Rapid Detection of Diarrheagenic Escherichia coli by a New Multiplex Real-Time Quantitative PCR Assay

Abstract

Diarrheagenic Escherichia coli (DEC) is a group of important foodborne pathogens that can spread and cause infection in humans. As a significant public health issue, DEC infection may lead to a series of diseases such as abdominal pain, diarrhea, hemorrhagic colitis, and hemolytic uremic syndrome. Therefore, its rapid and accurate detection has become an important concern for food safety issues and healthcare-associated infections. We have developed a multiplex real-time quantitative PCR assay (qPCR), DEC Sensor Test, to simultaneously recognize 5 major DEC pathotypes in a single tube, enterotoxigenic, enterohemorrhagic, enteropathogenic, enteroaggregative and enteroinvasive E. coli. In this assay, 13 DEC virulence genes, stp, sth, lt, stx1, stx2, eae, escV, bfpB, aggR, astA, pic, invE, and ipaH, can be simultaneously detected along with a spiked-in internal amplification control to avoid false negative results. All the constituent PCR for the 13 DEC virulence genes had high analytical sensitivity and specificity. Detection of all virulence genes by DEC Sensor Test can be much easier, cheaper and faster to perform than conventional tests. It also has added advantages of being able to distinguish live or dead bacteria as well as eliminating the possibility of switching partial results between different samples associated with multi-tube tests. Therefore, the application of this assay may significantly enhance our ability to prevent and fight DEC-associated diseases and to improve public health.