Characterization of the eaeA gene from rabbit enteropathogenic Escherichia coli strain RDEC-1 and comparison to other eaeA genes from bacteria that cause attaching-effacing lesions

FEMS Microbiol Lett. 1996 Nov 1;144(2-3):249-58. doi: 10.1111/j.1574-6968.1996.tb08538.x.


A number of enteric pathogens, including enteropathogenic (EPEC) and enterohemorrhagic (EHEC) Escherichia coli, Hafnia alvei, a strain of Citrobacter freundii, and rabbit EPEC strain RDEC-1 cause attaching-effacing (AE) lesions in the gut mucosa. These bacteria have a pathogenicity cassette (locus of enterocyte effacement or LEE) containing the eaeA gene. This gene encodes intimin, an outer membrane protein required for production of AE lesions. RDEC-1, a non-invasive enteropathogen in young rabbits, produces AE lesions morphologically indistinguishable from lesions caused by human AE bacterial strains. The RDEC-1 example of E. coli diarrhea in rabbits is an important model for studying the pathogenesis of AE bacteria in a natural infection and for analyzing specific roles of the components of LEE. In order to better understand the role of intimin in the development of AE lesions, a portion of DNA within RDEC-1 LEE, containing the eaeA gene and an upstream open reading frame (ORF), was sequenced. The RDEC-1 eaeA gene shared 87%, 92%, and 93% DNA sequence identity and > 80% amino acid sequence identity with the eaeA genes of C. freundii biotype 4280, EHEC O157:H7, and EPEC O127:116, respectively. The carboxy-terminal 280 amino acid residues of intimin has 80%, 56%, and 54% identity with C. freundii, EHEC O157:H7, and EPEC O127:H6 intimins, respectively. The predicted protein encoded by the upstream ORF (156 amino acids) shares 95%, 97%, and 99% amino acid identity with predicted proteins from C. freundii. EHEC O157:H7, and EPEC O127:H6, respectively. The high degree of sequence homology of the ORF and the eueA gene of RDEC-1 with those of other AE bacteria suggests an evolutionary relationship of LEE and supports and facilitates the use of the RDEC-1 model for studying the role of LEE in pathogenesis.

Publication types

  • Comparative Study
  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Adhesins, Bacterial*
  • Amino Acid Sequence
  • Animals
  • Bacterial Outer Membrane Proteins / genetics*
  • Base Sequence
  • Carrier Proteins*
  • Diarrhea / microbiology
  • Diarrhea / pathology
  • Diarrhea / veterinary
  • Disease Models, Animal
  • Escherichia coli / genetics*
  • Escherichia coli / isolation & purification
  • Escherichia coli / pathogenicity
  • Escherichia coli Infections / microbiology
  • Escherichia coli Infections / pathology
  • Escherichia coli Infections / veterinary
  • Escherichia coli Proteins*
  • Evolution, Molecular
  • Genes, Bacterial*
  • Humans
  • Molecular Sequence Data
  • Open Reading Frames
  • Rabbits
  • Species Specificity


  • Adhesins, Bacterial
  • Bacterial Outer Membrane Proteins
  • Carrier Proteins
  • Escherichia coli Proteins
  • eaeA protein, E coli

Associated data

  • GENBANK/U60002