Bovine Virus Research Articles

Protective efficacy of a recombinant adenovirus expressing novel dual F and HN proteins of bovine parainfluenza virus type 3

Bovine parainfluenza virus type 3 (BPIV3) is a viral respiratory pathogen that infects cattle and causes significant economic losses. We generated a recombinant adenovirus called rHAd5-F + HN by expressing the fusion (F) and hemagglutinin-neuraminidase (HN) glycoprotein of BPIV3 using the human adenovirus serotype 5 (rHAd5). We evaluated its effects on humoral and cellular immune responses in mice (n = 45) and calves (n = 9). Serum antibody responses were assessed by enzyme-linked immunosorbent assay (ELISA), hemagglutination inhibition (HI), and neutralising antibodies (NAb). After boosting immunity with rHAd5-F + HN, mice produced significantly higher levels of antibodies against the BPIV3 genotype A and genotype C strains. The production of antibodies exceeded those produced by adenoviruses rHAd5-F and rHAd5-HN, which express the F and HN glycoprotein, respectively. The percentages of splenic CD3+/CD8+T lymphocytes and IL-4+ cytokines in rHAd5-F + HN mice were considerably higher than those in the control group. Mice immunised with rHAd5-F + HN exhibited much lower viral loads in the lungs and tracheas compared to the control group. Additionally, the lungs of mice vaccinated with rHAd5-F + HN showed no notable histopathological changes. On the other hand, rHAd5-F + HN produced a humoral immune response in calves. Following the booster intramuscular injection with the rHAd5-F + HN, the serum antibody levels against BPIV3 genotype C strain were 1:20 452, 1:1024, and 1:426 in calves, as detected by ELISA, HI, and NAb, respectively. The HI and NAb levels against the BPIV3 genotype A strain were 1:213 and 1:85 in calves, respectively. These results indicate that rHAd5-F + HN effectively induced immunity against BPIV3 infection.

Detection and molecular characterization of lumpy skin disease and bovine papular stomatitis viruses in lumpy skin disease-suspected outbreaks in Tanzania.

Lumpy Skin Disease (LSD) is endemic in sub-Saharan countries and is currently a global threat to the cattle industry. Information on the circulating Capripoxvirus lumpyskinpox, formerly known as Lumpy Skin Disease Virus (LSDV), and other poxviruses infecting cattle is very scant in Tanzania. The current study aimed to confirm and characterize LSDV and other poxviruses infecting cattle, from LSD suspected outbreaks in Tanzania. A total of 24 samples were collected from four LSD suspected outbreaks reported in Tanzania between February and May 2023. Samples were screened for LSDV genome by real-time PCR and then subjected to a high-resolution multiplex melting (HRM) assay where 10 samples were positive for Capripoxvirus (CaPV) and one sample was Parapoxvirus (PPV) positive. Four LSDV genes; RPO30, GPCR, EEV glycoprotein and B22R and the partial B2L gene of PPVs were analyzed. All targeted LSDV genes from the Tanzanian isolates showed 100% similarity and isolates clustered with commonly circulating LSDV field isolates. Furthermore, the single nucleotide polymorphism (SNP) at position 240 (A-> G) of the EEV gene differentiates the Tanzanian LSDVs from the group of ancient Kenyan LSDV isolates while the B22R sequences of the Tanzanian LSDV isolates differed from the LSDV Neethling and LSDV KSGP-0240 derived vaccines. Sequence analysis of the partial B2L gene of the Tanzanian parapoxvirus bovinestomatitis, formerly known as Bovine papular stomatitis virus (BPSV) showed a different BPSV strain circulating compared to publicly available sequences. These findings confirm the presence of LSDV in Tanzania, which suggesting the need for establishing an effective control program and continuous monitoring. The presence of a typical profile for Tanzania BPSV is an indication that, although never reported before, BPSV is established in the country therefore this virus should be included in the differential diagnosis of LSDV.

A human isolate of bovine H5N1 is transmissible and lethal in animal models.

