mcr-1.2 , a New mcr Variant Carried on a Transferable Plasmid from a Colistin-Resistant KPC Carbapenemase-Producing Klebsiella pneumoniae Strain of Sequence Type 512

Abstract

ABSTRACT A novel mcr variant, named mcr-1.2 , encoding a Gln 3 -to-Leu functional variant of MCR-1, was detected in a KPC-3-producing ST512 Klebsiella pneumoniae isolate collected in Italy from a surveillance rectal swab from a leukemic child. The mcr-1.2 gene was carried on a transferable IncX4 plasmid whose structure was very similar to that of mcr-1 -bearing plasmids previously found in Escherichia coli and K. pneumoniae strains from geographically distant sites (Estonia, China, and South Africa).