Functional genomics of drug resistance genes in Escherichia coli

In order to expedite gene discovery coding for either drug targets or antibiotic resistance, we have developed a functional genomic strategy termed Plas-Seq. This technique is coupling muticopy suppressor library to next generation sequencing. We generated an Escherichia coli plasmid genomic library that was transformed into E. coli. These transformants were selected step by step using 0.25× to 2× minimum inhibitory concentrations for ceftriaxone, gentamicin, levofloxacin, tetracycline and trimethoprim. Plasmids were isolated at each selection steps and subjected to Illumina sequencing. This has allowed to observe an increase in reads abundance and fold enrichment for 48 different genomic loci.