180 research outputs found
Neoplasms and novel gammaherpesviruses in critically endangered captive European minks (Mustela lutreola)
13 Päg.
Centro de Investigación en Sanidad Animal (CISA)The European mink (Mustela lutreola) is a riparian mustelid, considered one of the most endangered carnivores in the world. Alpha, beta and gammaherpesviruses described in mustelids have been occasionally associated with different pathological processes. However, there is no information about the herpesviruses species infecting European minks. In this study, 141 samples of swabs (oral, conjunctival, anal), faeces and tissues from 23 animals were analysed for herpesvirus (HV) using a pan-HV-PCR assay. Two different, potentially novel, gammaherpesvirus species were identified in 12 samples from four animals (17.3%), and tentatively named Mustelid gammaherpesvirus-2 (MUGHV-2) and MuGHV-3. Gross examination was performed on dead minks (n = 11), while histopathology was performed using available samples from HV-positive individuals (n = 2), identifying several neoplasms, including B-cell lymphoma (identified by immunohistochemistry) with intralesional syncytia and intranuclear inclusion bodies characteristic of HV (n = 1), pulmonary adenocarcinoma (n = 1), and biliary (n = 1) and preputial (n = 1) cystadenomas, as well as other lesions (e.g., axonal vacuolar degeneration [n = 2] and neuritis [n = 1]). Viral particles, consistent with HVs, were observed by electron microscopy in the mink with neural lymphoma and inclusion bodies. This is the first description of neoplasms and concurrent gammaherpesvirus infection in European minks. The pathological, ultrastructural and PCR findings (MuGHV-2) in the European mink with lymphoma strongly suggest a potential role for this novel gammaherpesvirus in its pathogenesis, as it has been reported in other HV-infected species with lymphoma. The occurrence of neural lymphoma with intralesional syncytia and herpesviral inclusions is, however, unique among mammals. Further research is warranted to elucidate the potential oncogenic properties of gammaherpesviruses in European mink and their epidemiology in the wild population.Innovation Initiative Grant (IIG) of the Edinburgh Fund (University of Edinburgh); Norwegian University of Life Sciences; Generalitat de Catalunya; São Paulo Research Foundation, Grant/Award Number: 2018/20956-08 and 2018/25069-7; University of EdinburghPeer reviewe
Evidence of alphaherpesvirus infections in Alaskan caribou and reindeer
<p>Abstract</p> <p>Background</p> <p>The reindeer (<it>Rangifer tarandus tarandus</it>) industry in Alaska began with animals imported from Siberia (Russia) in the 1890's. Cervid herpes virus 2 (CvHV2) is endemic in reindeer in Scandinavia. We sought to determine if the same virus, or similar herpesviruses, were circulating in Alaskan reindeer and caribou (<it>Rangifer tarandus granti</it>). Serum samples from 292 reindeer were collected during annual reindeer handlings (1988-2005) near Nome, Alaska. In 2005, swab samples were collected from 40 calves from this herd, near Nome, Alaska. In 2007, ocular and nasal swab samples were collected from 30 apparently healthy reindeer calves near Wales, Alaska. Samples of plasma and white blood cells were collected from three Alaskan caribou herds, Mulchatna (n = 24), Teshekpuk (n = 34) and the Western Arctic (n = 87) in 2009.</p> <p>Results</p> <p>Of 292 reindeer samples tested by ELISA for antibodies against alphaherpesvirus (bovine herpesvirus 1 as antigen), seroprevalence was 47% (136/292) and adult reindeer had higher seroprevalence than yearlings. The overall seroprevalence for caribou was 60% (87/145), with no significant differences among caribou herds. A virus neutralization test of 20 samples from both reindeer and caribou showed that ELISA positive samples always neutralized CvHV2 to a greater extent than BoHV1 or elk herpesvirus (ElkHV), indicating that CvHv2 is the most likely virus circulating. PCR of nasal and ocular swabs sampled from 30 reindeer calves in Wales, Alaska (2007) yielded four CvHV2 positive samples. PCR amplicons of the expected size (294 bp) were obtained from 2 of the 36 buffy coats samples from caribou, and the amplicon sequences were consistent with CvHV2.</p> <p>Conclusions</p> <p>This study shows that Alaskan reindeer and Caribou are infected with an alphaherpesvirus. Based on sequence similarity, CvHV-2 is the most likely virus. Further studies should be conducted to determine the impact of this infection on the health of these animals.</p
Characterisation of South African field Ehrlichia ruminantium using multilocus sequence typing
DATA AVAILABILITY : The data that support the findings of this study are available
on request from the corresponding author, Z.D.Heartwater, one of the major tick-borne diseases of some domestic and wild ruminants in
Africa, is caused by Ehrlichia ruminantium. The genetic diversity of E. ruminantium isolates
renders the available vaccine ineffective against certain virulent isolates. To better
understand the E. ruminantium genotypes in South Africa, a total of 1004 Amblyomma
hebraeum tick deoxyribonucleic acid (DNA) samples from cattle in three South African
provinces were tested by pCS20 Sol1 real-time polymerase chain reaction (qPCR) and
characterised by multilocus sequence typing (MLST) using five housekeeping genes. Out
of 1004 samples tested, 222 (22%) were positive for E. ruminantium. The occurrence of E.
ruminantium in Mpumalanga, KwaZulu-Natal and Limpopo provinces was 19%, 22% and
27%, respectively. The E. ruminantium positive samples were screened for housekeeping
genes and sequenced. Phylogenetic analysis revealed three main lineages: clade 1 made up
of worldwide isolates (eastern, southern Africa, and Caribbean isolates), clade 2 comprised
only West African isolates and clade 3 consisted of Omatjenne, KuĚmm2 and Riverside.
