Search Results (15)

Water buffaloes in northern Australia occupy tropical wetlands where conditions favour the proliferation of arthropod vectors and the transmission of vector-borne livestock diseases. However, their role in maintaining economically important arboviruses such as Akabane virus (AKAV), bluetongue virus (BTV), and bovine ephemeral fever virus (BEFV) remains poorly understood. These three viruses cause significant production losses in cattle and pose ongoing surveillance challenges in remote areas. To assess exposure to these viruses, a convenience sample of feral water buffaloes from the Northern Territory, Australia, was collected. Commercial enzyme-linked immunosorbent assays (ELISAs) were used to detect antibodies against AKAV, BTV, and BEFV in 119 samples stored as dried blood on filter paper. Seroprevalence was 18.5% for AKAV, 66.4% for BTV, and 15.1% for BEFV. These results are consistent with previous serological studies in northern Australian cattle, confirming the circulation of these pathogens in the region. Our findings demonstrate that water buffaloes are exposed to these economically important arboviruses and may contribute to their maintenance, highlighting the need to consider feral buffalo populations in regional arbovirus surveillance strategies and livestock disease management. Full article

Background/Objectives: Bovine ephemeral fever (BEF) is a significant disease affecting the cattle industry. The current control strategy for BEF in the field primarily relies on inactivated vaccines. However, some individuals have experienced hypersensitive reactions to these vaccines, prompting the exploration of subunit vaccines as a potential alternative for BEF prevention. Glycoprotein (G protein)-based subunit vaccines derived from virions have successfully induced neutralizing antibodies in cattle for over a decade. Nevertheless, the lack of recent studies evaluating their efficacy using recombinant proteins has raised concerns regarding the development of BEF subunit vaccines for practical field application. Therefore, the objective of this study was to evaluate the antigenicity of a novel truncated G protein produced in mammalian cells as a candidate subunit vaccine for BEF in cattle. Methods: In this study, the G protein with full ectodomain and a version truncated at the C-terminal domain were successfully generated using the ExpiCHO™ expression system. Vaccine efficacy was evaluated weekly by measuring neutralizing antibody titers and cytokine mRNA expression levels following vaccination. Results: Results show that the recombinant protein s510, derived from the G protein of BEF, can stimulate cattle to produce an average 35-fold increase in neutralizing antibodies after three doses of vaccination. The significant upregulation of IFN-γ mRNA supports the effectiveness of the s510-based subunit vaccine and indicates the activation of a cytotoxic immune response in cattle following vaccination. Conclusions: In conclusion, the results indicate that the recombinant protein s510 is a promising antigen for future BEF subunit vaccine development in this study. Full article

Bovine ephemeral fever is an arthropod-borne viral disease that affects cattle and buffalo in many regions of the world; it causes heavy economic losses in the cattle industry. To date, all BEFV-specific diagnostic molecular assays have been based on the variable glycoprotein (G-protein)-coding genome region, potentially allowing the pathogen to escape detection. We developed two new assays, based on the less variable nucleoprotein genome region, and compared them with two G-protein-based assays. For this comparison, we used 245 samples comprising positive and negative field samples from Israeli outbreaks caused by different strains, belonging to lineage I and IIIa, as well as Australian and Japanese strains (lineages IV and IIIb). The new assays showed high agreement with the previous assay (Kappa = 0.92), detecting 144 out of 147 positive samples (sensitivity of 97.96%), and detected 6 more samples as positive out of 98 samples found negative by the G-protein-based assay. All nine non-agreeing results were validated as positive using a conventional RT-PCR assay. The new assays have higher analytical sensitivity than the previous assays, can be combined with internal controls, and enable the detection of all known BEFVs. The results indicate that these two nucleoprotein-based real-time RT-qPCRs can serve as fast, sensitive, and specific assays for the sustainable detection of BEFV strains. Full article

One of the major factors hindering efficient livestock production is the presence of high-impact infectious animal diseases, such as foot and mouth disease (FMD), lumpy skin disease (LSD), and bovine ephemeral fever (BEF), which are notable viral infections affecting cattle in Egypt, leading to significant economic losses. FMD is caused by the foot and mouth disease virus (FMDV) of the genus Aphthovirus in the Picornaviridae family. LSD is caused by lumpy skin disease virus (LSDV) of Capripox genus within the Poxviridae family, subfamily Chordopoxvirinae. BEF is caused by bovine ephemeral fever virus (BEFV) of genus Ephemerovirus in the Rhabdoviridae family. FMD is a highly contagious viral infection of domestic and wild cloven-hooved animals and can spread through the wind. On the other hand, LSD and BEF are arthropod-borne viral diseases that mainly affect domestic cattle and water buffalo. Despite government vaccination efforts, these three viral diseases have become widespread in Egypt, with several reported epidemics. Egypt’s importation of large numbers of animals from different countries, combined with unregulated animal movements through trading and borders between African countries and Egypt, facilitates the introduction of new FMDV serotypes and lineages not covered by the current vaccination plans. To establish an effective control program, countries need to assess the real epizootic situation of various infectious animal diseases to develop an efficient early warning system. This review provides information about FMD, LSD, and BEF, including their economic impacts, causative viruses, global burden, the situation in Egypt, and the challenges in controlling these diseases. Full article

