title: Enterotoxin production by Bacillus cereus under gastrointestinal conditions and their immunological detection by commercially available kits.
abstract: Currently, three commercial kits for Bacillus cereus enterotoxins Nhe and/or Hbl detection are available, namely, the Bacillus diarrheal enterotoxin visual immunoassay (BDE VIA™) kit (3M Tecra), B. cereus enterotoxin reversed passive latex agglutination (BCET-RPLA) kit (Oxoid), and the Duopath(®) Cereus Enterotoxins (Merck). The performance of the kits and their applicability to gastrointestinal simulation samples were evaluated. Then, the stability and production of enterotoxins Hbl and Nhe under gastrointestinal conditions were investigated. Enterotoxin production was absent or impaired at acidic pH, i.e., in gastric medium with pH 5.0 and lasagne verde with pH 5.5. B. cereus did produce enterotoxins Nhe and Hbl during anaerobic growth in intestinal medium at pH 7.0, but the toxins were instantly degraded by the enzymes in the host's digestive secretions. Preformed enterotoxins did not withstand gastrointestinal passage under the simulated conditions, which suggests that preformed enterotoxins in food do not contribute to the diarrheal food poisoning syndrome. In conclusion, diarrhea is probably caused by de novo enterotoxin production by B. cereus cells located closely to the host's intestinal epithelium.
authors.affiliation: Faculty of Bioscience Engineering, Laboratory of Food Microbiology and Food Preservation, Ghent University, Ghent, Belgium.
authors.forename: Siele
authors.initials: S
authors.lastname: Ceuppens
authors.forename: Andreja
authors.initials: A
authors.lastname: Rajkovic
authors.forename: Stefanie
authors.initials: S
authors.lastname: Hamelink
authors.forename: Tom
authors.initials: T
authors.lastname: Van de Wiele
authors.forename: Nico
authors.initials: N
authors.lastname: Boon
authors.forename: Mieke
authors.initials: M
authors.lastname: Uyttendaele
mesh_terms: D000818:Animals; D000942:Antigens, Bacterial / Q000276:immunology; D001409:Bacillus cereus / Q000276:immunology / Q000302:isolation & purification / Q000378:metabolism*; D001431:Bacteriological Techniques; D003470:Culture Media; D004269:DNA, Bacterial / Q000235:genetics; D003967:Diarrhea; D004768:Enterotoxins / Q000032:analysis* / Q000096:biosynthesis* / Q000276:immunology; D005516:Food Microbiology; D041981:Gastrointestinal Tract / Q000382:microbiology; D006460:Hemolysin Proteins / Q000235:genetics; D006863:Hydrogen-Ion Concentration; D007118:Immunoassay; D057230:Limit of Detection; D011933:Reagent Kits, Diagnostic; D013045:Species Specificity; D013997:Time Factors
chemical_list: D000942:Antigens, Bacterial; D003470:Culture Media; D004269:DNA, Bacterial; D004768:Enterotoxins; D006460:Hemolysin Proteins; D011933:Reagent Kits, Diagnostic; C040792:enterotoxin, Bacillus cereus