UMR408 SQPOV « Sécurité et Qualité des Produits d'Origine Végétale », INRA, University of Avignon, 84000, Avignon, France.
Norwegian University of Life Sciences, NMBU School of Veterinary Science, Oslo, Norway.
Food Microbiol. 2017 Aug;65:130-135. doi: 10.1016/j.fm.2017.02.006. Epub 2017 Feb 16.
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.
除了蜡样芽孢杆菌外，一些耐低温、潜在食源性病原体的解淀粉芽孢杆菌菌株也可以产生呕吐毒素（cereulide）。这种毒素是一种耐热、耐酸的环状十二肽，可引起呕吐型食物中毒。然而，已经有一些严重的临床病例导致了致命的后果。如果呕吐毒素可以在冷藏储存期间产生，那么再加热食物并不能使其失活，这对消费者来说是食源性中毒的一个重要风险。在本文中，我们确定了 B.weihenstephanensis 菌株 BtB2-4 和 MC67 在琼脂培养基中从 8°C 到 25°C 和 pH 值从 5.4 到 7.0 的温度下生长和产生 cereulide 的能力。在 8°C 时，菌株 BtB2-4 产生了可量化的呕吐毒素，而菌株 MC67 则达到了检测极限。对于 BtB2-4 菌株，在 8°C 到 10-15°C 之间，呕吐毒素的产生增加了 5 倍，在 15°C 到 25°C 之间增加了 100 倍以上。在 10°C 及以上的温度下，呕吐毒素的浓度在先前报道的与呕吐性中毒有关的食品中的浓度范围内。在 25°C 时，将 pH 值降低至 5.4 使 BtB2-4 菌株的呕吐毒素产量至少降低了 20 倍。
