This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Kidney, Subject name: Pediatrics
Most common cause of hemolytic uremic syndrome is: 
Select and explain. 
A. E. coli, B. Shigella, C. Salmonella, D. Pseudomonas
A: E. coli
Answer: A: E. coli 
Explanation: a. E. coli(Ref: Nelson's 20/e p 2508-2510, Ghai 8/e p 492-493)Etiology of HUS: HUS usually follows an episode of acute gastroenteritis (less commonly, upper respiratory infection).The organisms responsible for HUS are:E. coli (most common) esp EHEC (shiga toxin producing)Salmonella; Shigella dysenteriaeStreptococcus pneumoniaeBartonella; CampylobacterViruses (Coxsackie virus, echovirus, influenza, varicella, HIV, EBV)