Comparison of the effect of teicoplanin and vancomycin on experimental methicillin-resistant staphylococcus aureus keratitis.

Abstract

To evaluate the early efficacy and safety of intrastromal injection of teicoplanin as the alternative treatment for the methicillin-resistant Staphylococcus aureus (MRSA) keratitis by comparing it with vancomycin. Twenty-four eyes of 24 New Zealand white rabbits were included in the study. MRSA keratitis was induced in the right eye of each rabbit by injecting 0.1mL MRSA suspension containing 1000 colony-forming units (CFU) intrastromally to the central cornea. The rabbits were divided into three treatment groups 24h after the inoculation of MRSA. Eight rabbits received intrastromal teicoplanin therapy, eight received intrastromal vancomycin therapy, and eight received balanced salt solution and served as the control group. Nine hours after the treatment, all rabbits were sacrificed and corneal tissues were collected for microbiological analysis. We also examined and scored all the rabbits clinically before and after the treatment. The control group scored higher with regard to conjunctival injection, iritis, fibrin, hypopyon, epithelial erosion, and corneal infiltrate than the vancomycin and teicoplanin groups (p = 0.031, 0.010, < 0.001, 0.029, 0.009, and < 0.001, respectively). Chemosis and corneal oedema were similar in all groups (p = 0.731 and 0.075, respectively). The severity of all clinical parameters was similar in both the vancomycin and teicoplanin groups after the treatment. The bacterial load was the highest (7.83 ± 0.71 log10CFU/g) in the control group. The eyes treated with vancomycin and teicoplanin had similar bacterial loads (6.40 ± 0.69 vs. 6.31 ± 0.75 log10CFU/g, p = 0.809). The efficiency of teicoplanin seems to be comparable to that of vancomycin when administered intrastromally in the early treatment of MRSA keratitis. The former may be preferred in the treatment of selected cases with vancomycin hypersensitivity or resistance.