Infectious disease: changing antibiotic susceptibility.

The field of ophthalmology is fortunate to have an array of antibiotics to treat bacterial infections. Because many of the older antibiotics are no longer useful for treating systemic infections, their use and associated acquired resistance have been reduced. These antibiotics, therefore, likely will continue to be effective for treating ophthalmic infections. The bacteria that cause recurrent infections (e.g., blepharitis) may acquire antibiotic resistance because of the repeated use of one particular agent for therapy (e.g., erythromycin). Recurrent pathologies and those that are treated with antibiotics that have varied broadspectrum activities should be cultured routinely to confirm infection and to institute appropriate therapy. Resistant trends of Staphylococcus aureus to the second-generation fluoroquinolones have been confirmed, and new trends of resistance for Pseudomonas aeruginosa have emerged. These antibiotics are effective but should be used judiciously to avoid bacterial resistance to them and to ensure their future potency.