Characterization and dynamics of middle ear fluid and nasopharyngeal isolates of Streptococcus pneumoniae from 12 children treated with levofloxacin.

Children who had acute otitis media and were treated with levofloxacin were assessed for the emergence of fluoroquinolone-resistant Streptococcus pneumoniae. Nasopharynx cultures were obtained from patients at the entry to and during levofloxacin therapy. All nasopharynx isolates (n = 59) from 12 children were levofloxacin susceptible without parC/E or gyrA/B mutations. Pneumococcal nasopharynx persistence was not associated with levofloxacin resistance.