中文摘要：由大肠杆菌O157:H7引起的食源性疾病日益流行加之其形成生物膜的能力，对全世界的公共卫生构成了重大威胁。随着对目前消毒剂处理的局限性的日益关注，噬菌体解聚酶可能被用作有前途的生物防治剂。本研究对一种专门针对大肠杆菌O157脂多糖的新型噬菌体解聚酶Dpo10，进行了鉴定、纯化和应用。Dpo10分子量为98 kDa，基因组分析预测其具有果胶裂解酶活性，并且是噬菌体的受体结合蛋白。通过观察Dpo10的不透明光晕，证实了纯化后它仅对大肠杆菌O157菌株具有O-多糖降解活性。在55℃以下及温和的碱性pH条件下，Dpo10在广泛的温度条件下保持酶活性稳定。值得注意的是，Dpo10不抑制细菌生长，但通过降解其O-多糖显著增加了补体介导的大肠杆菌O157血清裂解。此外，Dpo10非生物聚苯乙烯和不锈钢表面的大肠杆菌O157生物膜的抑制率分别为8倍和2.56 log CFU/coupon。因此，大肠杆菌siphophage新型解聚酶对大肠杆菌O157的脂多糖具有特异性结合和裂解活性，可以用作对抗大肠杆菌O157:H7生物膜的药剂。
外文摘要：The increasing prevalence of foodborne diseases caused by Escherichia coli O157:H7 as well as its ability to form biofilms poses major threats to public health worldwide. With increasing concerns about the limitations of current disinfectant treatments, phage-derived depolymerases may be used as promising biocontrol agents. Therefore, in this study, the characterization, purification, and application of a novel phage depolymerase, Dpo10, specifically targeting the lipopolysaccharides of E. coli O157, was performed. Dpo10, with a molecular mass of 98 kDa, was predicted to possess pectate lyase activity via genome analysis and considered to act as a receptor-binding protein of the phage. We confirmed that the purified Dpo10 showed O-polysaccharide degrading activity only for the E. coli O157 strains by observing its opaque halo. Dpo10 maintained stable enzymatic activities across a wide range of temperature conditions under 55 degrees C and mild basic pH. Notably, Dpo10 did not inhibit bacterial growth but significantly increased the complement-mediated serum lysis of E. coli O157 by degrading its O-polysaccharides. Moreover, Dpo10 inhibited the biofilm formation against E. coli O157 on abiotic polystyrene by 8-fold and stainless steel by 2.56 log CFU/coupon. This inhibition was visually confirmed via fieldemission scanning electron microscopy. Therefore, the novel depolymerase from E. coli siphophage exhibits specific binding and lytic activities on the lipopolysaccharide of E. coli O157 and may be used as a promising anti-biofilm agent against the E. coli O157:H7 strain.
外文关键词：Escherichia coli O157；H7；bacteriophage；depolymerase；lipopolysaccharide；biofilm；food application
作者：Park, DW；Park, JH
作者单位：Gachon Univ
期刊名称：JOURNAL OF MICROBIOLOGY
期刊影响因子：2.845
出版年份：2021
出版刊次：
点击下载：针对大肠杆菌O157:H7的新型噬菌体解聚酶的特性及其在非生物表面的生物膜控制