Replacement of KPC-producing pandemic lineages and dissemination of plasmids associated with antimicrobial resistance determinants during inpatient’s hospitalization

Abstract

ABSTRACT: Objectives: The emergence of blaKPC-2 within nosocomial settings has become a major public health crisis worldwide. Our aim was to perform whole-genome sequencing (WGS) of three KPC-producing Gram-negative bacilli (KPC-GNB) strains isolated from a hospitalized patient to identify acquired antimicrobial resistance genes (ARGs). Methods: WGS was performed using Illumina MiSeq-I, and de novo assembly was achieved using SPAdes. Bioinformatics analysis was done using Resfinder, AMRFinder, ISFinder, plasmidSPAdes, PlasmidFinder, MOB-suite, PLSDB database, and IntegronFinder. Conjugation assays were performed to assess the ability of blaKPC-2 to transfer via a plasmid-related mobilization mechanism. Results: High-risk clone KPC-producing Klebsiella pneumoniae sequence type (ST) 258 (HA3) was colonizing an inpatient who later was infected by KPC-producing Escherichia coli ST730 (HA4) and subsequently by KPC-producing K. pneumoniae ST11 (HA15) during hospitalization. Although belonging to different species, both strains causing infections harbored the same gene configuration for dissemination of blaKPC-2 in related IncM1 plasmids recently found in other KPC-GNB isolated from Hospital Alemán at Ciudad Autónoma de Buenos Aires. Conjugation assays revealed that only pDCVEA4-KPC from E. coli HA4 was successfully transferred with a conjugation frequency of 3.66 × 101. Conclusions: Interchange of multidrug-resistant K. pneumoniae lineages ST258 replaced by ST11 in the framework of colonization and infection by KPC-GNB of an inpatient from our institution was found. In addition, the transfer of the gene configuration of blaKPC–2 between infecting strains may have occurred in the nosocomial environment, but we cannot rule out that the event took place in vivo, within the patient, during hospitalization.

Keywords

• Klebsiella pneumoniae ST258
• Klebsiella pneumoniae ST11
• Carbapenem resistance
• blaKPC-2