Study of mesophilic Aeromonas salmonicida A527 strain sheds light on the species' lifestyles and taxonomic dilemma. Issue 23 (8th November 2017)

• Record Type: Journal Article
• Authors: Vincent, Antony T; Rouleau, François D; Moineau, Sylvain; Charette, Steve J
• Is Part Of: FEMS microbiology letters. Volume 364:Issue 23(2017)
• Publication Date: 2017-11-08
• Subjects: Aeromonas salmonicida -- taxonomy -- insertion sequences -- lifestyle -- mesophile -- psychrophile; Microbiology -- Periodicals; 579
• DOI: 10.1093/femsle/fnx239
• Languages: English
• ISSNs: 0378-1097

Abstract

Abstract: The Gram-negative bacterium Aeromonas salmonicida contains five subspecies: salmonicida, smithia, achromogenes, masoucida and pectinolytica . Pectinolytica is a mesophilic subspecies with the ability to thrive at a wide range of temperatures, including 37°C, while the four other subspecies are psychrophilic, restricted to lower temperatures. The psychrophilic subspecies are known to infect a wide range of fishes. However, there is no evidence of pathogenicity for the mesophilic subspecies pectinolytica . Study of the differences between the mesophilic and psychrophilic subspecies is hampered by the lack of completely sequenced and closed genomes from the mesophilic subspecies. A previous study reported that insertion sequences, which can induce genomic rearrangements at temperatures around 25°C, could be one of the determinants explaining the differences in lifestyle (mesophilic or psychrophilic) between the subspecies. In this study, the genome of mesophilic strain A527 of A. salmonicida was sequenced, closed and analyzed to investigate the mesophilic–psychrophilic discrepancy. This reference genome supports the hypothesis that insertion sequences are major determinants of the lifestyle differences between the A. salmonicida subspecies. Moreover, the phylogenetic analysis performed to position strain A527 within the taxonomy raises an issue regarding the intraspecies structure of A. salmonicida . Abstract : This study reports the first closed genome of a mesophilic Aeromonas salmonicida and suggests that insertion sequences could be determinants of the lifestyle between A. salmonicida subspecies.