title: Bacillus cereus Adhesion to Simulated Intestinal Mucus Is Determined by Its Growth on Mucin, Rather Than Intestinal Environmental Parameters.
abstract: Adhesion of pathogenic bacteria to intestinal mucus, the protective layer of the gastrointestinal epithelium, is often considered a virulence factor. The ability of food-poisoning Bacillus cereus strains to attach to mucus and the factors affecting this interaction have not yet been investigated. Therefore, the role of adhesion in pathogenesis of B. cereus still remains unknown. In the present study, an in vitro assay based on mucin agar was used to simulate adhesion of B. cereus to mucus. Bacterial-associated factors (e.g., strain specificity and microbial competition) known to influence adhesion to different surfaces and a variety of environmental conditions (e.g., pH and oxygen) encountered in the gastrointestinal tract were investigated. The effect of these parameters on B. cereus NVH 0500/00 mucin adhesion was generally limited even in the presence of microbial competition. This suggests that B. cereus NVH 0500/00 is a versatile pathogen. Inoculation of 4 to 5 log colony-forming units (CFU) per milliliter. B. cereus NVH 0500/00 resulted in 5-6 log CFU/mL mucin-associated bacteria after a short incubation period. This indicates that this pathogenic strain could grow in the presence of mucin agar. This growth may potentially mask the effect of the studied conditions. Yet, extensive attachment of B. cereus to mucin is not necessarily a prerequisite for virulence, because other pathogenic strains do not adhere with the same efficiency to mucin. Nevertheless, adhesion may contribute to the disease by providing close contact to nutrient sources, such as mucin, which would not only result in bacterial proliferation, but also in disruption of the protective host mucus surface.
authors.affiliation: 1 Laboratory of Microbial Ecology and Technology (LabMET), Department of Biochemical and Microbial Technology, Ghent University, Ghent, Belgium .|2 Laboratory of Food Microbiology and Food Preservation (LFMFP), Department of Food Safety and Food Quality, Ghent University , Ghent, Belgium .
authors.forename: Varvara
authors.initials: V
authors.lastname: Tsilia
authors.affiliation: 2 Laboratory of Food Microbiology and Food Preservation (LFMFP), Department of Food Safety and Food Quality, Ghent University , Ghent, Belgium .
authors.forename: Mieke
authors.initials: M
authors.lastname: Uyttendaele
authors.affiliation: 1 Laboratory of Microbial Ecology and Technology (LabMET), Department of Biochemical and Microbial Technology, Ghent University, Ghent, Belgium .
authors.forename: Frederiek-Maarten
authors.initials: FM
authors.lastname: Kerckhof
authors.affiliation: 2 Laboratory of Food Microbiology and Food Preservation (LFMFP), Department of Food Safety and Food Quality, Ghent University , Ghent, Belgium .
authors.forename: Andreja
authors.initials: A
authors.lastname: Rajkovic
authors.affiliation: 3 Technology and Food Science Unit, Institute for Agricultural and Fisheries Research (ILVO) , Melle, Belgium .|4 Department of Pathology, Bacteriology, and Poultry Diseases, Ghent University , Merelbeke, Belgium .
authors.forename: Marc
authors.initials: M
authors.lastname: Heyndrickx
authors.affiliation: 1 Laboratory of Microbial Ecology and Technology (LabMET), Department of Biochemical and Microbial Technology, Ghent University, Ghent, Belgium .
authors.forename: Tom
authors.initials: T
authors.lastname: Van de Wiele
mesh_terms: D001409:Bacillus cereus / Q000254:growth & development*; D001422:Bacterial Adhesion / Q000502:physiology*; D015169:Colony Count, Microbial; D041981:Gastrointestinal Tract / Q000737:chemistry / Q000382:microbiology; D066298:In Vitro Techniques; D007413:Intestinal Mucosa / Q000382:microbiology*; D009077:Mucins / Q000378:metabolism*
chemical_list: D009077:Mucins