Promoter Variation and Gene Expression of <i>mcr-1</i> -Harboring Plasmids in Clinical Isolates of Escherichia coli and Klebsiella pneumoniae from a Chinese Hospital

Abstract

Next-generation sequencing of 6 <i>mcr-1</i>-harboring <i>Escherichia coli</i> and <i>Klebsiella pneumoniae</i> isolates collected from a tertiary care hospital in China revealed significant sequence variations in the regions flanking the <i>mcr-1</i> gene. While sequence variations significantly affected the expression and promoter activity of <i>mcr-1</i>, the <i>mcr-1</i> gene expression levels did not correlate with the <i>in vitro</i> colistin resistance levels, which warrants further in-depth investigations.