Autographivirinae Bacteriophage Arno 160 Infects Pectobacterium carotovorum via Depolymerization of the Bacterial O-Polysaccharide

Abstract

Phytopathogenic bacteria belonging to the Pectobacterium and Dickeya genera (soft-rot Pectobacteriaceae) are in the focus of agriculture-related microbiology because of their diversity, their substantial negative impact on the production of potatoes and vegetables, and the prospects of bacteriophage applications for disease control. Because of numerous amendments in the taxonomy of P. carotovorum, there are still a few studied sequenced strains among this species. The present work reports on the isolation and characterization of the phage infectious to the type strain of P. carotovorum. The phage Arno 160 is a lytic Podovirus representing a potential new genus of the subfamily Autographivirinae. It recognizes O-polysaccahride of the host strain and depolymerizes it in the process of infection using a rhamnosidase hydrolytic mechanism. Despite the narrow host range of this phage, it is suitable for phage control application.

Tailed Lytic Bacteriophages of Soft Rot Pectobacteriaceae

“…Structures of OPS of some strains of Pectobacterium sp. [ 97 , 98 , 99 , 100 , 101 , 102 ] and Dickeya sp. [ 80 , 95 , 103 , 104 ] have been revealed by NMR, and they were found to be very diverse.…”

“…The list of SRP bacteriophages contains 68 phages with Podoviral morphology belonging to two families ( Autographiviridae and Schitoviridae ) and one genus ( Kafunavirus ). The micrographs of the Pectobacterium phage Arno160 ( Autographiviridae family) [ 101 ], Pectobacterium phage vB_PatP_CB4 ( Schitoviridae family) [ 130 ] and Dickeya phage Amaethon ( Kafunavirus genus) [ 131 ], representing these taxa, are shown in Figure 7 . All three phages possess the C1 morphotype with an icosahedral capsid of about 60 nm (Arno160), 70 nm (vB_PatP_CB4) and 67 nm (Amaethon) in size, and distinct collar structures beneath the capsid.…”

“…All three phages possess the C1 morphotype with an icosahedral capsid of about 60 nm (Arno160), 70 nm (vB_PatP_CB4) and 67 nm (Amaethon) in size, and distinct collar structures beneath the capsid. The phage Arno160 has a short tail about 10 nm in length, with tail spikes attached [ 101 ]. The phage vB_PatP_CB4 (and close phages CB1 and CB3) has a 25 nm tail and a set of short (25 nm) whiskers attached to a collar structure, with whiskers ending with elongated globular appendices at their distal end [ 130 ].…”

“…The adsorption apparatus of Autographiviridae SRP bacteriophages can include T7-like tail fibres or tail spikes, which possess an enzymatic activity, degrading the host OPS or assisting in adsorption, or having both of these impacts [ 101 , 102 , 135 , 136 , 137 , 138 ]. The phages can exchange the modules of adsorption proteins with the participation of bacterial hosts [ 139 ], and this process has been shown to happen for Autographiviridae phages infecting Pectobacterium hosts [ 136 ].…”

“…Some phages (Jarilo, PP47, Q19, etc.) have a relatively broad host range [ 135 , 138 ], while others demonstrate a narrower host range (Arno160, CB5) [ 101 , 136 ]. It is probable that the use of multiple host strains for phage isolation can result in an increase in the frequency of phages with a broad host range [ 146 ].…”