title: Cereulide production by Bacillus weihenstephanensis strains during growth at different pH values and temperatures.
abstract: Besides Bacillus cereus, some strains of the psychrotolerant, potentially foodborne pathogen Bacillus weihenstephanensis can produce the emetic toxine (cereulide). This toxin is a heat- and acid-stable cyclic dodecadepsipeptide that causes food intoxication with vomiting. However, some severe clinical cases with lethal outcomes have been described. If cereulide can be produced during refrigerated storage, it will not be inactivated by reheating food, representing an important risk of food intoxication for consumers. In this paper, we determined the capacity of the B. weihenstephanensis strains BtB2-4 and MC67 to grow and produce cereulide on agar media at temperatures from 8 °C to 25 °C and at a pH from 5.4 to 7.0. At 8 °C, strain BtB2-4 produced quantifiable amounts of cereulide, whereas the limit of detection was reached for strain MC67. For BtB2-4, cereulide production increased 5-fold between 8 °C and 10-15 °C and by more than 100-fold between 15 °C and 25 °C. At temperatures of 10 °C and higher, cereulide concentrations were within the range of those reported by previous works in foods implicated in emetic poisoning. At 25 °C, decreasing the pH to 5.4 reduced cereulide production by strain BtB2-4 by at least 20-fold.
authors.affiliation: UMR408 SQPOV « Sécurité et Qualité des Produits d'Origine Végétale », INRA, University of Avignon, 84000, Avignon, France.
authors.forename: Alizée
authors.initials: A
authors.lastname: Guérin
authors.affiliation: Norwegian University of Life Sciences, NMBU School of Veterinary Science, Oslo, Norway.
authors.forename: Helene Thorsen
authors.initials: HT
authors.lastname: Rønning
authors.affiliation: UMR408 SQPOV « Sécurité et Qualité des Produits d'Origine Végétale », INRA, University of Avignon, 84000, Avignon, France.
authors.forename: Claire
authors.initials: C
authors.lastname: Dargaignaratz
authors.affiliation: UMR408 SQPOV « Sécurité et Qualité des Produits d'Origine Végétale », INRA, University of Avignon, 84000, Avignon, France.
authors.forename: Thierry
authors.initials: T
authors.lastname: Clavel
authors.affiliation: UMR408 SQPOV « Sécurité et Qualité des Produits d'Origine Végétale », INRA, University of Avignon, 84000, Avignon, France.
authors.forename: Véronique
authors.initials: V
authors.lastname: Broussolle
authors.affiliation: Laboratory of Food and Environmental Microbiology, Université catholique de Louvain, Louvain-la-Neuve, Belgium.
authors.forename: Jacques
authors.initials: J
authors.lastname: Mahillon
authors.affiliation: Norwegian University of Life Sciences, NMBU School of Veterinary Science, Oslo, Norway.
authors.forename: Per Einar
authors.initials: PE
authors.lastname: Granum
authors.affiliation: UMR408 SQPOV « Sécurité et Qualité des Produits d'Origine Végétale », INRA, University of Avignon, 84000, Avignon, France. Electronic address: christophe.nguyen-the@inra.fr.
authors.forename: Christophe
authors.initials: C
authors.lastname: Nguyen-The
mesh_terms: D001407:Bacillus / Q000254:growth & development* / Q000302:isolation & purification / Q000378:metabolism*; D003470:Culture Media; D047630:Depsipeptides / Q000032:analysis* / Q000302:isolation & purification; D006863:Hydrogen-Ion Concentration; D057230:Limit of Detection; D012988:Soil Microbiology; D013696:Temperature
chemical_list: D003470:Culture Media; D047630:Depsipeptides; C089294:cereulide
keywords: Acid; Bacillus cereus; Cold; Emetic toxin; Psychrotolerant