Purpose: The purpose of this study was to explore the therapeutic potential of the novel combination of Bacillus bacteriophage lysin (PlyB) and a synthetic TLR2/4 inhibitor (oxidized 1-palmitoyl-2-arachidonoyl-sn-glycero-3-phosphocholine, OxPAPC) in the treatment of experimental Bacillus cereus endophthalmitis.
Methods: C57BL/6J mice were injected with 100 colony forming units (CFUs) Bacillus cereus to induce endophthalmitis. Two hours postinfection, groups of mice were treated with either PlyB, PlyB with OxPAPC, or the groups were left untreated to serve as a control.
Aging is a complex biological process that is characterized by low-grade inflammation, called inflammaging. Aging affects multiple organs including eye and lacrimal gland. Tumor necrosis factor (TNF) is a pleiotropic cytokine that participates in inflammation, activation of proteases such as cathepsin S, and formation of ectopic lymphoid organs.
View Article and Find Full Text PDFOcular infections can be medical emergencies that result in permanent visual impairment or blindness and loss of quality of life. Bacteria are a major cause of ocular infections. Effective treatment of ocular infections requires knowledge of which bacteria are the likely cause of the infection.
View Article and Find Full Text PDFBacteriophage lytic enzymes (i.e., phage lysins) are a trending alternative for general antibiotics to combat growing antimicrobial resistance.
View Article and Find Full Text PDFBacillus cereus (B. cereus) endophthalmitis is a vision-threatening bacterial infection. Uncontrolled inflammatory responses are the hallmark of this disease which cause irreversible damage to the retina.
View Article and Find Full Text PDFInvest Ophthalmol Vis Sci
November 2021
Purpose: The purpose of this study was to explore the C-X-C chemokines CXCL2 and CXCL10 as potential anti-inflammatory targets for Bacillus endophthalmitis.
Methods: Bacillus endophthalmitis was induced in C57BL/6J, CXCL2-/-, and CXCL10-/- mice. At specific times postinfection, eyes were analyzed for Bacillus, retinal function, and inflammation.
Endophthalmitis is a devastating infection that can cause blindness. Over half of endophthalmitis cases result in significant loss of useful vision. produces many virulence factors that may contribute to retinal damage and robust inflammation.
View Article and Find Full Text PDFIntraocular bacterial infections are a danger to the vision. Researchers use animal models to investigate the host and bacterial factors and immune response pathways associated with infection to identify viable therapeutic targets and to test drugs to prevent blindness. The intravitreal injection technique is used to inject organisms, drugs, or other substances directly into the vitreous cavity in the posterior segment of the eye.
View Article and Find Full Text PDFInvest Ophthalmol Vis Sci
November 2020
Purpose: To explore the consequences of innate interference on intraocular inflammatory responses during Bacillus endophthalmitis.
Methods: Bacillus endophthalmitis was induced in mice. Innate immune pathway activation was interfered by injecting S layer protein-deficient (∆slpA) B.
endophthalmitis is a severe intraocular infection. Hallmarks of endophthalmitis include robust inflammation and rapid loss of vision. We reported that the absence of surface layer protein (SLP) significantly blunted endophthalmitis severity.
View Article and Find Full Text PDFInvest Ophthalmol Vis Sci
September 2019
Purpose: Bacillus causes a sight-threating infection of the posterior segment of the eye. The robust intraocular inflammatory response in this disease is likely activated via host innate receptor interactions with components of the Bacillus cell envelope. S-layer proteins (SLPs) of some Gram-positive pathogens contribute to the pathogenesis of certain infections.
View Article and Find Full Text PDFBacterial endophthalmitis is a potentially blinding intraocular infection. The bacterium Bacillus cereus causes a devastating form of this disease which progresses rapidly, resulting in significant inflammation and loss of vision within a few days. The outer surface of B.
View Article and Find Full Text PDFDuring intraocular bacterial infections, the primary innate responders are neutrophils, which may cause bystander damage to the retina or perturb the clarity of the visual axis. We hypothesized that cytokine IL-6 and chemokine CXCL1 contributed to rapid neutrophil recruitment during Bacillus cereus endophthalmitis, a severe form of intraocular infection that is characterized by explosive inflammation and retinal damage that often leads to rapid vision loss. To test this hypothesis, we compared endophthalmitis pathogenesis in C57BL/6J, IL-6, and CXCL1 mice.
