Plasmids identified in this study.

Abbreviations: RFLP, restriction fragment length polymorphism; ST, sequence type; NI, not identified.aPlasmid type RFLP_12 (Rep17.2/pRUM-like + Rep2/pRE25/pEF1 + Rel6/pEF1) contains a partial sequence of the replication gene of the RCR plasmid pEFNP1 (GenBank accession number AB038522), suggesting the integration of this RCR plasmid on the mobile element carrying Tn1546 involving truncation of the rep14/pRI1/pEFNP1.bPlasmid types RFLP_3, _4, _5, _6 and _13 (Rep17.2/pRUM-like + Rel6/pEF1 and eventually containing Rep1/pIP501, Rep2/pRE25/pEF1 or TAInc18) shared common bands and were identified in the same or different clonal backgrounds in different cities for extended periods of time.cPlasmids types RFLP 8, _9 and _10 also shared a variable number of common bands.dPlasmids showing patterns related to RFLP_27 (75–85 kb; rep9/pAD1 + rel5/pAD1 + rep1/pIP501 + parpAD1 and/or rep2/pRE25/pEF1) initially recovered from the widespread ST6-CC2 Efs clone in Coimbra in 1996 and other Efs (ST55 and ST159) and Efm clones contained similar ISEf1-Tn1546 variants (PP-2a, PP-4, PP-9). Other highly related mosaic Inc18-pAD1-related plasmids carrying IS1216-Tn1546 were recovered from ST6 VREfs and ST80 VREfm isolates (type ˝IIEfs ˝, rep9/pAD1 +rel5/pAD1 + parpAD1 + rep2/pRE25/pEF1versus type ˝IIEfm ˝, rep9/pAD1 + rep2/pRE25/pEF1).