Enterotoxin-associated DNA sequence homology between Salmonella species and Escherichia coli

A. K. Chopra, J. W. Peterson, C. W. Houston, R. Pericas, R. Prasad

Research output: Contribution to journalArticlepeer-review

10 Scopus citations


Multiple HindIII-restriction fragments of Salmonella typhimurium and Salmonella typhi chromosomal DNA exhibited homology with the heat-labile enterotoxin (LT1) gene of Escherichia coli as determined by Southern blot analysis. A 9.4 kb HindIII restriction fragment identified in S. typhimurium and S. typhi chromosomal DNA reacted with both eltA and eltB gene probes. However, the homology of the 9.4 kb DNA fragment from these Salmonella species was greater with eltB than eltA. In addition, a synthetic oligonucleotide probe, made to a portion of the putative GM1-ganglioside binding region of cholera toxin (CT) and LT1, hybridized with the 9.4 kb DNA fragment of S. typhimurium but not with the 9.4 kb fragment found in S. typhi isolates. The hybridization of multiple restriction fragments of Salmonella DNA with eltA and eltB gene sequences further suggests duplication of the stx operon on the chromosome of these bacteria.

Original languageEnglish (US)
Pages (from-to)133-138
Number of pages6
JournalFEMS Microbiology Letters
Issue number2-3
StatePublished - Jan 15 1991


  • Cholera toxin
  • Chromosomal DNA
  • G-Ganglioside
  • LT1 Enterotoxin
  • Southern blot hybridization
  • Synthetic oligonucleotide

ASJC Scopus subject areas

  • Microbiology
  • Molecular Biology
  • Genetics


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