Bacterial 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. cereus incites the intraocular inflammatory response, likely through interactions with innate immune receptors such as TLRs. This study analyzed the role of B. cereus pili, adhesion appendages located on the bacterial surface, in experimental endophthalmitis. To test the hypothesis that the presence of pili contributed to intraocular inflammation and virulence, we analyzed the progress of experimental endophthalmitis in mouse eyes infected with wild type B. cereus (ATCC 14579) or its isogenic pilus-deficient mutant (ΔbcpA-srtD-bcpB or ΔPil). One hundred CFU were injected into the mid-vitreous of one eye of each mouse. Infections were analyzed by quantifying intraocular bacilli and retinal function loss, and by histology from 0 to 12 h postinfection. In vitro growth and hemolytic phenotypes of the infecting strains were also compared. There was no difference in hemolytic activity (1:8 titer), motility, or in vitro growth (p > 0.05, every 2 h, 0-18 h) between wild type B. cereus and the ΔPil mutant. However, infected eyes contained greater numbers of wild type B. cereus than ΔPil during the infection course (p ≤ 0.05, 3-12 h). Eyes infected with wild type B. cereus experienced greater losses in retinal function than eyes infected with the ΔPil mutant, but the differences were not always significant. Eyes infected with ΔPil or wild type B. cereus achieved similar degrees of severe inflammation. The results indicated that the intraocular growth of pilus-deficient B. cereus may have been better controlled, leading to a trend of greater retinal function in eyes infected with the pilus-deficient strain. Although this difference was not enough to significantly alter the severity of the inflammatory response, these results suggest a potential role for pili in protecting B. cereus from clearance during the early stages of endophthalmitis, which is a newly described virulence mechanism for this organism and this infection.
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http://dx.doi.org/10.1016/j.exer.2017.03.007 | DOI Listing |
Front Pharmacol
December 2024
Beijing Tongren Eye Center, Beijing Ophthalmology and Visual Science Key Lab, Beijing Tongren Hospital, Capital Medical University, Beijing, China.
Background: Corticosteroids are extensively used in ophthalmology, particularly for treating various inflammatory conditions. Despite their effectiveness, prolonged or high-dose corticosteroid use is associated with significant adverse drug reactions (ADRs), such as increased intraocular pressure, cataract formation, and secondary infections. However, there is currently no systematic study comparing the side effects of ophthalmic corticosteroids.
View Article and Find Full Text PDFFront Cell Infect Microbiol
December 2024
Department of Laboratory Medicine, Fudan University Eye Ear Nose and Throat Hospital, Shanghai, China.
Objective: Acute retinal necrosis (ARN) caused by varicella-zoster virus (VZV) is associated with changes in specific proteins in the eye's fluid, particularly matrix metalloproteinase-3 (MMP-3), an enzyme that breaks down tissue structures, and tissue inhibitor of metalloproteinase-1 (TIMP-1), which regulates MMP activity. This study aims to investigate how these proteins correlate with the progression of ARN.
Methods: We analyzed aqueous humor samples from 33 patients with ARN and 23 control patients with virus-negative uveitis.
J Family Med Prim Care
November 2024
Flinders University College of Medicine and Public Health, Adelaide, Australia.
Up to 10% of uveitis cases occur in children, with notable implications due to the risk of chronicity and vision loss. It can result from infections, autoimmune and autoinflammatory diseases, trauma, or masquerade syndromes. Primary care providers are vital in early detection, symptom management, and timely specialist referral.
View Article and Find Full Text PDFWorld J Virol
December 2024
Department of Ophthalmology, University Hospital of Udine, Udine 33100, Italy.
Background: Blepharoconjunctivitis poses a diagnostic challenge due to its diverse etiology, including viral infections. Blepharoconjunctivits can be acute or chronic, self-limiting, or needing medical therapy.
Aim: To review possible viral agents crucial for accurate differential diagnosis in cases of blepharoconjunctivitis.
Drug Des Devel Ther
December 2024
Department of Anesthesiology, Faculty of Medicine, University of Yamanashi, Chuo, Yamanashi, Japan.
Purpose: Corneal pain is one of the most common eye symptoms caused by various types of epithelial injuries, including traumatic abrasion, chemical injury, ulcers, ultraviolet exposure, and infection. However, current therapeutic options for corneal pain are limited. In this study, we synthesized a novel quaternary ammonium compound, N-propylamiodarone bromide (NPA), and employed a rodent model of corneal injury to investigate whether NPA offers prolonged corneal analgesia through transient receptor potential vanilloid 1 (TRPV1) channel-mediated selective cellular entry, without hindering corneal epithelial recovery.
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