Contribution of phenotypic heterogeneity to adaptive antibiotic resistance.

ABSTRACT: Antibiotic-resistant isolates of Salmonella enterica were selected on plates containing lethal concentrations of rifampicin, kanamycin, and nalidixic acid. The stability of the resistance phenotype was scored after nonselective growth. Rifampicin-resistant (Rif(r)) isolates were stable, suggesting that they had arisen by mutation. Mutations in the rpoB gene were detected indeed in Rif(r) mutants. In contrast, a fraction of kanamycin-resistant (Km(r)) and nalidixic acid-resistant (Nal(r)) isolates showed reduced resistance after nonselective growth, suggesting that mechanisms other than mutation had contributed to bacterial survival upon lethal selection. Single-cell analysis revealed heterogeneity in expression of the porin gene ompC, and subpopulation separation provided evidence that red

SUBMITTER: Sanchez-Romero MA 

PROVIDER: S-EPMC3890857 | biostudies-literature | 2014 Jan

REPOSITORIES: biostudies-literature