Fan Qiuxia, Yuan Yahong, Jia Hang, Zeng Xuejun, Wang Zhouli, Hu Zhongqiu, Gao Zhenpeng, Yue Tianli
College of Food Science and Engineering, Northwest A&F University, 22 Xinong Road, Yangling, 712100, Shaanxi, China.
Laboratory of Quality & Safety Risk Assessment for Agro-products (Yangling), Ministry of Agriculture, Yangling, 712100, China.
Appl Microbiol Biotechnol. 2021 Jun;105(11):4709-4718. doi: 10.1007/s00253-021-11295-x. Epub 2021 May 20.
Shigella flexneri (Sh. flexneri), a common foodborne pathogen, has become one of the main threats to food safety and human health due to its high pathogenicity and persistent infection. The objective of this study was to explore the antimicrobial and anti-biofilm activities and the possible mechanism of thymoquinone (TQ) against Sh. flexneri. The minimum inhibitory concentration (MIC) and minimal bactericidal concentration (MBC) of TQ against Sh. flexneri were 0.4 and 0.5 mg/mL, respectively. TQ showed bactericidal activity against Sh. flexneri in culture medium and milk system. Scanning electron microscopy (SEM) and confocal laser scanning microscopy (CLSM) observations demonstrated that TQ could induce abnormal cell morphology and destroy cell membrane. Sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) analysis suggested that TQ could inhibit protein synthesis in Sh. flexneri. Also, at sub-inhibitory concentrations (SICs), TQ exhibited an inhibitory effect on Sh. flexneri biofilm formation, which was confirmed by crystal violet quantitative analysis and SEM observation. Real-time quantitative PCR (RT-qPCR) analyses revealed that TQ downregulated the expression of genes involved in Sh. flexneri biofilm formation. Thus, TQ has potential as a natural antimicrobial and anti-biofilm agent to address the contamination and infection caused by Sh. flexneri. KEY POINTS: • Antimicrobial and anti-biofilm activity of TQ on Shigella flexneri were investigated. • TQ inhibited biofilm formation by Shigella flexneri. • TQ provided a new strategy for Shigella flexneri control.
福氏志贺菌是一种常见的食源性病原体，因其高致病性和持续性感染，已成为食品安全和人类健康的主要威胁之一。本研究的目的是探讨百里醌（TQ）对福氏志贺菌的抗菌和抗生物膜活性及其可能的作用机制。TQ对福氏志贺菌的最小抑菌浓度（MIC）和最小杀菌浓度（MBC）分别为0.4和0.5mg/mL。TQ在培养基和牛奶体系中均对福氏志贺菌表现出杀菌活性。扫描电子显微镜（SEM）和共聚焦激光扫描显微镜（CLSM）观察表明，TQ可诱导细胞形态异常并破坏细胞膜。十二烷基硫酸钠聚丙烯酰胺凝胶电泳（SDS-PAGE）分析表明，TQ可抑制福氏志贺菌的蛋白质合成。此外，在亚抑菌浓度（SICs）下，TQ对福氏志贺菌生物膜形成具有抑制作用，这通过结晶紫定量分析和SEM观察得到证实。实时定量PCR（RT-qPCR）分析显示，TQ下调了福氏志贺菌生物膜形成相关基因的表达。因此，TQ有潜力作为一种天然的抗菌和抗生物膜剂，用于解决福氏志贺菌引起的污染和感染问题。要点：• 研究了TQ对福氏志贺菌的抗菌和抗生物膜活性。• TQ抑制福氏志贺菌生物膜的形成。• TQ为控制福氏志贺菌提供了一种新策略。
