Genetic markers for improved disease resistance in animals (BPI)

A method for determining improved disease resistance in animals is disclosed. The method assays for a novel genetic alleles of the BPI gene of the animal. The alleles are correlated with superior disease resistance. Novel nucleotide sequences, assays and primers are disclosed for the methods of the invention

Genetic markers for screening animals for improved disease resistance (NRAMP)

A method for determining improved innate immunity, disease resistance or performance in animals is disclosed. The method involves assays for a genetic differences in the NRAMP1 gene of the animal which is associated with superior disease resistance. Novel NRAMP1 sequence, assays, and compositions for identifying the presence of absence of these alleles are provided

Early Epithelial Invasion by Salmonella enterica Serovar Typhimurium DT104 in the Swine Ileum

Salmonella enterica serovar Typhimurium is an important intestinal pathogen in swine. This study was performed to document the early cellular invasion of Salmonellaserovar Typhimurium in swine ileum. Ileal gut-loops were surgically prepared in ten 4- to 5-week-old mixed-breed pigs and inoculated for 0-60 minutes. Loops were harvested and prepared for both scanning and transmission electron microscopy (SEM and TEM, respectively). Preferential bacterial adherence to microfold cells (M cells) was seen within 5 minutes, and by 10 minutes bacterial invasion of the apical membrane was seen in M cells, goblet cells, and enterocytes. This multicellular invasion was observed throughout the course of infection. In addition, SEM revealed a specific affinity of Salmonella serovar Typhimurium to sites of cell extrusion. Using TEM, bacteria in these areas were focused in the crevices formed by the extruding cell and the adjacent cells and in the cytoplasm immediately beneath the extruding cell. Our results suggest that early cellular invasion by Salmonella serovar Typhimurium is nonspecific and rapid in swine. Furthermore, the combination of SEM and TEM data suggests that Salmonella serovar Typhimurium may use sites of cell extrusion as an additional mechanism for early invasion

Salmonella Immunity: Development of a Neutrophil Phagocytosis Assay and Stress Model in Swine

Our laboratory is interested in the immunomodulation of porcine defense mechanisms against bacterial intracellular pathogens such as Salmonella typhimurium and S. choleraesuis. Past studies indicate that levels of serum tumor necrosis factor-a (TNF-a) increase after intranasal challenge with S. typhimurium but not after oral inoculation. Challenge with S. choleraesuis has no effect on serum TNF-a concentration in the blood, regardless of route. Route of inoculation with S. choleraesuis has been shown to affect levels of lymphocyte proliferation. Both oral and intranasal routes of inoculation stimulate peripheral blood B-cells while the intranasal route is more effective at stimulating peripheral blood T-cells. The inoculum dose of S. typhimurium or S. choleraesuis can also play an important role in the host immune response. TNF-a concentrations in the blood are much greater after a 106 S. typhimurium challenge than after a 104 S. typhimurium challenge. At high doses (;:o:l09 CFU) S. choleraesuis causes signs of lymphocyte suppression, which may affect the ability of the immune system to eliminate the bacteria. Pigs administered an intranasal dose of 108 CFU S. choleraesuis have similar immune responses as naturally infected animals

Pathogenesis, Transmission, and Control of Salmonellosis in Swine

The objectives of our project at the National Animal Disease Center are: 1. To identify virulence factors important in the pathogenesis of Salmonella choleraesuis and Salmonella typhimurium in swine 2. To define the epidemiology and transmission of Salmonella in swine 3. To define the porcine immune response to acute and chronic Salmonella infection focusing on mechanisms to reduce or eliminate the pathogenic organism 4. To identify methods to control Salmonella in swine

Association of bacterial infection traits with genetic variation at candidate genes for porcine disease resistance

