Proteomics Analysis of Evolved Escherichia coli Populations from Cyclic Antibiotic Treatment

When the survivors of antibiotic treatment (persisters) are repeatedly regrown and retreated with the same antibiotic for several cycles, the new population will soon adapt to the treatment condition and become tolerant to the drug. Here, we did evolution experiments on Escherichia coli populations by treating it with daily high concentration of different antibiotics (ampicillin, ciprofloxacin and apramycin) approximating clinical dosage, during the rapid growth-exponential phase. After a few cycles, we observed that the evolved populations exhibit extremely high tolerance to the drug, which are achieved by single point mutations in one of several genes. Interestingly, treatment with different antibiotics led to the selection of different mutants despite the shared persistence phenotype. Here, we applied spectral counting-based quantitative proteomics to study the proteome profile of the evolved E. coli populations from different cyclic antibiotic treatments.