Biological Sciences Program - Molecular and Cellular Biology, University of Maryland, College Park, MD, USA.
Department of Animal and Avian Sciences, University of Maryland, College Park, MD, USA.
J Microbiol. 2020 Jun;58(6):489-498. doi: 10.1007/s12275-020-9545-1. Epub 2020 Apr 22.
The growing threat of emergent multidrug-resistant enteric bacterial pathogens, and their adopted virulence properties are directing to find alternative antimicrobials and/or development of dietaries that can improve host gut health and/or defense. Recently, we found that modified Lactobacillus casei (Lc + CLA) with increased production of conjugated linoleic acid has antimicrobial and other beneficial properties. Further, prebiotic alike products such as berry pomace extracts (BPEs), increase the growth of probiotics and inhibit the growth of certain bacterial pathogens. In this study, we evaluated the antibacterial effect of genetically modified Lc + CLA along with BPEs against major enteric pathogen Salmonella enterica serovar Typhimurium (ST). In mixed culture condition, the growth of ST was significantly reduced in the presence of Lc + CLA and/or BPEs. Bacterial cell-free cultural supernatant (CFCS) collected from wild-type Lc or modified Lc + CLA strains also inhibited the growth and survival of ST, and those inhibitory effects were enhanced in the presence of BPEs. We also found that the interaction of the pathogen with cultured host (HD-11 and INT-407) cells were also altered in the presence of either Lc or Lc + CLA strain or their CFCSs significantly. Furthermore, the relative expression of genes related to ST virulence and physicochemical properties of ST was altered by the effect of CFCSs of either Lc or Lc + CLA. These findings indicate that a diet containing synbiotic, specifically linoleic acid, over-produced Lc + CLA and prebiotic product BPEs, might have the potential to be effective in controlling ST growth and pathogenesis.
不断增长的新兴多重耐药肠源性细菌病原体的威胁及其采用的毒力特性促使人们寻找替代抗菌药物和/或开发可改善宿主肠道健康和/或防御功能的饮食。最近，我们发现，增加共轭亚油酸（CLA）产量的改良干酪乳杆菌（Lc + CLA）具有抗菌和其他有益特性。此外，类似于益生元的产品，如浆果渣提取物（BPE），可以增加益生菌的生长并抑制某些细菌病原体的生长。在这项研究中，我们评估了遗传修饰的 Lc + CLA 与 BPE 联合对主要肠病原体鼠伤寒沙门氏菌（ST）的抗菌作用。在混合培养条件下，Lc + CLA 和/或 BPE 的存在显著抑制了 ST 的生长。从野生型 Lc 或改良的 Lc + CLA 菌株收集的细菌无细胞培养上清液（CFCS）也抑制了 ST 的生长和存活，并且在存在 BPE 的情况下，这些抑制作用得到增强。我们还发现，病原体与培养宿主（HD-11 和 INT-407）细胞的相互作用也在 Lc 或 Lc + CLA 菌株或其 CFCS 的存在下发生改变。此外，CFCS 对 Lc 或 Lc + CLA 的相对表达基因与 ST 毒力和理化特性有关的基因表达也发生了改变。这些发现表明，含有合生元（特别是亚油酸）的饮食、过生产 Lc + CLA 和益生元产品 BPE 可能具有控制 ST 生长和发病机制的潜力。
