The need and new tools for surveillance of Escherichia coli pathogens

Among foodborne pathogens, diarrhoeagenic Escherichia coli is of major concern because of its commensal status, abundance in the natural environment, and ability to acquire virulence determinants by horizontal gene transfer from other microbes. From enterotoxigenic E. coli (ETEC) strains to the more virulent enterohemorrhagic E. coli (EHEC), the mechanisms of pathogenicity within this species are intriguing. Recent advances in molecular diagnostics are providing novel tools for improved rapid detection and quantification of this and other pathogenic bacteria from clinical, food, and environmental specimens. These include simple and inexpensive colorimetric and immunological methods to more elaborate nucleic acid-based assays that combine extreme specificity to unparalleled sensitivity and high sample throughput. This review summarizes the current state of E. coli pathogenesis with emphasis on the need for incorporating detection and surveillance tools as part of pre- and post-harvest food safety ideals.