Screening of Cytotoxic B. cereus on Differentiated Caco-2 Cells and in Co-Culture with Mucus-Secreting (HT29-MTX) Cells.
B. cereusis an opportunistic foodborne pathogen able to cause diarrhoea. However, the diarrhoeal potential of aB. cereusstrain remains difficult to predict, because no simple correlation has yet been identified between the symptoms and a unique or a specific combination of virulence factors. In this study, 70B. cereusstrains with different origins (food poisonings, foods and environment) have been selected to assess their enterotoxicity. TheB. cereuscell-free supernatants have been tested for their toxicity in vitro, on differentiated (21 day-old) Caco-2 cells, using their ATP content, LDH release and NR accumulation. The genetic determinants of the main potential enterotoxins and virulence factors (ces,cytK,entFM,entS,hbl,nhe,nprA,piplCandsph) have also been screened by PCR. This analysis showed that none of these genes was able to fully explain the enterotoxicity ofB. cereusstrains. Additionally, in order to assess a possible effect of the mucus layer in vitro, a cytotoxicity comparison between a monoculture (Caco-2 cells) and a co-culture (Caco-2 and HT29-MTX mucus-secreting cells) model has been performed with selectedB. cereussupernatants. It appeared that, in these conditions, the mucus layer had no notable influence on the cytotoxicity ofB. cereussupernatants.
Laboratory of Food and Environmental Microbiology, Earth and Life Institute, Université catholique de Louvain, Croix du Sud 2, L7.05.12, Louvain-la-Neuve B-1348, Belgium. virginie.castiaux@uclouvain.be.
Virginie
V
Castiaux
Laboratory of Cellular, Nutritional and Toxicological Biochemistry, Institute of Life Sciences, Université catholique de Louvain, Croix du Sud 4-5, L7.07.03, Louvain-la-Neuve B-1348 , Belgium. laurie.laloux@uclouvain.be.
Laurie
L
Laloux
Laboratory of Cellular, Nutritional and Toxicological Biochemistry, Institute of Life Sciences, Université catholique de Louvain, Croix du Sud 4-5, L7.07.03, Louvain-la-Neuve B-1348 , Belgium. yjs@uclouvain.be.
Yves-Jacques
YJ
Schneider
Laboratory of Food and Environmental Microbiology, Earth and Life Institute, Université catholique de Louvain, Croix du Sud 2, L7.05.12, Louvain-la-Neuve B-1348, Belgium. jacques.mahillon@uclouvain.be.
Jacques
J
Mahillon
D000255:Adenosine Triphosphate / Q000378:metabolism; D001409:Bacillus cereus / Q000235:genetics; D018938:Caco-2 Cells; D002454:Cell Differentiation; D002470:Cell Survival; D018920:Coculture Techniques; D004269:DNA, Bacterial / Q000235:genetics; D004768:Enterotoxins / Q000235:genetics; D019073:HT29 Cells; D006801:Humans; D007770:L-Lactate Dehydrogenase / Q000378:metabolism; D009093:Mucus / Q000378:metabolism; D014774:Virulence / Q000235:genetics; D037521:Virulence Factors / Q000235:genetics
D004269:DNA, Bacterial; D004768:Enterotoxins; D037521:Virulence Factors; D000255:Adenosine Triphosphate; D007770:L-Lactate Dehydrogenase
B. cereus; Caco-2; HT29-MTX; cytotoxicity; enterotoxin