Uncovering New Mutations Conferring Azole Resistance in the Aspergillus fumigatus cyp51A Gene

Chen, Pei‐Ying; Liu, Musang; Zeng, Qiuqiong; Zheng, Z. P.; Liu, Weida; Sang, Hong; Lü, Ling

doi:10.3389/fmicb.2019.03127

Cited by 19 publications

(13 citation statements)

References 29 publications

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“…Interestingly, two of the A. fumigatus strains in this work presented the combined TR34/L98H and the TR46/Y121F/T289A. We also identified other changes in proteins encoded by cyp51A and fks1 that can be used in the future to generate mutants and test the effect of mutations in well-studied wild-type strains of A. fumigatus (Chen et al, 2020).…”

Section: Discussionmentioning

confidence: 76%

“…Mechanisms of azole resistance involving mutations in the cyp51 genes have been identified in diverse fungi, including in multiple animal and plant pathogens (Parker et al, 2014). In A. fumigatus, research has focused on azole susceptibility testing and correlation with point mutations in the cyp51A gene and TR insertions in its promoter region (Chen et al, 2020;Zakaria et al, 2020). Major changes in protein Cyp51A that correlated with azole resistance include point mutations, such as in positions G54, G138, M220, and G448, or combination of point mutations with TRs in the promoter region, such as the TR34/L98H and the TR46/Y121F/T289A (Wei et al, 2015;Beardsley et al, 2018).…”

Section: Discussionmentioning

confidence: 99%

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Genomic and Phenotypic Heterogeneity of Clinical Isolates of the Human Pathogens Aspergillus fumigatus, Aspergillus lentulus, and Aspergillus fumigatiaffinis

et al. 2020

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Fungal pathogens are a global threat to human health. For example, fungi from the genus Aspergillus cause a spectrum of diseases collectively known as aspergillosis. Most of the >200,000 life-threatening aspergillosis infections per year worldwide are caused by Aspergillus fumigatus. Recently, molecular typing techniques have revealed that aspergillosis can also be caused by organisms that are phenotypically similar to A. fumigatus but genetically distinct, such as Aspergillus lentulus and Aspergillus fumigatiaffinis. Importantly, some of these so-called cryptic species are thought to exhibit different virulence and drug susceptibility profiles than A. fumigatus, however, our understanding of their biology and pathogenic potential has been stymied by the lack of genome sequences and phenotypic profiling of multiple clinical strains. To fill this gap, we phenotypically characterized the virulence and drug susceptibility of 15 clinical strains of A. fumigatus, A. lentulus, and A. fumigatiaffinis from Spain and sequenced their genomes. We found heterogeneity in drug susceptibility across species and strains. We further found heterogeneity in virulence within each species but no significant differences in the virulence profiles between the three species. Genes known to influence drug susceptibility (cyp51A and fks1) vary in paralog number and sequence among these species and strains and correlate with differences in drug susceptibility. Similarly, genes known to be important for virulence in A. fumigatus showed variability in number of paralogs across strains and across species. Characterization of the genomic similarities and differences of clinical strains of A. lentulus, A. fumigatiaffinis, and A. fumigatus that vary in disease-relevant traits will advance our understanding of the variance in pathogenicity between Aspergillus species and strains that are collectively responsible for the vast majority of aspergillosis infections in humans.

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Section: Discussionmentioning

confidence: 76%

Section: Discussionmentioning

confidence: 99%

Genomic and Phenotypic Heterogeneity of Clinical Isolates of the Human Pathogens Aspergillus fumigatus, Aspergillus lentulus, and Aspergillus fumigatiaffinis

et al. 2020

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“…2015 A. fumigatus CYP51A (M172V, N248T, D255E, E427K, F46Y) Voriconazole Resistance did not impact virulence but was associated with reduced treatment efficacy Garcia-Rubio et al. 2018a A. fumigatus CYP51A (N248K/V436A, Y433N substitution) Itraconazole, posaconazole, 8voriconazole Resistance did not impact virulence but was associated with reduced treatment efficacy Chen et al. 2019a A. fumigatus CYP51A (G54, M220, TR/L98) N/A Resistance did not impact virulence Gomez-Lopez et al.…”

