Usual drug resistance describes isolates that are not fully susceptible wild-type strains but that can nonetheless be readily treated with standard therapies.
UDR is a recently proposed category defining resistance in bacteria which may still be effectively treated with first-line drugs. It may be useful in the context of clinical trials but requires knowledge of first-line drugs within the regional or local context.
Progress in the fight against multidrug-resistant bacteria 2005–2016: modern noninferiority trial designs enable antibiotic development in advance of epidemic bacterial resistance (Clinical Infectious Diseases, 2017)
Efficient delivery of investigational antibacterial agents via sustainable clinical trial networks (Clinical Infectious Diseases, 2016)
Characterization of resistance in gram-negative urinary isolates using existing and novel indicators of clinical relevance: A 10-year data analysis (Life, 2020)