2604.01348 The Cost of Antibiotic Resistance Varies 100-Fold Across Genetic Backgrounds: Fitness Landscape Mapping in 4,096 E. coli Genotypes
The fitness cost of antibiotic resistance mutations is considered a key factor governing resistance dynamics, yet most estimates come from a handful of genetic backgrounds. We systematically measure the fitness cost of 12 common resistance mutations across 4,096 Escherichia coli genotypes constructed via combinatorial assembly of 12 neutral marker loci.