Purpose: This study analyzed the toxicity of purified gamma-toxin from Staphylococcus aureus and the protectiveness of antisera to gamma-toxin in the rabbit cornea.
Materials And Methods: Gamma-toxin was purified from cultures of alpha-toxin deficient S. aureus strain Newman Δhla. Antisera to native gamma-toxin (Hlg) were produced in rabbits. These antisera and a commercial polyclonal antibody to recombinant HlgB (rHlgB) were analyzed for specificity and toxin neutralization. Heat-inactivated gamma-toxin, active gamma-toxin either alone or with antisera or with commercial antibody to rHlgB, was injected into the rabbit cornea to observe the pathological effects using slit lamp examination scoring (SLE) and histological analyses.
Results: Eyes with intrastromal injection of gamma-toxin developed SLE scores that were significantly higher than eyes injected with heat-inactivated gamma-toxin (p ≤ 0.003). Slit lamp and histological examination of eyes revealed that gamma-toxin injected into the cornea mediated conjunctival injection and chemosis, iritis, fibrin accumulation in the anterior chamber, and polymorphonuclear neutrophil infiltration of the cornea and iris. Also, eyes injected with gamma-toxin plus antisera to native whole gamma-toxin or HlgB, but not with commercial antibody to rHlgB, yielded significantly lower SLE scores than eyes injected with gamma-toxin alone (p ≤ 0.003).
Conclusions: This study illustrates that S. aureus gamma-toxin is capable of causing significant corneal pathology. Furthermore, the use of polyclonal antisera specific for native gamma-toxin was found to inhibit the damaging effects of the toxin in the rabbit cornea.
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http://dx.doi.org/10.1080/02713683.2017.1279636 | DOI Listing |
Microb Pathog
January 2025
Pierre Fabre Dermo-Cosmétique et Personal Care, 31000, Toulouse, France. Electronic address:
As a part of the human skin commensal bacterial community, Staphylococcus aureus contributes to the host's immune system education. Nevertheless, it is also considered as an opportunistic pathogen involved in cutaneous infections or skin pathologies, in particular atopic dermatitis. To switch to a pathogenic behavior, S.
View Article and Find Full Text PDFAntibiotics (Basel)
February 2022
Department of Internal Medicine and Infectious Diseases, Faculty of Veterinary Medicine, Mansoura University, Mansoura 35516, Egypt.
This work aimed to characterize isolates from the eyes of healthy and clinically affected equines in the Kafrelsheikh Governorate, Egypt. A total of 110 animals were examined for the presence of , which was isolated from 33 animals with ophthalmic lesions and 77 healthy animals. We also investigated the antimicrobial resistance profile, oxacillin resistance mechanism, and the major virulence factors implicated in many studies of the ocular pathology of pathogenic .
View Article and Find Full Text PDFMethods Mol Biol
June 2021
Department of Biology, Center for RNA Biology, University of Rochester, Rochester, NY, USA.
The post-transcriptional modification of tRNAs at the wobble position plays a critical role in proper mRNA decoding and efficient protein synthesis. In particular, certain wobble uridines in eukaryotes are converted to 5-methoxycarbonylmethyl-2-thiouridine (mcm5s2U). The mcm5s2U modification modulates decoding during translation by increasing the stringency of the wobble uridine to base pair with its canonical nucleotide partner, thereby restricting decoding to its cognate codon.
View Article and Find Full Text PDFToxins (Basel)
January 2020
Laboratory of Pharmacology, Butantan Institute, Av. Dr. Vital Brazil 1500, São Paulo 05503-900, Brazil.
Here, we report the neurotoxic effects aroused by the intracerebral injection (in rats) of Tb1, which is a neurotoxin isolated from scorpion venom. Biochemical analyses have demonstrated that this toxin is similar to the gamma toxin from , which is a β-scorpion toxin that acts on sodium channels, causing the activation process to occur at more hyperpolarized membrane voltages. Male Wistar rats were stereotaxically implanted with intrahippocampal electrodes and cannulas for electroencephalographic recording and the evaluation of amino acid neurotransmitters levels.
View Article and Find Full Text PDFToxins (Basel)
June 2019
Department of Ophthalmology, University of Oklahoma Health Sciences Center, Oklahoma City, OK 73104, USA.
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. 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.
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