High-throughput method characterizes hundreds of previously unknown antibiotic resistance mutations

The study presents Quantitative Mutational Scan sequencing (QMS-seq), a high-throughput technique that identifies mutations leading to antimicrobial resistance in a given genomic background and environment. It identifies 812 resistance mutations in four E. coli strains exposed to ciprofloxacin, cycloserine, or nitrofurantoin, revealing that mutations lead to multi-drug and antibiotic-specific resistance, and minor genotypic differences significantly influence resistance evolution.