-- Some strains are harmless to humans and are Normal Flora of the G.I. tract.
-- E. Coli Normal Flora produce Vitamin K that humans bodies use in digestion.
-- E. Coli acts as "Guardian" Competing and blocking other bacteria from growing in the G.I. Tract
-- E. Coli 0157:H7 is harmful to Humans
-- E.Coli can survive outside of the G.I. tract, thus causing food poisoning.

E.Coli 0157:H7
-- Gram Negative Rod Microbe
-- received a Plasmid from a shigella Microbe making 0157:H7 capable of producing virulent toxins
-- Causes lesions in the G.I. tract
-- Produces a toxin that blocks host cells mRNA causing cell death.
-- Causes a bloody diarrhea
-- Can lead to Kidney failure (especially in the elderly and youth populations)
-- Causes fever and abdominal cramps.

Transfered by:
-- Unpasteurized milk
-- Under cooked Ground beef
-- Swimming or drinking contaminated water.
-- Contaminated Vegetables

Treatment
-- Blood transfusions
-- Kidney Dialysis
-- No proof that antibiotics help one to overcome E. Coli faster.
-- Anti diarrhea medicine are not recommended