Immunogenicity and Protection by DnaK and SpaA Recombinant Proteins Against Erysipelothrix Rhusiopathiae in a Murine Model.

BACKGROUND/AIMS: Swine erysipelas is a disease caused by Erysipelothrix rhusiopathiae, a Gram-positive bacillus, which has great economic importance because it leads to the loss of the swine herd. To control this disease, animals are immunized with a cellular vaccine of killed or attenuated E. rhusiopathiae, but even with herd vaccination, cases of swine erysipelas outbreaks have been reported in the United States, China and Japan, leading to the search for other antigenic components of the bacteria that may promote greater protection against E. rhusiopathiae. The surface protein SpaA from E. rhusiopathiae has been shown to be a candidate to constitute a subunit vaccine, since it has already been reported to induce a host immune response against the bacterium. DnaK, a hsp70 molecular chaperone, also seems to be a good candidate in the composition of a vaccine, as it has been demonstrated to be an antigenic protein of the bacteria. METHODS: This work evaluated the immunogenicity and protection induced by the E. rhusiopathiaee SpaA and DnaK recombinant proteins in a murine model, by intramuscular administration to mice with two doses of 100 µg at 21-day interval between them. The candidate proteins were tested either separately and together, compared with the commercial vaccine and the non-vaccination condition, and mice were challenged with a virulent strain of E. rhusiopathiae. Serum was collected to assess the produced antibodies and peripheral blood cells, whereas spleen and kidney tissues were assayed for E. rhusiopathiae presence by colony counting. RESULTS: A survival curve of the animals was performed, which confirmed the protection induced by the proteins. IgG antibodies increased in the animal serum inoculated with the proteins when compared to the control, and a significant delay in disease symptoms was observed. CONCLUSION: These results suggest that E. rhusiopathiae DnaK and SpaA are immunogenic in mice and interfere with the disease development.

Trends in science on glyphosate toxicity: a scientometric study.

As part of the most used herbicides, glyphosate is the most successful ingredient of agrochemical companies. The main objective of this study was to demonstrate research trends related to the glyphosate toxicity and its main effects on human and environmental health. For this purpose, 443 articles published, from 1995 to 2020, on the platform Web of Science™ Thomson Reuters were selected. The main toxicity results related in literature are genotoxicity, cytotoxicity, and endocrine disruption. The environmental effects come mostly from the contamination of groundwater and soils. Several studies have concluded that herbicide concentrations right below the official safety limits induced toxic effects. The results presented a highlighted harmful effect of glyphosate on both human and environmental health. It has been observed that countries where publish the most about the glyphosate toxicity are great investors in large-scale agriculture. It is important to ponder that these countries are in a route of ecosystem exploitation that includes not only fauna and flora, but also human beings. Unfortunately, science does not provide concise data for these pesticide disapproval in the global consumer market. It is necessary to search sustainable global interest alternatives to increase agriculture production based on peoples' food sovereignty.

Analysis of HLA-G protein expression in leprosy.

The aim of this study was to evaluate the expression of human leukocyte antigen G (HLA-G) in leprosy. Biopsy and serum samples were collected from 18 patients presenting with leprosy and from healthy controls. Samples were analyzed using immunohistochemistry and ELISA techniques. HLA-G expression was observed in biopsy samples of all patients. The healthy control samples were consistently negative for HLA-G expression. Control plasma samples displayed significantly higher HLA-G expression than those from the patients (p < 0.01). These results are the first demonstration of the expression of HLA-G in leprosy.