Related Experiment Video
Updated: Jun 10, 2026

Detection of Live Escherichia coli O157:H7 Cells by PMA-qPCR
Published on: February 1, 2014
[Comparison of enteropathogenic Escherichia coli (EPEC) diagnosis by serology and by polymerase chain reaction (PCR)]
Angela Lluque1, Eric Mercado, Maribel Riveros
1Laboratorio de Enfermedades Entéricas y Nutrición (LEEN), Instituto de Medicina Tropical Alexander von Humboldt, Universidad Peruana Cayetano Heredia, Lima, Perú. Theresa.J.Ochoa@uth.tmc.edu
Introduction:
The identification of EPEC in clinical laboratories is based on the determination of the serotypes by agglutination with O and H antiserum. Currently the proper diagnosis of EPEC should be done by the identification of the intimin gen (eaeA) by PCR.
Objectives:
To compare the diagnosis of EPEC by serotyping and by PCR.
Materials And Methods:
We collected EPEC strains, identify by their O antigen, from 4 clinical laboratories in Lima from diarrheal samples in children less than 5 years of age. In those strains we have searched for virulence genes by a real time multiplex PCR for the diarrheagenic E. coli.
Results:
We collected 113 strains; 82% from children less than 2 years of age. Only 15 strains (13.3%) had the intimin gene and therefore a confirmatory diagnosis of EPEC. In addition we found 3 enterotoxigenic (ETEC), 3 shiga toxin-producing (STEC), 1 enteroagreggative (EAEC) and 1 enteroinvasive (EIEC) strains.
Conclusions:
PCR should be use for the proper identification of EPEC. However, molecular methods are still not easily available in clinical laboratories worldwide.
More Related Videos
Related Concept Videos
Enzyme-Linked Immunosorbent Assay
There are many different types of ELISAs, but they all involve an antibody molecule whose constant region binds an enzyme, leaving the variable region free to bind its specific antigen. Enzyme-substrate reaction allows the antigen to be visualized or quantified.
Bacterial Gastroenteritis