Bovine ephemeral fever (BEF) is an arthropod-borne viral disease, which frequently causes significant epizootics in susceptible water buffalo and cattle in Africa, Australia, Asia and the Middle East. In the current study, a two-stage protocol for BEFV viral isolation was developed. Data on the clinical signs, geographic distribution and phylogenetic analysis of BEFV strains isolated in Israel in 2015, 2018, 2021 and 2023 were summarized. It was found that during 2015–2021, all BEF outbreaks were caused by local BEFV strains, whereas the epizootic of BEFV in 2023 was caused by a new “Mayotte-like” BEFV strain. A comparison of bluetongue (BT) and BEF outbreaks during 2023 in Israel demonstrated that the incidence of BEFV was 2.21 times higher and its pathogenicity was more serious for the cattle population compared to that caused by BTVs. A phylogenetic analysis of Israeli and global BEFV revealed the emergence of non-local strains in new areas. This finding suggests that BEFV can no longer be classified based only upon geographic distribution. Considering a phylogenetic, genetic and proteomic analysis of all available BEFV strains, we suggest classifying them as a single serotype, which includes four lineages. Full article

The water buffalo (Bubalus bubalis) has great adaptability to rustic environments and more variable conditions than cattle, who generally share the habitat. Diseases carried by buffaloes are relatively unknown and ignored and could be transmissible; an imbalance occurs between pathogens, environment, and susceptible hosts, generating a severe animal health problem. Also relevant is the effect of climate change on the populations of vectors that transmit viral diseases. The discovery of new virus variants that can pass from bovine (Bos) to buffalo or vice versa or to humans has highlighted the relevance of viruses crossing the host barrier. This review discusses the clinical viral diseases most reported in the water buffalo, characteristics, epidemiology, and recent findings about disease behavior, interaction with other species, the host, vectors, and pathogens. Diseases reviewed include Foot and Mouth Disease, Rinderpest, Malignant Catarrhal Fever, Infectious Bovine Rhinotracheitis, Bovine Viral Diarrhea, and Rabies. Also, vector-borne diseases include Lumpy Skin Disease, Ephemeral Fever, and Blue Tongue. The review also considers emerging viruses such as Buffalo Pox and Schmallenberg and, finally, other viruses such as papillomatosis. The knowledge and epidemiology of buffalo viral diseases must be constantly reconsidered and updated for adequate prevention and control programs. Full article

Bovine ephemeral fever virus (BEFV) is an arthropod-borne virus (arbovirus) transmitted by blood-feeding insects (mosquitoes and Culicoides biting midges). While the dispersal of arboviral diseases such as bovine ephemeral fever (BEF) into naive areas is often the result of globalization and animal movement, the endemization and local outbreaks of these diseases are mainly influenced by environmental changes. Climate change affects the activity, distribution, dynamics, and life cycles of these vectors (arthropods), the replication of viruses within their vectors, and weakens animal’s immune systems. Although BEF does not currently occur in the Americas and Europe (other than in the western regions of Turkey), the risk of BEFV emergence, spread, and endemization in Europe is real. Over the past two decades, arboviruses such as the bluetongue virus (BTV) and Schmallenberg virus (SBV) have emerged in Europe without warning and caused significant losses to the dairy and meat industries. Since the European cattle population has never been exposed to BEFV, the economic losses to dairy and beef production in this continent due to the reduction in milk production, loss of valuable cows, and abortion, should BEF emerge, would probably be considerable. Moreover, arboviruses can also cause substantial financial damage due to restrictions on animal trade and transportation, like the current EHDV-8 outbreak in the Mediterranean basin. In this study, we used national data stored in the Israeli herd book to examine the economic aspects of BEF outbreaks in affected dairy cattle farms countrywide. Our results demonstrate that BEF outbreaks can have immediate and delayed effects, causing severe economic losses due to culling (loss of valuable cows) and a reduction in milk production that affects dairy farm income for months after clinical diagnosis. To our knowledge, this is the first extensive study on the impact of a BEF outbreak at a population level, enabling to conduct accurate risk assessments in future cases of BEFV emergence and re-emergence. Full article

