Abstract
Purpose:
Effective initial treatment is of great importance in patients with infectious keratitis, since if inadequately treated the duration of the disease might be prolonged and the visual outcome potentially severely decreased. Optimal empiric antibiotic therapy requires knowledge of the current bacterial spectrum and susceptibility of these bacteria to the antibiotics in use. We thus analyzed the data from the last 10 years at our clinic.<br /> <br />
Methods:
All ocular surface specimens worked up in the medical microbiology department of the University Düsseldorf between 2005 and 2014 were analyzed. Special attention was paid to resistance to antibiotics relevant in ophthalmology and the possible change in both bacterial spectrum and resistance profile over the study period. Statistical analysis was performed with SPSS 21.0 applying non-parametric tests (level of significance: p ≦ 0,05)<br /> <br />
Results:
Over the 10 year period the number of swabs increased significantly. In total, 430 of 2897 collected specimens from 1913 patients showed a positive culture result (14.8 %). Gram-positive species were found in 252 specimens, Gram-negative species in 145 specimens and fungi in 33 specimens. The most common organisms were: Staphylococcus aureus (22 %), Pseudomonas spp. (14%), coagulase-negative Staphylococcus (14%) and Streptococcus spp. (10%). The resistance profile over the study period only changed for erythromycin from 2009 - 2010 (p=0.031).<br /> For the most frequently used antibiotics, the fluoroquinolones and aminoglycosides, a resistance rate of ~ 10 % was found. A combination of those 2 antibiotic agents yielded a resistance rate of ~ 5 % (gentamicin + levofloxacin: 4,6%; gentamicin + moxifloxacin: 5.8%).
Conclusions:
Our analysis revealed that the number of microbiological tests increased over the 10 year period, which underlines the growing importance of quality assurance and evidence-based targeted therapy. The bacterial spectrum in ocular surface swabs in the University eye clinic Düsseldorf is similar to the spectrum reported in other comparable centers. Before determination of the pathogen a combination of aminoglycosides and fluoriquinolone seems to be the most effective for the initial therapy in suspected bacterial ocular surface infection.