The outbreak of clade 2.3.4.4b highly pathogenic avian influenza viruses of the H5N1 subtype (HPAI H5N1) in dairy cows in the US has so far resulted in spillover infections of at least thirteen farm workers1-3, who presented with mild respiratory symptoms or conjunctivitis, and one individual with no known animal exposure who was hospitalized but recovered3,4. Here, we characterized A/Texas/37/2024 (huTX37-H5N1), a virus isolated from the eyes of an infected farm worker who developed conjunctivitis5. huTX37-H5N1 replicated efficiently in primary human alveolar epithelial cells, but less efficiently in corneal epithelial cells. Despite causing mild disease in the infected worker, huTX37-H5N1 was lethal in mice and ferrets and spread systemically with high titres in respiratory and non-respiratory organs. Importantly, in four independent experiments in ferrets, huTX37-H5N1 transmitted via respiratory droplets in 17%-33% of transmission pairs and five of six exposed ferrets that became infected died. PB2-631L (encoded by bovine isolates), promoted influenza polymerase activity in human cells, suggesting a role in mammalian adaptation like that of PB2-627K (encoded by huTX37-H5N1). Additionally, bovine HPAI H5N1 viruses were found to be susceptible to polymerase inhibitors both in vitro and in mice. Thus, HPAI H5N1 virus derived from dairy cattle transmits by respiratory droplets in mammals without prior adaptation and causes lethal disease in animal models.

Pre-existing H1N1 immunity reduces severe disease with bovine H5N1 influenza virus.

The emergence of highly pathogenic H5N1 avian influenza in dairy cattle herds across the United States has caused multiple mild human infections. There is an urgent need to understand the risk of spillover into humans. Here, we show that pre-existing immunity from the 2009 H1N1 pandemic influenza virus provided protection from mortality and severe clinical disease to ferrets intranasally infected with bovine H5N1. H1N1 immune ferrets exhibited a differential tissue tropism with little bovine H5N1 viral dissemination to organs outside the respiratory tract and significantly less H5N1 virus found in nasal secretions and the respiratory tract. Additionally, ferrets with H1N1 prior immunity produced antibodies that cross-reacted with H5N1 neuraminidase protein. Taken together, these results suggest that mild disease in humans may be linked to prior immunity to human seasonal influenza viruses.

Immune History Modifies Disease Severity to HPAI H5N1 Clade 2.3.4.4b Viral Challenge.

The most recent outbreak of highly pathogenic avian H5 influenza (HPAI) virus in cattle is now widespread across the U.S. with spillover events happening to other mammals, including humans. Several human cases have been reported with clinical signs ranging from conjunctivitis to respiratory illness. However, most of those infected report mild to moderate symptoms, while previously reported HPAI H5Nx infections in humans have had mortality rates upwards of 50%. We recently reported that mice with pre-existing immunity to A/Puerto Rico/08/1934 H1N1 virus were protected from lethal challenge from highly pathogenic clade 2.3.4.4b H5N1 influenza virus. Here, we demonstrate that mice infected with the 2009 pandemic H1N1 virus strain A/California/04/2009 (Cal09) or vaccinated with a live-attenuated influenza vaccine (LAIV) were moderately-to-highly protected against a lethal A/bovine/Ohio/B24OSU-439/2024 H5N1 virus challenge. We also observed that ferrets with mixed pre-existing immunity-either from LAIV vaccination and/or from Cal09 infection-showed protection against a HPAI H5N1 clade 2.3.4.4b virus isolated from a cat. Notably, this protection occurred independently of any detectable hemagglutination inhibition titers (HAIs) against the H5N1 virus. To explore factors that may contribute to protection, we conducted detailed T cell epitope mapping using previously published sequences from H1N1 strains. This analysis revealed a high conservation of amino acid sequences within the internal proteins of our bovine HPAI H5N1 virus strain. These data highlight the necessity to explore additional factors that contribute to protection against HPAI H5N1 viruses, such as memory T cell responses, in addition to HA-inhibition or neutralizing antibodies.

