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Sharma S, Pellett S, Morse SA. Special Issue: Gram-Positive Bacterial Toxins. Microorganisms 2023; 11:2054. [PMID: 37630614 PMCID: PMC10459523 DOI: 10.3390/microorganisms11082054] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2023] [Revised: 07/31/2023] [Accepted: 08/01/2023] [Indexed: 08/27/2023] Open
Abstract
The Gram stain classifies most bacteria into one of two groups, Gram-negative or Gram-positive, based on the composition of their cell walls [...].
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Affiliation(s)
- Shashi Sharma
- Division of Microbiology, Office of Regulatory Science, CFSAN/US Food and Drug Administration, College Park, MD 20740, USA
| | - Sabine Pellett
- Department of Bacteriology, University of Wisconsin, 1550 Linden Drive, Madison, WI 53706, USA
| | - Stephen A Morse
- IHRC, Inc., 2 Ravinia Drive, Suite 1200, Atlanta, GA 30346, USA
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Wurtz M, Ruhland E, Liu X, Namer IJ, Mazzoleni V, Lipsker D, Keller D, Prévost G, Gaucher D. Panton-Valentine Leucocidin of Staphylococcus aureus Induces Oxidative Stress and Neurotransmitter Imbalance in a Retinal Explant Model. Invest Ophthalmol Vis Sci 2021; 62:4. [PMID: 33393970 PMCID: PMC7794257 DOI: 10.1167/iovs.62.1.4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
Purpose Endophthalmitis models have reported the virulent role of Panton-Valentine leucocidin (PVL) secreted by Staphylococcus aureus on the retina. PVL targets retinal ganglion cells (RGCs), expressing PVL membrane receptor C5aR. Interactions between PVL and retinal cells lead to glial activation, retinal inflammation, and apoptosis. In this study, we explored oxidative stress and retinal neurotransmitters in a rabbit retinal explant model incubated with PVL. Methods Reactive oxygen species (ROS) production in RGCs has been assessed with fluorescent probes and immunohistochemistry. Nuclear magnetic resonance (NMR) spectroscopy quantified retinal concentrations of antioxidant molecules and neurotransmitters, and concentrations of neurotransmitters released in the culture medium. Quantifying the expression of some pro-inflammatory and anti-inflammatory factors was performed using RT-qPCR. Results PVL induced a mitochondrial ROS production in RGCs after four hours’ incubation with the toxin. Enzymatic sources of ROS, involving nicotinamide adenine dinucleotide phosphate–oxidase and xanthine oxidase, were also activated after four hours in PVL-treated retinal explants. Retinal antioxidants defenses, that is, glutathione, ascorbate and taurine, decreased after two hours’ incubation with PVL. Glutamate retinal concentrations and glutamate release in the culture medium remained unaltered in PVL-treated retinas. GABA, glycine, and acetylcholine (Ach) retinal concentrations decreased after PVL treatment. Glycine release in the culture medium decreased, whereas Ach release increased after PVL treatment. Expression of proinflammatory and anti-inflammatory cytokines remained unchanged in PVL-treated explants. Conclusions PVL activates oxidative pathways and alters neurotransmitter retinal concentrations and release, supporting the hypothesis that PVL could induce a neurogenic inflammation in the retina.
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Affiliation(s)
- Mathieu Wurtz
- University of Strasbourg, Hôpitaux Universitaires de Strasbourg, Fédération de Médecine Translationnelle de Strasbourg, UR7290 Virulence Bactérienne Précoce, Institute of Bacteriology, Strasbourg, France.,Hôpitaux Universitaires de Strasbourg, Department of Ophthalmology, Nouvel Hôpital Civil, Strasbourg, France
| | - Elisa Ruhland
- MNMS Platform, Department of Biophysics and Nuclear Medicine, Hôpitaux Universitaires de Strasbourg, Hôpital de Hautepierre, Strasbourg, France
| | - XuanLi Liu
- University of Strasbourg, Hôpitaux Universitaires de Strasbourg, Fédération de Médecine Translationnelle de Strasbourg, UR7290 Virulence Bactérienne Précoce, Institute of Bacteriology, Strasbourg, France
| | - Izzie-Jacques Namer
- MNMS Platform, Department of Biophysics and Nuclear Medicine, Hôpitaux Universitaires de Strasbourg, Hôpital de Hautepierre, Strasbourg, France
| | - Viola Mazzoleni
- University of Strasbourg, Hôpitaux Universitaires de Strasbourg, Fédération de Médecine Translationnelle de Strasbourg, UR7290 Virulence Bactérienne Précoce, Institute of Bacteriology, Strasbourg, France
| | - Dan Lipsker
- Hôpitaux Universitaires de Strasbourg, Department of Dermatology, Nouvel Hôpital Civil, Strasbourg, France
| | - Daniel Keller
- University of Strasbourg, Hôpitaux Universitaires de Strasbourg, Fédération de Médecine Translationnelle de Strasbourg, UR7290 Virulence Bactérienne Précoce, Institute of Bacteriology, Strasbourg, France
| | - Gilles Prévost
- University of Strasbourg, Hôpitaux Universitaires de Strasbourg, Fédération de Médecine Translationnelle de Strasbourg, UR7290 Virulence Bactérienne Précoce, Institute of Bacteriology, Strasbourg, France
| | - David Gaucher
- University of Strasbourg, Hôpitaux Universitaires de Strasbourg, Fédération de Médecine Translationnelle de Strasbourg, UR7290 Virulence Bactérienne Précoce, Institute of Bacteriology, Strasbourg, France.,Hôpitaux Universitaires de Strasbourg, Department of Ophthalmology, Nouvel Hôpital Civil, Strasbourg, France
