Detection of the enteroaggregative Escherichia coli heat-stable enterotoxin 1 (EAST1) gene and its relationship with fimbrial and enterotoxin markers in E. coli isolates from pigs with diarrhoea

Vet Microbiol. 2003 Jan 2;91(1):65-72. doi: 10.1016/s0378-1135(02)00262-6.

Abstract

The presence of the astA gene responsible for production of enteroaggregative Escherichia coli heat-stable enterotoxin 1 (EAST1) was examined in E. coli strains isolated from pigs with postweaning diarrhoea. Two hundred and seven isolates were tested using PCR for the astA marker and for heat-labile I (LTI), heat-stable I (STI), and heat-stable II (STII) enterotoxin genes. Moreover, the isolates were also analysed for their serotypes (O and K antigens) as well as for fimbrial adhesins using agglutination methods. It was shown that 96 (46.4%) of the isolates possessed the astA genetic determinant. The most common EAST1-positive E. coli serotype was O149:K91 and these strains were mostly LTI/STII-positive. A close correlation between the presence of F4 fimbriae and the EAST1 gene was also observed: 88 of 96 (91.7%) astA(+) isolates tested possessed the F4 antigen. Thus, EAST1 enterotoxin may represent an additional virulence determinant playing a role in the pathogenesis of porcine colibacillosis.

MeSH terms

  • Agglutination Tests / veterinary
  • Animals
  • Bacterial Toxins / genetics*
  • Bacterial Toxins / metabolism
  • DNA, Bacterial / chemistry
  • DNA, Bacterial / genetics
  • Diarrhea / microbiology
  • Diarrhea / veterinary*
  • Enterotoxins / genetics*
  • Enterotoxins / metabolism
  • Escherichia coli / genetics*
  • Escherichia coli / growth & development
  • Escherichia coli / pathogenicity
  • Escherichia coli Infections / microbiology
  • Escherichia coli Infections / veterinary*
  • Escherichia coli Proteins / genetics*
  • Escherichia coli Proteins / metabolism
  • Fimbriae, Bacterial / genetics
  • Fimbriae, Bacterial / metabolism
  • O Antigens / isolation & purification
  • Polymerase Chain Reaction / veterinary
  • Swine
  • Swine Diseases / microbiology*
  • Virulence

Substances

  • Bacterial Toxins
  • DNA, Bacterial
  • Enterotoxins
  • Escherichia coli Proteins
  • O Antigens
  • heat stable toxin (E coli)