Microbiological Profile of the Upper and Lower Respiratory Tract of Suckling and Weaned Dairy Calves with Acute Respiratory Disease

Bovine respiratory disease (BRD) is a significant global health issue in cattle farming, leading to substantial economic losses. This study analyzed the microbiological profiles of BRD outbreaks in nine dairy cattle herds in southern Brazil. We examined 36 biological samples, including 24 deep nasopharyngeal swabs (NS) and 12 lung tissue, from 29 suckling and 7 weaned heifer calves with acute BRD. PCR and RT-PCR techniques were used to partially amplify the genes of five viruses and four respiratory bacteria. A total of 8 different microorganisms, 4 viruses (bovine viral diarrhea virus, n = 5; bovine coronavirus, n = 3; bovine alphaherpesvirus 1, n = 3; and bovine parainfluenza virus 3, n = 2), and 4 bacteria (Pasteurella multocida, n = 16; Mycoplasma bovis, n = 8; Histophilus somni, n = 7; and Mannheimia haemolytica, n = 4) were identified in 29 (80.5%) samples. Seven samples (four lung tissue and three NS) were negative for all the microorganisms. Mixed infections were more common (62.1%) than single infections (37.9%). Bacterial nucleic acids were more commonly co-detected in NS than in lung tissue. Nucleic acids from a single pathogen were more frequently detected in lung tissues than in NS. M. bovis was the only bacterium detected in the lower respiratory tract. Understanding the microbiological profiles of the respiratory tracts of dairy calves with clinical signs of BRD is crucial for implementing effective biosecurity measures to prevent BRD in suckling and weaned dairy heifer calves.

STAT6 promotes innate immunity against BEFV and VSV by inhibiting STUB1 and NIX-mediated MAVS degradation

Signal transducers and activators of transcription 6 (STAT6), an essential member of the STAT protein family, plays vital roles in innate immunity, however, its function in regulating innate immunity through the degradation of MAVS has not been described. In this study, we found that STAT6 suppresses the replication of both bovine ephemeral fever virus (BEFV) and vesicular stomatitis virus (VSV). Further investigations revealed that STAT6 promotes the type I IFN (IFN-I) signaling pathway in the context of BEFV and VSV infection. Moreover, the knockout of STAT6 leads to the degradation of MAVS through both the ubiquitin-proteasome and autophagolysosomal pathways. Mechanistically, STAT6 results in the downregulation of E3 ubiquitin ligase STIP1 homology and Ubox-containing protein 1 (STUB1), inhibits the interaction between STUB1 and MAVS, and reduces STUB1- mediated K48-linked MAVS ubiquitination, thereby inhibiting the MAVS degradation through the ubiquitin-proteasome pathway. Furthermore, STAT6 also suppresses MAVS degradation through the autophagy receptor Bcl2 interacting protein 3 like (NIX)-mediated autophagy pathway. Taken together, our study unveils a novel mechanism by which STAT6 acts as a positive regulator of the type I IFN signaling pathway during BEFV and VSV infection, predominantly by inhibiting MAVS degradation and ultimately suppressing BEFV and VSV infection. These findings provide valuable insights into the regulation of MAVS degradation by STAT6, which may serve as a basis for the design of novel antiviral agents.

A broad-spectrum biological activities of Heracleum humile extracts: A first report of the antiviral, anti-cancer and chemical properties

