title: A novel plasmid pEA68 of Erwinia amylovora and the description of a new family of plasmids.
abstract: Recent genome analysis of Erwinia amylovora, the causal agent of fire blight disease on Rosaceae, has shown that the chromosome is highly conserved among strains and that plasmids are the principal source of genomic diversity. A new circular plasmid, pEA68, was found in E. amylovora strain 692 (LMG 28361), isolated in Poland from Sorbus (mountain ash) with fire blight symptoms. Annotation of the 68,763-bp IncFIIa-type plasmid revealed that it contains 79 predicted CDS, among which two operons (tra, pil) are associated with mobility. The plasmid is maintained stably in E. amylovora and does not possess genes associated with antibiotic resistance or known virulence genes. Curing E. amylovora strain 692 of pEA68 did not influence its virulence in apple shoots nor amylovoran synthesis. Of 488 strains of E. amylovora from seventeen countries, pEA68 was only found in two additional strains from Belgium. Although the spread of pEA68 is currently limited to Europe, pEA68 comprises, together with pEA72 and pEA78 both found in North America, a new plasmid family that spans two continents.
authors.affiliation: Research Institute of Horticulture, ul. Konstytucji 3 Maja 1/3, 96-100, Skierniewice, Poland.
authors.forename: Emadeldeen
authors.initials: E
authors.lastname: Ismail
authors.forename: Jochen
authors.initials: J
authors.lastname: Blom
authors.forename: Alain
authors.initials: A
authors.lastname: Bultreys
authors.forename: Milan
authors.initials: M
authors.lastname: Ivanović
authors.forename: Aleksa
authors.initials: A
authors.lastname: Obradović
authors.forename: Joop
authors.initials: J
authors.lastname: van Doorn
authors.forename: Maria
authors.initials: M
authors.lastname: Bergsma-Vlami
authors.forename: Martine
authors.initials: M
authors.lastname: Maes
authors.forename: Anne
authors.initials: A
authors.lastname: Willems
authors.forename: Brion
authors.initials: B
authors.lastname: Duffy
authors.forename: Virginia O
authors.initials: VO
authors.lastname: Stockwell
authors.forename: Theo H M
authors.initials: TH
authors.lastname: Smits
authors.forename: Joanna
authors.initials: J
authors.lastname: Puławska
mesh_terms: D044084:Erwinia amylovora / Q000235:genetics* / Q000302:isolation & purification / Q000472:pathogenicity; D027845:Malus / Q000382:microbiology; D008969:Molecular Sequence Data; D010935:Plant Diseases / Q000382:microbiology; D010957:Plasmids; D011044:Poland; D011135:Polysaccharides, Bacterial / Q000096:biosynthesis; D017422:Sequence Analysis, DNA; D014774:Virulence / Q000235:genetics
chemical_list: D011135:Polysaccharides, Bacterial; C100769:amylovoran