Molecular Analysis of -Harboring Plasmids: Tn Interplasmid Transposition and Tn-Carrying ColRNAI Plasmid Mobilization from Klebsiella pneumoniae to Citrobacter europaeus and Morganella morganii in a Single Patient.

The spread of Klebsiella pneumoniae carbapenemase (KPC)-producing is a public health concern. KPC-encoding is predominantly spread by strains of a particular phylogenetic lineage, clonal group 258, but can also be spread by horizontal transfer of -carrying plasmids. Here, we report the transfer of a -harboring plasmid via mobilization from K. pneumoniae to Citrobacter freundii complex and Morganella morganii strains in a single patient. We performed draft whole-genome sequencing to analyze 20 carbapenemase-producing strains (15 of K. pneumoniae, two of C. freundii complex, and three of M. morganii) and all K. pneumoniae strains using MiSeq and/or MinION isolated from a patient who was hospitalized in New York and Montreal before returning to Japan. All strains harbored -containing Tn. The 15 K. pneumoniae strains each belonged to sequence type 258 and harbored a Tn-carrying multireplicon-type plasmid, IncN and IncR (IncN+R). Three of these K. pneumoniae strains also possessed a Tn-carrying ColRNAI plasmid, suggesting that Tn underwent interplasmid transposition. Of these three ColRNAI plasmids, two and one were identical to plasmids harbored by two Citrobacter europaeus and three M. morganii strains, respectively. The Tn-carrying ColRNAI plasmids were each 23,753 bp long and incapable of conjugal transfer via their own genes alone, but they mobilized during the conjugal transfer of Tn-carrying IncN+R plasmids in K. pneumoniae. Interplasmid transposition of Tn from an IncN+R plasmid to a ColRNAI plasmid in K. pneumoniae and mobilization of Tn-carrying ColRNAI plasmids contributed to the acquisition of in and M. morganii. Plasmid transfer plays an important role in the interspecies spread of carbapenemase genes, including the Klebsiella pneumoniae carbapenemase (KPC)-coding gene, . We conducted whole-genome sequencing (WGS) analysis and transmission experiments to analyze -carrying mobile genetic elements (MGEs) between the -harboring K. pneumoniae, Citrobacter europaeus, and Morganella morganii strains isolated from a single patient. was contained within an MGE, Tn. WGS of -carrying K. pneumoniae, , and M. morganii strains isolated from one patient revealed that Tn-carrying ColRNAI plasmids were generated by plasmid-to-plasmid transfer of Tn from a multireplicon-type IncN and IncR (IncN+R) plasmid in K. pneumoniae strains. Tn-carrying ColRNAI plasmids were incapable of conjugal transfer in and M. morganii but mobilized from K. pneumoniae to a recipient Escherichia coli strain during the conjugal transfer of Tn-carrying IncN+R plasmid. Therefore, Tn-carrying ColRNAI plasmids contributed to the acquisition of in and M. morganii.