Search results for "host"

Invasion biology and host specificity of the grapevine yellows disease vector Hyalesthes obsoletus in Europe

2008

Within the past 10 years, the yellows disease ‘bois noir’ (BN) has become one of the commercially most important diseases of grapevine [ Vitis vinifera L. (Vitaceae)] in Europe. Infection pressure is caused by phytoplasmas of the stolbur 16SrXII-A group that are transmitted by a planthopper vector, Hyalesthes obsoletus Signoret (Homoptera: Auchenorrhyncha). Infestation happens as an accidental side-effect of the feeding behaviour of the vector, as vector and pathogen proliferation is dependent on other plants. In Germany, the increase of BN is correlated with the use of a new host plant by the vector, increase in abundance of the vector on the new host plant, and dissemination of host plant…

Arabidopsis thalianagenes contributing to differences in the outcome of infection with generalist and specialist strains ofTurnip mosaic virusidentif…

2020

AbstractPathogens can be classified as generalists or specialists depending on their host breadth. While generalists are able to successfully infect a wide variety of host species, the host range of specialists is limited to a few related species. Even though generalists seem to gain an advantage due to their wide host range, they usually pay a cost in terms of fitness within each host species (i.e., the jack-of-all trades, master of none). On the contrary, specialists have high fitness within their own host. A highly relevant yet poorly explored question is whether generalist and specialist viruses differ in the way they interact with their host’s gene expression networks. To identify host…

The haplotype distribution of two genes of citrus tristeza virus is altered after host change or aphid transmission.

1999

Genetic variability of citrus tristeza virus (CTV) was studied using the haplotypes detected by single-strand conformation polymorphism (SSCP) analysis of genes p18 and p20 in six virus populations of two origins. The Spanish group included a CTV isolate and subisolates obtained by graft-transmission to different host species. The other included two subisolates aphid-transmitted from a single Japanese isolate. The homozygosity observed for gene p20 was always significantly higher than that expected under neutral evolution, whereas only three populations showed high homozygosity for p18, suggesting stronger host constraints for p20 than for p18. Sequential transmissions of a Spanish isolate …

Survival relative to new and ancestral host plants, phytoplasma infection, and genetic constitution in host races of a polyphagous insect disease vec…

2014

Dissemination of vectorborne diseases depends strongly on the vector's host range and the pathogen's reservoir range. Because vectors interact with pathogens, the direction and strength of a vector's host shift is vital for understanding epidemiology and is embedded in the framework of ecological specialization. This study investigates survival in host-race evolution of a polyphagous insect disease vector, Hyalesthes obsoletus, whether survival is related to the direction of the host shift (from field bindweed to stinging nettle), the interaction with plant-specific strains of obligate vectored pathogens/symbionts (stolbur phytoplasma), and whether survival is related to genetic differentia…

Metabolic Networks of Sodalis glossinidius: A Systems Biology Approach to Reductive Evolution

2012

BackgroundGenome reduction is a common evolutionary process affecting bacterial lineages that establish symbiotic or pathogenic associations with eukaryotic hosts. Such associations yield highly reduced genomes with greatly streamlined metabolic abilities shaped by the type of ecological association with the host. Sodalis glossinidius, the secondary endosymbiont of tsetse flies, represents one of the few complete genomes available of a bacterium at the initial stages of this process. In the present study, genome reduction is studied from a systems biology perspective through the reconstruction and functional analysis of genome-scale metabolic networks of S. glossinidius.ResultsThe functiona…

Interactions among bacterial strains and fluke genotypes shape virulence of co-infection.

2015

Most studies of virulence of infection focus on pairwise host–parasite interactions. However, hosts are almost universally co-infected by several parasite strains and/or genotypes of the same or different species. While theory predicts that co-infection favours more virulent parasite genotypes through intensified competition for host resources, knowledge of the effects of genotype by genotype (G × G) interactions between unrelated parasite species on virulence of co-infection is limited. Here, we tested such a relationship by challenging rainbow trout with replicated bacterial strains and fluke genotypes both singly and in all possible pairwise combinations. We found that virulence (host mo…

PSYCHOBEHAVIORAL DISORDERS, ORTHOSTATIC HYPOTENSION, AND FALLS RELATED TO A PHEOCHROMOCYTOMA IN A VERY ELDERLY SUBJECT: A CASE REPORT

2010

Ética de la asistencia primaria a los niños de procedencia internacional

2012

La inmigración se ha convertido en un fenómeno universal. Uno de sus efectos es el incremento de los niños de procedencia internacional en las consultas de pediatría. Se trata de una población doblemente vulnerable, por tratarse de niños y por proceder de contextos culturales extraños a los del país de acogida. Ante esta realidad emergente es imprescindible preguntarse por el tipo de asistencia sanitaria que deben recibir. En el presente artículo se proponen principios éticos de actuación inspirados en las principales normas internacionales sobre bioética y derechos de los niños: principio de vulnerabilidad; principio de respeto y amor, y principio de acceso y atención sanitaria. Finalmente…

Ghosts from the Abyss. The imagination of new worlds in the sea-narratives of Afrofuturism

2022

This contribution aims to investigate a different ghostscape, shaped by the turbulent materiality of the sea: the abyss. A space of trauma and simultaneously of becoming, it is populated by spectral objects, traces, fragments, and, above all, ghosts. Looking into the abyss through the turbulent materiality of the sea (where the turbulence recalls Haraway’s trouble and the materiality a livingness of the world in which “matter comes to matter”), sea-related ghosts from the Black Atlantic to the Black Mediterranean emerge as absences-presences that matter. The emersion of sea-related new worlds is one of the main topics of Afrofuturism narratives: from the Drexciya world to the Novella The De…

Endoparasites of the blue whiting, Micromesistius poutassou from north-west Spain.

2005

AbstractThe communities of metazoan endoparasites of blue whiting, Micromesistius poutassou, in waters of north-west Spain were analysed and a geographical comparison made with other localities. Four hundred blue whiting collected in July 1999 and September 2000 were examined for parasites, excluding the head and gills. Six species were found: Anisakis simplex s.l. (L3), A. physeteris (L3), Hysterothylacium aduncum (L2 and L3), Stephanostomum lophii (metacercaria), S. pristis (adult), and Prosorhynchus crucibulum (metacercaria). The latter is a new host record, and A. physeteris is reported for the first time in blue whiting from the north-east Atlantic. Host gender was not a significant pr…