MCR-1.6, a New MCR Variant Carried by an IncP Plasmid in a Colistin-Resistant Salmonella enterica Serovar Typhimurium Isolate from a Healthy Individual

Abstract

In this study, we report a novel <i>mcr-1</i> gene variant, named <i>mcr-1.6</i>, carried by an IncP plasmid in a colistin-resistant <i>Salmonella enterica</i> serovar Typhimurium isolate from a healthy person. Compared with <i>mcr-1</i>, the <i>mcr-1.6</i> gene contains two single-nucleotide polymorphisms, one of which results in an arginine to histidine variation (Arg536→His). The plasmid carrying the <i>mcr-1.6</i> gene was designated pMCR1.6_P053 and is similar to a recently discovered <i>mcr-1</i>-bearing plasmid found in <i>Klebsiella pneumoniae</i>.