Department of Microbiology, School of Pharmacy, Kitasato University, Tokyo, Japan.
Department of Hygienic Chemistry, School of Pharmacy, Kitasato University, Tokyo, Japan.
Infect Immun. 2022 Jul 21;90(7):e0018422. doi: 10.1128/iai.00184-22. Epub 2022 Jun 2.
Long-chain-fatty-acid (LCFA) metabolism is a fundamental cellular process in bacteria that is involved in lipid homeostasis, energy production, and infection. However, the role of LCFA metabolism in Salmonella enterica serovar Typhimurium (. Tm) gut infection remains unclear. Here, using a murine gastroenteritis infection model, we demonstrate involvement of LCFA metabolism in . Tm gut colonization. The LCFA metabolism-associated transcriptional regulator FadR contributes to . Tm gut colonization. deletion alters the gene expression profile and leads to aberrant flagellar motility of . Tm. Colonization defects in the mutant are attributable to altered swimming behavior characterized by less frequently smooth swimming, resulting from reduced expression of the phase 2 flagellin FljB. Notably, changes in lipid LCFA composition by deletion lead to reduced expression of , which is restored by exogenous LCFA. Therefore, LCFA homeostasis may maintain proper flagellar motility by activating expression, contributing to . Tm gut colonization. Our findings improve the understanding of the effect of luminal LCFA on the virulence of enteric pathogens.
长链脂肪酸（LCFA）代谢是细菌中的一个基本细胞过程，涉及脂类动态平衡、能量产生和感染。然而，LCFA 代谢在沙门氏菌肠炎亚种（Tm）肠道感染中的作用尚不清楚。在这里，我们使用小鼠胃肠炎感染模型，证明了 LCFA 代谢参与了 Tm 肠道定植。LCFA 代谢相关转录调节因子 FadR 有助于 Tm 肠道定植。缺失改变了基因表达谱，并导致 Tm 的鞭毛运动异常。突变体的定植缺陷归因于游泳行为的改变，其特征是平滑游动的频率降低，这是由于相位 2 鞭毛蛋白 FljB 的表达减少所致。值得注意的是，缺失导致的脂质 LCFA 组成的变化导致表达减少，而外源性 LCFA 可恢复其表达。因此，LCFA 动态平衡可能通过激活表达来维持适当的鞭毛运动，从而有助于 Tm 肠道定植。我们的发现提高了对腔 LCFA 对肠道病原体毒力的影响的理解。