Outbreaks of arthropod-borne (arbo) viruses that infect livestock impact the health and welfare of domestic and wild animals are often responsible for significant economic losses in livestock production. Surveillance and early warning systems effectively predict the emergence and re-emergence of arboviral disease. This paper presents the interim results of five years monitoring the exposure of sentinel naïve heifers and Culicoides biting midges (Diptera; Ceratopogonidae) to bovine ephemeral fever virus (BEFV), Simbu serogroup viruses, bluetongue viruses (BTV), and epizootic hemorrhagic disease viruses (EHDV). The data were collected from 11 dairy farms situated within eight different geographical regions in Israel. The results indicate that cattle in Israel are affected by all four viruses from the early summer onward. The investigated viruses exhibit unique site-specific profiles in both ruminants and vectors. The potential of several vectors to transmit these viruses and lack of cross-protection to re-infection with multiple serotypes (BTV and EHDV) or species (Simbu serogroup viruses) highlights some likely mechanisms that may play a role in these viruses’ maintenance cycle and possible endemization in our region. Full article

Infectious agents including viruses are important abortifacients and can cause fetal abnormalities in livestock animals. Here, samples that had been collected in Israel from aborted or malformed ruminant fetuses between 2015 and 2019 were investigated for the presence of the following viruses: the reoviruses bluetongue virus (BTV) and epizootic hemorrhagic disease virus (EHDV), the flaviviruses bovine viral diarrhea virus (BVDV) and border disease virus (BDV), the peribunyaviruses Shuni virus (SHUV) and Akabane virus (AKAV), bovine herpesvirus type 1 (BoHV-1) and bovine ephemeral fever virus (BEFV). Domestic (cattle, sheep, goat) and wild/zoo ruminants were included in the study. The presence of viral nucleic acid or antigen could be confirmed in 21.8 % of abnormal pregnancies (213 out of 976 investigated cases), with peribunyaviruses, reoviruses and pestiviruses being the most prevalent. At least four different BTV serotypes were involved in abnormal courses of pregnancy in Israel. The subtyping of pestiviruses revealed the presence of two BDV and several distinct BVDV type 1 strains. The peribunyaviruses AKAV and SHUV were identified annually throughout the study period, however, variation in the extent of virus circulation could be observed between the years. In 2018, AKAV even represented the most detected pathogen in cases of small domestic ruminant gestation abnormalities. In conclusion, it was shown that various viruses are involved in abnormal courses of pregnancy in ruminants in Israel. Full article

Dual vaccines (n = 6) against both lumpy skin disease (LSD) and bovine ephemeral fever (BEF) were constructed, based on the BEFV glycoprotein (G) gene, with or without the BEFV matrix (M) protein gene, inserted into one of two different LSDV backbones, nLSDV∆SOD-UCT or nLSDVSODis-UCT. The inserted gene cassettes were confirmed by PCR; and BEFV protein was shown to be expressed by immunofluorescence. The candidate dual vaccines were initially tested in a rabbit model; neutralization assays using the South African BEFV vaccine (B-Phemeral) strain showed an African consensus G protein gene (Gb) to give superior neutralization compared to the Australian (Ga) gene. The two LSDV backbones expressing both Gb and M BEFV genes were tested in cattle and shown to elicit neutralizing responses to LSDV as well as BEFV after two inoculations 4 weeks apart. The vaccines were safe in cattle and all vaccinated animals were protected against virulent LSDV challenge, unlike a group of control naïve animals, which developed clinical LSD. Both neutralizing and T cell responses to LSDV were stimulated upon challenge. After two inoculations, all vaccinated animals produced BEFV neutralizing antibodies ≥ 1/20, which is considered protective for BEF. Full article

Bovine ephemeral fever virus (BEFV) is an overlooked pathogen, recently gaining widespread attention owing to its associated enormous economic impacts affecting the global livestock industries. High endemicity with rapid spread and morbidity greatly impacts bovine species, demanding adequate attention towards BEFV prophylaxis. Currently, a few suboptimum vaccines are prevailing, but were confined to local strains with limited protection. Therefore, we designed a highly efficacious multi-epitope vaccine candidate targeted against the geographically distributed BEFV population. By utilizing immunoinformatics technology, all structural proteins were targeted for B- and T-cell epitope prediction against the entire allele population of BoLA molecules. Prioritized epitopes were adjoined by linkers and adjuvants to effectively induce both cellular and humoral immune responses in bovine. Subsequently, the in silico construct was characterized for its physicochemical parameters, high immunogenicity, least allergenicity, and non-toxicity. The 3D modeling, refinement, and validation of ligand (vaccine construct) and receptor (bovine TLR7) then followed molecular docking and molecular dynamic simulation to validate their stable interactions. Moreover, in silico cloning of codon-optimized vaccine construct in the prokaryotic expression vector (pET28a) was explored. This is the first time HTL epitopes have been predicted using bovine datasets. We anticipate that the designed construct could be an effective prophylactic remedy for the BEF disease that may pave the way for future laboratory experiments. Full article

