Department of Ophthalmology, University of Texas Southwestern Medical Center, Dallas, Texas 75390-9057, USA.
Invest Ophthalmol Vis Sci. 2011 Apr 27;52(5):2844-50. doi: 10.1167/iovs.10-6469. Print 2011 Apr.
To evaluate the capacity of neutrophils to enhance biofilm formation on contact lenses by an infectious Pseudomonas aeruginosa (PA) corneal isolate. Agents that target F-actin and DNA were tested as a therapeutic strategy for disrupting biofilms formed in the setting of neutrophils in vitro and for limiting the infectious bioburden in vivo.
Biofilm formation by infectious PA strain 6294 was assessed in the presence of neutrophils on a static biofilm plate and on unworn etafilcon A soft contact lenses. A d-isomer of poly(aspartic acid) was used alone and with DNase to reduce biofilm formation on test contact lenses. The gentamicin survival assay was used to determine the effectiveness of the test compound in reducing subsequent intracellular bacterial load in the corneal epithelium in a contact lens infection model in the rabbit.
In a static reactor and on hydrogel lenses, PA biofilm density was enhanced 30-fold at 24 hours in the presence of neutrophils (P < 0.0001). The combination of DNase and anionic poly(aspartic acid) reduced the PA biofilms formed in the presence of activated neutrophils by 79.2% on hydrogel contact lenses (P < 0.001). An identical treatment resulted in a 41% reduction in internalized PA in the rabbit corneal epithelium after 24 hours (P = 0.03).
These results demonstrate that PA can exploit the presence of neutrophils to form biofilm on contact lenses within a short time. Incorporation of F-actin and DNA represent a mechanism for neutrophil-induced biofilm enhancement and are targets for available agents to disrupt pathogenic biofilms formed on contact lenses and as a treatment for established corneal infections.
评估中性粒细胞增强接触镜上传染性绿脓假单胞菌（PA）生物膜形成的能力。测试靶向 F-肌动蛋白和 DNA 的药物作为一种治疗策略，用于破坏体外中性粒细胞环境中形成的生物膜，并限制体内感染性生物负荷。
在静态生物膜板和未佩戴的亲水软性隐形眼镜上，评估感染性 PA 株 6294 形成生物膜的能力。单独使用和与 DNA 酶一起使用 d-异构体聚天冬氨酸来减少测试隐形眼镜上的生物膜形成。庆大霉素存活试验用于确定测试化合物在兔接触镜感染模型中减少角膜上皮内随后的细胞内细菌负荷的有效性。
在静态反应器中和水凝胶镜片上，中性粒细胞存在时，PA 生物膜密度在 24 小时内增强了 30 倍（P <0.0001）。DNA 酶和阴离子聚天冬氨酸的组合使在激活的中性粒细胞存在下形成的 PA 生物膜在水凝胶隐形眼镜上减少了 79.2%（P <0.001）。相同的处理导致兔角膜上皮内内化的 PA 在 24 小时后减少了 41%（P = 0.03）。
这些结果表明，PA 可以利用中性粒细胞在短时间内形成接触镜上的生物膜。F-肌动蛋白和 DNA 的结合代表了中性粒细胞诱导生物膜增强的一种机制，并且是现有药物破坏形成在接触镜上的致病性生物膜和治疗已建立的角膜感染的靶点。
