Emergence of carbapenem-resistant harbouring -like genes in China.

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 -like carbapenemases. To this end, four ertapenem-resistant isolates producing OXA-48-like carbapenemases were isolated from two patients. Genome sequencing revealed that one sequence type (ST) 17 isolate carried , whilst three isolates from a single patient, two ST76 and one ST15, carried . The 50514 bp -harbouring plasmid, pOXA-181_YML0508, was X3-type with a conjugation frequency to of 1.94×10 transconjugants per donor. The gene was located on a 6141 bp ColKP3-type plasmid, pOXA-232_WSD, that was identical in the ST76 and ST15 isolates. This plasmid could be transferred from to at low frequency, 8.13×10 transconjugants per donor. Comparative analysis revealed that the X3 plasmid acquired the -like gene via IS-mediated co-integration of the ColKP3-type plasmid. Our study highlights how plasmid integration and rearrangements can contribute to the spread of -like genes, which provides important clues for clinical prevention of the dissemination of strains carrying -like carbapenemases.