Share

Cryotolerance of Escherichia coli O157:H7 in laboratory media and food.

Author(s) : GRZADKOWSKA D., GRIFFITHS M. W.

Type of article: Article

Summary

This study compares the cryotolerance of E. coli O157:H7 strains with nonpathogenic strains of E. coli. Cold shocked (exposed to 10 °C for 6 h) and non-cold shocked (held at 20 °C) cultures were frozen at -18 °C for up to 240 h in brain heart infusion broth, apple juice, frozen yoghurt, and ground beef. The E. coli O157:H7 strains showed the greatest cold shock effect and cryotolerance. The cold shocked E. coli O157:H7 strains showed a 25 to 35% increase in their ability to survive frozen storage for 24 h at -18 °C compared to non-cold shocked cells. The corresponding value for non-O157 strains was only about 5%. The food matrix changed the cold shock response in all strains, particularly with broth cultures. Cryotolerance of E. coli was not observed in frozen yoghurt and ground beef. The effect of prior cold shock was most pronounced in E. coli O157:H7 strains after 24 h of freezing.

Details

  • Original title: Cryotolerance of Escherichia coli O157:H7 in laboratory media and food.
  • Record ID : 2002-2330
  • Languages: English
  • Source: Ital. J. Food Sci. - vol. 66 - n. 8
  • Publication date: 2001/10
  • Document available for consultation in the library of the IIR headquarters only.

Links


See other articles in this issue (4)
See the source

Indexing