Turicea Bactelius, Sahoo Dipak K, Allbaugh Rachel A, Stinman Chloe C, Kubai Melissa A
Department of Veterinary Clinical Sciences, College of Veterinary Medicine, Iowa State University, Ames, Iowa, USA.
Veterinary Diagnostic Laboratory, Iowa State University, Ames, Iowa, USA.
Vet Ophthalmol. 2024 Aug 8. doi: 10.1111/vop.13265.
To investigate the therapeutic effect of 275 nm wavelength ultraviolet C (UV-C) light for treatment of bacterial keratitis in canine corneas using an affordable, broadly available modified handheld device.
UV-C therapy (UVCT) was evaluated in two experiments: in vitro using triplicates of three bacterial genera (Staphylococcus, Streptococcus, Pseudomonas spp., and a mix of all species) where the UVCT was performed at a distance of 10, 15, and 20 mm with 1 or 2 doses (4 h apart) for 5, 15, or 30 s; ex vivo model where healthy canine corneal buttons were inoculated superficially and deep (330 μm) with the same bacterial isolates and treated at a 10 mm distance for 15 s with one dose of 22.5 mJ/cm. Fluorescent marker (STYO9-PI) was used to label (green = live bacteria, red = dead bacteria), and confocal microscopy was used to image the bacteria.
In vitro results showed all plates treated with UVCT had 100% bactericidal effect for all isolates with single dose of 15 s at 10 mm distance or two doses, 4 h apart at 15 mm and was ineffective with single dose at 15-20 mm. The ex vivo results confirmed a significant decrease in bacterial load for all isolates on samples inoculated superficially but were inconclusive for intrastromal ones.
UVCT confirmed the therapeutic potential for all tested isolates, for both in vitro and ex vivo experiments using a single exposure of 15 s. While safety studies are underway, clinical trials are warranted.
使用一种价格低廉、广泛可得的改良手持设备，研究275纳米波长的紫外线C（UV-C）光治疗犬角膜细菌性角膜炎的疗效。
在两项实验中评估UV-C疗法（UVCT）：体外实验，使用三种细菌属（葡萄球菌、链球菌、假单胞菌属以及所有物种的混合物）的三份重复样本，在距离为10、15和20毫米处进行UVCT，给予1或2剂（间隔4小时），持续5、15或30秒；体外模型，将健康犬角膜纽扣分别进行浅层和深层（330微米）接种相同的细菌分离株，在距离10毫米处给予一剂22.5毫焦/平方厘米的剂量，治疗15秒。使用荧光标记物（STYO9-PI）进行标记（绿色=活细菌，红色=死细菌），并使用共聚焦显微镜对细菌进行成像。
体外实验结果显示，所有接受UVCT治疗的平板，对于所有分离株，在距离10毫米处单次给予15秒剂量或在距离15毫米处给予两剂、间隔4小时的情况下，均有100%的杀菌效果，而在距离15 - 20毫米处单次给药则无效。体外实验结果证实，对于浅层接种样本中的所有分离株，细菌载量显著降低，但对于基质内接种的样本结果尚无定论。
UVCT证实了在体外和体外实验中，对于所有测试分离株，单次暴露15秒均具有治疗潜力。虽然正在进行安全性研究，但仍有必要开展临床试验。
