 Azithromycin, an antibiotic of the macrolide family, binds to the 50S subunit of the bacterial ribosome and inhibits protein synthesis by blocking transpeptidation. This mechanism inhibits the production and the release of Shiga toxin in STEC Ohara et al. 2002. Studies on animal models of DHUS mice, piglet showed a drastic reduction in mortality. Moreover, in addition to its inhibitory action on the synthesis of Stx, azithromycin has a modulating effect on the inflammatory reaction on the vascular endothelium induced by the Shigatoxin that contribute to thrombotic microangiopathy. Indeed, azithromycin dramatically decreased secretion of IL6, IL1 and TNFα Gantzhorn et al. 2009 Ohara et al. 2002 Zhang Q et al. 2009. 