School of Life Sciences & Basic Medicine, Xinxiang University, Xinxiang 453000, China.
Key Laboratory of Biomedicine and Health Risk Warning of Xinxiang City, Xinxiang University, Xinxiang 453000, China.
Molecules. 2022 May 18;27(10):3234. doi: 10.3390/molecules27103234.
is a major foodborne pathogen that can cause listeriosis in humans and animals. Andrographolide is known as a natural antibiotic and exhibits good antibacterial activity. We aimed to investigate the effect of andrographolide on two quorum-sensing (QS) systems, LuxS/AI-2 and Agr/AIP of , as well as QS-controlled phenotypes in this study. Our results showed that neither expression nor AI-2 production was affected by andrographolide. Nevertheless, andrographolide significantly reduced the expression levels of the genes and the activity of the promoter P. Results from the crystal violet staining method, confocal laser scanning microscopy (CLSM), and field emission scanning electron microscopy (FE-SEM) demonstrated that andrographolide remarkably inhibited the biofilm-forming ability of 10403S. The preformed biofilms were eradicated when exposed to andrographolide, and reduced surviving cells were also observed in treated biofilms. treated with andrographolide exhibited decreased ability to secrete LLO and adhere to and invade Caco-2 cells. Therefore, andrographolide is a potential QS inhibitor by targeting the Agr QS system to reduce biofilm formation and virulence of .
李斯特菌是一种主要的食源性致病菌，可引起人类和动物李斯特菌病。穿心莲内酯是一种天然抗生素，具有良好的抗菌活性。本研究旨在探讨穿心莲内酯对李斯特菌两种群体感应（QS）系统 LuxS/AI-2 和 Agr/AIP 以及 QS 控制表型的影响。结果表明，穿心莲内酯既不影响表达，也不影响 AI-2 的产生。然而，穿心莲内酯显著降低了基因的表达水平和启动子 P 的活性。结晶紫染色法、共聚焦激光扫描显微镜（CLSM）和场发射扫描电子显微镜（FE-SEM）的结果表明，穿心莲内酯显著抑制了 10403S 的生物膜形成能力。当用穿心莲内酯处理预先形成的生物膜时，生物膜被消除，并且在处理的生物膜中也观察到减少的存活细胞。用穿心莲内酯处理的李斯特菌分泌 LLO 的能力和黏附并侵袭 Caco-2 细胞的能力降低。因此，穿心莲内酯通过靶向 Agr QS 系统减少生物膜形成和李斯特菌的毒力，是一种有潜力的 QS 抑制剂。
