耐药菌严重危害我国水产养殖业，不仅造成巨大的经济损失，而且危害人体健康和食品安全，因此减量增效使用抗生素已成为国家的重大需求。申请者发现，丙氨酸、谷氨酸和葡萄糖可以通过申请人新近发现的丙酮酸循环，逆转细菌耐药性，促进耐药菌对抗生素的高效摄取，实现减量增效（Cell Metabolism，2015； PNAS, 2018）。然而，其如何调节外膜通道蛋白质使抗生素进入胞内这一关键机制尚不清楚，影响其应用。本研究拟继续以迟缓爱德华菌为对象，通过筛选全基因组突变库，发现与丙氨酸、谷氨酸和葡萄糖促进卡那霉素高效杀菌的相关全部基因；深入系统地研究这些代谢物通过丙氨酸循环-双组份系统-外膜抗生素通道蛋白这一调节途径的作用机制；揭示丙氨酸循环下游代谢通路如嘌呤和嘧啶生物合成等在其中的作用。旨在揭示代谢调节促进耐药菌对抗生素摄取的分子机制，建立一种利用代谢调节有效控制耐药性的新策略并促进其临床应用。

Antibiotic-resistant bacteria severely impairs sustainable development of aquaculture in China, which not only causes huge economic loss but also threaten human health and food safety. Therefore, the national government calls for reducing the use of antibiotics in farming industry. In recent years, we show that exogenous metabolites alanine, glutamate and glucose could revert antibiotic resistance via a newly defined metabolic cycle, the pyruvate cycle, which increases the uptake of antibiotics (Cell Metabolism, 2015; PNAS, 2018). However, how pyruvate cycle regulates the porins that allows the entry of the antibiotics remains poorly understood. This proposal is thus to address this issue by screening transposon-insertion mutagenesis library to identify key genes for metabolite-enabled killing, investigating how metabolites regulate the pyruvate cycle-two component system-porins axis, and exploring the effect of downstream metabolic pathways like purine metabolism and pyrimidine metabolism in regulating antibiotic entry. We believe this research would not only elucidate the mechanism by which how metabolism regulates antibiotic uptake but also develop a metabolism-based approach to control antibiotic-resistant bacteria, which set up the basis for potential clinic application.