title: Genome comparison of the epiphytic bacteria Erwinia billingiae and E. tasmaniensis with the pear pathogen E. pyrifoliae.
abstract: BACKGROUND
  The genus Erwinia includes plant-associated pathogenic and non-pathogenic Enterobacteria. Important pathogens such as Erwinia amylovora, the causative agent of fire blight and E. pyrifoliae causing bacterial shoot blight of pear in Asia belong to this genus. The species E. tasmaniensis and E. billingiae are epiphytic bacteria and may represent antagonists for biocontrol of fire blight. The presence of genes that are putatively involved in virulence in E. amylovora and E. pyrifoliae is of special interest for these species in consequence.
  
  
  RESULTS
  Here we provide the complete genome sequences of the pathogenic E. pyrifoliae strain Ep1/96 with a size of 4.1 Mb and of the non-pathogenic species E. billingiae strain Eb661 with a size of 5.4 Mb, de novo determined by conventional Sanger sequencing and next generation sequencing techniques. Genome comparison reveals large inversions resulting from homologous recombination events. Furthermore, comparison of deduced proteins highlights a relation of E. billingiae strain Eb661 to E. tasmaniensis strain Et1/99 and a distance to E. pyrifoliae for the overall gene content as well as for the presence of encoded proteins representing virulence factors for the pathogenic species. Pathogenicity of E. pyrifoliae is supposed to have evolved by accumulation of potential virulence factors. E. pyrifoliae carries factors for type III secretion and cell invasion. Other genes described as virulence factors for E. amylovora are involved in the production of exopolysaccharides, the utilization of plant metabolites such as sorbitol and sucrose. Some virulence-associated genes of the pathogenic species are present in E. tasmaniensis but mostly absent in E. billingiae.
  
  
  CONCLUSIONS
  The data of the genome analyses correspond to the pathogenic lifestyle of E. pyrifoliae and underlines the epiphytic localization of E. tasmaniensis and E. billingiae as a saprophyte.
authors.affiliation: Max Planck Institute for Molecular Genetics, htpt group, Ihnestr, 63, D-14195 Berlin, Germany. kube@molgen.mpg.de
authors.forename: Michael
authors.initials: M
authors.lastname: Kube
authors.forename: Alexander M
authors.initials: AM
authors.lastname: Migdoll
authors.forename: Isabel
authors.initials: I
authors.lastname: Gehring
authors.forename: Katja
authors.initials: K
authors.lastname: Heitmann
authors.forename: Yvonne
authors.initials: Y
authors.lastname: Mayer
authors.forename: Heiner
authors.initials: H
authors.lastname: Kuhl
authors.forename: Florian
authors.initials: F
authors.lastname: Knaust
authors.forename: Klaus
authors.initials: K
authors.lastname: Geider
authors.forename: Richard
authors.initials: R
authors.lastname: Reinhardt
mesh_terms: D000818:Animals; D030541:Databases, Genetic; D004885:Erwinia / Q000235:genetics* / Q000378:metabolism / Q000472:pathogenicity; D016680:Genome, Bacterial / Q000235:genetics*; D023281:Genomics; D008969:Molecular Sequence Data; D010935:Plant Diseases / Q000382:microbiology*; D031989:Pyrus / Q000382:microbiology*; D017422:Sequence Analysis, DNA; D037521:Virulence Factors / Q000235:genetics
chemical_list: D037521:Virulence Factors