Examinando por Autor "Schlotterbeck, Trinidad"
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Ítem In Vivo Efficacy of Purified Quillaja Saponin Extracts in Protecting against Piscirickettsia salmonis Infections in Atlantic Salmon (Salmo salar)(Multidisciplinary Digital Publishing Institute (MDPI), 2023-09) Cortés, Hernán; Castillo-Ruiz, Mario; Cañon-Jones, Hernán; Schlotterbeck, Trinidad; San Martín, Ricardo; Padilla, LeandroPiscirickettsiosis, the main infectious disease affecting salmon farming in Chile, still has no efficient control measures. Piscirickettsia salmonis is a facultative intracellular bacterium that can survive and replicate within the host macrophages, evading the immune response. Triterpenic saponins obtained from the Quillaja saponaria tree have been widely studied, and have been shown to be immunomodulatory agents, suitable for feed and vaccine applications for veterinary and human uses. The impact of the oral administration of two extracts of Quillaja saponins on the infection of P. salmonis in Salmo salar and the corresponding gene expressions of immunomarkers were studied under three in vivo models. In the intraperitoneal challenge model, the group fed with Quillaja extracts showed lower mortality (29.1% treated vs. 37.5% control). Similar results were obtained in the cohabitation model trial (36.3% vs. 60.0%). In the commercial pilot trial, the results showed a significant reduction of 71.3% in mortality caused by P. salmonis (0.51% vs. 1.78%) and antibiotic use (reduction of 66.6% compared to untreated control). Also, Quillaja extracts significantly modulated the expression of IFN-II and CD8. These results represent evidence supporting the future use of purified Quillaja extracts as a natural non-pharmacological strategy for the prevention and control of P. salmonis infections in salmon. © 2023 by the authors.Ítem Quillaja saponaria (Molina) Extracts Inhibits In Vitro Piscirickettsia salmonis Infections(MDPI AG, 2020-12) Cañon-Jones, Hernán; Cortes, Hernán; Castillo-Ruiz, Mario; Schlotterbeck, Trinidad; San Martín, RicardoP. salmonis infections are the cause of major bacterial disease in salmonids in Chile, and the reason for using more antibiotics compared to other salmon-producing countries. Vaccination and antibiotics have not been efficient and new approaches are needed. The safety of Quillaja saponaria extracts was measured by cytotoxicity using flow cytometry of cytopathic and death of fish cell cultures and efficacy was assessed using in vitro infection models with pathogenic P. salmonis. Cytotoxicity was low and control of in vitro infections was achieved with all products, with protection of over 90%. Minimum inhibitory concentrations were much higher than those in the infection using cell cultures. These results suggest a dual mechanism of action where less purified extracts with a combination of saponin and non-saponin components simultaneously decrease P. salmonis infection while protecting cell lines, rather than exerting a direct antimicrobial effect. Quillaja saponins controlled in vitro infections with P. salmonis and could be considered good candidates for a new, safe and sustainable method of controlling fish bacterial infectious diseases. © 2020 by the authors. Licensee MDPI, Basel, Switzerland.