Submitted to: Encyclopedia of Life Support Systems
Publication Type: Book / Chapter
Publication Acceptance Date: 2/1/2012
Publication Date: 11/21/2012
Citation: Feng, P., Strockbine, N., Fratamico, P.M. 2012. Methods of detection and characterization of pathogenic Escherichia coli. In: Eds.UNESCO-EOLSS Joint Committee. Encyclopedia of Life Support Systems. Oxford,UK: Eolss Publishers. Available: http://www.eolss.net. Interpretive Summary:
Technical Abstract: Pathogenic E. coli that cause diarrheal diseases are most often transmitted via contaminated water and foods. Microbiological testing for the presence of pathogenic bacteria in foods is a complex, multi-step process that entails culture enrichment of the food sample, screening the enriched sample with a target specific assay, and confirming the presence of the pathogen by isolate identification and characterization. To perform this task to detect pathogenic E. coli is even more difficult due to the large diversity of strains that belong to the various pathogenic groups. As a result, few assays exist that can be used to test for pathogenic E. coli as a whole, but serotype and strain specific assays are available. This chapter presents background and epidemiological information on the 6 recognized pathogenic E. coli groups and discusses the logistical details involved at each step to facilitate the detection of these pathogens in foods. In addition, since pathogenic E. coli are grouped based on distinct epidemiological and clinical features and/or unique virulence factors, it is often essential to test for virulence factors to identify the strains that belong to the different groups. Lastly, as many of the virulence factors carried by pathogenic E. coli reside on mobile genetic elements, such as plasmids and phages, gene transfer among strains occurs, resulting in the emergence of new variants that can cause disease in humans.