title: Mutation frequency of Haemophilus influenzae to rifampin resistance.
abstract: Twenty-two susceptible strains of Haemophilus influenzae were examined for mutation to rifampin resistance (minimal inhibitory concentration, greater than or equal to 10 micrograms/ml). All strains had detectable apparent mutation frequencies with a median minimal inhibitory concentration 2,000-fold greater than that of their wild-type parents. Of the type b strain mutants, 80% (8 of 10) expressed high-level resistance (minimal inhibitory concentration, 750 micrograms/ml) that was 75-fold greater than readily achievable serum concentrations.
mesh_terms: D004352:Drug Resistance, Microbial; D006193:Haemophilus influenzae / Q000187:drug effects / Q000235:genetics*; D009154:Mutation; D012293:Rifampin / Q000494:pharmacology*
chemical_list: D012293:Rifampin