Front Cell Infect Microbiol
December 2023
Introduction: causes vision threatening keratitis. The transcription factor regulates virulence factors in response to the quorum sensing molecule N-3-oxo-dodecanoyl-L-homoserine lactone. isolates with mutations are characterized by an iridescent high sheen phenotype caused by a build-up of 2-heptyl-4-quinolone.
View Article and Find Full Text PDFcauses severe vision threatening keratitis. LasR is a transcription factor that regulates virulence associated genes in response to the quorum sensing molecule N-3-oxo-dodecanoyl-L-homoserine lactone. isolates with mutations are characterized by an iridescent high sheen phenotype caused by a build-up of 2-heptyl-4-quinolone.
View Article and Find Full Text PDFBiologics are almost exclusively administered systemically, but localized delivery is preferable as it minimizes off-target exposure and allows more aggressive treatments. Topical application of biologics to epithelia is generally ineffective because most are covered with fluids and biologics are washed out too quickly to have significant therapeutic effects. Here we explore the idea that attaching a binding domain can serve as an "anchor" to extend the residency time of biologics on wet epithelia, allowing their effective use even with infrequent applications.
View Article and Find Full Text PDFAdenovirus ocular infections are common ocular viral infections seen worldwide, for which there is no approved antiviral therapy available. Ranpirnase is a novel ribonuclease which preferentially degrades tRNA resulting in an inhibition of protein synthesis. The study goal was to determine the anti-adenoviral activity of topical formulations of ranpirnase (OKG-0301) on adenoviral replication in the Ad5/NZW rabbit ocular replication model.
View Article and Find Full Text PDFPurpose: Presently, there is no approved antiviral therapy for adenovirus (HAdV) ocular infections. During the COVID-19 pandemic, increased attention has been focused on antiviral treatments. Remdesivir, hydroxychloroquine, ivermectin, and umifenovir (Arbidol) have been touted as potential antiviral treatments for COVID-19.
View Article and Find Full Text PDFPurpose: Females and males respond differently to a number of systemic viral infections. Differences between females and males with respect to the severity of keratitis caused by Gram-negative bacteria such as are less well established.
Methods: In this study, we injected female and male New Zealand White rabbit corneas with a keratitis isolate of and evaluated the eyes after 48 hours for a number of clinical and microbiological parameters.
Coagulase-negative staphylococci (CoNS) are frequently occurring ocular opportunistic pathogens that are not easily identifiable to the species level. The goal of this study was to speciate CoNS and document antibiotic susceptibilities from cases of endophthalmitis ( = 50), keratitis ( = 50), and conjunctivitis/blepharitis ( = 50) for empiric therapy. All 150 isolates of CoNS were speciated using (1) API Staph (biochemical system), (2) Biolog GEN III Microplates (phenotypic substrate system), and (3) DNA sequencing of the gene.
View Article and Find Full Text PDFIn this study, we tested the hypothesis that the conserved bacterial IgaA-family protein, GumB, mediates microbial pathogenesis associated with Serratia marcescens ocular infections through regulation of the Rcs stress response system. The role of the Rcs system and bacterial stress response systems for microbial keratitis is not known, and the role of IgaA proteins in mammalian pathogenesis models has only been tested with partial-function allele variants of Salmonella. Here, we observed that an Rcs-activated mutant had a >50-fold reduction in proliferation compared to the wild type within rabbit corneas at 48 h and demonstrated a notable reduction in inflammation based on inflammatory signs, including the absence of hypopyons, and proinflammatory markers measured at the RNA and protein levels.
View Article and Find Full Text PDFPurpose: Topical vancomycin 5% (50 mg/mL) has been used for the treatment of methicillin-resistant Staphylococcus aureus (MRSA) keratitis, but patient comfort has many clinicians using lower concentrations. We compared the efficacy of different concentrations of vancomycin in the treatment of experimental MRSA keratitis.
Methods: The corneas of 45 rabbits were infected with 2000 colony-forming units (CFUs) of MRSA.
is an ocular bacterial pathogen isolated in cases of keratitis, conjunctivitis, and endophthalmitis. Gram-negative brick-shaped diplobacilli from ocular specimens, and slow growth in culture, are early indications of ocular infection; however, identifying to species can be complex and inconsistent. In this study, bacteria consistent with were identified to species using: (1) DNA sequencing coupled with vancomycin susceptibility, (2) MALDI-TOF mass spectrometry, and (3) the Biolog ID system.
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