A P7 Phage-Like Plasmid Carrying in an ST15 Clinical Isolate.

A clinical strain, named SCKP83, was isolated and found to be resistant to colistin thanks to the presence plasmid-borne colistin resistant gene . The strain was subjected to whole genome sequencing and conjugation experiments. The subsequent analysis indicated that the strain belongs to ST15 and the capsular type K41. In SCKP83, was carried by a 97.4-kb non-self-transmissible plasmid, a 90.9-kb region of which was predicted as an intact phage. This phage was 47.79% GC content, encoded 105 proteins and contained three tRNAs. was located downstream of two copies of the insertion sequence IS (one complete and one truncated) and was inserted in the gene, which encodes a putative antirepressor for antagonizing C1 repression, in this phage. The phage is highly similar to phage P7 (77% coverage and 98% identity) from . Several similar -carrying plasmids have been found in at various locations in China, suggesting that these phage-like plasmids have circulated in China. The findings in this study suggest that the P7 phage-like plasmids are not restricted to and may represent new vehicles to mediate the inter-species spread of .