Emergence Of Carbapenem- Resistant Klebsiella Pneumoniae Harbouring Blaoxa-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 blaOXA-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 blaOXA-181, whilst three isolates from a single patient, two ST76 and one ST15, carried blaOXA-232. The 50514 bp blaOXA-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 blaOXA-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 blaOXA-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 blaOXA-48- like genes, which provides important clues for clinical prevention of the dissemination of K. pneumoniae strains carrying blaOXA-48-like carbapenemases.