Some study sample sequences were not identical to any of the reference isolates. However,
they could all be grouped into the worldwide clade. Genetic variation in the sequenced
regions was observed in the form of single nucleotide polymorphisms (SNPs). Using
MLST to characterise E. ruminantium field isolates allowed the South African genotypes to
be clearly distinguished from the distinct West African isolates.
CONTRIBUTION : Characterisation of E. ruminantium field isolates is important for the control of
heartwater and contributes to preliminary knowledge required for the development of a more
practical vaccine against heartwater.LEAP-Agri (ANR), AgriSETA and the Belgian Directorate-General for Development Co-operation Framework Agreement 4.http://www.ojvr.orgam2024Veterinary Tropical DiseasesSDG-03:Good heatlh and well-bein
Seroprevalence and associated risk factors of bovine neosporosis in the Khomas region of Namibia
DATA AVAILABILITY : The data gathered during this research is available from the
corresponding author upon reasonable request.Neospora caninum is a coccidian parasite that occurs worldwide and is one of the most important causes of abortion, especially in cattle. However, no studies have been performed in Namibia to determine the N. caninum status in livestock. Therefore, this study aimed to determine the seroprevalence of N. caninum in cattle and the associated risk factors in the Khomas region of Namibia. A total of 736 sera were collected from cows in 32 farming establishments. These comprised 698 beef and 38 dairy cattle sera and were tested using a commercial enzyme-linked immunosorbent assay (ELISA) kit. Questionnaires were concurrently administered to determine possible risk factors associated with N. caninum seropositivity. A total of 42 sera were positive (all beef), giving an animal-level seroprevalence rate of 5.7%. Eight of the 32 establishments had at least one positive animal, giving a herd-level seroprevalence of 25%. There was no significant association between seropositivity and the presence of dogs, jackals, history of abortions, farm size, number of cattle or average annual rainfall. The establishments with moderate to high numbers of Feliformia were 9.8 times more likely to be seropositive to N. caninum than those with none to low levels of the former (p = 0.0245). The authors concluded that the seroprevalence level of N. caninum in the Khomas region was relatively low compared with other parts of the world and that the role of Feliformia in the epidemiology of bovine neosporosis needed to be further investigated.
CONTRIBUTION: Serological evidence of bovine neosporosis and the associated risk factors are reported in Namibia for the first time. This study contributes to the scientific body of knowledge on N. caninum in Africa, which is currently limited.The Meat Board of Namibia funded the purchase of the IDEXX ELISA kits used in this study.http://www.ojvr.orgam2024Veterinary Tropical DiseasesSDG-02:Zero HungerSDG-03:Good heatlh and well-bein
Genome-wide diversity, population structure and signatures of inbreeding in the African buffalo in Mozambique
DATA AVAILABILITY : All sequence data presented here (fastq format) have been deposited into the NCBI SRA database (accession number: PRJNA971211).The African buffalo, Syncerus caffer, is a key species in African ecosystems. Like other large herbivores, it plays a fundamental role in its habitat acting as an ecosystem engineer. Over the last few centuries, African buffalo populations have declined because of range contraction and demographic decline caused by direct or indirect human activities. In Mozambique, historically home to large buffalo herds, the combined effect of colonialism and subsequent civil wars has created a critical situation that urgently needs to be addressed. In this study, we focused on the analysis of genetic diversity of Syncerus caffer caffer populations from six areas of Mozambique. Using genome-wide SNPs obtained from ddRAD sequencing, we examined the population structure across the country, estimated gene flow between areas under conservation management, including national reserves, and assessed the inbreeding coefficients. Our results indicate that all studied populations of Syncerus caffer caffer are genetically depauperate, with a high level of inbreeding. Moreover, buffaloes in Mozambique present a significant population differentiation between southern and central areas. We found an unexpected genotype in the Gorongosa National Park, where buffaloes experienced a dramatic population size reduction, that shares a common ancestry with southern populations of Catuane and Namaacha. This could suggest the past occurrence of a connection between southern and central Mozambique and that the observed population structuring could reflect recent events of anthropogenic origin. All the populations analysed showed high levels of homozygosity, likely due to extensive inbreeding over the last few decades, which could have increased the frequency of recessive deleterious alleles. Improving the resilience of Syncerus caffer caffer in Mozambique is essential for preserving the ecosystem integrity. The most viable approach appears to be facilitating translocations and re-establishing connectivity between isolated herds. However, our results also highlight the importance of assessing intraspecific genetic diversity when considering interventions aimed at enhancing population viability such as selecting suitable source populations.This research was supported by the projects âTraining in Biodiversity and Biotechnology for sustainable developmentâ (AID 11096) and BioForMoz âSupport for Environmental Researchâ (AID 12089) managed by the Department of Biomedical Sciences, University of Sassari, Italy, and funded by the Italian Agency for Development Cooperation, Italy.
Open Access funding enabled and organized by Projekt DEAL.https://bmcecolevol.biomedcentral.comhj2024Veterinary Tropical DiseasesSDG-15:Life on lan
Risk assessment on import of Australian redclaw crayfish to Norway. Opinion of the Panel on Animal Health and Welfare of the Norwegian Scientific Committee for Food Safety
Source at https://vkm.no/english/riskassessments/allpublications/assessmentofriskstoanimalhealthandbiodiversityfromimportandfarmingofaustralianredclawcrayfish.4.2375207615dac0245aee2789.html.Main message: It seems unlikely that the Australian red claw clayfish will establish reproductive populations under Norwegian climate conditions, but hitchhiker organisms and infectious agents could potentially follow the import, and unless managed, may pose risks to biodiversity and aquatic animal health. This is the conclusion in a risk assessment from the Norwegian Scientific Committee for Food Safety (VKM)
- âŚ