During industrial-scale production of viruses for vaccine manufacturing, anti-viral response of host cells can dampen maximal viral antigen yield. In addition to interferon responses, many other cellular responses, such as the AMPK signaling pathway or senescence-like response may inhibit or slow down virus amplification in the cell culture system. In this study, we first performed a Gene Set Enrichment Analysis of the whole-genome mRNA transcriptome and found a senescence-like cellular response in BHK-21 cells when infected with bovine ephemeral fever virus (BEFV). To demonstrate that this senescence-like state may reduce virus growth, BHK-21 subclones showing varying degrees of a senescence-like state were infected with BEFV. The results showed that the BHK-21 subclones showing high senescence staining could inhibit BEFV replication while low senescence-staining subclones are permissive to virus replication. Using a different approach, a senescence-like state was induced in BHK-21 using a small molecule, camptothecin (CPT), and BEFV susceptibility were examined. The results showed that CPT-treated BHK-21 is more resistant to virus infection. Overall, these results indicate that a senescence-like response may be at play in BHK-21 upon virus infection. Furthermore, cell clone selection and modulating treatments using small molecules may be tools in countering anti-viral responses. Full article

In this study, we demonstrate the synthesis of carbonized nanogels (CNGs) from an amino acid (lysine hydrochloride) using a simple pyrolysis method, resulting in effective viral inhibition properties against infectious bronchitis virus (IBV). The viral inhibition of CNGs was studied using both in vitro (bovine ephemeral fever virus (BEFV) and pseudorabies virus (PRV)) and in ovo (IBV) models, which indicated that the CNGs were able to prevent virus attachment on the cell membrane and penetration into the cell. A very low concentration of 30 μg mL⁻¹ was found to be effective (>98% inhibition) in IBV-infected chicken embryos. The hatching rate and pathology of IBV-infected chicken embryos were greatly improved in the presence of CNGs. CNGs with distinctive virus-neutralizing activities show great potential as a virostatic agent to prevent the spread of avian viruses and to alleviate the pathology of infected avian species. Full article

Since deer were introduced into Australia in the mid-1800s, their wild populations have increased in size and distribution, posing a potential risk to the livestock industry, through their role in pathogen transmission cycles. In comparison to livestock, there are limited data on viral infections in all wildlife, including deer. The aim of this study was to assess blood samples from wild Australian deer for serological evidence of exposure to relevant viral livestock diseases. Blood samples collected across eastern Australia were tested by ELISA to detect antigens and antibodies against Pestivirus and antibodies against bovine herpesvirus 1. A subset of samples was also assessed by RT-PCR for Pestivirus, Simbu serogroup, epizootic hemorrhagic disease virus and bovine ephemeral fever virus. Our findings demonstrated a very low seroprevalence (3%) for ruminant Pestivirus, and none of the other viruses tested were detected. These results suggest that wild deer may currently be an incidental spill-over host (rather than a reservoir host) for Pestivirus. However, deer could be a future source of viral infections for domestic animals in Australia. Further investigations are needed to monitor pathogen activity and quantify possible future infectious disease impacts of wild deer on the Australian livestock industry. Full article

Bovine ephemeral fever is an arthropod-borne viral disease affecting mainly domestic cattle and water buffalo. The etiological agent of this disease is bovine ephemeral fever virus, a member of the genus Ephemerovirus within the family Rhabdoviridae. Bovine ephemeral fever causes economic losses by a sudden drop in milk production in dairy cattle and loss of condition in beef cattle. Although mortality resulting from this disease is usually lower than 1%, it can reach 20% or even higher. Bovine ephemeral fever is distributed across many countries in Asia, Australia, the Middle East, and Africa. Prevention and control of the disease mainly relies on regular vaccination. The impact of bovine ephemeral fever on the cattle industry may be underestimated, and the introduction of bovine ephemeral fever into European countries is possible, similar to the spread of bluetongue virus and Schmallenberg virus. Research on bovine ephemeral fever remains limited and priority of investigation should be given to defining the biological vectors of this disease and identifying virulence determinants. Full article