苯基乳酸(PLA)通常被认为是一种天然有机酸,显示出抗副溶血弧菌的活性。在这项研究中,V.副溶血杆菌ATCC17802(Vp17802)在1/2MICPLA的胁迫下培养,然后通过转录组学探索抗菌机制。PLA对Vp17802的最低抑菌浓度(MIC)为3.2mg/mL,时间杀伤分析结果表明,Vp17802受到抑制。PLA能够破坏细菌膜,导致细胞内物质的泄漏和ATP水平的下降。RNA测序分析结果表明,共鉴定出1616个显著差异表达基因,其中190例上调,1426例下调。在TCA循环中,icd2基因的下调介导酪氨酸代谢的阻断,精氨酸生物合成,和氧化磷酸化,导致VP17802的能量供应不足。此外,PLA可能会导致氨基酸,金属离子,和磷酸盐运输者被封锁,影响营养的获取。PLA的治疗改变了与群体感应有关的编码功能的基因的表达,鞭毛组装,和细胞趋化途径,这可能会干扰Vp17802中生物膜的形成,降低细胞运动性。总的来说,1.6mg/mLPLA通过破坏营养素的摄取来抑制Vp17802的生长,细胞代谢,和生物膜的形成。该结果为探索PLA对Vp17802的活性提供了新的方向,并为食品工业中细菌病原体的控制提供了理论依据。关键点:•进行RNA测序以表明Vp17802的抗菌机制。•TCA循环中的icd2基因介导Vp17802代谢的阻断。•生物膜形成干扰了1.6mg/mLPLA,可以降低细胞的运动性和毒力。
Phenyllactic acid (PLA) generally recognized as a natural organic acid shows against Vibrio parahaemolyticus activity. In this study, V. parahaemolyticus ATCC17802 (Vp17802) was cultured under the stress of 1/2MIC PLA, and then the antibacterial mechanisms were explored via transcriptomics. The minimum inhibitory concentration (MIC) of PLA against Vp17802 was 3.2 mg/mL, and the time-kill analysis resulted that Vp17802 was inhibited. PLA was able to destroy the bacterial membrane, leading to the leakage of intracellular substances and decline of ATP levels. The RNA-sequencing analysis results indicated that 1616 significantly differentially expressed genes were identified, among which 190 were up-regulated and 1426 were down-regulated. Down-regulation of the icd2 gene in the TCA cycle mediates blockage of tyrosine metabolic, arginine biosynthesis, and oxidative phosphorylation, causing insufficient energy supply of Vp17802. Moreover, PLA could cause amino acids, metal ions, and phosphate transporters to be blocked, affecting the acquisition of nutrients. The treatment by PLA altered the expression of genes encoding functions involved in quorum sensing, flagellar assembly, and cell chemotaxis pathway, which may be interfering with the biofilm formation in Vp17802, reducing cell motility. Overall, 1.6 mg/mL PLA inhibited the growth of Vp17802 by disrupting to uptake of nutrients, cell metabolism, and the formation of biofilms. The results suggested a new direction for exploring the activity of PLA against Vp17802 and provided a theoretical basis for bacterial pathogen control in the food industry. KEY POINTS: •RNA sequencing was carried out to indicate the antibacterial mechanism of Vp17802. •The icd2 gene in the TCA cycle mediates blockage of metabolic of Vp17802. •The biofilm formation has interfered with 1.6 mg/mL PLA, which could reduce cell motility and virulence.