AUTHOR=Liapis Eleni , Bour Maxime , Triponney Pauline , Jové Thomas , Zahar Jean-Ralph , Valot Benoît , Jeannot Katy , Plésiat Patrick 

TITLE=Identification of Diverse Integron and Plasmid Structures Carrying a Novel Carbapenemase Among Pseudomonas Species

JOURNAL=Frontiers in Microbiology

VOLUME=10

YEAR=2019

URL=https://www.frontiersin.org/journals/microbiology/articles/10.3389/fmicb.2019.00404

DOI=10.3389/fmicb.2019.00404

ISSN=1664-302X

ABSTRACT=<p>A novel carbapenem-hydrolyzing beta-lactamase, called IMP-63, was identified in three clonally distinct strains of <italic>Pseudomonas aeruginosa</italic> and two strains of <italic>Pseudomonas putida</italic> isolated within a 4 year timeframe in three French hospitals. The <italic>bla</italic><sub>IMP–63</sub> gene that encodes this carbapenemase turned out to be located in the variable region of four integrons (In<italic>1297</italic>, In<italic>1574</italic>, In<italic>1573</italic>, and In<italic>1572</italic>) and to coexist with novel or rare gene cassettes (<italic>fosM</italic>, <italic>gcu170</italic>, <italic>gcuF1</italic>) and insertion elements (IS<italic>Psp7v</italic>, IS<italic>Pa16v</italic>). All these integrons except one (In<italic>1574</italic>) were flanked by a copy of insertion sequence IS<italic>Pa17</italic> next to the <italic>orf6</italic> putative gene, and were carried by non-conjugative plasmids (pNECK1, pROUSS1, pROUSS2, pROUE1). These plasmids exhibit unique modular structures and partial sequence homologies with plasmids previously identified in various non-fermenting environmental Gram-negative species. Lines of evidence suggest that IS<italic>Pa17</italic> promoted <italic>en bloc</italic> the transposition of IMP-63-encoding integrons on these different plasmids. As demonstrated by genotyping experiments, isolates of <italic>P. aeruginosa</italic> harboring the 28.9-kb plasmid pNECK1 and belonging to international “high-risk” clone ST308 were responsible for an outbreak in one hospital. Collectively, these data provide an insight into the complex and unpredictable routes of diffusion of some resistance determinants, here <italic>bla</italic><sub>IMP–63</sub>, among <italic>Pseudomonas</italic> species.</p>