Search results for "Columna"

Data from: Intensive aquaculture selects for increased virulence and interference competition in bacteria

2016

Although increased disease severity driven by intensive farming practices is problematic in food production, the role of evolutionary change in disease is not well understood in these environments. Experiments on parasite evolution are traditionally conducted using laboratory models, often unrelated to economically important systems. We compared how the virulence, growth and competitive ability of a globally important fish pathogen, Flavobacterium columnare, change under intensive aquaculture. We characterized bacterial isolates from disease outbreaks at fish farms during 2003-2010, and compared F. columnare populations in inlet water and outlet water of a fish farm during the 2010 outbreak…

Data from: Higher resource level promotes virulence in an environmentally transmitted bacterial fish pathogen

2017

Diseases have become a primary constraint to sustainable aquaculture, but remarkably little attention has been paid to a broad class of pathogens: the opportunists. Opportunists often persist in the environment outside the host and their pathogenic features are influenced by changes in the environment. To test how environmental nutrient levels influence virulence, we used strains of Flavobacterium columnare, an environmentally transmitted fish pathogen, to infect rainbow trout and zebra fish in two different nutrient concentrations. To separate the effects of dose and nutrients, we used three infective doses and studied the growth of bacteria in vitro. High nutrient concentration promoted b…

Data from: Coinfection outcome in an opportunistic pathogen depends on the inter-strain interactions

2017

Background In nature, organisms are commonly coinfected by two or more parasite strains, which has been shown to influence disease virulence. Yet, the effects of coinfections of environmental opportunistic pathogens on disease outcome are still poorly known, although as host-generalists they are highly likely to participate in coinfections. We asked whether coinfection with conspecific opportunistic strains leads to changes in virulence, and if these changes are associated with bacterial growth or interference competition. We infected zebra fish (Danio rerio) with three geographically and/or temporally distant environmental opportunist Flavobacterium columnare strains in single and in coinf…

Data from: Broad thermal tolerance is negatively correlated with virulence in an opportunistic bacterial pathogen

2018

Predicting the effects of global increase in temperatures on disease virulence is challenging, especially for environmental opportunistic bacteria, because pathogen fitness may be differentially affected by temperature within and outside host environment. So far, there is very little empirical evidence on the connections between optimal temperature range and virulence in environmentally growing pathogens. Here we explored if the virulence of an environmentally growing opportunistic fish pathogen, Flavobacterium columnare, is malleable to evolutionary changes via correlated selection on thermal tolerance. To this end, we experimentally quantified the thermal performance curves (TPCs) for max…

Data from: Rearing background and exposure environment together explain higher survival of aquaculture fish during a bacterial outbreak

2019

1. Parasitic diseases represent one of the greatest challenges for aquaculture worldwide and there is an increasing emphasis on ecological solutions to prevent infections. One proposed solution is enriched rearing, where traditional stimulus-poor rearing tanks are equipped with different types of structures to increase habitat complexity. Such spatial enrichment is known to increase survival of fish during parasite epidemics, but the underlying mechanisms are still unclear. 2. We studied whether enriched rearing affected infection of an important fish pathogen Flavobacterium columnare in young Atlantic salmon (Salmo salar) and sea-migrating brown trout (Salmo trutta). First, we used natural…

Bacteriophage Adherence to Mucus Mediates Preventive Protection against Pathogenic Bacteria

2019

The mucosal surfaces of animals are habitat for microbes, including viruses. Bacteriophages—viruses that infect bacteria—were shown to be able to bind to mucus. This may result in a symbiotic relationship in which phages find bacterial hosts to infect, protecting the mucus-producing animal from bacterial infections in the process. Here, we studied phage binding on mucus and the effect of mucin on phage-bacterium interactions. The significance of our research is in showing that phage adhesion to mucus results in preventive protection against bacterial infections, which will serve as basis for the development of prophylactic phage therapy approaches. Besides, we also reveal that exposure to m…

La televisión de la sociedad democrática: ¿Una necesidad imposible?

2004

Research data of an article: "Application of high resolution melting assay (HMR) to study temperature dependent infraspecific competition in an patho…

2017

Studies on species’ responses to climate change have focused largely on the direct effect of abiotic factors and in particular temperature, neglecting the effects of biotic interactions in determining the outcome of climate change projections. Many microbes rely on strong interference competition; hence the fitness of many pathogenic bacteria could be a function of both their growth properties and intraspecific competition. However, due to technical challenges in distinguishing and tracking individual strains, experimental evidence on intraspecific competition has been limited so far. Here, we developed a robust application of the high-resolution melting (HRM) assay to study head-to-head co…

Estrategias para mejorar la calidad de las separaciones en cromatografía líquida de fase inversa

2015

La Memoria de Tesis Doctoral propone estrategias dirigidas a mejorar la separación de mezclas que muestran una resolución cromatográfica extraordinariamente baja, en las condiciones usuales de elución, mediante cromatografía líquida de alta eficacia (HPLC, high-performance liquid chromatography). La HPLC es actualmente la técnica analítica de separación más extendida, debido a su amplio campo de aplicación, fiabilidad, robustez y sensibilidad. Lamentablemente, la eficacia que proporciona suele ser inferior a la conseguida en cromatografía de gases, electroforesis capilar y otras técnicas de electromigración, lo que representa una limitación para el análisis de muestras complejas. Los estudi…

Strategies to find optimal resolution in liquid chromatography

2018

La cromatografía líquida de alta resolución o alto rendimiento es actualmente la técnica de separación analítica más utilizada, debido a su versatilidad, fiabilidad, robustez y sensibilidad. Desafortunadamente, en cromatografía líquida, la eficacia suele ser inferior a la ofrecida por la cromatografía de gases, electroforesis capilar y otras técnicas de electromigración. Con una menor eficacia, no es posible el análisis de muestras de muy elevada complejidad. Así, se ha dedicado un considerable esfuerzo en investigación, tanto básica como aplicada, al incremento de la eficacia y selectividad, produciéndose avances muy significativos desde los orígenes de la técnica. A pesar de los progresos…