title: Resistance to ten different fluoroquinolone antibiotics following in vitro exposures to nalidixic acid.
abstract: Ten different fluoroquinolone antibiotics were tested against selected Enterobacteriaceae. Against nalidixic acid-resistant clinical isolates, minimal inhibitory concentrations for all 10 drugs were eightfold to 32-fold greater than those against comparable nalidixic acid-susceptible strains. When the latter strains were serially exposed to increasing concentrations of nalidixic acid, susceptibility to all 10 fluoroquinolones decreased as resistance to nalidixic acid and cinoxacin was acquired in vitro.
mesh_terms: D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D004352:Drug Resistance, Microbial; D004755:Enterobacteriaceae / Q000187:drug effects*; D006845:Hydrocarbons, Fluorinated / Q000494:pharmacology*; D009268:Nalidixic Acid / Q000494:pharmacology*; D011804:Quinolines / Q000494:pharmacology*
chemical_list: D000900:Anti-Bacterial Agents; D006845:Hydrocarbons, Fluorinated; D011804:Quinolines; D009268:Nalidixic Acid