title: Screening and Characterization of a Non-cyp51A Mutation in an Aspergillus fumigatus cox10 Strain Conferring Azole Resistance.
abstract: The rapid and global emergence of azole resistance in the human pathogen Aspergillus fumigatus has drawn attention. Thus, a thorough understanding of its mechanisms of drug resistance requires extensive exploration. In this study, we found that the loss of the putative calcium-dependent protein-encoding gene algA causes an increased frequency of azole-resistant A. fumigatus isolates. In contrast to previously identified azole-resistant isolates related to cyp51A mutations, only one isolate carries a point mutation in cyp51A (F219L mutation) among 105 independent stable azole-resistant isolates. Through next-generation sequencing (NGS), we successfully identified a new mutation (R243Q substitution) conferring azole resistance in the putative A. fumigatus farnesyltransferase Cox10 (AfCox10) (AFUB_065450). High-performance liquid chromatography (HPLC) analysis verified that the decreased absorption of itraconazole in related Afcox10 mutants is the primary reason for itraconazole resistance. Moreover, a complementation experiment by reengineering the mutation in a parental wild-type background strain demonstrated that both the F219L and R243Q mutations contribute to itraconazole resistance in an algA-independent manner. These data collectively suggest that the loss of algA results in an increased frequency of azole-resistant isolates with a non-cyp51A mutation. Our findings indicate that there are many unexplored non-cyp51A mutations conferring azole resistance in A. fumigatus and that algA defects make it possible to isolate drug-resistant alleles. In addition, our study suggests that genome-wide sequencing combined with alignment comparison analysis is an efficient approach to identify the contribution of single nucleotide polymorphism (SNP) diversity to drug resistance.
authors: Jiangsu Key Laboratory for Microbes and Functional Genomics, Jiangsu Engineering and Technology Research Center for Microbiology, College of Life Sciences, Nanjing Normal University, Nanjing, China.
authors: Xiaolei
authors: X
authors: Wei
authors: Jiangsu Key Laboratory for Microbes and Functional Genomics, Jiangsu Engineering and Technology Research Center for Microbiology, College of Life Sciences, Nanjing Normal University, Nanjing, China.|Department of Dermatology, Jinling Hospital, School of Medicine, Nanjing University, Nanjing, China.
authors: Peiying
authors: P
authors: Chen
authors: Jiangsu Key Laboratory for Microbes and Functional Genomics, Jiangsu Engineering and Technology Research Center for Microbiology, College of Life Sciences, Nanjing Normal University, Nanjing, China.
authors: Rongsui
authors: R
authors: Gao
authors: Jiangsu Key Laboratory for Microbes and Functional Genomics, Jiangsu Engineering and Technology Research Center for Microbiology, College of Life Sciences, Nanjing Normal University, Nanjing, China.
authors: Yeqi
authors: Y
authors: Li
authors: Jiangsu Key Laboratory for Microbes and Functional Genomics, Jiangsu Engineering and Technology Research Center for Microbiology, College of Life Sciences, Nanjing Normal University, Nanjing, China.
authors: Anxue
authors: A
authors: Zhang
authors: Jiangsu Key Laboratory for Microbes and Functional Genomics, Jiangsu Engineering and Technology Research Center for Microbiology, College of Life Sciences, Nanjing Normal University, Nanjing, China.
authors: Feifei
authors: F
authors: Liu
authors: Jiangsu Key Laboratory for Microbes and Functional Genomics, Jiangsu Engineering and Technology Research Center for Microbiology, College of Life Sciences, Nanjing Normal University, Nanjing, China linglu@njnu.edu.cn.
authors: Ling
authors: L
authors: Lu
mesh_terms: D000935:Antifungal Agents / Q000494:pharmacology; D001232:Aspergillus fumigatus / Q000187:drug effects* / Q000235:genetics / Q000254:growth & development / Q000378:metabolism; D003577:Cytochrome P-450 Enzyme System / Q000235:genetics / Q000378:metabolism; D025141:Drug Resistance, Fungal / Q000235:genetics*; D051231:Farnesyltranstransferase / Q000235:genetics* / Q000378:metabolism; D005656:Fungal Proteins / Q000235:genetics* / Q000378:metabolism; D015870:Gene Expression; D005816:Genetic Complementation Test; D059014:High-Throughput Nucleotide Sequencing; D006801:Humans; D017964:Itraconazole / Q000494:pharmacology; D009154:Mutation; D020641:Polymorphism, Single Nucleotide
chemical_list: D000935:Antifungal Agents; D005656:Fungal Proteins; D017964:Itraconazole; D003577:Cytochrome P-450 Enzyme System; C465526:cytochrome P-450 CYP51A, Aspergillus; D051231:Farnesyltranstransferase
keywords: Aspergillus fumigatus; azole resistance; cox10; cyp51A; mutation