Table 1.
MICs of ß-lactams for E. coli clinical isolate Gue, E. coli J53 pGUE-NDM and E. coli J53 reference strains.
Figure 1.
Major structural features of pGUE-NDM, encoding NDM-1 MBL, in comparison with incFII plasmids pC15-1a (genbank n°AY458016) and pEK516 (Genbank n°EU935738) CTX-M-15 encoding plasmids.
Resistance genes are indicated by colored boxes as follows: green, tetracycline resistance (tetA, tetR); azure, β-lactams resistance genes (blaNDM-1, blaOXA-1, blaCTX-M-15, blaTEM-1); orange, aminoglycosides resistance genes (aacA4, aacC2, aadA2); dark green, trimethoprime resistance gene (dfrA12). Transposon-related genes and insertion sequences are indicated in red boxes. Class 1 integrase gene is indicated by a black box. Partitioning-associated genes (parB, parM, ssb) are indicated by black-squared white boxes. The locus tra-trb is indicated by a squared white box with capital letters indicating the respective genes. The toxin-antitoxin genes (pemI/pemK, hok/mok)are indicated by light blue vertical lines. Replicons are indicated by purple boxes.
Figure 2.
Schematic representation of multi-drug resistance regions of pGUE-NDM, pC15-1a and pEK516 incFII plasmids.
The genes and their corresponding transcriptional orientations are indicated by horizontal arrows. Function of each genes are indicated by colored arrows as follows: green, tetracycline resistance; azure, β-lactams resistance genes; orange, aminoglycosides resistance genes; dark green, trimethoprim resistance gene. Transposon-related genes and insertion sequences are indicated in red arrows. Class 1 integrase gene is indicated by black arrow. Deletion is indicated by blue dashed lines. Homologous recombination event leading to inversion is indicated by black dashed lines. Homologous recombination event leading to allelic exchange of blaCTX-M-15 locus by blaNDM-1 locus is indicated by red dashed lines. The accession numbers were: pC15-1a (genbank n°AY458016) and pEK516 (genbank n°EU935738).
Figure 3.
Schematic representation of the DNA sequences surrounding the blaNDM-1 genes in Acinetobacter baumannii strain ML, E. coli HK-NDM NDM-1 encoding plasmid pHK-NDM, E. coli 271 p271a NDM-1 harboring plasmid, K. pneumoniae pNDM-KN harboring plasmid, and E. coli GUE NDM-1 harboring pGUE-NDM plasmid.
Gene names are abbreviated according to their corresponding proteins: Δiso for phosphoribosylanthranilate isomerase; tat for twin-arginine translocation pathway signal sequence protein; dvt for divalent cation tolerance protein; Δpac for truncated phospholipid acetyltransferase. The oriIS of ISCR21 is indicated by a circle. Function of each genes are indicated by colored arrows as follows: green, non-aminoglycosides non-β-lactams resistance genes; azure, β-lactams resistance genes; orange, aminoglycosides resistance genes. Transposon-related genes and insertion sequences are indicated in red arrows. Class 1 integrase gene is indicated by black arrow. GroES, GroEL are indicated in dark blue. ORF of unknown function are indicated by grey arrows. Conserved blaNDM-1 locus was indicated by vertical black lines. The Genbank accession numbers were: pHK-NDM n°HQ451074, p271A n°JF785549, pNDM-KN pending, pGUE-NDM pending and Tn125 pending.