Department of Food Hygiene and Environmental Health, Faculty of Veterinary Medicine, University of Helsinki, P. O. Box 66, 00014, Helsinki, Finland.
Sci Rep. 2020 Dec 9;10(1):21571. doi: 10.1038/s41598-020-78622-6.
Clostridium botulinum poses a serious threat to food safety and public health by producing potent neurotoxin during its vegetative growth and causing life-threatening neuroparalysis, botulism. While high temperature can be utilized to eliminate C. botulinum spores and the neurotoxin, non-thermal elimination of newly germinated C. botulinum cells before onset of toxin production could provide an alternative or additional factor controlling the risk of botulism in some applications. Here we introduce a putative phage lysin that specifically lyses vegetative C. botulinum Group I cells. This lysin, called CBO1751, efficiently kills cells of C. botulinum Group I strains at the concentration of 5 µM, but shows little or no lytic activity against C. botulinum Group II or III or other Firmicutes strains. CBO1751 is active at pH from 6.5 to 10.5. The lytic activity of CBO1751 is tolerant to NaCl (200 mM), but highly susceptible to divalent cations Ca and Mg (50 mM). CBO1751 readily and effectively eliminates C. botulinum during spore germination, an early stage preceding vegetative growth and neurotoxin production. This is the first report of an antimicrobial lysin against C. botulinum, presenting high potential for developing a novel antibotulinal agent for non-thermal applications in food and agricultural industries.
肉毒梭菌在其营养生长阶段会产生强效神经毒素，从而导致危及生命的神经瘫痪，即肉毒中毒，对食品安全和公共健康构成严重威胁。虽然高温可以用来消灭肉毒梭菌孢子和神经毒素，但在毒素产生之前，消灭新萌发的肉毒梭菌细胞，可能是在某些应用中控制肉毒中毒风险的替代或附加因素。在这里，我们介绍一种可能的噬菌体溶素，它可以特异性溶解营养型肉毒梭菌 I 组细胞。这种溶素称为 CBO1751，在 5 μM 的浓度下可以有效地杀死肉毒梭菌 I 组菌株的细胞，但对肉毒梭菌 II 组或 III 组或其他厚壁菌门菌株几乎没有或没有溶菌活性。CBO1751 在 pH 值为 6.5 到 10.5 之间具有活性。CBO1751 的溶菌活性耐受 NaCl（200 mM），但对 Ca 和 Mg 等二价阳离子（50 mM）高度敏感。CBO1751 可以在孢子萌发过程中迅速有效地消灭肉毒梭菌，这是在营养生长和神经毒素产生之前的早期阶段。这是针对肉毒梭菌的抗菌溶素的首次报道，为在食品和农业工业中的非热应用开发新型抗肉毒梭菌制剂提供了巨大潜力。
