title: Isolation and characterization of a T4-like phage with a relatively wide host range within Escherichia coli.
abstract: Avian pathogenic Escherichia coli (APEC) causes colibacillosis in poultry, resulting in severe economic losses worldwide. Coliphages represent alternative antibacterial substitutes based on high lytic efficiency and few side-effects. However, the complete genome sequences information of APEC phages are limited, and knowledge of undesired genes and the narrow host range restrict their applications. In this study, we isolated a virulent phage QL01, with a relatively broad lytic spectrum (41 of 78 APEC strains). Transmission electron micrography showed it belonged to the family Myoviridae with an elongated head and a contractile tail. Whole genome sequencing revealed a linear double-stranded DNA (170,527 kb; GC content, 39.6%) with 275 possible ORFs. Comparative genome analysis revealed high homology between QL01 and other T4-like phages. However, it also showed some unique features, for example, ORF142 and ORF143, which encode IP9 and IP8, respectively, and may counteract host resistance only exist in a few T4-like phages such as IME08 and vB_EcoM_VR5. Furthermore, phage therapy in artificially infected ducks showed a 26.67% decrease in mortality compared with the untreated group. Our study indicates the potential antibacterial function of phage QL01 against APEC infections and highlights unique molecular features underlying the relatively broad host range.
authors.affiliation: College of Veterinary Medicine, Nanjing Agricultural University, Nanjing City, Jiangsu Province, China.
authors.forename: Juntian
authors.initials: J
authors.lastname: Xu
authors.affiliation: College of Veterinary Medicine, Nanjing Agricultural University, Nanjing City, Jiangsu Province, China.
authors.forename: Mianmian
authors.initials: M
authors.lastname: Chen
authors.affiliation: College of Veterinary Medicine, Nanjing Agricultural University, Nanjing City, Jiangsu Province, China.
authors.forename: Lingchen
authors.initials: L
authors.lastname: He
authors.affiliation: College of Veterinary Medicine, Nanjing Agricultural University, Nanjing City, Jiangsu Province, China.
authors.forename: Shuqing
authors.initials: S
authors.lastname: Zhang
authors.affiliation: College of Veterinary Medicine, Nanjing Agricultural University, Nanjing City, Jiangsu Province, China.
authors.forename: Tianyun
authors.initials: T
authors.lastname: Ding
authors.affiliation: College of Veterinary Medicine, Nanjing Agricultural University, Nanjing City, Jiangsu Province, China.
authors.forename: Huochun
authors.initials: H
authors.lastname: Yao
authors.affiliation: College of Veterinary Medicine, Nanjing Agricultural University, Nanjing City, Jiangsu Province, China.
authors.forename: Chengping
authors.initials: C
authors.lastname: Lu
authors.affiliation: College of Veterinary Medicine, Nanjing Agricultural University, Nanjing City, Jiangsu Province, China.
authors.forename: Wei
authors.initials: W
authors.lastname: Zhang
mesh_terms: D000818:Animals; D001717:Birds / Q000382:microbiology; D003090:Coliphages / Q000235:genetics / Q000302:isolation & purification* / Q000502:physiology / Q000648:ultrastructure; D004279:DNA, Viral / Q000235:genetics; D004372:Ducks / Q000382:microbiology; D004926:Escherichia coli / Q000821:virology*; D004927:Escherichia coli Infections / Q000628:therapy / Q000662:veterinary; D005243:Feces / Q000821:virology; D016679:Genome, Viral; D058507:Host Specificity; D046529:Microscopy, Electron, Transmission; D017900:Myoviridae / Q000235:genetics / Q000302:isolation & purification* / Q000502:physiology / Q000648:ultrastructure; D000071059:Phage Therapy; D011201:Poultry Diseases / Q000382:microbiology / Q000628:therapy / Q000821:virology
chemical_list: D004279:DNA, Viral
keywords: Genome analysis; Phage; Phage therapy; Wide host range