Effects of L-lysine aescinat on intracranial pressure in patients with severe traumatic brain injury

Restoring tigecycline efficacy with lysine supplementation in tmexCD-toprJ-positive bacteria

Antimicrobial resistance is one of the most pressing challenges to global society. Tigecycline, a last-resort antibiotic, is undermined by the emergence of the tmexCD1-toprJ1 gene cluster, a transferable RND-type efflux pump that confers resistance. Metabolite-enabled killing of antibiotic-resistant pathogens by antibiotics is an attractive strategy to tackle antibiotic resistance. Herein, we show that lysine synergistically enhances the antibacterial efficacy of tigecycline against tmexCD-toprJ-positive bacteria. Mechanistic studies indicate that lysine supplementation promotes tigecycline uptake by upregulating ∆pH and disrupting membrane permeability. Transcriptomic analysis, coupled with phenotypic experiments, indicates that lysine not only triggers the generation of reactive oxygen species (ROS) by inhibiting hydrogen sulfide (H2S) production but also downregulates energy metabolism pathways essential for efflux pump function. These effects promote intracellular accumulation of tigecycline, thereby overcoming tmexCD-toprJ-mediated resistance. In mouse infection models, the combination of lysine and tigecycline shows improved therapeutic efficacy compared to tigecycline monotherapy. Collectively, our findings indicate that lysine can serve as a promising tigecycline booster to tackle infections caused by tmexCD-toprJ-positive bacteria.

A metabolomic study on high-risk stroke patients determines low levels of serum lysine metabolites: a retrospective cohort study

Metabolic alteration at early neurological deterioration during cerebral ischemia.