Delineation of the Direct Contribution of Candida auris ERG11 Mutations to Clinical Triazole Resistance.
Delineation of the Direct Contribution of Candida auris ERG11 Mutations to Clinical Triazole Resistance.
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DOI：
10.1128/spectrum.01585-21
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发表时间：
2021-12-22
影响因子：
3.7
通讯作者：
Rogers PD
中科院分区：
文献类型：
--
作者：
Rybak JM;Sharma C;Doorley LA;Barker KS;Palmer GE;Rogers PD
对氟康唑的耐药性是侵袭性耳念珠菌感染治疗中最常见的临床特征之一，并且在>90%的所有特征性临床分离株中观察到。在这项工作中，原生C。使用Cas9-核糖核蛋白（RNP）介导的转化系统，将先前表征的氟康唑敏感临床分离株中的ERG 11等位基因替换为来自三个高度氟康唑耐药临床分离株（MIC ≥256 mg/L）的ERG 11等位基因，编码氨基酸取代VF 125 AL、Y132 F和K143 R。反过来，使用相同的方法，将来自相同氟康唑敏感临床分离株的ERG 11 WT等位基因（缺乏任何耐药相关突变）引入先前表征的氟康唑耐药临床分离株中，替换天然ERG 11 K143 R等位基因。对所得的菌株集合进行全面的三唑敏感性测试，并确定这些临床来源的ERG 11突变中的每一种对三唑MIC的直接影响。观察到引入三种突变ERG 11等位基因中的每一种都会使氟康唑和伏立康唑的MIC增加8至16倍。其他临床可用的三唑类药物的MIC未受到任何ERG 11突变的显著影响。在氟康唑耐药的临床分离株背景中，K143 R编码突变的校正导致氟康唑MIC降低16倍，伏立康唑MIC降低8倍，而其他三唑类药物的MIC变化极小。综上所述，这些发现表明，C。耳念珠菌ERG 11对氟康唑和伏立康唑耐药有显著作用，但单独不能解释临床分离株中观察到的MIC显著升高。耳。重要性耳念珠菌是一种新出现的多重耐药和卫生保健相关的病原体，迫切需要临床关注。三唑类药物是世界范围内使用最广泛的抗真菌药物，通常用于治疗侵袭性念珠菌感染。90%以上的C。耳念珠菌临床分离株对氟康唑耐药，几乎所有的氟康唑耐药株都对氟康唑耐药。在编码三唑靶点ERG 11的基因中，发现耳道感染者具有三种突变之一（编码VF 125 AL、Y132 F或K143 R）。然而，ERG 11中这些突变对氟康唑耐药的直接贡献以及这些突变可能对其他三唑类药物敏感性的影响仍然未知。本研究旨在解决这一知识空白，并可能告知未来的应用三唑类抗真菌药治疗由C。耳。
Resistance to fluconazole is one of clinical characteristics most frequently challenging the treatment of invasive Candida auris infections, and is observed among >90% of all characterized clinical isolates. In this work, the native C. auris ERG11 allele in a previously characterized fluconazole-susceptible clinical isolate was replaced with the ERG11 alleles from three highly fluconazole-resistant clinical isolates (MIC ≥256 mg/L), encoding the amino acid substitutions VF125AL, Y132F, and K143R, using Cas9-ribonucleoprotein (RNP) mediated transformation system. Reciprocally, the ERG11WT allele from the same fluconazole-susceptible clinical isolate, lacking any resistance-associated mutation, was introduced into a previously characterized fluconazole-resistant clinical isolate, replacing the native ERG11K143R allele, using the same methods. The resulting collection of strains was subjected to comprehensive triazole susceptibility testing, and the direct impact each of these clinically-derived ERG11 mutations on triazole MIC was determined. Introduction of each of the three mutant ERG11 alleles was observed to increase fluconazole and voriconazole MIC by 8- to 16-fold. The MIC for the other clinically available triazoles were not significantly impacted by any ERG11 mutation. In the fluconazole-resistant clinical isolate background, correction of the K143R encoding mutation led to a similar 16-fold decrease in fluconazole MIC, and 8-fold decrease in voriconazole MIC, while the MIC of other triazoles were minimally changed. Taken together, these findings demonstrate that mutations in C. auris ERG11 significantly contribute to fluconazole and voriconazole resistance, but alone cannot explain the substantially elevated MIC observed among clinical isolates of C. auris. IMPORTANCE Candida auris is an emerging multidrug-resistant and health care-associated pathogen of urgent clinical concern. The triazoles are the most widely prescribed antifungal agents worldwide and are commonly utilized for the treatment of invasive Candida infections. Greater than 90% of all C. auris clinical isolates are observed to be resistant to fluconazole, and nearly all fluconazole-resistant isolates of C. auris are found to have one of three mutations (encoding VF125AL, Y132F, or K143R) in the gene encoding the target of the triazoles, ERG11. However, the direct contribution of these mutations in ERG11 to fluconazole resistance and the impact these mutations may have the susceptibility of the other triazoles remains unknown. The present study seeks to address this knowledge gap and potentially inform the future application the triazole antifungals for the treatment of infections caused by C. auris.