Department of Ophthalmology, Institute of Health Biosciences, University of Tokushima Graduate School, 3-18-15 Kuramoto-cho, Tokushima, Tokushima 770-8503, Japan.
J Infect Chemother. 2009 Oct;15(5):279-83. doi: 10.1007/s10156-009-0708-6. Epub 2009 Oct 24.
The purpose of this study was to investigate an experimental model of methicillin-resistant Staphylococcus aureus (MRSA) keratitis, and to evaluate the inhibitory effect of vancomycin ointment on the manifestation of keratitis in this model. For the development of the MRSA keratitis model, 16 rabbits received 0.3-ml intrastromal injections of 1 x 10(7) colony forming units/ml MRSA inoculated to each of their corneas. After the MRSA inoculation, the rabbits were examined for a period of 14 days. Vehicle only was applied to each left eye for 2 days as an experimental control. Prototype vancomycin ointments, at concentrations of 0.03%, 0.1%, 0.3%, and 1.0%, were applied to each right eye for 2 days. The treatment commenced immediately after the MRSA inoculation and was administered five times a day at 2-h intervals. Four rabbits were used for each vancomycin ointment concentration. Anterior segments were examined daily, and the minimum inhibitory concentration of vancomycin (percentage in the ointment) for treating MRSA keratitis was determined on day 2. On day 14, no recurrences of infection were observed in the eyes that had not exhibited keratitis on day 2. Forty-eight hours post-inoculation, all left eyes demonstrated severe conjunctivitis, stromal infiltrates at injection sites, and fibroid reactions in the anterior chamber. MRSA keratitis was completely inhibited by 0.3% and 1.0% vancomycin ointments. Although the 0.1% ointment generally could prevent keratitis, punctate infiltrates were found in some eyes. Numerous infiltrates were found in eyes treated with 0.03% ointment. In conclusion, the present study substantiates the view that vancomycin ointment has a potent inhibitory effect upon the manifestations of MRSA keratitis, and indicates that a 0.3% concentration is necessary for effective treatment.
本研究旨在探讨耐甲氧西林金黄色葡萄球菌（MRSA）角膜炎的实验模型，并评估万古霉素眼膏对该模型中角膜炎表现的抑制作用。为了建立 MRSA 角膜炎模型，16 只兔子的每只角膜中均注射 0.3ml 浓度为 1×10(7)菌落形成单位/ml 的 MRSA 菌液。MRSA 接种后，对兔子进行了 14 天的观察。每只左眼仅应用载体 2 天作为实验对照。将浓度为 0.03%、0.1%、0.3%和 1.0%的万古霉素眼膏分别应用于每只右眼 2 天。治疗在 MRSA 接种后立即开始，每天 5 次，每 2 小时一次。每种万古霉素眼膏浓度各用 4 只兔子。每天检查眼前段，在第 2 天确定治疗 MRSA 角膜炎的万古霉素最小抑菌浓度（眼膏中的百分比）。第 14 天，在第 2 天未发生角膜炎的眼睛中未观察到感染复发。接种后 48 小时，所有左眼均表现出严重的结膜炎、注射部位的基质浸润和前房的纤维瘤反应。0.3%和 1.0%的万古霉素眼膏完全抑制了 MRSA 角膜炎。虽然 0.1%的眼膏通常可以预防角膜炎，但在一些眼中发现了点状浸润。在使用 0.03%眼膏治疗的眼中发现了大量的浸润。总之，本研究证实了万古霉素眼膏对 MRSA 角膜炎表现具有很强的抑制作用，并表明 0.3%的浓度是有效治疗所必需的。