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Glickman RD, Onorato M, Campos MM, O'Boyle MP, Singh RK, Zarembinski TI, Binette F, Nasonkin IO. Intraocular Injection of HyStem Hydrogel Is Tolerated Well in the Rabbit Eye. J Ocul Pharmacol Ther 2021; 37:60-71. [PMID: 33449859 DOI: 10.1089/jop.2020.0042] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Purpose: To determine the long-term biocompatibility of HyStem® hydrogel in the rabbit eye for use as a carrier for cell or drug delivery into the ocular space. Methods: HyStem hydrogel formulation solidifies ∼20 min after reconstitution, thus can potentially form a solid deposit after injection in situ. To study the ocular disposition of fluorescein-labeled HyStem, we delivered 50 μL/eye over 1 min into the vitreous space of the rabbit. We used 3 Dutch-Belted and 3 New Zealand-pigmented rabbits, all females, delivered the gel into the right eyes, and injected 50 μL BSS Plus into the left eyes as a control. Retinal morphology was assessed by optical coherence tomography (OCT) and white light fundus photography. Fluorescence fundus photography enabled measurement of the clearance of the labeled hydrogel from the posterior chamber. Visual function was evaluated using flash and flicker electroretinography (ERG) pre- and postinjection and at weekly intervals thereafter for 6 weeks. Retinal immunohistochemistry for microglial inflammatory markers was carried out with antiglial fibrillary acidic protein (GFAP) antibody, isolectin B4 (IB4), and 4',6-diamidino-2-phenylindole (DAPI). Results: The gel was successfully delivered into the vitreous space without the formation of a discrete retinal deposit. Fundus imaging, OCT measurements of retinal thickness, and immunohistochemical data indicated an absence of retinal inflammation, and ERG indicated no impact on retinal function. The half-time of HyStem clearance calculated from the loss of fundus fluorescence was 3.9 days. Conclusions: HyStem hydrogel appears to be biocompatible in the ocular space of a large eye and safe for long-term intraocular application.
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Affiliation(s)
- Randolph D Glickman
- Department of Ophthalmology, University of Texas Health Science Center at San Antonio, San Antonio, Texas, USA
| | | | - Maria M Campos
- Histopathology Core, National Eye Institute, National Institutes of Health, Bethesda, Maryland, USA
| | - Michael P O'Boyle
- Research Imaging Institute, University of Texas Health Science Center at San Antonio, San Antonio, Texas, USA
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Astley R, Miller FC, Mursalin MH, Coburn PS, Callegan MC. An Eye on Staphylococcus aureus Toxins: Roles in Ocular Damage and Inflammation. Toxins (Basel) 2019; 11:E356. [PMID: 31248125 PMCID: PMC6628431 DOI: 10.3390/toxins11060356] [Citation(s) in RCA: 36] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2019] [Revised: 06/13/2019] [Accepted: 06/15/2019] [Indexed: 12/12/2022] Open
Abstract
Staphylococcus aureus (S. aureus) is a common pathogen of the eye, capable of infecting external tissues such as the tear duct, conjunctiva, and the cornea, as well the inner and more delicate anterior and posterior chambers. S. aureus produces numerous toxins and enzymes capable of causing profound damage to tissues and organs, as well as modulating the immune response to these infections. Unfortunately, in the context of ocular infections, this can mean blindness for the patient. The role of α-toxin in corneal infection (keratitis) and infection of the interior of the eye (endophthalmitis) has been well established by comparing virulence in animal models and α-toxin-deficient isogenic mutants with their wild-type parental strains. The importance of other toxins, such as β-toxin, γ-toxin, and Panton-Valentine leukocidin (PVL), have been analyzed to a lesser degree and their roles in eye infections are less clear. Other toxins such as the phenol-soluble modulins have yet to be examined in any animal models for their contributions to virulence in eye infections. This review discusses the state of current knowledge of the roles of S. aureus toxins in eye infections and the controversies existing as a result of the use of different infection models. The strengths and limitations of these ocular infection models are discussed, as well as the need for physiological relevance in the study of staphylococcal toxins in these models.
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Affiliation(s)
- Roger Astley
- Department of Ophthalmology, University of Oklahoma Health Sciences Center, Oklahoma City, OK 73104, USA.
| | - Frederick C Miller
- Department of Cell Biology and Department of Family and Preventive Medicine, University of Oklahoma Health Sciences Center, Oklahoma City, OK 73104, USA.
| | - Md Huzzatul Mursalin
- Department of Microbiology and Immunology, University of Oklahoma Health Sciences Center, Oklahoma City, OK 73104, USA.
| | - Phillip S Coburn
- Department of Ophthalmology, University of Oklahoma Health Sciences Center, Oklahoma City, OK 73104, USA.
| | - Michelle C Callegan
- Department of Ophthalmology, University of Oklahoma Health Sciences Center, Oklahoma City, OK 73104, USA.
- Department of Microbiology and Immunology, University of Oklahoma Health Sciences Center, Oklahoma City, OK 73104, USA.
- Dean McGee Eye Institute, 608 Stanton L. Young Blvd., DMEI PA-418, Oklahoma City, OK 73104, USA.
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