The IncP-6 Plasmid p10265-KPC from Pseudomonas aeruginosa Carries a Novel ΔIS Ec33-Associated bla _KPC-2 Gene Cluster

Pseudomonas aeruginosa strain 10265 was recovered from a patient with pneumonia in a Chinese public hospital, and it displays the carbapenem resistance phenotype due to the acquisition of a non-conjugative but mobilizable IncP-6-type plasmid p10265-KPC. p10265-KPC carries a Tn 5563-borne defective mer locus, and a novel ΔIS Ec33-associated bla _KPC-2 gene cluster without paired inverted repeats and paired direct repeats at both ends. Mobilization of this ΔIS Ec33-associated element in p10265-KPC would be attributed to homologous recombination-based insertion of a foreign structure Tn 3-IS Apu1- orf7-IS Apu2- IS Kpn27-Δ bla _TEM-1 -bla _KPC-2 -ΔIS Kpn6- korC-orf6- klcA-Δ repB into a pre-existent intact IS Ec33, making IS Ec33 truncated at the 3′ end. The previously reported pCOL-1 represents the first sequenced KPC-producing IncP-6 plasmid, while p10265-KPC is the second one. These two plasmids carry two distinct bla _KPC-2 gene clusters, which are inserted into the different sites of the IncP-6 backbone and have different evolutionary histories of assembly and mobilization. This is the first report of identification of the IncP-6-type resistance plasmid in China.