Survival of Salmonella serovar Typhimurium inside porcine monocytes is associated with complement binding and suppression of the production of reactive oxygen species

Macrophages are thought to play a major role in the development of Salmonella carriers in swine. It was the aim of the present study to characterize the interactions of a Salmonella serovar Typhimurium strain with porcine peripheral blood monocytes. The production of reactive oxygen species (ROS) by monocytes and the numbers of intracellularly killed bacteria differed significantly between the different pigs used. Opsonization of Salmonella bacteria with complement significantly decreased bacterial killing. Interestingly, monocytic ROS production was suppressed by metabolically active bacteria. In conclusion, binding to host complement and suppression of monocyte ROS production enable ser. Typhimurium to survive for at least 6 hours in porcine monocytes. Moreover, individual differences of porcine monocytes to produce ROS and to kill the intracellular Salmonella bacteria might account for the development of the carrier state in some pigs and not in others

The influence of fatty acids on the expression of virulence genes of Salmonella Typhimurium and the colonization of pigs

Salmonella Typhimurium infections in pigs are a major source of human foodborne salmonellosis. To reduce the number of infected pigs, actdified feed or drinking water can be administrated. A study was carried out to evaluate the use of short-chain fatty acids (SCFA) and medium-chain fatty acids (MCFA) for the control of Salmonella Typhimurium infections in ptgs. Short-chain fatty acids formate, acetate, propionate and butyrate (pH 6, osm 600, cone 1 OmM) and medium-chain fatty acids caproic, caprylic and capric acid (pH6, osm 600, cone 2mM) were used

Evolution of antimicrobial resistance of Salmonella isolates from pigs in Belgium

The aim of the present study was to investigate the antimicrobial sensitivity of Salmonella isolates from pigs between 2011 and 2015. In total, 275 Salmonella isolates from samples originating from pigs sent in for diagnostic examination at Animal Health Care Flanders were tested for their sensitivity against different antimicrobials. Except for colistin, where the disk prediffusion test was used, the disk diffusion test was used. E. coli ATCC 25922 was used as reference isolate and the interpretative breakpoints were based on the Clinical and Laboratory Standards Institute

SPI-2 of Salmonella Typhimurium is not necessary for long term colonization of pigs

Unravelling the role of Salmonella virulence factors in the porcine host could greatly contribute to the development of control measures such as vaccination. The virulence genes located on the Salmonella Pathogenicity Island 2 (SPI-2) are indispensable for the induction of systemic disease and persistence in BALB/c mice. The role of this pathogenicity island in the pathogenesis of Salmonella Typhimurium infections in pigs is not documented. Therefore, in the present study, the interactions of a porcine field strain of Salmonella Typhimurium and a non-polar isogenic SPI-2 (D-ssrA) deletion mutant were compared in both in vitro and in vivo models. The ssrA mutant strain displayed decreased SPI-2 expression levels in vitro and was attenuated in a mouse model after oral inoculation. No difference was seen in the expression of SPI-1 related virulence genes. Through flowcytometric analysis, the ssrA mutant strain was found to be moderately attenuated in intracellular replication in porcine macrophages in vitro. In an infection experiment, 2 groups of 10 piglets were orally inoculated with the wild type or the ssrA mutant strain. The infection of the animals inoculated with the ssrA mutant strain followed a similar course as the animals infected with the wild type strain. At days 5 and 28 post inoculation, the animals of both groups were infected to the same extent in the gut and gut-associated lymphoid tissue, as well as in the mternal organs. These results suggest that SPI-2 of Salmonella Typhimurium may not contribute to the colonization of pigs to the same extent as it contributes to the colonization of BALB/c mice

Mitigating amphibian chytridiomycoses in nature

Amphibians across the planet face the threat of population decline and extirpation caused by the disease chytridiomycosis. Despite consensus that the fungal pathogens responsible for the disease are conservation issues, strategies to mitigate their impacts in the natural world are, at best, nascent. Reducing risk associated with the movement of amphibians, non-amphibian vectors and other sources of infection remains the first line of defence and a primary objective when mitigating the threat of disease in wildlife. Amphibian-associated chytridiomycete fungi and chytridiomycosis are already widespread, though, and we therefore focus on discussing options for mitigating the threats once disease emergence has occurred in wild amphibian populations. All strategies have shortcomings that need to be overcome before implementation, including stronger efforts towards understanding and addressing ethical and legal considerations. Even if these issues can be dealt with, all currently available approaches, or those under discussion, are unlikely to yield the desired conservation outcome of disease mitigation. The decision process for establishing mitigation strategies requires integrated thinking that assesses disease mitigation options critically and embeds them within more comprehensive strategies for the conservation of amphibian populations, communities and ecosystems

Transmission study of Salmonella in pigs with 3 intervention strategies

In this study, the effect of 3 different intervention strategies on the transmission of Salmonella in pigs was evaluated: feed supplementation with coated calcium-butyrate salt, vaccination and acidified drinking water. Strategies were evaluated serologically and bacteriologically using an experimental in vivo seeder setup. Significantly higher antibody titers were detected in the groups with acidified drinking water and vaccination

Remote severity assessment in atopic dermatitis:Validity and reliability of the remote Eczema Area and Severity Index and Self-Administered Eczema Area and Severity Index

Background: Reliable assessment of atopic dermatitis (AD) severity is necessary for clinical practice and research. Valid and reliable remote assessment is essential to facilitate remote care and research. Objectives: Assess the validity and reliability of the Eczema Area and Severity Index (EASI) based on images and patient-assessed severity based on the Self-Administered EASI (SA-EASI). Methods: Whole-body clinical images were taken during consultation from children with AD. After consultations, caregivers completed the SA-EASI and provided images from home. Four raters assessed all images twice using EASI. Results: A total of 1534 clinical images and 425 patient-provided images were collected from 87 and 32 children. Excellent (0.90) validity, good inter (0.77) and intrarater reliability (0.91), and standard error of measurement (4.31) was found for the EASI based on clinical images. Feasibility of patient-provided images showed limitations with missing images (43.8%) and quality issues (23.1%). However, good validity (0.86), inter (0.74) and intrarater reliability (0.94) were found when assessment was possible. Moderate correlation (0.60) between SA-EASI and EASI was found. Limitations: Low portion patient-provided images. Conclusion: AD severity assessment based on images strongly correlates with in-person AD assessment. Good measurement properties confirm the potential of remote assessment. Moderate correlation between SA-EASI and in-person EASI suggest limited value of self-assessment.</p

Stress induced Salmonella Typhimurium re-excretion by pigs is associated with cortisol induced increased intracellular proliferation in porcine macrophages

Infections of pigs with Salmonella enterica subspecies enterica serovar Typhimurium (Salmonella Typhimurium) often result in the development of carriers that intermittently excrete Salmonella in very low numbers. During periods of stress, recrudescence of Salmonella may occur

Expanding distribution of lethal amphibian fungus Batrachochytrium salamandrivorans in Europe

Emerging fungal diseases can drive amphibian species to local extinction. During 2010-2016, we examined 1,921 urodeles in 3 European countries. Presence of the chytrid fungus Batrachochytrium salamandrivorans at new locations and in urodeles of different species expands the known geographic and host range of the fungus and underpins its imminent threat to biodiversity