Tidsskriftspublikasjon » Vitenskapelig artikkel
Integron-containing IncU plasmids pRAS1 and pAr-32 from the fish pathogen Aeromonas salmonicida
Antimicrobial Agents and Chemotherapy ; Volume 47. p. 1285–1290. 2003
Sørum, Henning; L'Abée-Lund, Trine; L'Abée-Lund, Trine Marie; Solberg, Asta; Åsli, Anette Wold
A 45 kb R plasmid, pRAS1, conferring resistance to tetracyclines, trimethoprim and sulphonamides, was isolated from fish pathogenic atypical Aeromonas salmonicida in 1989. This plasmid could be transferred by conjugation to Escherichia coli with high efficiency (F 0.48). The following year pRAS1 was isolated from A. salmonicida subspecies salmonicida in the same area, but the conjugation was 103 less efficient with this subspecies as donor. The IncU plasmid pRAS1 contained a drug resistance region of12 kb consisting of; a class 1 integron similar to In4 of Tn1696, but with a dfrA16 gene cassette inserted, a copy of IS6100 and a deleted Tn1721. Restriction enzyme analysis showed that the R plasmid pAr-32 isolated from A. salmonicida in Japan in 1970had the same backbone structure as pRAS1, while the drug resistance region contained a complex class 1 integron with an aadA2 cassette, the chloramphenicol resistance gene catA2 as in In6 of pSa and a duplicate of the 3’– conserved segment of the integron.