Abstract
Abstract: :
Purpose: To assess the preoperative incidence of multiresistant Staphylococcus epidermidis (S. epidermidis) colonization of the conjunctiva in outpatients undergoing intraocular surgery. Methods: Conjunctival smears were obtained from 82 consecutive eyes of 72 patients before anterior segment surgery. All cultures were obtained prior to the application of preoperative prophylaxis. After 10 days of incubation, all isolates were identified, and a masked microbiologist using the Kirby-Bauer disc-diffusion method determined susceptibility to twenty-one antibiotics. The antibiotics tested included penicillins, cephalosporins, carbapenems, aminoglycosides, and fluoroquinolones, as well as, erythromycin, tetracycline, chloramphenicol, and vancomycin. Multiresistance was defined as resistance to seven or more antibiotics. Preoperatively, signs of eyelid inflammation were noted and the patient’s immune status assessed by review of the patient’s past medical history. Results: Ninety-five bacterial strains were obtained from 82 ocular samples. Seventy-six of these conjunctival bacterial strains (80%) grew S. epidermidis that was found to be multiresistant in 20 cases (26%). Multiresistant S. epidermidis was isolated from the conjunctiva in 20/95 (21%) of bacterial strains, 19/82 (23%) of eyes, and 19/72 (26%) of patients. Seven of 17 (41%) of multiresistant S. epidermidis had associated eyelid inflammation compared to only 9/46 (20%) of non-multiresistant S. epidermidis (P=0.15). Systemic diseases related to immunosuppresion were present in 7/16 (44%) and 17/47 (36%) of patients with and without multiresistant S. epidermidis colonization, respectively (P=0.81). Ocular inflammation and systemic disease results were not available for 13 S. epidermidis strains. Conclusions: Multiresistant S. epidermidis, traditionally considered a nosocomial pathogen, may be a frequent contaminant of the conjunctiva. The presence of multiresistant S. epidermidis on the conjunctiva in approximately one in four patients highlights the importance of antiseptic use and should be considered when choosing a prophylactic antibiotic. Our results suggest a trend in a higher prevalence of multiresistant S. epidermidis in patients with eyelid inflammation.
Keywords: 587 Staphylococcus • 354 clinical (human) or epidemiologic studies: prevalence/incidence • 365 conjunctiva