole resistant clinical Aspergillus fumigatus isolate

Cited by 22 publications

References 26 publications

A 23 bp cyp51A Promoter Deletion Associated With Voriconazole Resistance in Clinical and Environmental Isolates of Neocosmospora keratoplastica

A 23 bp cyp51A Promoter Deletion Associated With Voriconazole Resistance in Clinical and Environmental Isolates of Neocosmospora keratoplastica

Relation of the polymorphism of cyp51A sequence and the susceptibility of Aspergillus fumigatus isolates to triazoles determined by commercial gradient test (Etest) and by reference methods

The Effect of Posaconazole, Itraconazole and Voriconazole in the Culture Medium on Aspergillus fumigatus Triazole Resistance

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