title: AsaGEI2b: a new variant of a genomic island identified in the Aeromonas salmonicida subsp. salmonicida JF3224 strain isolated from a wild fish in Switzerland.
abstract: Aeromonas salmonicida subsp. salmonicida is the causal agent of furunculosis in salmonids. We recently identified a group of genomic islands (AsaGEI) in this bacterium. AsaGEI2a, one of these genomic islands, has almost exclusively been identified in isolates from North America. To date, Aeromonas salmonicida subsp. salmonicida JF3224, a strain isolated from a wild brown trout (Salmo trutta) caught in Switzerland, was the only European isolate that appeared to bear AsaGEI2a. We analyzed the genome of JF3224 and showed that the genomic island in JF3224 is a new variant of AsaGEI, which we have called AsaGEI2b. While AsaGEI2b shares the same integrase gene and insertion site as AsaGEI2a, it is very different in terms of many other features. Additional genomic investigations combined with PCR genotyping revealed that JF3224 is sensitive to growth at 25°C, leading to insertion sequence-dependent rearrangement of the locus on the pAsa5 plasmid that encodes a type three secretion system, which is essential for the virulence of the bacterium. The analysis of the JF3224 genome confirmed that AsaGEIs are accurate indicators of the geographic origins of A. salmonicida subsp. salmonicida isolates and is another example of the susceptibility of the pAsa5 plasmid to DNA rearrangements.
authors.affiliation: Institut de biologie intégrative et des systèmes, Pavillon Charles-Eugène-Marchand, Université Laval, 1030 avenue de la Médecine, Quebec City, QC G1V 0A6, Canada Centre de recherche de l'Institut universitaire de cardiologie et de pneumologie de Québec (Hôpital Laval), 2725 Chemin Sainte-Foy, Quebec City, QC G1V 4G5, Canada Département de biochimie, de microbiologie et de bio-informatique, Faculté des sciences et de génie, Université Laval, 1045 avenue de la Médecine, Quebec City, QC G1V 0A6, Canada.
authors.forename: Jean-Guillaume
authors.initials: JG
authors.lastname: Emond-Rheault
authors.affiliation: Institut de biologie intégrative et des systèmes, Pavillon Charles-Eugène-Marchand, Université Laval, 1030 avenue de la Médecine, Quebec City, QC G1V 0A6, Canada Centre de recherche de l'Institut universitaire de cardiologie et de pneumologie de Québec (Hôpital Laval), 2725 Chemin Sainte-Foy, Quebec City, QC G1V 4G5, Canada Département de biochimie, de microbiologie et de bio-informatique, Faculté des sciences et de génie, Université Laval, 1045 avenue de la Médecine, Quebec City, QC G1V 0A6, Canada.
authors.forename: Antony T
authors.initials: AT
authors.lastname: Vincent
authors.affiliation: Institut de biologie intégrative et des systèmes, Pavillon Charles-Eugène-Marchand, Université Laval, 1030 avenue de la Médecine, Quebec City, QC G1V 0A6, Canada Centre de recherche de l'Institut universitaire de cardiologie et de pneumologie de Québec (Hôpital Laval), 2725 Chemin Sainte-Foy, Quebec City, QC G1V 4G5, Canada Département de biochimie, de microbiologie et de bio-informatique, Faculté des sciences et de génie, Université Laval, 1045 avenue de la Médecine, Quebec City, QC G1V 0A6, Canada.
authors.forename: Mélanie V
authors.initials: MV
authors.lastname: Trudel
authors.affiliation: Institut of Veterinary Bacteriology, University of Bern, Länggassstrasse 122, CH-3012 Bern, Switzerland.
authors.forename: Joachim
authors.initials: J
authors.lastname: Frey
authors.affiliation: Département de biochimie, de microbiologie et de bio-informatique, Faculté des sciences et de génie, Université Laval, 1045 avenue de la Médecine, Quebec City, QC G1V 0A6, Canada Groupe de Recherche en Écologie Buccale (GREB), Faculté de médecine dentaire, Université Laval, Quebec City, QC G1V 0A6, Canada.
authors.forename: Michel
authors.initials: M
authors.lastname: Frenette
authors.affiliation: Institut de biologie intégrative et des systèmes, Pavillon Charles-Eugène-Marchand, Université Laval, 1030 avenue de la Médecine, Quebec City, QC G1V 0A6, Canada Centre de recherche de l'Institut universitaire de cardiologie et de pneumologie de Québec (Hôpital Laval), 2725 Chemin Sainte-Foy, Quebec City, QC G1V 4G5, Canada Département de biochimie, de microbiologie et de bio-informatique, Faculté des sciences et de génie, Université Laval, 1045 avenue de la Médecine, Quebec City, QC G1V 0A6, Canada steve.charette@bcm.ulaval.ca.
authors.forename: Steve J
authors.initials: SJ
authors.lastname: Charette
mesh_terms: D048409:Aeromonas salmonicida / Q000145:classification / Q000235:genetics* / Q000254:growth & development / Q000302:isolation & purification*; D000818:Animals; D000835:Animals, Wild / Q000382:microbiology; D004251:DNA Transposable Elements; D005667:Furunculosis / Q000382:microbiology; D016680:Genome, Bacterial / Q000235:genetics; D044404:Genomic Islands; D005838:Genotype; D019426:Integrases / Q000235:genetics; D010957:Plasmids; D016415:Sequence Alignment; D017422:Sequence Analysis, DNA; D013557:Switzerland; D014337:Trout / Q000382:microbiology*; D000069296:Type III Secretion Systems / Q000235:genetics; D037521:Virulence Factors / Q000235:genetics
chemical_list: D004251:DNA Transposable Elements; D000069296:Type III Secretion Systems; D037521:Virulence Factors; D019426:Integrases
keywords: Aeromonas salmonicida subsp. salmonicida; AsaGEI2b; genomic island; type three secretion system