School of Food Science and Technology, Dalian Polytechnic University, Dalian 116034, PR China.
School of Food Science and Technology, Dalian Polytechnic University, Dalian 116034, PR China; Dalian Probiotics Function Research Key Laboratory, Dalian Polytechnic University, Dalian 116034, PR China.
Int J Biol Macromol. 2023 Dec 31;253(Pt 5):127048. doi: 10.1016/j.ijbiomac.2023.127048. Epub 2023 Sep 23.
Shigella is a specific enteric pathogen in humans, causing symptoms of bacterial dysentery. The biofilm formation of S. flexneri contributes to the emergence of multidrug resistance and facilitates the establishment of persistent chronic infections. This study investigated the regulatory effects of Lactiplantibacillus plantarum Y12 exopolysaccharide (L-EPS) on gene expression and its spatial hindrance effects in inhibiting the biofilm formation of S. flexneri. The transcriptome analysis revealed a significant impact of L-EPS on the gene expression profile of S. flexneri, with a total of 968 genes showing significant changes (507 up-regulated and 461 down-regulated). The significantly down-regulated KEGG metabolic pathway enriched in phosphotransferase system, Embden-Meyerhf-Parnas, Citrate cycle, Lipopolysaccharide biosynthesis, Cationic antimicrobial peptide resistance, Two-component system. Moreover, L-EPS significantly down-regulated the gene expression levels of fimbriae synthesis (fimF), lipopolysaccharide synthesis (lptE, lptB), anchor protein repeat domain (arpA), virulence factor (lpp, yqgB), antibiotic resistance (marR, cusB, mdtL, mdlB), heavy metal resistance (zraP), and polysaccharide synthesis (mtgA, mdoB, mdoC). The expression of biofilm regulator factor (bssS) and two-component system suppressor factor (mgrB) were significantly up-regulated. The RT-qPCR results indicated that a major component of L-EPS (L-EPS 2-1) exhibited the gene regulatory effect on the S. flexneri biofilm formation. Furthermore, electrophoresis and isothermal microtitration calorimetry demonstrated that the interaction between L-EPS 2-1 and eDNA is electrostatic dependent on the change in environmental pH, disrupting the stable spatial structure of S. flexneri biofilm. In conclusion, L-EPS inhibited the biofilm formation of S. flexneri through gene regulation and spatial obstruction effects.
志贺氏菌是人类特定的肠道病原体，引起细菌性痢疾的症状。S. flexneri 的生物膜形成有助于多药耐药性的出现，并促进持续性慢性感染的建立。本研究探讨了植物乳杆菌 Y12 胞外多糖（L-EPS）对 S. flexneri 基因表达的调控作用及其空间阻碍作用抑制生物膜形成的作用。转录组分析显示，L-EPS 对 S. flexneri 的基因表达谱有显著影响，共有 968 个基因发生显著变化（507 个上调，461 个下调）。KEGG 代谢途径显著下调的富集磷酸转移酶系统、Embden-Meyerhf-Parnas、柠檬酸循环、脂多糖生物合成、阳离子抗菌肽抗性、双组分系统。此外，L-EPS 显著下调了菌毛合成（fimF）、脂多糖合成（lptE、lptB）、锚蛋白重复结构域（arpA）、毒力因子（lpp、yqgB）、抗生素抗性（marR、cusB、mdlL、mdlB）、重金属抗性（zraP）和多糖合成（mtgA、mdoB、mdoC）的基因表达水平。生物膜调节因子（bssS）和双组分系统抑制因子（mgrB）的表达显著上调。RT-qPCR 结果表明，L-EPS 的主要成分（L-EPS 2-1）对 S. flexneri 生物膜形成具有基因调控作用。此外，电泳和等温微量热法表明，L-EPS 2-1 与 eDNA 之间的相互作用依赖于环境 pH 值的变化，是静电的，破坏了 S. flexneri 生物膜的稳定空间结构。综上所述，L-EPS 通过基因调控和空间阻碍作用抑制 S. flexneri 生物膜的形成。
