From the Departments of Clinical Sciences and Biomedical Sciences, Cornell University, Ithaca, New York, USA.
College of Veterinary Medicine, Cornell University, Ithaca, New York, USA.
Vet Ophthalmol. 2023 May;26(3):211-218. doi: 10.1111/vop.13077. Epub 2023 Feb 25.
To describe the clinical features of dogs with Nocardia and Streptomyces keratitis, including the results of in vivo confocal microscopy examinations.
A 15-year-old, male-castrated, miniature Schnauzer was presented with a multilobulated, cystic, pink, ulcerated corneal mass with surrounding dense leukocyte infiltrates. Cytologic evaluation of a corneal scraping identified pyogranulomatous inflammation and filamentous bacteria. Nocardia nova was cultured from corneal samples. Anterior lamellar keratectomy was performed to excise the affected corneal region and histopathologic evaluation confirmed the diagnosis of pyogranulomatous keratitis. A 10-year-old, male-castrated, Yorkshire terrier was presented for evaluation of a chronic anterior stromal corneal ulcer associated with a brown corneal plaque. Cytologic evaluation of a corneal scraping identified suppurative inflammation and filamentous bacteria. A Streptomyces sp. was cultured from corneal samples. The keratitis in both dogs resolved with therapy.
In vivo confocal microscopy examination of the corneal lesions in both dogs revealed dense accumulations of leukocytes and clusters of hyperreflective, slender, branching bacterial structures that were approximately 1.5-2.0 μm in diameter and 25-50 μm in length. Confocal microscopy imaging of the Nocardia isolate in vitro, and ex vivo canine corneas experimentally infected with the bacteria, was performed to corroborate the in vivo findings. The morphology of the filamentous bacteria was similar between the in vivo, in vitro, and ex vivo confocal microscopy examinations.
Nocardia and Streptomyces spp. can be associated with infectious keratitis in dogs. In vivo detection of filamentous bacteria in the cornea can be accomplished by confocal microscopy.
描述患有诺卡氏菌和链霉菌角膜炎的犬的临床特征，包括体内共聚焦显微镜检查的结果。
一只 15 岁的雄性去势迷你雪纳瑞犬出现多叶状、囊性、粉红色、溃疡性角膜肿块，伴有周围密集的白细胞浸润。角膜刮片的细胞学评估发现化脓性炎症和丝状细菌。从角膜样本中培养出新星诺卡氏菌。进行前板层角膜切除术切除受影响的角膜区域，组织病理学评估证实了化脓性角膜炎的诊断。一只 10 岁的雄性去势约克夏梗犬因慢性前基质角膜溃疡伴棕色角膜斑块就诊。角膜刮片的细胞学评估发现化脓性炎症和丝状细菌。从角膜样本中培养出链霉菌属。两只犬的角膜炎均通过治疗得到缓解。
对两只犬的角膜病变进行体内共聚焦显微镜检查，发现白细胞密集堆积，并出现簇状高反射性、纤细、分支状细菌结构，直径约为 1.5-2.0μm，长度为 25-50μm。对体外分离的诺卡氏菌和体内感染该菌的实验性犬角膜进行共聚焦显微镜成像，以证实体内发现。体内、体外和体外共聚焦显微镜检查中，丝状细菌的形态相似。
诺卡氏菌和链霉菌属可引起犬的感染性角膜炎。共聚焦显微镜可在体内检测到角膜中的丝状细菌。
