Carbapenem-Resistant Klebsiella pneumoniae Producing Single or Dual Carbapenemases and Emergence of ST395 Strains Co-harbouring NDM-5 and OXA-232 in Selected University Hospitals

Background Emergence of carbapenem-resistant Klebsiella pneumoniae (CRKP) strains poses a serious global threat, driven by expansion of high-risk clones producing dual carbapenemases and exhibiting increased antimicrobial resistance. Materials and methods We investigated 256 CRKP strains from 241 patients hospitalized in two healthcare facilities – No. 1 and No. 2, which are part of the University Hospital Bratislava. Carbapenemases were detected using Carba NP test, immunochromatographic assay and PCR. In three selected strains, genomic characteristics, relatedness, and similarity to other CRKP strains in the Klebsiella PasteurMLST database were analysed using Illumina MiSeq platform. Antimicrobial susceptibility was determined using colourimetric micro-method. Results In our study, 226 (88.3%) CRKP strains originated from medical facility No. 1 and 30 (11.7%) from No. 2. Of all strains, 252 (98.4%) harboured the following genes: bla KPC (117; 45.7%), bla NDM (69; 26.9%), bla VIM (2; 0.8%), bla OXA−48−like (7; 2.7%), and co-occurrence of bla NDM with bla OXA−48−like (57; 22.3%). Sequencing of three selected strains showed the same sequence type – ST395, capsular type – KL64, enterobactin and yersiniabactin; carbapenemases – NDM-5 and OXA-232, and ESBL CTX-M-15. cgMLST analysis revealed high similarity or identity within the strains. Significant differences in resistance ( p < 0.001) were observed among KPC- vs. NDM- and OXA-48-like-producing Klebsiella pneumoniae for meropenem (73.3% vs. 100%), gentamicin (28.4% vs. 91.2%), and amikacin (10.3% vs. 93%), or NDM vs. NDM and OXA-48-like producers for tigecycline (55.9% vs. 92.6%). Conclusion Essential measures to limit CRKP spread in medical facilities include early detection of high-risk clones, carbapenemases identification for appropriate treatment, and reduction in antimicrobial resistance.