title: IS-mediated loss of virulence by Aeromonas salmonicida: A tangible piece of an evolutionary puzzle.
abstract: Insertion sequences (IS) are abundant in the bacterial fish pathogenAeromonas salmonicidagenome. IS are involved in rearrangement events that lead to the loss of virulence. In previous work, we studied a plasmid rearrangement that causes the deletion of the type three secretion system inA. salmonicida, resulting in a loss of virulence. We showed that the rearrangement is caused by the recombination of two IS (ISAS11) on an unstable plasmid (pAsa5). However, many rearrangements cannot be explained by our experimental approach and are thought to be the result of more complex or incomplete rearrangement events, as suggested by other plasmid loss profiles observed in variousA. salmonicidastrains. In this commentary, we examine the genetic instability ofA. salmonicidaindicating that its genome is rapidly evolving.
authors.affiliation: Institut de biologie intégrative et des système; Pavillon Charles-Eugène-Marchand; Université Laval; Quebec City, QC Canada ; Centre de recherche de l'Institut universitaire de cardiologie et de pneumologie de Québec; Hôpital Laval; Quebec City, QC Canada.
authors.forename: Katherine H
authors.initials: KH
authors.lastname: Tanaka
authors.forename: Michel
authors.initials: M
authors.lastname: Frenette
authors.forename: Steve J
authors.initials: SJ
authors.lastname: Charette
keywords: Aeromonas salmonicida; DNA rearrangement; IS256; furunculosis; insertion sequence; plasmid; type three secretion system