The current work focused on researching the bioactive potential of ethyl acetate (EA), methanol (MeOH), and water extract of H. humile plant, specifically ethyl acetate, methanol extracts were acquired with maceration method, and water extract was obtained by the infusion method. The highest total phenolic ingredient was determined in the water extract, while the highest total flavonoid ingredient was found in the MeOH extract. The water extract displayed the most potent antioxidant activity in the assays used. The ethyl acetate extract showed the highest enzyme inhibition activity in Butyrylcholinesterase inhibition (BChE) and amylase assay. Antibacterial efficiency was analyzed using microdilution analysis. The minimum inhibitory concentration (MIC) amounts ranged from 125 to 500 μg/mL except for water extract. The antiviral potential of the extracts was assessed against Bovine herpes virus 1 (BoHV-1) (Cooper strain). Methanol extract showed more potent antiviral effect. Selectivity indices were calculated for ethyl acetate and methanol extract as 3.32 and 13.39, respectively. All extracts displayed Deoxyribonucleic Acid (DNA) protection activity at approximately 25%–35%. For cell viability evaluation, 3-(4,5-Dimethylthiazol-2-yl)-2,5-Diphenyltetrazolium Bromide (MTT) test was performed against triple-negative human breast adenocarcinoma cells (MDA-MB-231) and Michigan Cancer Foundation-7 (MCF-7) cells. The most effective results were found in ethyl acetate extract at 48h. The 50% inhibitor concentrations (IC50) were determined for MDA-MB-231 and MCF-7 as 116.7 μg/mL and 247.9 μg/mL, respectively. Based on the bioactive compound content results, extracts of H. humile include valuable compounds that possess significant biological properties. In conclusion, these extracts could offer promising novel plant-derived therapeutics.

The Current Epizootiological Situation of Three Major Viral Infections Affecting Cattle in Egypt.

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.

On the issue of prevention and eradication of minor viral bovine diseases in Ukraine

The study aimed to evaluate the epizootic status of livestock in Ukraine concerning the prevalence of bovine immunodeficiency virus and bovine foamy virus infections. A literature review was conducted to analyze the epizootic status of livestock farming in various countries regarding bovine immunodeficiency and spumavirus infections. To investigate this issue in Ukrainian livestock, blood samples were collected from 10–15 cows with further DNA extraction and studies via PCR, according to the developers’ recommendations. The biological characteristics of bovine foamy virus and bovine immunodeficiency virus were studied by infecting bovine fetal lung (LEK) and calf coronary vessels (KST) cell cultures, with each passage being visually monitored and examined through light microscopy. PCR was performed on the third and fifth passages to detect the genetic material. The genetic material of bovine leukemia virus, bovine immunodeficiency virus, and bovine foamy virus was confirmed in 12 farms across 8 regions of Ukraine. It was demonstrated that bovine immunodeficiency virus and bovine foamy virus can integrate into homologous cell cultures derived from cattle. The immunosuppressive effects of bovine foamy virus and its capability to inhibit components of the non-specific immune system were established on laboratory animal models. Emphasis is placed on the necessity to develop domestic tools for the retrospective diagnosis of bovine immunodeficiency and spumavirus infections and to implement a national anti-epizootic program

Putative G-quadruplexes in the genome of unconventional retrovirus bovine foamy virus

Putative G-quadruplexes in the genome of unconventional retrovirus bovine foamy virus

Research progress on the structure and function of the main glycoproteins of bovine infectious rhinotracheitis virus

Research progress on the structure and function of the main glycoproteins of bovine infectious rhinotracheitis virus

Multiplex reverse transcription recombinase polymerase amplification combined with lateral flow biosensor for simultaneous detection of three viral pathogens in cattle

Bovine viral diarrhea virus (BVDV), bovine epidemic fever virus (BEFV), and bovine respiratory syncytial virus (BRSV) cause respiratory symptoms in cattle. The absence of rapid, precise, and easily accessible diagnostic methods poses difficulties for herders and veterinary epidemiologists during outbreaks of major infectious animal diseases. Considering the mixed infection of viruses, a multiple-detection method, reverse transcription recombinase polymerase amplification (mRT-RPA) combined with a lateral flow biosensor (LFB), was established to simultaneously detect the three pathogens. This technique is based on the specific binding of three differently labeled RT-RPA products (DNA sequences) to antibodies on the three test lines of the LFB, achieving multiplex detection through the presence or absence of coloration on the LFB test lines. The fluorescence values of the LFB test lines are recorded by a test strip reader. The mRT-RPA-LFB assay completes detection at a constant temperature of 41 °C within 33 min. The limits of detection (LODs) for BVDV, BEFV and BRSV were 2.62 × 101, 2.42 × 101 and 2.56 × 101 copies/μL, respectively. No cross-reactivity was observed with the other six bovine viruses. The developed method showed satisfactory intra- and inter-assay precision, and the average coefficients of variation were ranged from 2.92 % to 3.99 %. The diagnostic sensitivity and specificity were 98.11 % and 100 %, respectively, which were highly consistent with the RT-qPCR assay, and the kappa value was 0.988 (95 % confidence interval, CI). In general, the mRT-RPA-LFB assay has the potential to become a powerful tool for rapid screening of cattle diseases because of its advantages such as fast detection speed, convenient operation, strong specificity, and high sensitivity.

