The <i>mcr-9</i> Gene of <i>Salmonella</i> and Escherichia coli Is Not Associated with Colistin Resistance in the United States
Gregory H. Tyson, Cong Li, Chih-Hao Hsu, Sherry Ayers, Stacey Borenstein, Sampa Mukherjee, Thu-Thuy Tran, Patrick F. McDermott, Shaohua Zhao
Abstract
Reports of transmissible colistin resistance show the importance of comprehensive colistin resistance surveillance. Recently, a new allele of the mobile colistin resistance ( mcr ) gene family designated mcr-9 , which shows variation in genetic context and colistin susceptibility, was reported. We tested over 100 Salmonella enterica and Escherichia coli isolates with mcr-9 from the National Antimicrobial Resistance Monitoring System (NARMS) in the United States for their susceptibility to colistin and found that every isolate was susceptible, with an MIC of ≤1 μg/ml.
Topics & Concepts
ColistinMCR-1Salmonella entericaEscherichia coliBiologyContext (archaeology)PlasmidMicrobiologySalmonellaAlleleEnterobacteriaceaeGeneticsGenePolymyxinAntibiotic resistanceAntimicrobialAntibioticsBacteriaPaleontologyAntibiotic Resistance in BacteriaSalmonella and Campylobacter epidemiologyPharmaceutical and Antibiotic Environmental Impacts