title: Absence of lysogeny in wild populations of Erwinia amylovora and Pantoea agglomerans.
abstract: Lytic bacteriophages are in development as biological control agents for the prevention of fire blight disease caused by Erwinia amylovora. Temperate phages should be excluded as biologicals since lysogeny produces the dual risks of host resistance to phage attack and the transduction of virulence determinants between bacteria. The extent of lysogeny was estimated in wild populations of E. amylovora and Pantoea agglomerans with real-time polymerase chain reaction primers developed to detect E. amylovora phages belonging to the Myoviridae and Podoviridae families. Pantoea agglomerans, an orchard epiphyte, is easily infected by Erwinia spp. phages, and it serves as a carrier in the development of the phage-mediated biological control agent. Screening of 161 E. amylovora isolates from 16 distinct geographical areas in North America, Europe, North Africa and New Zealand and 82 P. agglomerans isolates from southern Ontario, Canada showed that none possessed prophage. Unstable phage resistant clones or lysogens were produced under laboratory conditions. Additionally, a stable lysogen was recovered from infection of bacterial isolate Ea110R with Podoviridae phage ΦEa35-20. These laboratory observations suggested that while lysogeny is possible in E. amylovora, it is rare or absent in natural populations, and there is a minimal risk associated with lysogenic conversion and transduction by Erwinia spp. phages.
authors: Department of Biological Science, Brock University, 500 Glenridge Avenue, St. Catharines, ON, L2S 3A1, Canada; Agriculture and Agri-Food Canada, 4902 Victoria Ave. North, P.O. Box 6000, Vineland Station, ON, L0R 2E0, Canada.
authors: Dwayne R
authors: DR
authors: Roach
authors: David R
authors: DR
authors: Sjaarda
authors: Calvin P
authors: CP
authors: Sjaarda
authors: Carlos Juarez
authors: CJ
authors: Ayala
authors: Brittany
authors: B
authors: Howcroft
authors: Alan J
authors: AJ
authors: Castle
authors: Antonet M
authors: AM
authors: Svircev
mesh_terms: D000349:Africa; D044084:Erwinia amylovora / Q000235:genetics / Q000821:virology*; D005060:Europe; D008242:Lysogeny; D017900:Myoviridae / Q000235:genetics / Q000302:isolation & purification; D009520:New Zealand; D009656:North America; D020636:Pantoea / Q000235:genetics / Q000821:virology*; D017902:Podoviridae / Q000235:genetics / Q000302:isolation & purification; D039002:Prophages / Q000235:genetics* / Q000302:isolation & purification; D060888:Real-Time Polymerase Chain Reaction