Search results for "Secondary infection"
showing 10 items of 20 documents
Species Richness, rRNA Gene Abundance, and Seasonal Dynamics of Airborne Plant-Pathogenic Oomycetes
2018
Oomycetes, also named Peronosporomycetes, are one of the most important and widespread groups of plant pathogens, leading to significant losses in the global agricultural productivity. They have been studied extensively in ground water, soil, and host plants, but their atmospheric transport vector is not well characterized. In this study, the occurrence of airborne Oomycetes was investigated by Sanger sequencing and quantitative PCR of coarse and fine aerosol particle samples (57 filter pairs) collected over a 1-year period (2006–2007) and full seasonal cycle in Mainz, Germany. In coarse particulate matter, we found 55 different hypothetical species (OTUs), of which 54 were plant pathogens …
Infection and spread of root rot caused byHeterobasidionspp. inPinus contortaplantations in Northern Europe: three case studies
2019
This study investigated the origins and spread patterns of Heterobasidion root disease in three Pinus contorta Dougl. ex Loudon plantations established on forest and agricultural land and subjected to three different management scenarios. Trees with decline symptoms and stumps remaining from the previous rotation were sampled for fungal isolations. Ten isolates of Heterobasidion parviporum Niemelä & Korhonen and 425 of Heterobasidion annosum (Fr.) Bref. were tested for clonality through somatic compatibility tests. The following conclusions were reached: (i) P. contorta is highly susceptible to H. annosum and H. parviporum and both pathogens cause dieback of P. contorta; (ii) H. annosum…
Effect of repeated exposure to Plasmodium relictum (lineage SGS1) on infection dynamics in domestic canaries.
2010
7 pages; International audience; Parasites are known to exert strong selection pressures on their hosts and, as such, favour the evolution of defence mechanisms. The negative impact of parasites on their host can have substantial consequences in terms of population persistence and the epidemiology of the infection. In natural populations, however, it is difficult to assess the cost of infection while controlling for other potentially confounding factors. For instance, individuals are repeatedly exposed to a variety of parasite strains, some of which can elicit immunological memory, further protecting the host from subsequent infections. Cost of infection is, therefore, expected to be partic…
Free Radicals Mediate Systemic Acquired Resistance
2014
Summary: Systemic acquired resistance (SAR) is a form of resistance that protects plants against a broad spectrum of secondary infections. However, exploiting SAR for the protection of agriculturally important plants warrants a thorough investigation of the mutual interrelationships among the various signals that mediate SAR. Here, we show that nitric oxide (NO) and reactive oxygen species (ROS) serve as inducers of SAR in a concentration-dependent manner. Thus, genetic mutations that either inhibit NO/ROS production or increase NO accumulation (e.g., a mutation in S-nitrosoglutathione reductase [GSNOR]) abrogate SAR. Different ROS function additively to generate the fatty-acid-derived azel…
SARS-CoV-2-Specific Memory T Lymphocytes From COVID-19 Convalescent Donors: Identification, Biobanking, and Large-Scale Production for Adoptive Cell …
2021
Syndrome coronavirus 2 (SARS-CoV-2) pandemic is causing a second outbreak significantly delaying the hope for the virus’ complete eradication. In the absence of effective vaccines, we need effective treatments with low adverse effects that can treat hospitalized patients with COVID-19 disease. In this study, we determined the existence of SARS-CoV-2-specific T cells within CD45RA– memory T cells in the blood of convalescent donors. Memory T cells can respond quickly to infection and provide long-term immune protection to reduce the severity of COVID-19 symptoms. Also, CD45RA– memory T cells confer protection from other pathogens encountered by the donors throughout their life. It is of vita…
Interleukin-25 Induces Resistance Against Intestinal Trematodes
2016
AbstractEchinostoma caproni is an intestinal trematode that has been extensively used as an experimental model to investigate the factors determining the resistance to intestinal helminths or the development of chronic infections. ICR mice are permissive hosts for E. caproni in which chronic infections are developed, concomitantly with local Th1 responses, elevated levels of local IFN-γ, inflammation and antibody responses. However, mice develop partial resistance to homologous challenge infections after cure of a primary infection, which converts this subject into an adequate model for the study of the mechanisms generating resistance against intestinal helminths. The purpose of the presen…
Resistance against Echinostoma caproni (Trematoda) secondary infections in mice is not dependent on the ileal protein production
2016
Echinostoma caproni (Trematoda: Echinostomatidae) is an intestinal trematode, which has been widely employed to investigate the factors determining the rejection of intestinal helminths. Protein production patterns of intestinal epithelial cells are related to the infection-induced changes that determine the course of E. caproni infections. Herein, we compare the protein production profiles in the ileum of four experimental groups of mice: control; infected; dewormed and reinfected. Worm burdens were significantly lower in secondary infections, confirming the generation of partial resistance to homologous secondary infections in mice. However, quantitative comparison by 2D-DIGE showed that …
Interleukin-25-mediated resistance against intestinal trematodes does not depend on the generation of Th2 responses
2020
AbstractInterleukin-25 (IL-25) is recognized as the most relevant initiator of protective Th2 responses in intestinal helminth infections. It is well known that IL-25 induces resistance against several species of intestinal helminths, including the trematode Echinostoma caproni. E. caproni has been extensively used as an experimental model to study the factors determining the resistance to intestinal infections. Herein, we assessed the role of IL-25 in the generation of resistance in mice to E. caproni infections. ICR mice are permissive hosts for E. caproni in which chronic infections are developed in relation to the lack of IL-25 production in response to primary infection and the consequ…
Enteral versus parenteral early nutrition in ventilated adults with shock: a randomised, controlled, multicentre, open-label, parallel-group study (N…
2017
International audience; BackgroundWhether the route of early feeding affects outcomes of patients with severe critical illnesses is controversial. We hypothesised that outcomes were better with early first-line enteral nutrition than with early first-line parenteral nutrition.MethodsIn this randomised, controlled, multicentre, open-label, parallel-group study (NUTRIREA-2 trial) done at 44 French intensive-care units (ICUs), adults (18 years or older) receiving invasive mechanical ventilation and vasopressor support for shock were randomly assigned (1:1) to either parenteral nutrition or enteral nutrition, both targeting normocaloric goals (20–25 kcal/kg per day), within 24 h after intubatio…
Free radical-mediated systemic immunity in plants.
2014
SPE IPM; Systemic acquired resistance (SAR) is a form of defense that protects plants against a broad-spectrum of secondary infections by related or unrelated pathogens. SAR related research has witnessed considerable progress in recent years and a number of chemical signals and proteins contributing to SAR have been identified. All of these diverse constituents share their requirement for the phytohormone salicylic acid, an essential downstream component of the SAR pathway. However, recent work demonstrating the essential parallel functioning of nitric oxide (NO)-derived and reactive oxygen species (ROS)-derived signaling together with SA provides important new insights in the overlapping …