biostudies-literatureUnknown12(6)Choi SEnterohemorrhagic <i>Escherichia coli</i> (EHEC) causes thrombotic microangiopathy, yet the red blood cell (RBC)-centered mechanism has remained unclear. We identify the RTX-family hemolysin EhxA as the driver of RBC-mediated thrombogenesis. Deletion of <i>ehxA</i> abolishes Ca²⁺ influx, phosphatidylserine (PS) exposure, progression from discocyte to echinocyte to spherocyte, thrombin generation, RBC-endothelium adhesion, and RBC aggregation. Genetic complementation restores these readouts to wild type, and purified EhxA in bacteria-free assays recapitulates them while localizing to intact RBC membranes. By contrast, Δ<i>stx2</i> mutants do not elicit these RBC phenotypes, distinguishing this pathway from Shiga toxin-dependent effects. Multiple regression quantifies the link betScience advanceseady8284https://www.ebi.ac.uk/biostudies/studies/S-EPMC12880542biostudies-literatureRTX-family toxin EhxA drives morphological remodeling and thrombogenesis in RBCs during enterohemorrhagic &lt;i&gt;Escherichia coli&lt;/i&gt; infection.PMC12880542Choi SPark HChung HYBian YBae ONIm HfalseRTX-family toxin EhxA drives morphological remodeling and thrombogenesis in RBCs during enterohemorrhagic &lt;i&gt;Escherichia coli&lt;/i&gt; infection.Enterohemorrhagic <i>Escherichia coli</i> (EHEC) causes thrombotic microangiopathy, yet the red blood cell (RBC)-centered mechanism has remained unclear. We identify the RTX-family hemolysin EhxA as the driver of RBC-mediated thrombogenesis. Deletion of <i>ehxA</i> abolishes Ca²⁺ influx, phosphatidylserine (PS) exposure, progression from discocyte to echinocyte to spherocyte, thrombin generation, RBC-endothelium adhesion, and RBC aggregation. Genetic complementation restores these readouts to wild type, and purified EhxA in bacteria-free assays recapitulates them while localizing to intact RBC membranes. By contrast, Δ<i>stx2</i> mutants do not elicit these RBC phenotypes, distinguishing this pathway from Shiga toxin-dependent effects. Multiple regression quantifies the link bet2026-01-01T00:00:00Z2026 Feb2026-07-15T07:39:53.514Z2026-07-01T03:07:47.54ZS-EPMC128805424165027310.1126/sciadv.ady8284