Metabolomic profiling for the identification of potential biomarkers involved in a laboratory azole resistance in <i>Candida albicans</i>

Candida albicans, one of the most common fungal pathogens, is responsible for several yeast infections in human hosts, being resistant to classically used antifungal drugs, such as azole drugs. Multifactorial and multistep alterations are involved in the azole resistance in Candida albicans. In this study, a FCZ-resistant C. albicans strain was obtained by serial cultures of a FCZ-susceptible C. albicans strain in incrementally increasing concentrations of FCZ. We performed an integrated profile of different classes of molecules related to azole resistance in C. albicans by combining several mass-spectrometry based methodologies. The comparative metabolomic study was performed with the sensitive and resistant strains of C.albicans to identify metabolites altered during the development of resistance to fluconazole, while the intervention strains and non-intervention strains of C.albicans to identify metabolites altered involved in cross-resistant to azole drugs. Our analysis of the different metabolites identified molecules mainly involved in metabolic processes such as amino acid metabolism, tricarboxylic acid cycle and phospholipid metabolism. We also compared the phospholipid composition of each group, revealing that the relative content of phospholipids significantly changed during the development of resistance to azole drugs. According with these results, we hypothesized that the metabolism shift might contribute to azole drugs resistance in C.albicans from multifactorial alterations. Our result paves the way to understand processes underlying the resistance to azole drugs in C. albicans, providing the basis for developing new antifungal drugs.白色念珠菌（Candida albicans）是最常见的致病性真菌之一，可引发人类宿主的多种酵母菌感染，且对唑类药物（azole drugs）等经典抗真菌药物具有耐药性。白色念珠菌的唑类耐药性形成涉及多因素、多步骤的分子改变。本研究通过逐步提升氟康唑（fluconazole，FCZ）浓度的连续传代培养，从氟康唑敏感的白色念珠菌菌株中成功获得了氟康唑耐药菌株。本研究结合多种基于质谱（mass-spectrometry）的分析技术，对白色念珠菌中与唑类耐药相关的各类分子开展了整合分子谱分析。本研究以白色念珠菌的敏感株与耐药株为对象开展比较代谢组学研究，以鉴定氟康唑耐药形成过程中发生改变的代谢物；同时对比干预组与非干预组白色念珠菌菌株，以探寻参与唑类药物交叉耐药的差异代谢物。对差异代谢物的分析结果显示，这些分子主要参与氨基酸代谢、三羧酸循环（tricarboxylic acid cycle）及磷脂代谢（phospholipid metabolism）等核心代谢通路。本研究同时对各组的磷脂组成进行了对比分析，结果表明在唑类药物耐药性形成过程中，磷脂的相对含量发生了显著变化。基于上述研究结果，我们提出假说：代谢重编程可能通过多因素改变参与白色念珠菌的唑类药物耐药过程。本研究结果为阐明白色念珠菌唑类耐药的潜在分子机制提供了重要思路，也为新型抗真菌药物的研发奠定了理论基础。