Evaluation of several fluoroquinolones and beta-lactams in terms of their capability to restrict the selection of fluoroquinolone-resistant Salmonella: in vitro models.

With a view to understanding the interaction between Salmonella and the drugs used to treat it, our aim was to compare the different capacities of various antibiotics to generate mutants resistant to fluoroquinolones following repeated exposure of the microorganisms to subinhibitory concentrations of these drugs. Mutants were generated by repeated exposure to fluoroquinolones and beta-lactams. In order to compare the different capacity to generate resistant mutants, we studied the minimum inhibitory concentration (MIC) and mutant prevention concentration (MPC) of the wild-type strains and of the mutants generated.