Laboratory of Marine Food Science and Technology, Faculty of Fisheries Sciences, Hokkaido University, Hakodate, Japan.
Laboratory of Marine Food Science and Technology, Faculty of Fisheries Sciences, Hokkaido University, Hakodate, Japan.
Int J Food Microbiol. 2022 Jul 2;372:109680. doi: 10.1016/j.ijfoodmicro.2022.109680. Epub 2022 Apr 21.
Shiga toxin-producing Escherichia coli and Salmonella enterica are important pathogens worldwide. Bacteriophages can be effectively used to reduce the incidence of foodborne pathogens. The host recognition systems of phages are highly specific, with the host range of a common phage being limited to the species or strain level. Here, we characterized a novel broad-host-range phage, EscoHU1, that infects several bacterial species, including E. coli and S. enterica, and evaluated its antimicrobial potential to inhibit E. coli O157:H7 and S. Typhimurium growth in food systems. The adsorption of EscoHU1 on E. coli was faster than that on S. Typhimurium; however, the one-step growth curves of EscoHU1 in both species were similar. Genomic analysis of EscoHU1 revealed that this phage has long direct terminal repeats at both ends of the genome, and phylogenetic analysis of the terminase large subunit confirmed that EscoHU1 belongs to the genus Epseptimavirus. Comparative analysis of structural proteins indicated a diversity of proteins related to the host range (receptor-binding proteins and L-shaped tail fibers). Challenge tests using beef and milk demonstrated the antimicrobial effects of EscoHU1 in inhibiting the growth of E. coli O157:H7 and S. Typhimurium in the food system. However, the antimicrobial effect of EscoHU1 on S. Typhimurium was lower than that on E. coli O157:H7. These results suggest that the novel broad-host-range phage EscoHU1 may serve as an effective antimicrobial agent to reduce food poisoning caused by E. coli O157:H7 and S. Typhimurium.
产志贺毒素大肠杆菌和沙门氏菌是全球重要的病原体。噬菌体可以有效地用于降低食源性病原体的发病率。噬菌体的宿主识别系统具有高度特异性，一种常见噬菌体的宿主范围仅限于物种或菌株水平。在这里，我们描述了一种新型的广谱噬菌体 EscoHU1，它可以感染包括大肠杆菌和沙门氏菌在内的几种细菌，并评估了其在食品系统中抑制大肠杆菌 O157:H7 和鼠伤寒沙门氏菌生长的抗菌潜力。EscoHU1 对大肠杆菌的吸附速度快于鼠伤寒沙门氏菌；然而，EscoHU1 在这两种细菌中的一步生长曲线相似。EscoHU1 的基因组分析表明，该噬菌体的基因组两端都有长的直接末端重复序列，末端酶大亚基的系统发育分析证实 EscoHU1 属于 Epseptimavirus 属。结构蛋白的比较分析表明，与宿主范围相关的蛋白（受体结合蛋白和 L 形尾纤维）存在多样性。使用牛肉和牛奶进行的挑战测试表明，EscoHU1 在抑制食品系统中大肠杆菌 O157:H7 和鼠伤寒沙门氏菌的生长方面具有抗菌作用。然而，EscoHU1 对鼠伤寒沙门氏菌的抗菌效果低于大肠杆菌 O157:H7。这些结果表明，新型广谱噬菌体 EscoHU1 可用作有效的抗菌剂，以减少由大肠杆菌 O157:H7 和鼠伤寒沙门氏菌引起的食物中毒。
