Pathogenesis of gram-positive bacterial endophthalmitis
Pathogenesis of gram-positive bacterial endophthalmitis
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DOI：
10.1128/iai.67.7.3348-3356.1999
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发表时间：
1999-07-01
影响因子：
3.1
通讯作者：
Gilmore, MS
中科院分区：
文献类型：
--
作者：
Callegan, MC;Booth, MC;Gilmore, MS
眼内炎的严重程度通常与致病病原体的毒力有关。然而，究竟是什么构成了眼内感染的毒力仍然不明确。因此，我们试图确定三种常见眼部病原体（蜡状芽孢杆菌、粪肠球菌和金黄色葡萄球菌）的毒力基础，包括眼内生长速率、细菌定位模式以及细胞指甲和分泌产物对眼内炎发病机制的贡献。兔眼玻璃体内注射（ii）活B。蜡样E.粪球菌或S.金黄色葡萄球菌，（ii）代谢无活性的B。cereus、蜡状假单胞菌E. faecalis或S.金黄色葡萄球菌，（iii）来自每种菌株的球囊制备物，或（iv）含有由每种菌株分泌的产物的培养液。在注射后的不同时间，通过裂隙灯生物显微镜、视网膜电图ERG、细菌和炎性细胞计数以及组织学对眼睛进行评估。B、蜡样芽胞杆菌眼内炎病程较E. faecalis或S.金黄色葡萄球菌性眼内炎，消除视网膜反应，如通过ERG测量的，到12小时。细菌定位分析表明，B.在感染过程中，蜡样细胞从后节迅速迁移到前段。尽管注射代谢不活跃的细菌和细胞壁球囊都不会对ERG产生很大影响，但观察到了显著的眼内炎症。注射B。cereus或S. Aurens培养液引起视网膜反应性的显著降低和显著的眼内炎症，与在自然感染中所见的相似。结果表明，毒素，眼内定位，以及在较小程度上，眼内宿主对细胞壁的反应都有助于B的发病机制。cereus，S.金黄色葡萄球菌和E.粪菌性眼内炎的病原体特异性的方式。这些眼内疾病的关键病理生理学差异突出了优化传统疗法和开发新疗法的机会。
The severity of endophthalmitis has been associated generally with the virulence of the offending pathogen. However, precisely what constitutes the virulence in intraocular infections remains ill defined. We therefore sought to identify the basis for virulence for three common ocular pathogens (Bacillus cereus, Enterococcus faecalis, and Staphylococcus aureus) in terms ofintraocular growth rates, bacterial localization patterns, and the contribution of cell nails and secreted products to the pathogenesis of endophthalmitis. Rabbit eyes were injected intravitreally with (ii) viable B. cereus, E. faecalis, or S. aureus, (ii) metabolically inactive B. cereus, E. faecalis, or S. aurens, (iii) sacculus preparations from each strain, or (iv) culture fluid containing products secreted by each strain. Eyes were assessed at various times following injection by slit lamp biomicroscopy, electroretinography ERG, bacterial and inflammatory cell enumeration, and histology. B, cereus endophthalmitis followed a more rapid and virulent course than E. faecalis or S. aureus endophthalmitis, eliminating retinal responsiveness, as measured by ERG, by 12 h. Analysis of bacterial localization revealed that B. cereus uniquely migrated rapidly from posterior to anterior segment during infection. Although injection of neither metabolically inactive bacteria nor cell wall sacculi greatly affected ERG, significant intraocular inflammation was observed. Injection of B. cereus or S. aurens culture fluids caused both significant reductions in retinal responsiveness and significant intraocular inflammation, paralleling that seen in natural infections. The results demonstrate that toxins, intraocular localization, and, to a lesser extent, the intraocular host response to cell walls all contribute to the pathogenesis of B. cereus, S. aureus, and E. faecalis endophthalmitis in a pathogen-specific manner. The key pathophysiologic differences in these intraocular diseases highlight opportunities for optimizing conventional therapies and deriving new ones.