Uridine as a potentiator of aminoglycosides through activation of carbohydrate transporters.

Abstract

Aminoglycosides (AGs) are broad-spectrum antibiotics effective against Gram-negative bacteria, with uptake dependent on membrane potential. However, the mechanisms of AG entry remain incompletely understood. Here, we identify a previously undescribed uptake pathway via carbohydrate transporters in <i>E. coli</i>. By deleting or overexpressing 26 carbohydrate transporters, we found that 18 facilitated AG uptake, a mechanism conserved across several Gram-negative ESKAPEE pathogens. Using fluorescent-labeled AGs and flow cytometry, we quantified differential uptake. To enhance AG efficacy, we screened 198 carbon sources for their ability to induce transporter expression using a <i>cmtA</i>-<i>gfp</i> fusion. Uridine emerged as a strong inducer of <i>cmtA</i> and 12 additional AG-importing transporters. Coadministration of uridine considerably improved AG efficacy against clinical and resistant <i>E. coli</i> strains by enhancing drug uptake. This combination also improved outcomes in human blood ex vivo and in a murine urinary tract infection model. Given uridine's clinical safety, it holds promise as an adjuvant to potentiate AG treatment against multidrug-resistant infections.