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

ABSTRACT 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 strain’s unique advantage is that the screen is performed at very high concentrations of the antibiotic, non-permissive for most strains. The transposon’s 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 .