A method for fast and simple detection of major diarrhoeagenic Escherichia coli in the routine diagnostic laboratory

S. Persson*, K. E.P. Olsen, F. Scheutz, K. A. Krogfelt, P. Gerner-Smidt

*Corresponding author for this work

Research output: Contribution to journalJournal articleResearchpeer-review

Abstract

A multiplex PCR was developed for the detection of the following genes characteristic of diarrhoeagenic Escherichia coli (DEC): verocytotoxins 1 (vtx1) and 2 (vtx2), characteristic of verocytotoxin-producing E. coli (VTEC); intimin (eae), found in enteropathogenic E. coli (EPEC), attaching and effacing E. coli and VTEC; heat-stable enterotoxin (estA) and heat-labile enterotoxin (eltA), characteristic of enterotoxigenic E. coli (ETEC); and invasive plasmid antigen (ipaH), characteristic of enteroinvasive E. coli (EIEC) and Shigella spp. The method allowed the simultaneous identification of all six genes in one reaction, and included a 16S rDNA internal PCR control. When applied to pure cultures from a reference strain collection, all virulence genes in 124 different DEC strains and 15 Shigella spp. were identified correctly, and there were no cross-reactions with 13 non-E. coli species. The detection limit of the method was 102 - 103 DEC CFU/PCR in the presence of 106 non-target cells. When the multiplex PCR was tested with colonies from plate cultures of clinical stool samples, it was a faster, more sensitive, less expensive and less laborious diagnostic procedure than DNA hybridisation. When used with DNA purified from spiked stool samples (by two different commercial kits), the method had a detection limit of 106 CFU/mL stool sample.

Original languageEnglish
JournalClinical Microbiology and Infection
Volume13
Issue number5
Pages (from-to)516-524
Number of pages9
ISSN1198-743X
DOIs
Publication statusPublished - May 2007
Externally publishedYes

Keywords

  • Detection
  • Diarrhoeagenic Escherichia coli
  • EIEC
  • EPEC
  • ETEC
  • Multiplex PCR

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