TY - ABST

T1 - Toxin profiles of Bacillus cereus occurring in high numbers in spontaneously fermented African locust beans (Parkia biglobosa)

AU - Thorsen, Line

AU - Azokpota, Paulin

AU - Hansen, Bjarne Munk

AU - Jakobsen, Mogens

N1 - Sider: 79

PY - 2007

Y1 - 2007

N2 - Bacillus cereus was reported to occur in high numbers (up to 107 CFU/g) during spontaneous fermentation of three different traditional Benin condiments; afitin, iru and sonru made from African locust beans. A total of nineteen B. cereus isolates from the ferments, were examined for the presence of toxin genes related to food poisoning using PCR. Isolates harboring the emetic specific gene fragment EM1 where highly representative, being one out of ten isolates from afitin, one of one isolate from iru and five of eight isolates from sonru. Three of the isolates from afitin harbored the cytotoxin K gene. The non hemolytic enterotoxin complex genes were present in all isolates, while the hemolytic enterotoxin complex genes were present in only one isolate from afitin. Food poisoning potential was evaluated using a Vero-cell assay measuring cytotoxity, and the toxin titers ranged between 80 and 1280. Isolates from afitin were the most cytotoxic. The emetic isolates from afitin, iru and sonru were low to high producers of cereulide, producing between 130-800 µg cereulide/g biomass (wet weight) at 30oC, as quantified using liquid chromatography mass spectrometry. Cereulide formation during fermentation of locust beans has not been demonstrated. Interestingly afitin, iru and sonru are considered safe food products, and as far as is known there has been no reports on diarrhea or vomiting due to the consumption of the three condiments.

AB - Bacillus cereus was reported to occur in high numbers (up to 107 CFU/g) during spontaneous fermentation of three different traditional Benin condiments; afitin, iru and sonru made from African locust beans. A total of nineteen B. cereus isolates from the ferments, were examined for the presence of toxin genes related to food poisoning using PCR. Isolates harboring the emetic specific gene fragment EM1 where highly representative, being one out of ten isolates from afitin, one of one isolate from iru and five of eight isolates from sonru. Three of the isolates from afitin harbored the cytotoxin K gene. The non hemolytic enterotoxin complex genes were present in all isolates, while the hemolytic enterotoxin complex genes were present in only one isolate from afitin. Food poisoning potential was evaluated using a Vero-cell assay measuring cytotoxity, and the toxin titers ranged between 80 and 1280. Isolates from afitin were the most cytotoxic. The emetic isolates from afitin, iru and sonru were low to high producers of cereulide, producing between 130-800 µg cereulide/g biomass (wet weight) at 30oC, as quantified using liquid chromatography mass spectrometry. Cereulide formation during fermentation of locust beans has not been demonstrated. Interestingly afitin, iru and sonru are considered safe food products, and as far as is known there has been no reports on diarrhea or vomiting due to the consumption of the three condiments.

M3 - Conference abstract for conference

Y2 - 17 June 2007 through 21 June 2007

ER -