New Insights in blaKPC Gene Mobilization in Pseudomonas aeruginosa: Acquisition of blaKPC-3 and Identification of a New Tn2-like NTE Mobilizing blaKPC-2

Carbapenem-resistant <i>Pseudomonas aeruginosa</i> is a major cause of healthcare associated infections in hospitalized patients and what is more warring with reduced therapeutic options. The KPC is a powerful enzyme capable of hydrolyzing the carbapenems, described first in <i>Klebsiella pneumoniae</i> and it already has found in <i>P. aeruginosa.</i><b>Objective</b>: To perform a comparative genomic analysis of two new genetic platforms mobilizing the <i>bla</i>_KPC-2 and <i>bla</i>_KPC-3 in two ST111 and ST235 pandemic clones of <i>P. aeruginosa</i> in Colombia, South America. <b>Methods</b>: Sixty-six <i>bla</i>_KPC-harboring <i>P. aeruginosa</i> isolates were identified and characterized during a prospective study conducted in six high complex hospitals in Colombia. Genetic platforms mobilizing the <i>bla</i>_KPC were analyzed. <b>Results</b>: The <i>bla</i>_KPC-2 and <i>bla</i>_KPC-3 were identified in 24 and 42 isolates, respectively. The <i>bla</i>_KPC-2-harboring isolates belonged to ST235 and <i>bla</i>_KPC-3 to ST111. The whole genome sequencing indicated that the <i>bla</i>_KPC-3 gene was mobilized by the Tn<i>4401b</i> within a 55-kb-size environmental origin plasmid, which, in other isolates, was inserted into the chromosome through a transposition event of IS<i>Pa38</i>. Regarding the <i>bla</i>_KPC-2 gene, this was mobilized by a new Non-Tn<i>4401</i> Element (NTE) derived from transposon Tn<i>2</i> (proposed as variant IIg), which has been transposed into a 43-Kb-size little-studied plasmid related to <i>Klebsiella</i> spp. <b>Conclusions</b>: Our results reveal a new acquisition event of <i>bla</i>_KPC in <i>P. aeruginosa,</i> in this case <i>bla</i>_KPC-3. Likewise, the pandemic high-risk clones ST111 and ST235 of <i>P. aeruginosa</i> continues to spread <i>bla</i>_KPC gene through different mobile genetic elements, jumping of conventional Tn<i>4401b</i> and acquiring new Tn<i>2</i>-derived NTE, which were inserted in diverse plasmids.