RESUMO
Microbial keratitis is a serious ocular infection which can result in visual loss due to corneal scarring. Complications of uncontrolled infectious keratitis can lead to endophthalmitis or systemic disease via the hematogenous route. Therapeutic intervention with appropriate use of antibiotics is mandatory for successful eradication of the causative organisms. Microbiologic diagnosis and antibiotic sensitivity testing are necessary so that the selection of antibiotic may be directed against susceptible organisms. Therefore the outcome is dependent on the clinician's having information regarding available antibiotics and known susceptibility patterns based on hundreds of indigenous isolates. We determined the prevalence and sensitivity patterns based on 455 organisms recovered from patients with microbial keratitis in Saudi Arabia. Gram-positive bacteria, particularly Staphylococcus epidermidis and Streptococcus pneumoniae were the most frequent isolates with Pseudomonas aeruginosa, the most common gram-negative isolate. In vitro sensitivity results revealed that antibiotic susceptibility could be achieved in most of the gram-positive isolates using minocycline, bacitracin, clindamycin, or vancomycin and most of the S. epidermidis strains were sensitive to Fucidin. Gram-negative sensitivity results varied depending on the species isolated; however, almost all Pseudomonas aeruginosa strains were susceptible to amikacin, gentamicin, and polymyxin B