AUTHOR=Kabanova Anastasia P. , Shneider Mikhail M. , Korzhenkov Aleksei A. , Bugaeva Eugenia N. , Miroshnikov Kirill K. , Zdorovenko Evelina L. , Kulikov Eugene E. , Toschakov Stepan V. , Ignatov Alexander N. , Knirel Yuriy A. , Miroshnikov Konstantin A. TITLE=Host Specificity of the Dickeya Bacteriophage PP35 Is Directed by a Tail Spike Interaction With Bacterial O-Antigen, Enabling the Infection of Alternative Non-pathogenic Bacterial Host JOURNAL=Frontiers in Microbiology VOLUME=Volume 9 - 2018 YEAR=2019 URL=https://www.frontiersin.org/journals/microbiology/articles/10.3389/fmicb.2018.03288 DOI=10.3389/fmicb.2018.03288 ISSN=1664-302X ABSTRACT=Dickeya solani, a recently emerged virulent bacterial potato pathogen, is a major threat to world agriculture. Because of the growing limitations in antibiotic use, the alternative strategies of bacteriosis control are considered, including the application of bacteriophages. Myoviridae bacteriophages recently re-ranked as a separate family Ackermannviridae are the attractive candidates for this purpose, and phage PP35 described in this paper is a good example of such potential phage. High specificity of PP35 is explained by the presence of the tail spike protein PP35 gp156 possessing enzymatic activity of depolymerization of the O-polysaccharide (OPS) of D. solani. The outer polysaccharide structure, →2)-β-D-6-deoxy-D-altrose-(1→, is unique among soft-rot Pectobacteriaceae, however it may be also present in non-virulent environmental Enterobacteriaceae. The phage tail spike depolymerase degrades the shielding polysaccharide, and launches the cell infection process. Thus, non-pathogenic commensal bacteria may maintain the population of the phage in soil environment. Also, such bacteria may serve as non-pathogenic host for the industrial production of phages.