Section: Application Of Murine and Insect Models To Identify Virulence Determinants And Antifungal Resistancementioning

confidence: 99%

Aspergillus fumigatusand aspergillosis: From basics to clinics

Arastehfar

Carvalho

Houbraken

et al. 2021

Studies in Mycology

156

112

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The airborne fungus Aspergillus fumigatus poses a serious health threat to humans by causing numerous invasive infections and a notable mortality in humans, especially in immunocompromised patients. Mould-active azoles are the frontline therapeutics employed to treat aspergillosis. The global emergence of azole-resistant A . fumigatus isolates in clinic and environment, however, notoriously limits the therapeutic options of mould-active antifungals and potentially can be attributed to a mortality rate reaching up to 100 %. Although specific mutations in CYP 51A are the main cause of azole resistance, there is a new wave of azole-resistant isolates with wild-type CYP 51A genotype challenging the efficacy of the current diagnostic tools. Therefore, applications of whole-genome sequencing are increasingly gaining popularity to overcome such challenges. Prominent echinocandin tolerance, as well as liver and kidney toxicity posed by amphotericin B, necessitate a continuous quest for novel antifungal drugs to combat emerging azole-resistant A . fumigatus isolates. Animal models and the tools used for genetic engineering require further refinement to facilitate a better understanding about the resistance mechanisms, virulence, and immune reactions orchestrated against A . fumigatus . This review paper comprehensively discusses the current clinical challenges caused by A . fumigatus and provides insights on how to address them.

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“…In addition, assays for detecting novel mechanisms can be incorporated into the Q24 Advanced PyroMark workflow with relative ease. For example, either the tyrosine 433 to asparagine (Y433N) in cyp51A 53 or the lysine 363 to arginine (K363R) erg5 polymorphism 52 may explain the pan-triazole and amphotericin B resistance found in the isolates in this study lacking cyp51A polymorphisms. The advantage of pyrosequencing over newer sequencing approaches is the determination of definitive sequence information rather than a reliance on the restriction pattern differences generated by surveyor nucleases and detected by gel electrophoresis.…”

Section: Discussionmentioning

confidence: 87%

Deciphering Aspergillus fumigatus cyp51A-mediated triazole resistance by pyrosequencing of respiratory specimens

Frazer

Anees-Hill

Hassan

et al. 2020

Journal of Antimicrobial Chemotherapy

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Background Infections caused by triazole drug-resistant Aspergillus fumigatus are an increasing problem. The sensitivity of standard culture is poor, abrogating susceptibility testing. Early detection of resistance can improve patient outcomes, yet tools for this purpose are limited. Objectives To develop and validate a pyrosequencing technique to detect resistance-conferring cyp51A polymorphisms from clinical respiratory specimens and A. fumigatus isolates. Methods Method validation was performed by Sanger sequencing and pyrosequencing of 50 A. fumigatus isolates with a spectrum of triazole susceptibility patterns. Then, 326 Aspergillus quantitative PCR (qPCR)-positive respiratory samples collected over a 27 month period (January 2017–March 2019) from 160 patients at the UK National Aspergillosis Centre were assessed by cyp51A pyrosequencing. The Sanger sequencing and pyrosequencing results were compared with those from high-volume culture and standard susceptibility testing. Results The cyp51A genotypes of the 50 isolates analysed by pyrosequencing and Sanger sequencing matched. Of the 326 Aspergillus qPCR-positive respiratory specimens, 71.2% were reported with no A. fumigatus growth. Of these, 56.9% (132/232) demonstrated a WT cyp51A genotype and 31.5% (73/232) a resistant genotype by pyrosequencing. Pyrosequencing identified the environmental TR34/L98H mutation in 18.7% (61/326) of the samples in contrast to 6.4% (21/326) pan-azole resistance detected by culture. Importantly, pyrosequencing detected resistance earlier than culture in 23.3% of specimens. Conclusions The pyrosequencing assay described could detect a wide range of cyp51A polymorphisms associated with triazole resistance, including those not identified by commercial assays. This method allowed prompt recognition of resistance and the selection of appropriate antifungal treatment when culture was negative.

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Uncovering New Mutations Conferring Azole Resistance in the Aspergillus fumigatus cyp51A Gene

Cited by 19 publications

References 29 publications

Genomic and Phenotypic Heterogeneity of Clinical Isolates of the Human Pathogens Aspergillus fumigatus, Aspergillus lentulus, and Aspergillus fumigatiaffinis

Genomic and Phenotypic Heterogeneity of Clinical Isolates of the Human Pathogens Aspergillus fumigatus, Aspergillus lentulus, and Aspergillus fumigatiaffinis

Aspergillus fumigatusand aspergillosis: From basics to clinics

Deciphering Aspergillus fumigatus cyp51A-mediated triazole resistance by pyrosequencing of respiratory specimens

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