animal by-products (feathers, viscera) as feed for the next generation of animals, and crowding the animals together in very close confinement, both of which favor the spread of the bacteria Salmonella often have no obvious effect on the animal carriers, but in humans can cause diarrhea and chronic infection in other parts of the body Escherichia coli is the collective name for many related strains of bacteria that are normal residents of the intestines of warmblooded animals, including humans But several strains are aliens, and if ingested will invade the cells of the digestive tract and cause illness The most notorious E coli, and the most dangerous, is a special strain called O157:H7 that causes bloody diarrhea and sometimes kidney failure, especially in children In the United States, about a third of people diagnosed with E coli O157:H7 need to be hospitalized, and about 5% die E coli O157:H7 is harbored in cattle, especially calves, and other animals, but has little if any effect on them Ground beef is by far the most common source of E coli O157:H7 infection Grinding mixes and spreads what may be only a small contaminated portion throughout the entire mass of meat Prevention Prevention of bacterial infection begins with the well warranted assumption that all meat has been contaminated with at least some disease bacteria It requires measures to ensure that those bacteria are not spread to other foods, and are eliminated from the meats during cooking Hands, knives, cutting boards, and countertops used to prepare meats should be cleaned with hot soapy water before being used to prepare other foods E coli are killed at 155ºF/68ºC, so ground meats are safest if their center gets at least this hot Salmonella and other bacteria can multiply at significant rates between 40 and 140ºF/5–60ºC, so meats should not be left ...calves, and other animals, but has little if any effect on them Ground beef is by far the most common source of E coli O157:H7 infection Grinding mixes and spreads what may be only a small contaminated portion throughout the. .. a small contaminated portion throughout the entire mass of meat Prevention Prevention of bacterial infection begins with the well warranted assumption that all meat has been contaminated with at least... prepare other foods E coli are killed at 155ºF/68ºC, so ground meats are safest if their center gets at least this hot Salmonella and other bacteria can multiply at significant rates between 40 and 140ºF/5–60ºC, so meats should not be left