AUTHOR=Lu Qunlin , Wang Yuanxiu , Liao Xing , Zhou Fu , Zhang Bin , Wu Xiaoyu 

TITLE=Physiological and transcriptome analysis of Candida albicans in response to X33 antimicrobial oligopeptide treatment

JOURNAL=Frontiers in Cellular and Infection Microbiology

VOLUME=13

YEAR=2023

URL=https://www.frontiersin.org/journals/cellular-and-infection-microbiology/articles/10.3389/fcimb.2023.1123393

DOI=10.3389/fcimb.2023.1123393

ISSN=2235-2988

ABSTRACT=<sec><title>Introduction</title><p><italic>Candida albicans</italic> is an opportunistic pathogenic fungus, which frequently causes systemic or local fungal infections in <italic>humans</italic>. The evolution of its drug-resistant mutants necessitate an urgent development of novel antimicrobial agents.</p></sec><sec><title>Results</title><p>Here, we explored the antimicrobial activity and inhibitory mechanisms of X33 antimicrobial oligopeptide (X33 AMOP) against <italic>C. albicans</italic>. The oxford cup test results showed that X33 AMOP had strong inhibitory activity against <italic>C. albicans</italic>, and its MIC and MFC were 0.625 g/L and 2.5 g/L, respectively. Moreover, SEM and TEM showed that X33 AMOP disrupted the integrity of cell membrane. The AKP, ROS, H<sub>2</sub>O<sub>2</sub> and MDA contents increased, while the reducing sugar, soluble protein, and pyruvate contents decreased after the X33 AMOP treatment. This indicated that X33 AMOP could damage the mitochondrial integrity of the cells, thereby disrupting the energy metabolism by inducing oxidative stress in <italic>C. albicans</italic>. Furthermore, transcriptome analysis showed that X33 AMOP treatment resulted in the differential expression of 1140 genes, among which 532 were up-regulated, and 608 were down-regulated. These DEGs were related to protein, nucleic acid, and carbohydrate metabolism, and their expression changes were consistent with the changes in physiological characteristics. Moreover, we found that X33 AMOP could effectively inhibit the virulence attributes of <italic>C. albicans</italic> by reducing phospholipase activity and disrupting hypha formation.</p></sec><sec><title>Discussion</title><p>These findings provide the first-ever detailed reference for the inhibitory mechanisms of X33 AMOP against <italic>C. albicans</italic> and suggest that X33 AMOP is a potential drug candidate for treating <italic>C. albicans</italic> infections.</p></sec>