Identification of Escherichia coli Genes Essential for High-Level, Clinically Relevant, Resistance to Antibiotics

Antibiotic resistance is one of the biggest public health challenges of our time. Here we present a novel approach to recognizing molecular mechanisms essential for maintaining high-level clinically relevant antibiotic resistance. To identify essential genes in this context, we subjected Escherichia coli EV18, a strain highly resistant to quinolones, to random transposon mutagenesis. This strains unique advantage is that the screen is performed at very high concentrations of the antibiotic, non-permissive for most strains. The transposons insertion affected the transcription of five genes required for the maintenance of resistance in EV18. Three of these genes (YihO, YhdP, and WaaY) have not been previously identified as essential for high-level antimicrobial resistance (AMR). Our work provides a new perspective to identify and characterize novel players crucial for maintaining AMR in E. coli.