Department of Ophthalmology, The University of Texas Southwestern Medical Center, Dallas, TX, USA.
Sci Rep. 2017 Apr 11;7:46116. doi: 10.1038/srep46116.
Pseudomonas aeruginosa is a pathogenic gram-negative organism that has the ability to cause blinding corneal infections following trauma and during contact lens wear. In this study, we investigated the directional movement and orientation of an invasive corneal isolate of P. aeruginosa in the corneal stroma during infection of ex vivo and in vivo rabbit corneas using multiphoton fluorescence and second harmonic generation (SHG) imaging. Ex vivo, rabbit corneas were subject to three partial thickness wounds prior to inoculation. In vivo, New Zealand white rabbits were fit with P. aeruginosa laden contact lenses in the absence of a penetrating wound. At all time points tested, infiltration of the corneal stroma by P. aeruginosa revealed a high degree of alignment between the bacteria and collagen lamellae ex vivo (p < 0.001). In vivo, P. aeruginosa traveled throughout the stroma in discrete regions or bands. Within each region, the bacteria showed good alignment with collagen lamellae (P = 0.002). Interestingly, in both the in vitro and in vivo models, P. aeruginosa did not appear to cross the corneal limbus. Taken together, our findings suggest that P. aeruginosa exploits the precise spacing of collagen lamellae in the central cornea to facilitate spread throughout the stroma.
铜绿假单胞菌是一种致病性革兰氏阴性菌，在创伤后和佩戴隐形眼镜时，具有引起致盲性角膜感染的能力。在这项研究中，我们使用多光子荧光和二次谐波产生（SHG）成像技术，研究了一种侵袭性角膜分离株铜绿假单胞菌在感染离体和体内兔角膜时在角膜基质中的定向运动和取向。离体时，在接种前，兔角膜经历了三个部分厚度的伤口。在体内，新西兰白兔在没有穿透性伤口的情况下佩戴载有铜绿假单胞菌的隐形眼镜。在所有测试的时间点，铜绿假单胞菌渗透到角膜基质中，显示出细菌与胶原板层之间高度的排列一致性（p < 0.001）。在体内，铜绿假单胞菌在离散区域或带中贯穿整个基质。在每个区域内，细菌与胶原板层排列良好（P = 0.002）。有趣的是，在体外和体内模型中，铜绿假单胞菌似乎都没有穿过角膜缘。总之，我们的发现表明，铜绿假单胞菌利用中央角膜中胶原板层的精确间距来促进其在基质中的传播。
