Park Do-Won, Park Jong-Hyun
Department of Food Science and Biotechnology, Gachon University, Seongnam 13120, Korea.
Viruses. 2021 Jul 27;13(8):1469. doi: 10.3390/v13081469.
O157:H7 is a global concern that causes serious diseases, such as hemolytic uremic syndrome and bloody diarrhea. To control O157:H7 in food, a novel siphophage, BECP10, that targets the O157 serotype was isolated and characterized. Unlike other phages, BECP10 can only infect O157 strains, and thus, did not infect other strains. The 48 kbp genome of BECP10 contained 76 open reading frames (ORFs), including 33 putative functional ORFs. The phage did not contain lysogeny-related modules or toxin-associated genes, suggesting that the phage might be strictly lytic. The tail spike protein (TSP) sequence had very low homology with the reported T1-like phages, indicating that TSP might be related to this unique host spectrum. The specific O-antigen residue of O157:H7 may be a key factor for phage infection by adsorption and receptor identification. The phage exhibited strong antibacterial activity against O157:H7 over a broad pH range and showed little development of phage-insensitive mutants. The phage sustained viability on the burger patties and reduced O157:H7 to a non-detectable level without the emergence of resistant cells at low temperatures for five days. Therefore, phage BECP10 might be a good biocontrol agent for O157:H7-contaminated food matrices.
O157:H7是一个引起全球关注的问题，它会引发严重疾病，如溶血尿毒综合征和血性腹泻。为了控制食品中的O157:H7，一种针对O157血清型的新型丝状噬菌体BECP10被分离并进行了特性分析。与其他噬菌体不同，BECP10只能感染O157菌株，因此不会感染其他菌株。BECP10的48千碱基对基因组包含76个开放阅读框（ORF），其中包括33个推定的功能ORF。该噬菌体不包含与溶原性相关的模块或毒素相关基因，这表明该噬菌体可能是严格的裂解性噬菌体。尾刺蛋白（TSP）序列与已报道的T1样噬菌体的同源性非常低，这表明TSP可能与这种独特的宿主谱有关。O157:H7的特定O抗原残基可能是噬菌体通过吸附和受体识别进行感染的关键因素。该噬菌体在广泛的pH范围内对O157:H7表现出强大的抗菌活性，并且几乎没有出现对噬菌体不敏感的突变体。该噬菌体在汉堡肉饼上保持活力，并在低温下五天内将O157:H7减少到无法检测的水平，且没有出现抗性细胞。因此，噬菌体BECP10可能是用于控制受O157:H7污染的食品基质的良好生物防治剂。
