Department of Microbiology, University of Mississippi Medical Center, Jackson, MS 39216, USA.
BMC Ophthalmol. 2013 Mar 11;13:8. doi: 10.1186/1471-2415-13-8.
Capsule and pneumolysin (PLY) are two major virulence factors of Streptococcus pneumoniae. S. pneumoniae is one of the leading causes of bacterial endophthalmitis. The aim of this study is to determine whether passive immunization with the 23-valent pneumococcal polysaccharide vaccine (Pneumovax® 23; PPSV23) or PLY protects against pneumococcal endophthalmitis.
New Zealand white rabbits were passively immunized with antiserum to PLY, PPSV23, a mixture of PPSV23/PLY, or PBS (mock). Vitreous was infected with a clinical strain of S. pneumoniae. In a separate group of experiments, vancomycin was injected 4 hours post-infection (PI) for each passively immunized group. Severity of infection, bacterial recovery, myeloperoxidase (MPO) activity and percent loss of retinal function were determined.
Passive immunization with each antiserum significantly lowered clinical severity compared to mock immunization (PPSV23 = 9.19, PPSV23/PLY = 10.45, PLY = 8.71, Mock = 16.83; P = 0.0467). A significantly higher bacterial load was recovered from the vitreous of PLY passively immunized rabbits 24 hours PI (7.87 log10 CFU) compared to controls (7.10 log10 CFU; P = 0.0134). Retinas from immunized rabbits were more intact. Vitreous of PLY (2.88 MPO untis/mL) and PPSV23/PLY (2.17) passively immunized rabbits had less MPO activity compared to controls (5.64; P = 0.0480), and both passive immunizations (PLY = 31.34% loss of retinal function, PPSV23/PLY = 27.44%) helped to significantly preserve retinal function compared to controls (64.58%; P = 0.0323). When vancomycin was administered 4 hours PI, all eyes were sterile at 24 hours PI. A significantly lower clinical severity was observed for rabbits administered the combination immunization (5.29) or PPSV23 (5.29) with vancomycin treatment compared to controls (17.68; P = 0.0469).
Passive immunization with antisera to these antigens is effective in reducing clinical severity of pneumococcal endophthalmitis in rabbits. Addition of vancomycin to immunization is effective at eliminating the bacteria.
胶囊和肺炎球菌溶血素（PLY）是肺炎链球菌的两种主要毒力因子。肺炎链球菌是细菌性眼内炎的主要病因之一。本研究旨在确定 23 价肺炎球菌多糖疫苗（Pneumovax®23；PPSV23）或 PLY 的被动免疫是否能预防肺炎球菌性眼内炎。
新西兰白兔用 PLY、PPSV23、PPSV23/PLY 混合物或 PBS（对照）抗血清被动免疫。玻璃体感染临床分离的肺炎链球菌。在另一组实验中，每组在感染后 4 小时注射万古霉素。通过比较临床严重程度、细菌回收率、髓过氧化物酶（MPO）活性和视网膜功能丧失率来评估感染严重程度。
与对照相比，用每种抗血清进行被动免疫均可显著降低临床严重程度（PPSV23=9.19，PPSV23/PLY=10.45，PLY=8.71，对照=16.83；P=0.0467）。与对照相比，24 小时时 PLY 被动免疫兔的玻璃体中细菌负荷显著增加（7.87 log10 CFU）（7.10 log10 CFU；P=0.0134）。免疫兔的视网膜更完整。与对照相比，PLY（2.88 MPO 单位/mL）和 PPSV23/PLY（2.17）被动免疫兔的玻璃体 MPO 活性较低（5.64；P=0.0480），两种被动免疫（PLY=31.34%视网膜功能丧失，PPSV23/PLY=27.44%）与对照相比，显著有助于保留视网膜功能（64.58%；P=0.0323）。当万古霉素在感染后 4 小时给药时，所有眼在 24 小时时均无菌。与对照相比，联合免疫（5.29）或 PPSV23（5.29）加万古霉素治疗的兔子的临床严重程度显著降低（17.68；P=0.0469）。
针对这些抗原的抗血清被动免疫可有效降低兔细菌性眼内炎的临床严重程度。免疫接种中加入万古霉素可有效清除细菌。
