A New Diagnostic Problem: Isolation of Escherichia Coli O157:H7 Strains With Aberrant Biochemical Properties

Diagn Microbiol Infect Dis. 2000 Nov;38(3):185-7. doi: 10.1016/s0732-8893(00)00196-6.


Over a five-year period (1995-1999) the Microbial Diseases Laboratory received 34 strains of E. coli O157:H7 each with a single aberrant biochemical property. In addition, 27 O157 strains with negative or delayed motility were noted during the same time period. These observations suggest that there may be an increased likelihood to misdiagnose O157:H7 infections using commercial systems in the future due to increasing phenotypic variability.

MeSH terms

  • Bacterial Typing Techniques
  • Escherichia coli Infections / diagnosis*
  • Escherichia coli Infections / microbiology*
  • Escherichia coli O157 / classification*
  • Escherichia coli O157 / isolation & purification
  • Escherichia coli O157 / physiology*
  • Humans
  • Phenotype
  • Sorbitol / metabolism
  • Urea / metabolism


  • Sorbitol
  • Urea