Characterization of an IncFII Plasmid Encoding NDM-1 from <em>Escherichia coli</em> ST131

<div><h3>Background</h3><p>The current spread of the gene encoding the metallo-ß-lactamase NDM-1 in <em>Enterobacteriaceae</em> is linked to a variety of surrounding genetic structures and plasmid scaffolds.</p> <h3>Methodology</h3><p>The whole sequence of plasmid pGUE-NDM carrying the <em>bla</em>_NDM-1 gene was determined by high-density pyrosequencing and a genomic comparative analysis with other <em>bla</em>_NDM-1-negative IncFII was performed.</p> <h3>Principal Findings</h3><p>Plasmid pGUE-NDM replicating in <em>Escherichia coli</em> confers resistance to many antibiotic molecules including β-lactams, aminoglycosides, trimethoprim, and sulfonamides. It is 87,022 bp in-size and carries the two β-lactamase genes <em>bla</em>_NDM-1 and <em>bla</em>_OXA-1, together with three aminoglycoside resistance genes <em>aacA4</em>, <em>aadA2</em>, and <em>aacC2</em>. Comparative analysis of the multidrug resistance locus contained a module encompassing the <em>bla</em>_NDM-1 gene that is actually conserved among different structures identified in other enterobacterial isolates. This module was constituted by the <em>bla</em>_NDM-1 gene, a fragment of insertion sequence IS<em>Aba125</em> and a bleomycin resistance encoding gene.</p> <h3>Significance</h3><p>This is the first characterized <em>bla</em>_NDM-1-carrying IncFII-type plasmid. Such association between the <em>bla</em>_NDM-1 gene and an IncFII-type plasmid backbone is extremely worrisome considering that this plasmid type is known to spread efficiently, as examplified with the worldwide dissemination of <em>bla</em>_CTX-M-15-borne IncFII plasmids.</p>