Yersiniosis (yer-sin-ee-o-sis) is an infection caused by the bacteria Yersinia. Yersinia is a strong bacteria that can continue to live in environments without much oxygen and in refrigeration. One common source of infection can be contaminated food such as raw or undercooked pork.
Escherichia coli, also called E. coli, are bacteria that are often found in the intestines of people and animals. There are different types of E. coli. Some types of E. coli are not harmful, but others like E. coli O157:H7, can make some people very sick. Usually illness is caused by eating contaminated food or water, having contact with someone who is sick with the bacteria, or animals that carry it.