Food Safety Laboratory, Department of Food Science and Engineering, Ocean University of China, Qingdao, China.
State Key Laboratory of Pathogen and Biosecurity, Beijing Institute of Microbiology and Epidemiology, Beijing, China.
J Basic Microbiol. 2018 Nov;58(11):968-976. doi: 10.1002/jobm.201800271. Epub 2018 Aug 26.
Advances in phage therapy and its application require more information on phage genome characteristics and host-phage interaction mechanisms. In this study, a so far unknown T1-like Escherichia coli phage was identified and named vB_EcoS_IME347 (IME347). The genome length of phage IME347 is 50,048 bp with a G + C content of 49.7%. BLASTn alignment showed that the phage has its highest homology (identity 78%, query cover 72%) with phage SRT8 (GenBank: MF996376). Electron microscopy showed that phage IME347 has an icosahedral head and a long non-contractiled tail, features of the family Siphoviridae. Phylogenetic analysis of the large subunit of the terminal enzyme and tail fiber protein revealed that phage IME347 is a novel member of the T1 virus. Furthermore, through comparative genomics, silencing mutation, phage spotting assay, and phage adsorption assay, an E. coli BL21 TonB-dependent receptor YncD was identified to be responsible for phage IME347 adsorption and entry. The identification of the phage receptor YncD enriches the phage receptor database and provides a theoretical basis for bacteriophage therapy.
噬菌体治疗及其应用的进展需要更多关于噬菌体基因组特征和宿主-噬菌体相互作用机制的信息。在本研究中，鉴定并命名了一种迄今为止未知的 T1 样大肠杆菌噬菌体，命名为 vB_EcoS_IME347（IME347）。噬菌体 IME347 的基因组长度为 50048bp，GC 含量为 49.7%。BLASTn 比对显示，噬菌体与噬菌体 SRT8（GenBank：MF996376）具有最高的同源性（同一性 78%，查询覆盖率 72%）。电子显微镜显示，噬菌体 IME347 具有二十面体头部和长非收缩尾部，属于肌尾噬菌体科。末端酶大亚基和尾丝蛋白的系统发育分析表明，噬菌体 IME347 是 T1 病毒的一个新成员。此外，通过比较基因组学、沉默突变、噬菌体点样测定和噬菌体吸附测定，鉴定出大肠杆菌 BL21 TonB 依赖性受体 YncD 负责噬菌体 IME347 的吸附和进入。噬菌体受体 YncD 的鉴定丰富了噬菌体受体数据库，为噬菌体治疗提供了理论依据。
