An antibiotic derivative as a new potential tool in the prevention of hemolytic uremic syndrome

Hemolytic uremic syndrome (HUS), the main cause of acute renal failure in early childhood, is associated with infections by Escherichia coli strains producing Shiga toxin 2 (Stx2). The microangiopathic injuries caused by the toxin occur mainly in the renal microvasculature when the glycolipid receptor globotriaosylceramide (Gb3Cer) is targeted. Before entering the kidney, Stx2 binds to circulating cells through Gb3Cer and Toll-like receptor 4 (TLR4) and is subsequently delivered in extracellular vesicles to target cells. Here, we have found a specific inhibitor of the Stx2/TLR4 interaction, the preclinical polymyxin B derivative NAB815. The compound impairs the formation of Stx2-containing extracellular vesicles produced by leukocytes and platelets and also reduces their toxic effects in cellular (Vero cells) and animal models (CD-1 mice). NAB815 would represent a useful tool in preventing HUS and is effective at sub-bactericidal concentrations, thus overcoming the concern that antibiotics are harmful to patients infected with Stx2-producing E. coli.