A naturally isolated symbiotic Lactobacillus murinus suppresses multidrug-resistant Campylobacter jejuni via...

Multidrug-resistant Campylobacter jejuni (MDR C. jejuni), the leading cause of food-borne gastroenteritis worldwide, poses a significant threat to public health and food safety. The intestinal microbiota prevents MDR C. jejuni colonization, but the specific mechanisms remain poorly understood. In this study, we performed a multi-omics analysis of the gut microbiota in C57BL/6 mice, combined with in vitro experiments, to investigate the role of gut microbiota in C. jejuni colonization. Treatment with tylvalosin, a new macrolide, altered the gut microbiota composition, reducing Bifidobacterium longum communities and decreasing levels of short-chain fatty acids (acetic acid, propionic acid, n-butyric acid, i-butyric acid, and i-valeric acid). This disruption of intestinal homeostasis facilitated C. jejuni colonization. Through metagenomic sequencing, we identified and isolated Lactobacillus murinus (L. murinus) from the mice's intestinal flora, which exhibited inhibitory activity against C. jejuni in vitro. Metabolomic analysis and in vitro validation further revealed the significance of L. murinus-derived metabolites. Our results indicate that L. murinus inhibits and kills C. jejuni in a co-culture system by secreting acids that synergistically induce apoptosis, leading to cell membrane disruption and the release of cellular contents.