The enterohemolysin phenotype of bovine Shiga-like toxin-producing Escherichia coli (SLTEC) is encoded by the EHEC-hemolysin gene

Vet Microbiol. 1996 Sep;52(1-2):153-64. doi: 10.1016/0378-1135(96)00058-2.


Naturally occurring enterohemolysin negative variants were observed during studies on bovine Shiga-like toxin-producing E. coli (SLTEC). Examination of three strains (413/89-1 and 332, 026:H-, and 570/89, O111:H-) and their isogenic variants (413/89-6, 332-I and 570/89-I, respectively) showed, that in each strain loss of the enterohemolytic phenotype correlated with the loss of a large plasmid ranging from 94 to 104 kb in size. The hemolysin determinant present on the 94 kb plasmid of strain 413/89-1 was cloned and discovered by DNA and N-terminal aminoacid sequence analysis to be highly homologous to the recently published EHEC-hemolysin (HlyEHEC; Schmidt et al., 1994; 1995). When a recombinant plasmid harboring this determinant was reintroduced into the enterohemolysin negative isogenic mutant 413/89-6, the enterohemolytic phenotype was restored. Southern blot hybridization analysis was used to demonstrate that the HlyEHEC is plasmid-borne in SLTEC-strains. Our cumulative data suggest that the enterohemolytic phenotype of SLTEC is encoded by the plasmid-borne HlyEHEC. These results further demonstrate the close similarity between SLTEC-isolates from bovine and human.

MeSH terms

  • Animals
  • Bacterial Toxins / biosynthesis*
  • Bacterial Toxins / genetics
  • Base Sequence
  • Cattle
  • Cattle Diseases*
  • DNA Primers
  • Enterotoxins / biosynthesis
  • Escherichia coli / genetics*
  • Escherichia coli / growth & development
  • Escherichia coli / isolation & purification
  • Escherichia coli Infections / microbiology
  • Escherichia coli Infections / veterinary*
  • Escherichia coli Proteins
  • Feces / microbiology
  • Genes, Bacterial
  • Genetic Variation
  • Hemolysin Proteins / biosynthesis*
  • Hemolysin Proteins / genetics
  • Humans
  • Phenotype
  • Polymerase Chain Reaction
  • Shiga Toxin 1
  • Shiga Toxin 2


  • Bacterial Toxins
  • DNA Primers
  • Enterotoxins
  • Escherichia coli Proteins
  • Hemolysin Proteins
  • Shiga Toxin 1
  • Shiga Toxin 2
  • enterohemolysin