Characterization and Genome Analysis of a Novel Escherichia coli Bacteriophage vB_EcoS_W011D

Abstract

Received: Revised: Accepted: Published online: August 11, 2019 September 25, 2019 October 16, 2019 November 06, 2019 The application of phages against the increased reported drug resistant Escherichia coli is one of the promising alternative therapeutic options. The total number of phages on the earth are more than 10, but the phages that have been isolated and studied are limited. Hence, discovering of new phage and uncovering its characteristics will provide materials for extensive use of phage therapy in the future. In this study, a novel E. coli phage named vB_EcoS_W011D was isolated and the characteristics and genome were explored. The typical morphology of vB_EcoS_W011D is comprised of an icosahedral head and a constricted flexible rolled up tail, revealing that it is the genus TLS virus of Tunavirinae subfamily. One-step growth curve showing the eclipse and latent period of vB_EcoS_W011D was 5 min and 10 min, respectively, with the burst size of 115 PFU/cell. The genome of vB_EcoS_W011D is double-stranded consisting of 49,847 bp with 46.24% of G+C contents and shows ≤77% similarities (with 38% query coverage) to other reported phages. A total 85 putative ORFs were identified. Of which, 43 predicted ORFs had significant homology with other phage proteins of known functions. A putative Zonula occludes toxin was found in its genome. In addition, a clear difference was revealed on the phylogenetic analysis of it terminates large subunit and capsid protein. In conclusion, our study clearly indicates that vB_EcoS_W011D is a newly discovered E. coli phage that could be further investigated to elucidate phage variety and evolutionary relationship between bacteria and phages. ©2019 PVJ. All rights reserved