Department of Life Sciences, Sogang University, Seoul, 121-742, Korea.
Interdisciplinary Program in Precision Public Health, Korea University, Seoul, Korea.
Appl Microbiol Biotechnol. 2022 May;106(9-10):3721-3734. doi: 10.1007/s00253-022-11935-w. Epub 2022 Apr 30.
Autoinducer-2 (AI-2), a quorum-sensing signal molecule from the human pathogen Vibrio vulnificus, was assessed for its effect on the gut microbiome of mice. For this, we employed 16S rRNA sequencing to compare the gut microbiome of mice infected with either wild-type V. vulnificus or with the isotype ΔluxS that has a deletion in luxS which encodes the biosynthetic function of AI-2. The relative ratio of wild-type Vibrio species in the jejunum and ileum of mice infected with the wild type was significantly higher than that in mice infected with ΔluxS, suggesting that AI-2 plays an important role in the colonization of V. vulnificus in the small intestine. The bacterial composition in the gut of mice infected with ΔluxS comprises a higher proportion of Firmicutes, composed mainly of Lactobacillus, compared to the mice infected with wild-type cells. In the large intestine, Vibrio species were barely detected regardless of genetic background. Three Lactobacillus spp. isolated from fecal samples from mice infected with ΔluxS manifested significant antibacterial activities against V. vulnificus. Culture supernatants from these three species were dissolved by HPLC, and a substance in fractions showing inhibitory activity against V. vulnificus was determined to be lactic acid. Our results suggest that luxS in V. vulnificus affects not only the ability of the species to colonize the host gut but also its susceptibility to the growth-inhibiting activity of commensal bacteria including Lactobacillus. KEY POINTS: • Gut microbiomes of ΔluxS-infected and WT Vibrio-infected mice differed greatly. • Difference was most prominent in the jejunum and ileum compared to the duodenum or large intestine. • In the small and large intestines of mice, the relative proportions of Vibrio and Lactobacillus species showed a negative relationship. • Effector molecules produced by Lactobacillus in mouse gut inhibit Vibrio growth.
自诱导物-2 (AI-2) 是一种来自人类病原体创伤弧菌的群体感应信号分子，我们评估了它对小鼠肠道微生物组的影响。为此，我们采用 16S rRNA 测序来比较感染野生型创伤弧菌或缺失 luxS 的同型突变体 ΔluxS 的小鼠的肠道微生物组，luxS 编码 AI-2 的生物合成功能。感染野生型的小鼠空肠和回肠中野生型创伤弧菌的相对比例明显高于感染 ΔluxS 的小鼠，这表明 AI-2 在创伤弧菌在小肠中的定植中发挥重要作用。感染 ΔluxS 的小鼠肠道中的细菌组成中厚壁菌门的比例较高，主要由乳杆菌组成，而感染野生型细胞的小鼠则较低。无论遗传背景如何，在大肠中几乎都检测不到创伤弧菌。从感染 ΔluxS 的小鼠粪便样本中分离出的三种乳杆菌对创伤弧菌表现出显著的抗菌活性。从这三种细菌分离出的培养上清液通过 HPLC 溶解，并确定抑制创伤弧菌活性的物质为乳酸。我们的结果表明，创伤弧菌中的 luxS 不仅影响该物种定植宿主肠道的能力，还影响其对包括乳杆菌在内的共生菌生长抑制活性的敏感性。关键点：• ΔluxS 感染和 WT 感染的小鼠肠道微生物组差异很大。• 与十二指肠或大肠相比，空肠和回肠的差异最为明显。• 在小鼠的小肠和大肠中，创伤弧菌和乳杆菌的相对比例呈负相关。• 小鼠肠道中乳杆菌产生的效应分子抑制创伤弧菌的生长。
