[Quick guide] E.coli

E.coli. What are they? Are they friends or foes? What harm can they do to our bodies? How does someone become infected by E.coli? What is a hemolytic uremic syndrome? If a person is infected with E.coli, does he become contagious? Why are there so many E.coli outbreak cases linked to romaine lettuce? Why did Tanimura and Antle and Dole fresh vegetables recall their romaine lettuce products? Is there any vaccine or antibiotics available for E.coli infection? How can we protect ourselves from getting E.coli infection?