Replicon-Based Typing About IncG Plasmids and Molecular Characterization of Five IncG Plasmids Carrying Carbapenem Resistance Gene blaKPC-2

Purpose: To investigate the genetic diversity of IncG plasmids, we have proposed a typing scheme based on replicon repA and performed comparative genomic analysis of five IncG plasmids from China. Methods: p30860-KPC, p116965-KPC, pA1705-KPC, pA1706-KPC and pNY5520-KPC total in five IncG plasmids from clinical isolates of Pseudomonas and Enterobacteriaceae , respectively, were fully sequenced and were compared with the previously collected reference plasmid p10265-KPC. Results: Based on phylogeny, IncG-type plasmids are divided into IncG-I to IncG-VIII, the five plasmids belong to IncG-VIII. A detailed sequence comparison was then presented that the IncG plasmid involved accessory region I (Tn 5563a/b/c/d/e ), accessory region II (IS pa19 ), and accessory region III ( bla KPC-2 -region). Expect for the pNY5520-KPC, the rest of the plasmids had the same backbone structure as the reference one. Within the plasmids, insertion sequences Tn 5563d and Tn 5563e were identified, a novel unknown insertion region was found in Tn 5563b/c/d/e . In addition, Tn 6376b and Tn 6376c were newly designated in the study. Conclusion: The data presented here including a typing scheme and detailed genetic comparison which provide an insight into the diversification and evolution history of IncG plasmids.