Complete sequence of Aliivibrio salmonicida pVSAL68. Aliivibrio salmonicida isolate:Vs289

The presence of multiple plasmids together with a prevalent occurrence of insertion sequence (IS) elements is characteristic of the fish pathogen Aliivibrio salmonicida. In particular the ISVSa9 is present in multiple copies both chromosomally and on the plasmids. The four plasmids pVSAL43, pVSAL54, pVSAL320 and pVSAL840 were published along with the complete genome sequence A. salmonicida LFI1238. Here we report the sequences of two additional cryptic plasmids named pVSAL68 (6.8 kb) and pVSAL111 (11.1 kb). Our findings show that pVSAL68 is identical to pVSAL54 with the addition of one copy of ISVSa9. pVSAL111 is a cointegrate of pVSAL43 and pVSAL54. The plasmid fusion seems to be mediated by the action of ISVSa9 harboured on pVSAL43. In addition, we have used targeted PCR to demonstrate that the A. salmonicida plasmids can be integrated into the chromosomes, and that the integration may be caused by the action of IS elements.