Antibiotic resistance observed in some patients undergoing intravitreal injections
Ophthalmology. 2010;117(12):2372-2378.
Click Here to Manage Email Alerts
Patients who underwent intravitreal injections for choroidal neovascularization showed resistance to third- and fourth-generation fluoroquinolones, especially those infected with coagulase-negative staphylococcus, a study said.
In the prospective, observational study, researchers identified 57 bacterial isolates, 65% of which were coagulase-negative staphylococci. Staphylococcus epidermidis made up 73% of the coagulase-negative staphylococci isolates and Staphylococcus lugdunensis accounted for 11%, the study said.
Unilateral nasopharyngeal cultures were collected from the conjunctiva of 48 eyes of 24 patients with an average age of 75 years. Eighty-three percent of patients were being treated for choroidal neovascularization due to age-related macular degeneration, and none had a history of intravitreal injection.
Of the coagulase-negative staphylococci isolates, 60% were resistant to three or more antibiotics and 30% were resistant to five or more antibiotics.
In addition, 33% of the cultures grew Staphylococcus aureus, with 13% of those isolates resistant to all penicillin, cephalosporin, macrolide and fluoroquinolone antibiotics.
"As with all in vitro susceptibility studies, our results should be taken with caution," the authors said. "A combination of pharmacokinetics and pharmacodynamics of drug, infection site and [minimum inhibitory concentration] is needed to properly predict in vivo efficacy of antibiotics against target pathogens."