Molecular Characterization of Carbapenemase-Producing Pseudomonas aeruginosa of Czech Origin and Evidence for Clonal Spread of Extensively Resistant Sequence Type 357 Expressing IMP-7 Metallo-β-Lactamase.

The objective of this study was to perform molecular surveillance for assessing the spread of carbapenemase-producing in Czech hospitals. One hundred thirty-six carbapenemase-producing isolates were recovered from 22 hospitals located throughout the country. Sequence type 357 (ST357) dominated ( = 120) among carbapenemase producers. One hundred seventeen isolates produced IMP-type (IMP-7 [ = 116] and IMP-1 [ = 1]) metallo-β-lactamases (MβLs), 15 produced the VIM-2 MβL, and the remaining isolates expressed the GES-5 enzyme. The -like genes were located in three main integron types, with In-p110-like being the most prevalent ( = 115). The two other IMP-encoding integrons (In1392 and In1393) have not been described previously. -carrying integrons included In59-like, In56, and a novel element (In1391). was carried by In717. Sequencing data showed that In-p110-like was associated with a Tn-like transposon inserted in genomic island LESGI-3 in the chromosome. The other integrons were also integrated into the chromosome. These findings indicated the clonal spread of ST357 , carrying the IMP-7-encoding integron In-p110, in Czech hospitals. Additionally, the sporadic emergence of producing different carbapenemase types, associated with divergent or novel integrons, punctuated the ongoing evolution of these bacteria.