Enterobacter cloacae Complex Isolates Harboring or -Type Class A Carbapenemase Genes on Novel Chromosomal Integrative Elements and Plasmids.

Carbapenem-resistant complex isolates submitted to a reference laboratory from 2010 to 2015 were screened by PCR for seven common carbapenemase gene groups, namely, KPC, NDM, OXA-48, VIM, IMP, GES, and NMC-A/IMI. Nineteen of the submitted isolates (1.7%) were found to harbor Ambler class A or -type carbapenemases. All 19 isolates were resistant to at least one carbapenem but susceptible to aminoglycosides, trimethoprim-sulfamethoxazole, tigecycline, and ciprofloxacin. Most isolates (17/19) gave positive results with the Carba-NP test for phenotypic carbapenemase detection. Isolates were genetically diverse by pulsed-field gel electrophoresis macrorestriction analysis, multilocus sequence typing, and gene analysis. The genes were found in various complex species; however, was highly associated with Whole-genome sequencing and bioinformatics analysis revealed that all NMC-A ( = 10), IMI-1 ( = 5), and IMI-9 ( = 2) producers harbored the carbapenemase gene on EludIMEX-1-like integrative mobile elements (EcloIMEXs) located in the identical chromosomal locus. Two novel genes, and , were harbored on different IncFII-type plasmids. complex isolates harboring -type carbapenemases are relatively rare in Canada. Though mostly found integrated into the chromosome, some variants are located on plasmids that may enhance their mobility potential.