Feng Wenli, Yang Jing, Yang Lu, Li Qing, Zhu Xin, Xi Zhiqin, Qiao Zusha, Cen Wen
Department of Dermatovenereology, The Second Hospital of Shanxi Medical University, Taiyuan, Shanxi 030001, P.R. China.
Exp Ther Med. 2018 Feb;15(2):1217-1224. doi: 10.3892/etm.2017.5518. Epub 2017 Nov 16.
The aim of the present study was to investigate the association between Mrr1, adenylyl cyclase-associated protein 1 (Cap1) and multi-drug resistance gene 1 (MDR1), and to assess the mutations in Mrr1 and Cap1 in azole-resistant strains. The study isolated 68 strains from patients with vulvovaginal candidiasis. Drug susceptibility testing was conducted to characterize the resistance profile of these strains to fluconazole, itraconazole and voriconazole. Polymerase chain reaction (PCR) amplification was performed for Cap1 and Mrr1, and the PCR products were sequenced to identify any mutations. Reverse transcription-quantitative PCR was performed to measure Cap1, Mrr1 and MDR1 mRNA in strains. The results of the present study indicated S381N, P311S and A390T missense mutations in Cap1 and T917M, T923I, N937K, E1020Q, F1032L and S1037L missense mutations in Mrr1 in azole-resistant strains. Fluconazole-resistant strains had significantly elevated Cap1 and MDR1 mRNA levels compared with fluconazole-sensitive strains (P<0.01). The mRNA levels of Cap1, Mrr1 and MDR1 were significantly increased in the strains resistant to all three of fluconazole, itraconazole and voriconazole compared with strains sensitive to the three agents (P<0.001, P=0.037 and P<0.001, respectively). Cap1 expression was positively correlated with MDR1 expression in fluconazole-resistant strains (P<0.05). No significant correlation was observed between Cap1, Mrr1 and MDR1 in the strains resistant to fluconazole, itraconazole or voriconazole. The results of the present study suggested that fluconazole resistance may involve MDR1 overexpression mediated by Cap1 overexpression. Cross-resistance between fluconazole, itraconazole and voriconazole may be associated with mutations in Cap1 and Mrr1, rather than their overexpression. In addition, the present study also revealed two novel mutations in Mrr1; T917M and T923I. These findings may provide a basis for elucidating the molecular mechanisms of and improving therapeutic treatments to tackle azole resistance.
本研究旨在探讨Mrr1、腺苷酸环化酶相关蛋白1（Cap1）与多药耐药基因1（MDR1）之间的关联，并评估唑类耐药菌株中Mrr1和Cap1的突变情况。该研究从外阴阴道念珠菌病患者中分离出68株菌株。进行药敏试验以表征这些菌株对氟康唑、伊曲康唑和伏立康唑的耐药情况。对Cap1和Mrr1进行聚合酶链反应（PCR）扩增，并对PCR产物进行测序以鉴定任何突变。进行逆转录定量PCR以测量菌株中Cap1、Mrr1和MDR1的mRNA水平。本研究结果表明，唑类耐药菌株中Cap1存在S381N、P311S和A390T错义突变，Mrr1存在T917M、T923I、N937K、E1020Q、F1032L和S1037L错义突变。与氟康唑敏感菌株相比，氟康唑耐药菌株的Cap1和MDR1 mRNA水平显著升高（P<0.01）。与对氟康唑、伊曲康唑和伏立康唑均敏感的菌株相比，对这三种药物均耐药的菌株中Cap1、Mrr1和MDR1的mRNA水平显著升高（分别为P<0.001、P=0.037和P<0.001）。在氟康唑耐药菌株中，Cap1表达与MDR1表达呈正相关（P<0.05）。在对氟康唑、伊曲康唑或伏立康唑耐药的菌株中，未观察到Cap1、Mrr1和MDR1之间存在显著相关性。本研究结果表明，氟康唑耐药可能涉及由Cap1过表达介导的MDR1过表达。氟康唑、伊曲康唑和伏立康唑之间的交叉耐药可能与Cap1和Mrr1的突变有关，而非其过表达。此外，本研究还揭示了Mrr1中的两个新突变；T917M和T923I。这些发现可能为阐明唑类耐药的分子机制和改进治疗方法提供依据。
