title: Fate and effect of ingested Bacillus cereus spores and vegetative cells in the intestinal tract of human-flora-associated rats.
abstract: The fate and effect of Bacillus cereus F4433/73R in the intestine of human-flora-associated rats was studied using bacteriological culturing techniques and PCR-denaturing gradient gel electrophoresis in combination with cell assays and immunoassays for detection of enterotoxins. In faecal samples from animals receiving vegetative cells, only few B. cereus cells were detected. Spores survived the gastric barrier well, and were in some cases detected up to 2 weeks after ingestion. Selective growing revealed no major changes in the intestinal flora during passage of B. cereus. However, denaturing gradient gel electrophoresis analysis with universal 16S rRNA gene primers revealed significant changes in the intestinal microbiota of animals dosed with spores. Vero cell assays and a commercial kit (BCET-RPLA) did not reveal any enterotoxin production from B. cereus F4433/73R in the intestinal tract.
authors.affiliation: Department of Microbiological Food Safety, Danish Institute for Food and Veterinary Research, Mørkhøj Bygade 19, DK-2860 Søborg, Denmark. anw@dfvf.dk
authors.forename: Andrea
authors.initials: A
authors.lastname: Wilcks
authors.forename: Bjarne Munk
authors.initials: BM
authors.lastname: Hansen
authors.forename: Niels Bohse
authors.initials: NB
authors.lastname: Hendriksen
authors.forename: Tine Rask
authors.initials: TR
authors.lastname: Licht
mesh_terms: D000818:Animals; D001409:Bacillus cereus / Q000235:genetics / Q000302:isolation & purification / Q000502:physiology*; D002522:Chlorocebus aethiops; D004269:DNA, Bacterial / Q000032:analysis; D004768:Enterotoxins / Q000032:analysis / Q000096:biosynthesis; D005243:Feces / Q000382:microbiology; D006801:Humans; D007422:Intestines / Q000382:microbiology*; D016133:Polymerase Chain Reaction; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D051381:Rats; D017207:Rats, Sprague-Dawley; D013170:Spores / Q000235:genetics / Q000302:isolation & purification / Q000502:physiology*; D014709:Vero Cells
chemical_list: D004269:DNA, Bacterial; D004768:Enterotoxins; D012336:RNA, Ribosomal, 16S