E. coli

A report by the CDC said the bacteria has infected at least 53 people, including 31 who have been hospitalized. The agency's advice: Throw out pre-cut romaine lettuce grown in Yuma, Ariz.

E.coli bacteria, each cell trapped in a tiny tube, are giving researchers the chance to study the pace and effects of single genetic mutations. Most mutations, the scientists find, aren't harmful.

Most people know not to eat raw cookie dough. But now it's serious: 46 people have now been sickened with E. coli-tainted flour. Here's how contamination might be occurring.

The germs caused a urinary tract infection in a Pennsylvania woman that was difficult to treat. The bacteria were resistant to the drug often used as the last-ditch treatment, but another one worked.

Mechanically tenderized meat — which has been punctured with needles to break down the muscle fibers and make it easier to chew — has a greater chance of being contaminated and making you sick.

Two E. coli outbreaks infected at least 60 people in 14 states. The Centers for Disease Control and Prevention hasn't been able to determine the source of the infections.

Thirty-nine people have been sickened with the same strain of E. coli in Washington and Oregon. Fourteen have been hospitalized. Most reported eating at several Chipotle locations before falling ill.

At least 22 people have been infected with E. coli, some of whom reported eating at Chipotle restaurants in the two states. This is the chain's third food-contamination outbreak since August.