TABLE 2.

IncU plasmids, their origins and resistance features, and presence of resistance elements and determinants, when known

IncU plasmidOriginal host/ environmentCountry or regionPhenotypic resistanceaKnown resistance elementsKnown resistance determinantsCommentsSource or reference(s)
pRAS1 A. salmonicida/diseased fishNorwaySUL, TMP,Tn1721 right part, In4-like integron dfrA16, Tet A, sulIIdentical to pIE420This paper; 20
pAr-32 A. salmonicida/diseased fishJapanSUL, STR, CHLIn6-like integron aadA2, sul1, catA2Identical to RA3This paper; 6, 20
RA3 A. hydrophila/ diseased fishJapanSUL, STR, CHLIncU reference plasmid; identical to pAr-326
pASOT A. salmonicida/diseased fishScotlandSUL, TET, CHLComplete Tn1721, integron aadA2 or dfrIIc (dfrB3), Tet A1, 20, 27
pASOT2 A. salmonicida/diseased fishScotlandSUL, TETIntegron aadA2, Tet A1, 20, 27
pASOT3 A. salmonicida/diseased fishScotlandSUL, TET, STRIntegron aadA2, Tet A1, 20, 27
pIE420 E. coli/human pyelonephritisGermanySUL, TMP, TET, STRbIdentical to pRAS127, 36
pFBAOT 6 A. caviae/hospital effluentEnglandTMP, STRComplete Tn1721Tet A27
pUG1001 A. hydrophila/fish hatcheryIrelandSUL, TMP, TET, STR EcoRI digests similar to those of pIE42016
  • a SUL, sulfonamides; TMP, trimethoprim; TET, tetracycline; STR, streptomycin; CHL, chloramphenicol.

  • b pIE420 is reported to confer streptomycin resistance. Strains of A. salmonicida with pRAS1 are phenotypically intermediately resistant to streptomycin, but we do not consider pRAS1 as conferring streptomycin resistance.