👉 Muricids are a class of bacteria that include Escherichia coli, which is responsible for many common illnesses and infections in humans and animals. They primarily cause diarrhea, but can also cause other gastrointestinal issues like colitis and gastroenteritis. This group includes species like E. coli 0157:H7, which is responsible for the severe E. coli O157:H7 infection that caused the worst food poisoning outbreak in human history in 2009.