[From Pneumococcus to Pseudomonas: the antibacterial behaviour through the time].

The worldwide use of fluoroquinolones in community and hospital settings, due to their high efficacy and tolerability, to the wide antibacterial spectrum and to the availability of an oral formulation, has created a relevant selective pressure for the emergence of resistant bacterial strains towards this antimicrobial class. Nevertheless, twenty years after development of first fluoroquinolones (e.g. norfloxacin and ciprofloxacin) and ten years after levofloxacin introduction, the antibacterial activity of these drugs remains, on the whole, high.