We predict that it may be possible to improve pig disease resistance to Salmonella infection by studying genes that control a piglet’s initial immune response. The NRAMP1 gene controls susceptibility to multiple pathogens and acts within the macrophage. The BPI gene encodes a neutrophil protein with inhibitory/killing functions against multiple gram-negative bacteria. We investigated NRAMP1 and BPI as candidate genes for contributing to resistance in Salmonella choleraesuis (SC) challenge in pigs. Five NRAMP1 sequence differences (polymorphisms, SNPs) were found, while we cloned and sequenced the full-length BPI gene and identified four polymorphisms at BPI. The effects these polymorphisms have on resistance to infection were tested in two experimental disease studies. In study 1, results showed NRAMP1 and BPI genotypes were associated with decreased fecal bacterial load during infection (P values: \u3c .0006 to \u3c .06). Immune cell numbers were also associated with BPI genotypes. In the second study, many additional immune traits and spleen and liver bacterial counts were collected. The NRAMP1 genotypes were associated with bacterial count in liver (P \u3c .05 and P \u3c .0006) and with polymorphonuclear phagocytes (P values from \u3c .003 to \u3c .05). The BPI genotypes were significantly associated with bacteria uptake by immune cells and with bacterial counts in liver (P\u3c.1) and lymphocyte response post-challenge (P\u3c.0001). These data indicate NRAMP1 and/or BPI gene variation may control, in part, response to Salmonella infection in pigs, and that these differences could be used to identify resistant animals

6-hydroxydopamine-mediated release of norepinephrine increases faecal excretion of Salmonella enterica serovar Typhimurium in pigs

Salmonella enterica serovar Typhimurium is an animal and zoonotic pathogen of worldwide importance. In pigs, transport and social stress are associated with reactivation and spread of Salmonella Typhimurium infection. The stress-related catecholamine norepinephrine (NE) has been reported to activate growth and virulence factor expression in Salmonella; however the extent to which NE contributes to stress-associated salmonellosis is unclear. We studied the impact of releasing NE from endogenous stores during Salmonella Typhimurium infection of pigs by administration of 6-hydroxydopamine (6-OHDA), which selectively destroys noradrenergic nerve terminals. Treatment of pigs with 6-OHDA 7 or 16 days post-oral inoculation with Salmonella Typhimurium produced elevated plasma NE levels and transiently, but significantly, increased faecal excretion of the challenge strain. Oral administration of NE to Salmonella Typhimurium-infected pigs also transiently and significantly increased shedding; however pre-culture of the bacteria with NE did not alter the outcome of infection. Salmonella has been proposed to sense and respond to NE via a homologue of the adrenergic sensor kinase QseC. A ΔqseC mutant of Salmonella Typhimurium was consistently excreted in lower numbers than the parent strain post-oral inoculation of pigs, though not significantly so. 6-OHDA treatment of pigs infected with the ΔqseC mutant also increased faecal excretion of the mutant strain, albeit to a lesser extent than observed upon 6-OHDA treatment of pigs infected with the parent strain. Our data support the notion that stress-related catecholamines modulate the interaction of enteric bacterial pathogens with their hosts

Few-photon storage on a second timescale by electromagnetically induced transparency in a doped solid

We present the experimental demonstration of light storage towards the single photon level at a long storage time by electromagnetically induced transparency in a rare-earth ion-doped Pr³⁺:Y₂SiO₅ crystal. We apply decoherence control by static magnetic fields and appropriately designed radio-frequency composite pulse sequences to prolong the storage time in the memory. A rare-earth ion-doped filter crystal prepared by optical pumping serves to efficiently separate the signal at the single photon level from optical noise. Multipass setups around the memory and the filter crystal improve the storage efficiency and filter selectivity. Already without decoherence control, the setup permits storage of single photons in the microsecond regime at a storage efficiency of 42%. With decoherence control we demonstrate storage of weak coherent pulses containing some 10 photons for up to 10 s at a storage efficiency of several percent. The experimental data clearly demonstrate the applicability of EIT light storage to implement a true quantum memory in Pr³⁺:Y₂SiO₅ at long storage times. The scientific findings and technical developments are of relevance also to other protocols and media for quantum information storage