Genetic analysis of colistin resistance in Salmonella enterica serovar Typhimurium.

ABSTRACT: Colistin is a cyclic cationic peptide that kills gram-negative bacteria by interacting with and disrupting the outer membrane. We isolated 44 independent mutants in Salmonella enterica serovar Typhimurium with reduced susceptibility to colistin and identified 27 different missense mutations located in the pmrA and pmrB genes (encoding the regulator and sensor of a two-component regulatory system) that conferred increased resistance. By comparison of the two homologous sensor kinases, PmrB and EnvZ, the 22 missense mutations identified in pmrB were shown to be located in four different structural domains of the protein. All five pmrA mutations were located in the phosphate receiver domain of the regulator protein. The mutants appeared at a mutation rate of 0.6 x 10(-6) per cell per generati

SUBMITTER: Sun S 

PROVIDER: S-EPMC2687247 | biostudies-literature | 2009 Jun

REPOSITORIES: biostudies-literature