NDM-1 and KPC-3 co-producing Klebsiella pneumoniae ST512 in bronchial secretion from a patient in an intensive care unit of a Greek Tertiary Care Hospital.

This study investigated a strain of Klebsiella pneumoniae, identified as GRTHES, which exhibited extensive antibiotic resistance. The strain was resistant to all beta-lactams, including combinations with newer agents such as meropenem/vaborbactam and imipenem/relebactam, as well as to aminoglycosides, fluoroquinolones, fosfomycin, trimethoprim-sulfamethoxazole and colistin. It remained susceptible to tigecycline. Whole-genome sequencing was performed by Ion Torrent platform on the K. pneumoniae strain. Genomic analysis revealed a genome length of 5,808,650 bp and a GC content of 56.9%. Advanced sequencing techniques and bioinformatic tools were used to assess resistance genes and plasmid replicons, highlighting the emergence of multidrug resistance and virulence traits. The strain carried blaNDM-1 and blaKPC-3 genes and was designated to KL107 O2afg type. Colistin resistance-associated mgrB/pmrB gene mutations were present, and the strain also harbored yersiniabactin-encoding ybt gene. Our findings provide insights into the genomic context of blaNDM-1 and blaKPC-3 carbapenemase-producing K. pneumoniae and emphasize the importance of continuous surveillance and novel therapeutic strategies to combat multidrug-resistant bacterial infections. It is the first time that an NDM-1 and KPC-3 co-producing strain of K. pneumoniae ST512 is identified in Greece. This study highlights the essential role of genomic surveillance as a proactive strategy to control the spread of carbapenemase-producing K. pneumoniae isolates, particularly when key antimicrobial resistance genes, such as blaNDM-1 and blaKPC-3, are plasmid-mediated. Detailed characterization of these isolates could reveal plasmid similarities that facilitate adaptation and transmission within and between hospitals. Although data on patient movements are limited, it is plausible that carbapenem-resistant isolate was selected to co-produce KPC and NDM through plasmid acquisition.