Emergence of carbapenem-resistant Klebsiella pneumoniae harbouring bla (OXA-48)-like genes in China

Klebsiella pneumoniae strains carrying OXA-48-like carbapenemases are increasingly prevalent across the globe. There is thus an urgent need to better understand the mechanisms that underpin the dissemination of bla (OXA-48)-like carbapenemases. To this end, four ertapenem-resistant K. pneumoniae isolates producing OXA-48-like carbapenemases were isolated from two patients. Genome sequencing revealed that one sequence type (ST) 17 isolate carried bla (OXA-181), whilst three isolates from a single patient, two ST76 and one ST15, carried bla (OXA-232). The 50514 bp bla (OXA-181)-harbouring plasmid, pOXA-181_YML0508, was X3-type with a conjugation frequency to Escherichia coli of 1.94×10(−4) transconjugants per donor. The bla (OXA-232) gene was located on a 6141 bp ColKP3-type plasmid, pOXA-232_WSD, that was identical in the ST76 and ST15 K. pneumoniae isolates. This plasmid could be transferred from K. pneumoniae to E. coli at low frequency, 8.13×10(−6) transconjugants per donor. Comparative analysis revealed that the X3 plasmid acquired the bla (OXA-48)-like gene via IS3000-mediated co-integration of the ColKP3-type plasmid. Our study highlights how plasmid integration and rearrangements can contribute to the spread of bla (OXA-48)-like genes, which provides important clues for clinical prevention of the dissemination of K. pneumoniae strains carrying bla (OXA-48)-like carbapenemases.