Infectious keratitis: isolated microbes and their antibiotic susceptibility pattern during 2004–2014 in Region Örebro County, Sweden

Abstract

Purpose: To describe predisposing risk factors, causative microorganisms and their antibiotic susceptibility patterns in infectious keratitis during an 11-year period in Region Örebro County, Sweden. Methods: This is a descriptive study conducted as a retrospective audit of clinical records. Patients who received treatment for infectious keratitis at any of the three ophthalmological departments within Region Örebro County, Sweden, between 2004 and 2014 were included if they fulfilled the predefined criteria for infectious keratitis. Data regarding culture results, antibiotic susceptibility pattern and risk factors for infectious keratitis were obtained from medical records and microbiological reports. Results: In total, 398 episodes of infectious keratitis in 392 patients were included, and 285 were culture positive. The most common predisposing risk factor was contact lens wear (45%). Coagulase-negative staphylococci (39.6%) was the most commonly isolated type of organism. Staphylococcus aureus (15.1%) followed by Moraxella spp. (7.4%) and Pseudomonas aeruginosa (6.7%) were among the most common isolated bacteria not considered to be commensal. Reduced susceptibility to fluoroquinolones was observed in five of 43 S. aureus isolates and in four of nine Streptococcus pneumoniae isolates. Conclusion: The most common predisposing risk factor for keratitis was contact lens wear. Among the most common microbes, not considered to be exclusively commensals, isolated from the cornea in microbial keratitis were S. aureus, Moraxella spp. and P. aeruginosa. The antibiotic susceptibility patterns showed low proportion of resistance. Empiric treatment of suspected infectious keratitis with topical fluoroquinolones and chloramphenicol might be considered in a setting like ours pending culture results.