<prompt> Most common cause of hemolytic uremic syndrome isE.coliShigellaSalmonellaPsedonomis  <response>: Etiology of HUSHUS usually follows an episode of acute gastroenteritis.Less commonly, patient may present after an upper respiratory tract infection.The organisms responsible are -E.coli most common EHEC shiga toxin producing Shigella dysenteriae Salmonella Bartonella Streptococcus pneumonia Campylobacter 