Departamento de Microbiología y Proteómica Ocular, Instituto de Oftalmología "Fundación de Asistencia Privada Conde de Valenciana", Mexico City, Mexico; Programa de Posgrado en Biomedicina y Biotecnología Molecular, Departamento de Microbiología, Escuela Nacional de Ciencias Biológicas, Instituto Politécnico Nacional, Mexico City, Mexico.
Departamento de Microbiología y Proteómica Ocular, Instituto de Oftalmología "Fundación de Asistencia Privada Conde de Valenciana", Mexico City, Mexico; Programa de Doctorado en Ciencias Biológicas y la Salud, Universidad Autónoma Metropolitana, Mexico City, Mexico.
Microb Pathog. 2020 Mar;140:103953. doi: 10.1016/j.micpath.2019.103953. Epub 2020 Jan 2.
To report the characterization and analysis of the biofilm formation in mixed keratitis induced by the coinfection of Staphylococcus aureus and Fusarium falciforme in a novel murine model.
Clinical ocular microbial isolates and female BALB/c mice were used to develop the murine model. Immunosuppression was achieved with cyclophosphamide and methylprednisolone. A corneoscleral lesion was performed with a micro-pocket technique. Mice received an inoculum with a concentration of 1 × 10 conidia of F. falciforme and S. aureus with 1 × 10 UFC/ml. Mice were sacrificed at 72 h after induction of infection, the right eye was enucleated and preserved in 10% formaldehyde to perform the PAS staining. In addition, cuts were obtained for the labeling with the fluorophores propidium iodide and Calcofluor White, and other eye cuts were processed to transmission microscopy.
F. falciforme and S. aureus were able to developed mono and mixed biofilm in vitro. Keratitis of F. falciforme, S. aureus and mixed, were established at immunosuppressed mice. Clinical symptoms were observed at murine cornea. Histological analysis by special stains identified bacterial, fungal and mixed biofilm structures at epithelial and stromal level. Extracellular matrix was observed surrounded clusters of bacterial, fungi and mixed by fluorescence and transmission electronic microscopy.
This study provides direct evidence of the establishment and formation of mixed biofilm in vitro, as well as in vivo on the corneal surface of mice in an experimentally induced S. aureus and F. falciforme mixed keratitis infection.
报告金黄色葡萄球菌和弯孢镰刀菌混合感染诱导的混合角膜炎生物膜形成的特征和分析，建立一个新型的小鼠模型。
临床眼部微生物分离株和雌性 BALB/c 小鼠被用于开发该小鼠模型。环磷酰胺和甲基强的松龙用于免疫抑制。使用微囊技术进行角膜巩膜病变。小鼠接种浓度为 1×10 个分生孢子的弯孢镰刀菌和 1×10 UFC/ml 的金黄色葡萄球菌。感染诱导后 72 小时处死小鼠，右眼眼球被切除并保存在 10%甲醛中进行 PAS 染色。此外，还获得了用荧光染料碘化丙啶和 Calcofluor White 进行标记的切片，并对其他眼部切片进行了透射显微镜处理。
弯孢镰刀菌和金黄色葡萄球菌能够在体外形成单和混合生物膜。在免疫抑制小鼠中建立了弯孢镰刀菌、金黄色葡萄球菌和混合角膜炎。在小鼠角膜上观察到临床症状。特殊染色的组织学分析在上皮和基质水平上鉴定了细菌、真菌和混合生物膜结构。荧光和透射电子显微镜观察到细胞外基质环绕着细菌、真菌和混合的簇。
本研究提供了金黄色葡萄球菌和弯孢镰刀菌混合感染诱导的混合生物膜在体外和体内（在实验诱导的金黄色葡萄球菌和弯孢镰刀菌混合角膜炎感染的小鼠角膜表面）形成的直接证据。