View Article and Find Full Text PDFThe blood-retinal barrier (BRB) functions to maintain the immune privilege of the eye, which is necessary for normal vision. The outer BRB is formed by tightly-associated retinal pigment epithelial (RPE) cells which limit transport within the retinal environment, maintaining retinal function and viability. Retinal microvascular complications and RPE dysfunction resulting from diabetes and diabetic retinopathy cause permeability changes in the BRB that compromise barrier function.
View Article and Find Full Text PDFPurpose: To report a case of polymicrobial keratitis caused by and coagulase-negative in a patient who cleaned their extended wear contact lenses with only tap water for 2 weeks.
Methods: Case report.
Results: An adult presented with a painful red eye after wearing the same contact lenses for two weeks.
Bacterial endophthalmitis is an infection and inflammation of the posterior segment of the eye which can result in significant loss of visual acuity. Even with prompt antibiotic, anti-inflammatory and surgical intervention, vision and even the eye itself may be lost. For the past century, experimental animal models have been used to examine various aspects of the pathogenesis and pathophysiology of bacterial endophthalmitis, to further the development of anti-inflammatory treatment strategies, and to evaluate the pharmacokinetics and efficacies of antibiotics.
View Article and Find Full Text PDFInvest Ophthalmol Vis Sci
November 2015
Purpose: To test the hypothesis that blood-retinal barrier compromise is associated with the development of endogenous Staphylococcus aureus endophthalmitis.
Methods: To compromise the blood-retinal barrier in vivo, streptozotocin-induced diabetes was induced in C57BL/6J mice for 1, 3, or 5 months. Diabetic and age-matched nondiabetic mice were intravenously injected with 108 colony-forming units (cfu) of S.
Inflammation caused by infection with Gram-positive bacteria is typically initiated by interactions with Toll-like receptor 2 (TLR2). Endophthalmitis, an infection and inflammation of the posterior segment of the eye, can lead to vision loss when initiated by a virulent microbial pathogen. Endophthalmitis caused by Bacillus cereus develops as acute inflammation with infiltrating neutrophils, and vision loss is potentially catastrophic.
View Article and Find Full Text PDFB. cereus possesses flagella which allow the organism to migrate within the eye during a blinding form of intraocular infection called endophthalmitis. Because flagella is a ligand for Toll-like receptor 5 (TLR5), we hypothesized that TLR5 contributed to endophthalmitis pathogenesis.
View Article and Find Full Text PDFPurpose/aim: Klebsiella pneumoniae causes a blinding infection called endogenous endophthalmitis. The role of innate immune recognition of K. pneumoniae in the eye during infection is not known.
View Article and Find Full Text PDFBacillus cereus causes a uniquely rapid and blinding intraocular infection, endophthalmitis. B. cereus replicates in the eye, synthesizes numerous toxins, and incites explosive intraocular inflammation.
View Article and Find Full Text PDFPurpose: The purpose of this study was to determine to what extent blood-retinal barrier (BRB) permeability occurred during experimental Bacillus cereus endophthalmitis and whether tight junction alterations were involved in permeability.
Methods: Mice were intravitreally injected with 100 colony-forming units of B. cereus, and eyes were analyzed at specific times after infection for permeability to fibrin and albumin, quantitation of intraocular plasma constituent leakage, production of inflammatory cytokines, and alterations in tight junction protein localization and expression at the level of the retinal pigment epithelium.
Purpose: To define the histopathology of Salzmann nodular degeneration and suggest potential mechanisms involved in its pathogenesis.
Methods: Archived corneal biopsy specimens from 5 patients with Salzmann nodular degeneration were evaluated by chemical and immunohistochemical staining to describe the structure of the Salzmann nodules and phenotypes of nodule epithelium and stromal cells.
Results: Each Salzmann nodule appeared as a hypercellular mound of extracellular matrix located between a thinned corneal epithelium and a fragmented Bowman layer.
We report for the first time, the detection of conjunctival lymphoid follicles (CLF) in the eyes of New World rodents. CLF were found in 7 of the 15 species examined, 6 of the 10 genera, and in at least one individual in four families of rodents. These follicles are dense collections of leukocytes in the conjunctival substantia propria with a thinned overlying epithelium lacking in goblet cells.
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