Liang Wen Xiang ¹ Jie Xiong ¹ Yang Han Wang ¹ Ting Cai ^1* Pei Shi ¹ Huan Qiu Zhao ¹ Jie Tang ¹ Min Yi Cai ²

• ¹ Xihua University, Chengdu, China
• ² Japan International Research Center for Agricultural Sciences (JIRCAS), Tsukuba, Ibaraki, Japan

Toxin-antitoxin (TA) modules are important mediators of persister cell formation in response to environmental stresses. However, the mechanisms through which persistence is controlled remain poorly understood. Weissella cibaria, a novel probiotic, can enter a persistent state upon encountering tetracycline stress. Here, we found that the Bro-Xre TA modules of W. cibaria were the typical tetracycline regulator. The Bro-Xre TA modules were activated when exposed to tetracycline stress, and the released toxin Bro acted on various cellular metabolic processes, including energy, amino acid and nucleotide metabolism. Among them, the genes related to intracellular energy metabolism such as PTS, EMP, HMP, TCA and oxidative phosphorylation were downregulated, leading to a reduction in ATP synthesis and proton motive force, with the phenotype of cells switching into a persistent state, that was, an increase in cell length of W. cibaria. Simultaneously, the frequency of persister cells also increased under tetracycline stress. These results provided a novel perspective for a comprehensive understanding of the mechanism by which TA modules induce the persistence of the probiotics to escape antibiotic stress by disrupting metabolism.