In vitro activity of ototopical drops against middle ear pathogens.

Five types of ear drops were each assessed for effectiveness on the basis of the in vitro antibacterial activity. Staphylococcus aureus, methicillin-resistant S. aureus (MRSA), and Pseudomonas aeruginosa isolated from purulent otitis media were evaluated by comparative analysis. Otic drops containing new fluorinated quinolones, Ofloxacin and NY-198, showed high in vitro activity against all the bacteria. Cortisporin expressed moderate activity against P. aeruginosa and relatively weak activity against S. aureus and MRSA. Bestron and Fosmicin possessed low activity against three clinical isolates. Otic drops containing the new quinolones may be effective for treating purulent otitis media infected by MRSA and P. aeruginosa.