En helgenomstudie om resistens mot pseudotuberkulos hos svenska lantrasgetter

Pseudotuberkulos, orsakat av bakterien Corynebacterium pseudotuberculosis, är en kronisk sjukdom som drabbar getter världen över, inklusive i Sverige. Sjukdomen ger upphov till abscesser i kroppen och orsakar ekonomiska förluster. Ingen effektiv behandling finns mot sjukdomen och vid diagnos rekommenderas avlivning. I den här studien användes genotypdata från 83 svenska lantrasgetter, 13 fall och 70 kontroller, analyserade med GoatSNP50 Illumina chip. En fall-kontroll helgenomstudie utfördes för att identifiera samband mellan SNP och sjuk-domsstatus. Analysen visade att tre SNP, lokaliserade på kromosom 17 och 10, var signifikant associerade med pseudotuberkulos. Vidare identifierades två SNP med P-värden strax över signi-fikansgränsen på kromosom 13 och 18. Bland gener nära ovannämnda SNP identifierades genen CDH1 på kromosom 18, som kodar för proteinet E-cadherin, som mest troligt associerad med pseudotuberkulos. Den här kunskapen om genetisk resistens mot pseudotuberkulos hos get kan i framtiden användas för ökad förståelse om sjukdomen och potentiellt kan avel implementeras för ökad motståndskraft.Caseous lymphadenitis (CLA), caused by the bacterium Corynebacterium pseudotuberculosis, is a chronic disease that affects goats all over the world, including in Sweden. The disease gives rise to abscesses in the body and causes economic losses. No effective treatment exists for the disease and after diagnosis euthanasia is recommended. In this study, genotype data from 83 Swedish landrace goats, 13 cases and 70 controls, analyzed with GoatSNP50 Illumina chip were used. A case-control genome-wide association study was performed to identify associations between SNPs and disease status. The analysis identified three SNPs, on chromosomes 17 and 10, that were sig-nificantly associated with CLA. Furthermore, two SNPs with P-values just above the significance limit were identified on chromosomes 13 and 18. Among genes close to above mentioned SNPs, the CDH1 gene on chromosome 18 that codes for the protein E-cadherin, was identified as most likely associated with CLA. This knowledge of genetic resistance to CLA in goats can be used in the future for increased understanding of the disease and potentially can selective breeding be implemented for increased resistance

Serological evidence and spatial analysis of small ruminant lentiviruses in herds in Maranhão, Brazil

Caprine arthritis encephalitis and Maedi-Visna are lentiviruses affecting goats and sheep, respectively. Despite the literature having studies about these diseases, there is a constant demand and the need to study the health status of flocks that exploit economically. Therefore, this study aimed to assess the frequency of small ruminant lentiviruses explored in regional locations of Chapadinha and Itapecuru Mirim, that compose the microregion of Low Parnaíba, Maranhão, Brazil, as well as analyze the spatial distribution of outbreaks in the studied regions. Therefore, 241 properties were visited, where blood was collected in 1150 sheep and 1260 goats and tested by agar gel immunodiffusion (AGID). Epidemiological questionnaire was applied and collected the geographic coordinates. There was a low frequency for lentivirus, with 0.39% (5/1260) of goats and 0.08% (1/1150) of sheep. Regarding the spatial analysis, the reagent flocks were distributed in strategic cities for commercialization throughout the microregion. There was a low occurrence of lentiviruses. The municipalities of Cantanhede and Pirapemas of the regional of Itapecuru Mirim and Brejo and Magalhães de Almeida had reagent flocks for CAE. Whereas the municipality of Matões do Norte presented flock reagent to Maedi-Visna, this belonging to the regional of Chapadinha. &nbsp

Genome-wide association study of the antibody response to <i>Corynebacterium pseudotuberculosis</i> in sheep

Caseous lymphadenitis (CLA) is a chronic and highly contagious disease that is widespread among sheep and goats and adversely affects animal welfare and production. This study aimed to reveal the host genomic influences on Corynebacterium pseudotuberculosis antibody levels as indicators of disease susceptibility or resistance, thereby potentially identifying genetic markers associated with these traits. Blood samples were collected from 321 sheep from four large Czech sheep herds. Animals of the Suffolk breed, ranging in age from 2 to 8 years, were sampled regularly once a year for 4 years. The sheep were classified into healthy and diseased groups based on two different commercial enzyme-linked immunosorbent assay (ELISA) serological antigen tests. Genomic DNA was genotyped with the GeneSeek® Genomic Profiler™ Ovine 50 K, and 41 301 markers were used for the genome-wide association analysis (GWAS). A case–control GWAS including 143 seropositive and 178 seronegative sheep was conducted to assess the relationship between the sheep genome and the antibody response to a phospholipase D antigen of C. pseudotuberculosis using GCTA software. The study revealed two suggestive SNPs (single-nucleotide polymorphisms) on chromosomes 11 and 20, with the most significant SNP in the first exon of the TRIM16 (tripartite-motif-containing 16) gene. By analysing genomic alterations and their context between positive and negative animals, including a gene ontology (GO) analysis of genes within ± 500 kb regions of the suggestive SNPs, we identified genes and immune-related processes and pathways potentially influencing CLA susceptibility. These include antigen processing and presentation of exogenous peptides via major histocompatibility complex (MHC) class I and II, Th17 mucosal cell differentiation, cellular autophagy, and phagosome-related mechanisms. This research provides insights into the genetic basis of the antibody response to C. pseudotuberculosis, identifying suggestive associations and underlying biological mechanisms that could guide future breeding and genetic strategies for improving resistance to CLA in sheep.</p

A Seroepidemiological Survey of <i>Corynebacterium pseudotuberculosis</i> Infection in South Tyrol, Italy

Corynebacterium pseudotuberculosis is the causative agent of caseous lymphadenitis, a bacterial infection that can affect livestock. This infection can cause low growth rates and milk yields and reproductive failure, along with the infection of humans, especially those in close contact with the animals. The aim of this study was to evaluate the local CLA prevalence, highlighting the parameters for the potential predisposition to infection in goats, and to implement a monitoring program based on the newly acquired scientific evidence. Of a total of 2365 goat farms in South Tyrol, 384 farms were selected for the present study. A statistically significant number of animals were subjected to serologic analysis for the detection of C. pseutotubercolosis antibodies. A total of 2948 goats belonging to the selected farms were tested for CLA, 713 of which showed a positive result. The data analysis led to an estimated CLA seroprevalence of 21.85%. The results achieved can enable the evaluation and possible implementation of a voluntary program that permits us to test a larger number of animals using serological techniques. This program would be of great importance, especially for those farms dedicated to the production of milk and dairy products, as some manufacturing practices may increase the risk of transmission of zoonotic pathogens such as C. pseudotuberculosis to humans