General overview of potential reservoirs and modes of transmission for pathogenic E. coli. General overview of potential reservoirs and modes of transmission for pathogenic E. coli. Pathogenic E. coli strains can be found in various animal reservoirs and can spread between these and other animals. Fecal matter can contaminate food, irrigation water, or recreational/drinking water. Humans can become exposed following the ingestion of contaminated food or water or through direct contact with colonized animals. Secondary transmission can occur between humans, commonly in day care centers or nursing homes. Food can become contaminated through poor cooking practice, where, for example, uncooked meat could come in contact with other food. Additionally, symptomatic or asymptomatic food handlers can contaminate food, particularly when hand hygiene is inadequate. Contamination of recreational or drinking water can occur through exposure of human sewage. Matthew A. Croxen et al. Clin. Microbiol. Rev. 2013; doi:10.1128/CMR.00022-13