The T788G Mutation in the cyp51C Gene Confers Voriconazole Resistance in Aspergillus flavus Causing Aspergillosis
The T788G Mutation in the cyp51C Gene Confers Voriconazole Resistance in Aspergillus flavus Causing Aspergillosis
复制标题
cyp51C 基因中的 T788G 突变使黄曲霉对伏立康唑产生耐药性，导致曲霉菌病
DOI：
10.1128/aac.05477-11
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发表时间：
2012-05-01
影响因子：
4.9
通讯作者：
Li, Ruoyu
中科院分区：
文献类型：
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作者：
Liu, Wei;Sun, Yi;Li, Ruoyu
随着伏立康唑（VRC）被批准为治疗侵袭性曲霉病（IA）的首选药物，其在治疗中的使用越来越多，出现了VRC耐药的黄曲霉菌株，这是仅次于烟曲霉的IA的第二大原因。抗VRC的A.首次从对VRC治疗无反应的IA患者的手术肺标本中分离出黄色。为了进一步阐明耐VRC的机制，对该菌株的唑类靶酶基因进行了研究。结果表明，在cyp51C基因中发现了4个发生氨基酸替换的突变。为了进一步确定该突变基因在A.黄曲霉中，应用根癌农杆菌介导的基因置换方法。因此，突变的cyp51C基因从该A.黄曲霉菌株被证明赋予VRC抗性。最后，为了辨别cyp51C基因中负责促成VRC抗性的四个突变中的一个，进行了与基因置换方法相结合的定点基因诱变程序。结果表明，cyp51C基因T788G错义突变是导致A.黄色的这些结果表明，在A.黄韧带可作为医生在IA治疗期间避免使用VRC的指标。进一步全面监测抗真菌药物敏感性，深入研究唑类药物耐药机制。黄病毒引起IA，将需要充分理解这一机制。
With voriconazole (VRC) being approved as the first choice in treating invasive aspergillosis (IA) and its increasing use in treatment, a VRC-resistant strain of Aspergillus flavus, the second leading cause of IA after Aspergillus fumigatus, has emerged. The VRC-resistant strain of A. flavus was isolated for the first time from the surgical lung specimen of an IA patient with no response to VRC therapy. In order to ascertain the mechanism of VRC resistance, the azole target enzyme genes in this strain of A. flavus were cloned and sequenced, and 4 mutations generating amino acid residue substitutions were found in the cyp51C gene. To further determine the role of this mutated gene for VRC resistance in A. flavus, an Agrobacterium tumefaciens-mediated gene replacement approach was applied. Consequently, the mutated cyp51C gene from this A. flavus strain was proven to confer the VRC resistance. Finally, to discern the one out of the four mutations in the cyp51C gene that is responsible for contributing to VRC resistance, a site-directed gene mutagenesis procedure combined with a gene replacement method was performed. As a result, the T788G missense mutation in the cyp51C gene was identified as responsible for VRC resistance in A. flavus. These findings indicated that the detection of this mutation in A. flavus could serve as an indicator for physicians to avoid the use of VRC during IA treatment. Further comprehensive surveillance for antifungal susceptibility, as well as intensive study on the mechanism of azole resistance in A. flavus causing IA, would be required to fully understand this mechanism.