Comparative analysis of KPC-2-encoding chimera plasmids with multi-replicon IncR:Inc:IncN1 or IncFII:Inc:IncN1.

BACKGROUND

IncR, IncFII, IncpA1763-KPC, and IncN1 plasmids have been increasingly found among species, but plasmids with hybrid structures derived from the above-mentioned incompatibility groups have not yet been described.

METHODS

Plasmids p721005-KPC, p504051-KPC, and pA3295-KPC were fully sequenced and compared with previously sequenced related plasmids pHN84KPC (IncR), pKPHS2 (IncFII), pKOX_NDM1 (IncFII), pHN7A8 (IncFII), and R46 (IncN1).

RESULTS

The backbone of p721005-KPC/p504051-KPC was a hybrid of the entire 10-kb IncR-type backbone from pHN84KPC, the entire 64.3-kb IncFII-type maintenance, and conjugal transfer regions from pKPHS2, a 15.5-kb IncFII-type maintenance region from pKOX_NDM1 and a 5.6-kb Inc-type backbone region from pA1763-KPC, and it contained a primary IncR replicon and two auxiliary Inc and IncN1 replicons. The backbone of pA3295-KPC was a hybrid of a 7.2-kb IncFII-type backbone region from pHN7A8, the almost entire 33.3-kb IncN1-type maintenance and conjugal transfer regions highly similar to R46, a 26.2-kb IncFII-type maintenance regions from pKPHS2, the above 15.5-kb IncFII-type maintenance region, and the above 5.6-kb Inc-type backbone region, and it contained a primary Inc-FII replicon and two auxiliary Inc and IncN1 replicons. Each of p721005-KPC, p504051-KPC, and pA3295-KPC acquired a wealth of accessory modules, carrying a range of intact and residue mobile elements (such as insertion sequences, unit transposons, and integrons) and resistance markers (such as , , and ).

CONCLUSION

In each of p721005-KPC, p504051-KPC, and pA3295-KPC, multiple replicons in coordination with maintenance and conjugation regions of various origins would maintain a broad host range and a stable replication at a steady-state plasmid copy number.