Rapid decline of bacterial drug-resistance in an antibiotic-free environment through phenotypic reversion

We present our study on the efficacy and phenotypic impact of compensatory evolution inEscherichia coli strains carrying multiple resistance mutations. We have demonstrated that drug-resistance frequently declines within 480 generations during exposure to an antibiotic-free environment. The extent of resistance loss was found to be generally antibiotic-specific, driven by mutations that reduce both resistance level and fitness costs of antibiotic-resistance mutations. We conclude that phenotypic reversion to the antibiotic-sensitive state can be mediated by the acquisition of additional mutations, while maintaining the original resistance mutations. Our study indicates that restricting antimicrobial usage could be a useful policy, but for certain antibiotics only.
Source: eLife - Category: Biomedical Science Tags: Evolutionary Biology Source Type: research