Major efforts have been made to reduce the use of colistin in livestock since the discovery of the plasmid-borne mobile colistin resistance () gene in a decade ago, to curb the burden of its potential transmission to other bacterial species, spread between animals, humans and the environment. This study explored the longitudinal prevalence and characteristics of colistin-resistant and extended-spectrum beta-lactamase-producing (ESBL) via in vivo fecal and ex vivo carcass swabs from two batches of conventional indoor and organic outdoor Wallon meat sheep from birth to slaughter in 2020 and 2021. Antimicrobial susceptibility testing via broth microdilution revealed that n = 16/109 (15%) isolates from conventional meat lamb fecal samples had a reduced colistin sensitivity (MIC = 0.
View Article and Find Full Text PDFDuring latency, herpesvirus infection results in the establishment of a dormant state in which a restricted set of viral genes are expressed. Together with alterations of the viral genome, several host genes undergo epigenetic silencing during latency. These epigenetic dysregulations of cellular genes might be involved in the development of cancer.
View Article and Find Full Text PDFGallid herpesvirus type 2 (GaHV-2) is an oncogenic alphaherpesvirus that induces malignant T-cell lymphoma in chicken. GaHV-2 encodes a viral telomerase RNA subunit (vTR) that plays a crucial role in virus-induced tumorigenesis, enhances telomerase activity, and possesses functions independent of the telomerase complex. vTR is driven by a robust viral promoter, highly expressed in virus-infected cells, and regulated by two c-Myc response elements (c-Myc REs).
View Article and Find Full Text PDFThe emergence of the SARS-CoV-2 virus and the exponential growth of COVID-19 cases have created a major crisis for public health systems. The critical identification of contagious asymptomatic carriers requires the isolation of viral nucleic acids, reverse transcription, and amplification by PCR. However, the shortage of specific proprietary reagents or the lack of automated platforms have seriously hampered diagnostic throughput in many countries.
View Article and Find Full Text PDFOrthobunyaviruses are arboviruses (Arthropod Borne Virus) and possess multipartite genomes made up of three negative RNAs corresponding to the small (S), medium (M) and large (L) segments. Reassortment and recombination are evolutionary driving forces of such segmented viruses and lead to the emergence of new strains and species. Retrospective studies based on phylogenetical analysis are able to evaluate these mechanisms at the end of the selection process but fail to address the dynamics of emergence.
View Article and Find Full Text PDFSchmallenberg virus (SBV), initially identified in Germany in 2011, spread rapidly throughout Europe causing significant economic losses in ruminant livestock. The ability to correctly detect emerging and re-emerging diseases such as SBV with reliable tests is of high importance. Firstly, we tested diagnostic performance, specificity, and sensitivity of three different assays used in SBV antibody detection using control sheep samples of determined status.
View Article and Find Full Text PDFModelling the long-term seroprevalence evolution against Schmallenberg virus (SBV) is of first interest to plan vaccination strategies and to predict viral resurgence. The objectives of this study were first to estimate the duration of colostral immunity and the persistence of active immunity in a sheep flock that encountered two episodes of natural SBV infection and then to model the evolution of SBV seroprevalence by considering immune status as well as zootechnical variables. The entire sheep flock of the University of Namur composed by around 400 ewes producing 600 lambs a year and characterized by an annual 24.
View Article and Find Full Text PDFA large sheep flock screened over a two-year period showed active spreading of Schmallenberg virus (SBV) during the summers of 2011 and 2012. Transplacental infections were observed during the two associated lambing periods (the winters of 2012 and 2013). Analysis of small (S) segment sequences of 38 SBV-positive samples, collected during periods of viral spreading and lambing revealed intra-herd sequences diversity and sub-consensus variability occurring after transplacental infections.
View Article and Find Full Text PDFIn 2011, European ruminant flocks were infected by Schmallenberg virus (SBV) leading to transient disease in adult cattle but abortions and congenital deformities in calves, lambs, and goat kids. SBV belonging to the Simbu serogroup (family Bunyaviridae and genus ) was first discovered in the same region where bluetongue virus serotype 8 (BTV-8) emerged 5 years before. Both viruses are transmitted by biting midges ( spp.
View Article and Find Full Text PDFSchmallenberg virus (SBV) is an emerging arbovirus infecting ruminants in Europe. SBV belongs to the Bunyaviridae family within the Simbu serogroup. Its genome comprises three segments, small (S), medium (M) and large (L), that together encode six proteins and contain NTRs.
View Article and Find Full Text PDFReemergence of Schmallenberg virus (SBV) occurred among lambs (n = 50) in a sheep flock in Belgium between mid-July and mid-October 2012. Bimonthly assessment by quantitative reverse transcription PCR and seroneutralization demonstrated that 100% of lambs were infected. Viremia duration may be longer in naturally infected than in experimentally infected animals.
View Article and Find Full Text PDFDetected for the first time in 2011, Schmallenberg virus (SBV) is an orthobunyavirus of the Simbu serogroup that caused a large outbreak in European ruminants. In a tight time frame, data have been obtained on SBV epidemiology and the clinical pictures associated with this new viral infection, but little information is available on the molecular biology of SBV. In this study, SBV sequence variability was characterized from the central nervous system of two stillborn lambs in a naturally infected herd.
View Article and Find Full Text PDFInfection with bluetongue virus serotype (BTV)-8 occurred in ruminants in 2006 in Central-Western Europe. The trans-placental passage of this virus has been demonstrated in naturally- and experimentally-infected cattle and in experimentally-infected sheep. Trans-placental transmission is potentially important in the 'over-wintering' of this virus and its subsequent impact on reproductive performance.
View Article and Find Full Text PDFHomologous recombination between different species of alphaherpesviruses has been described between herpes simplex viruses 1 and 2 but has not yet been observed between other alphaherpesviruses. In the present study we chose to assess to what extent in vitro recombination can occur between members of a well-defined group of closely related viruses such as ruminant alphaherpesviruses. At 24 h after infection of epithelial bovine kidney cells with a double-deleted mutant of bovine herpesvirus 1 (BoHV-1) (containing green fluorescent protein and red fluorescent protein genes) and different ruminant alphaherpesviruses, four types of progeny viruses were detected and distinguished according to their phenotype.
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