Escherichia coli serogroup O2 and O28ac O-antigen gene cluster sequences and detection of pathogenic E. coli O2 and O28ac by PCR

Pina M. Fratamico, Xianghe Yan, Yanhong Liu, Chitrita DebRoy, Brian Byrne, Aine Monaghan, Seamus Fanning, Declan Bolton

Research output: Contribution to journalArticlepeer-review

21 Scopus citations


The O-antigen gene clusters of Escherichia coli serogroups O2 and O28ac were sequenced, and PCR assays were developed to identify strains belonging to these 2 serogroups. Sixteen and 8 open reading frames were mapped to these loci in E. coli O2:H4 U 9-41 and E. coli O28ac:H25 96-3286, respectively. The wzx (O-antigen flippase) and wzy (O-antigen polymerase) genes in the E. coli O2 and O28ac O-antigen gene clusters were selected as targets for PCR assays for their identification. PCR assays targeting the wzx and wzy genes were specific for these serogroups, with one exception. Escherichia coli serogroup O42 strains gave positive results with wzx and wzy PCR assays targeting E. coli O28ac, and antiserum raised against O42 cross-reacted with serogroup O28ac strains. The O-antigen gene cluster of a strain of E. coli serogroup O42 was sequenced, and there were only 3 nt differences between the O-antigen gene clusters of the O28ac and O42 strains. Multiplex PCR assays targeting the O2 wzx gene, the stx1, stx2, hly, eae, and saa genes, and the O28ac wzx, ial, ipaC, and ipaH genes were developed for detecting Shiga toxin-producing E. coli O2 strains and enteroinvasive E. coli O28ac strains, respectively. The O2 and O28ac wzx and wzy genes can be used as diagnostic markers in PCR assays for rapid identification of these serogroups as an alternative to serotyping, and the multiplex PCR assays targeting serogroup-specific genes in combination with virulence genes can be used to identify and to detect pathogenic serogroup O2 and O28ac strains.

Original languageEnglish (US)
Pages (from-to)308-316
Number of pages9
JournalCanadian Journal of Microbiology
Issue number4
StatePublished - Apr 2010

All Science Journal Classification (ASJC) codes

  • Microbiology
  • Immunology
  • Applied Microbiology and Biotechnology
  • Molecular Biology
  • Genetics


Dive into the research topics of 'Escherichia coli serogroup O2 and O28ac O-antigen gene cluster sequences and detection of pathogenic E. coli O2 and O28ac by PCR'. Together they form a unique fingerprint.

Cite this