Publications by authors named "Ricardo Oyarzun-Salazar"

Piscirickettsiosis causes the highest mortality in Atlantic salmon (Salmo salar) farming, and prophylactic treatment has not provided complete protection to date. In this study, we analyzed the immune and metabolic responses of Atlantic salmon inoculated with live and inactivated Piscirickettsia salmonis, monitoring plasma markers related to immune and stress responses. The fish were inoculated with inactivated P.

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Fish cell culture is a common in vitro tool for studies in different fields such as virology, toxicology, pathology and immunology of fish. Fish cell cultures are a promising help to study how to diagnose and control relevant viral and intracellular bacterial infections in aquaculture. They can also be used for developing vaccines and immunostimulants, especially with the ethical demand aiming to reduce and replace the number of fish used in research.

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Nutritional immunity regulates the homeostasis of micronutrients such as iron, manganese, and zinc at the systemic and cellular levels, preventing the invading microorganisms from gaining access and thereby limiting their growth. Therefore, the objective of this study was to evaluate the activation of nutritional immunity in specimens of Atlantic salmon () that are intraperitoneally stimulated with both live and inactivated . The study used liver tissue and blood/plasma samples on days 3, 7, and 14 post-injections (dpi) for the analysis.

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The innate immune system can limit the growth of invading pathogens by depleting micronutrients at a cellular and tissue level. However, it is not known whether nutrient depletion mechanisms discriminate between living pathogens (which require nutrients) and pathogen-associated molecular patterns (PAMPs) (which do not). We stimulated SHK-1 cells with different PAMPs (outer membrane vesicles of "OMVs", protein extract of "TP" and lipopolysaccharides of "LPS") isolated from and evaluated transcriptional changes in nutritional immunity associated genes.

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The brain's immune system is selective and hermetic in most species, including fish, favoring immune responses mediated by soluble immunomodulatory factors such as serotonin and the availability of nutrients against infectious processes. Francisella noatunensis coexist with fish such as Eleginops maclovinus, which raises questions about the susceptibility and immune response of the brain of E. maclovinus against Francisella.

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Maximum and minimum Critical thermal limits (CTMax and CTMin) have been studied extensively to assess thermal tolerance in ectotherms by means of ramping assays. Notothenioid fish have been proposed as particularly sensitive to temperature increases related to global climate change. However, there are large gaps in our understanding of the thermal responses of these extreme cold-adapted fish in assays with heating rates.

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Global warming is having a significant impact around the world, modifying environmental conditions in many areas, including in zones that have been thermally stable for thousands of years, such as Antarctica. Stenothermal sedentary intertidal fish species may suffer due to warming, notably if this causes water freshening from increased freshwater inputs. Acute decreases in salinity, from 33 down to 5, were used to assess osmotic responses to environmental salinity fluctuations in Antarctic spiny plunderfish Harpagifer antarcticus, in particular to evaluate if H.

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Francisella noatunensis subsp. noatunensis is the responsible agent of Francisellosis, a bacterial disease that affects an important amount of aquatic farmed species. Eleginops maclovinus is a fish that cohabits with salmonids cages in Chile and can also act as a vector of this bacterial disease.

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