Characterisation of a non-haemolytic enterotoxin complex from Bacillus cereus isolated after a foodborne outbreak

Authors

  • Terje Lund,

    1. Department of Pharmacology, Microbiology and Food Hygiene, Norwegian College of Veterinary Medicine P.O. Box 8146, Dep., N-0033 Oslo, Norway
    Search for more papers by this author
  • Per Einar Granum

    Corresponding author
    1. Department of Pharmacology, Microbiology and Food Hygiene, Norwegian College of Veterinary Medicine P.O. Box 8146, Dep., N-0033 Oslo, Norway
    Search for more papers by this author

*Corresponding author. Tel.; +47 22 96 48 45; Fax: +47 22 96 48 50; E-mail: per.e.granum@veths.no

Abstract

Abstract Three enterotoxic components have been isolated from a strain of Bacillus cereus which was involved in a large food poisoning outbreak in Norway in 1995. The components were purified by chromatography on three different columns. Three proteins of 39, 45 and 105 kDa, respectively, were found to be necessary for maximum cytotoxicity. The amino acid N-terminal sequences of the 39 and 45 kDa proteins were determined. The 45 kDa component was the same protein as the main antigen detected in the Bacillus Diarrhoeal Enterotoxin Visual Immunoassay (Tecra). The 39 kDa protein showed some similarity to the l1 protein of haemolysin BL from B. cereus. Furthermore, the three toxic components were all recognised by a polyclonal antiserum reported to detect enterotoxin from B. cereus. The proteins were different from the B- and L2-components of haemolysin BL, previously suggested to be a primary virulence factor, and had no detectable haemolytic activity.

Ancillary