Food inspectors will start testing ground beef for six additional strains of E. coli. There are currently more than 700 different strains of the bacteria.
Food scientists say most types are harmless, but some can attack your intestines and cause serious problems.
The new quicker testing is designed to detect contaminated meat and chicken faster before it enters the food supply.
Samples testing positive for a dangerous strain of E. coli will be taken out of stores and could be subject to a recall, and an investigation would launch 24 to 48 hours sooner than before, when food scientists would have to wait for a confirmed positive test result.
U.S. agriculture secretary Tom Vilsack says the new effort is focused on preventing food-borne illnesses among Americans.