Evaluation of the in vitro Effect of the Interferon Produced by Bovine Ephemeral Fever Virus on Foot and Mouth Disease Virus

Evaluation of the in vitro Effect of the Interferon Produced by Bovine Ephemeral Fever Virus on Foot and Mouth Disease Virus

Respiratory illness in young and adult cattle caused by bovine viral diarrhea virus subgenotype 2b in singular and mixed bacterial infection in a BVDV-vaccinated dairy herd.

Bovine respiratory disease (BRD) is a common global health problem in dairy cattle. The definitive diagnosis of BRD is complex because its etiology involves several predisposing and determining factors. This report describes the etiology of a BRD outbreak in a dairy herd in the mesoregion of Central Eastern Paraná, which simultaneously affected young (calves and heifers) and adult (cows) Holstein-Friesian cattle. Nine biological samples, consisting of five lung samples from two cows and three suckling calves, and four nasal swab samples from heifers, were used for etiological diagnosis. The nucleic acids extracted from lung fragments and nasal swabs were subjected to PCR and RT-PCR assays for partial amplification of the genes of five viruses [bovine viral diarrhea virus (BVDV), bovine alphaherpesvirus 1 (BoAHV1), bovine respiratory syncytial virus (BRSV), bovine parainfluenza virus 3 (BPIV-3), and bovine coronavirus (BCoV)] and four bacteria (Mycoplasma bovis, Mannheimia haemolytica, Pasteurella multocida, and Histophilus somni) involved in the etiology of BRD. All nine biological samples from the animals with BRD tested negative for BoAHV1, BRSV, BPIV-3, BCoV, and H. somni. Therefore, the involvement of these microorganisms in the etiology of BRD outbreak can be ruled out. It was possible to identify the presence of BVDV and M. bovis in singular and mixed infections of the lower respiratory tract in cattle. BVDV was also identified in two nasal swabs: one as a single etiological agent and the other in association with two bacteria (P. multocida and M. haemolytica). The phylogenetic analysis conducted in the nucleotide sequence of the 5'UTR region and Npro gene of the BVDV amplicons demonstrated that the BVDV field strains of this BRD outbreak belong to subgenotype 2b. To the best of our knowledge, this is the first report of BVDV-2b involvement in the etiology of BRD in Brazil. Finally, it is necessary to highlight that the cattle were obtained from an open dairy herd with biannual vaccinations for BVDV-1a and - 2a.

Development of two competitive ELISAs based on monoclonal antibodies for the serological detection of Bovine ephemeral fever virus

Bovine ephemeral fever virus (BEFV) is a member of the genus Ephemerovirus in the family Rhabdoviridae. It is an arthropod-borne virus transmitted by many species of midges and mosquitoes. It can cause severe economic consequences due to losses in milk production and the general condition of cattle and water buffalo. BEF occurs in some tropical, subtropical and warm temperate regions of Africa, Australia, the Middle East and Asia with seasonal outbreaks, but its possible spread to other areas (e.g. Europe) cannot be excluded. Therefore, using and developing rapid diagnostic methods with optimal performance is essential for identifying emerging pathogens and their control. In the present study, we developed two competitive serological ELISAs based on monoclonal antibodies (mAbs), designed by using BEFV inactivated antigen and the BEF recombinant nucleoprotein (N), respectively. A panel of 77 BEF-positive and 338 BEF-negative sera was used to evaluate the two tests. With a diagnostic sensitivity of 97.4 % using the inactivated virus and 98.7 % using the recombinant N, and a diagnostic specificity of 100 % using both antigens, our results suggest that these tests are suitable for the serological diagnosis of BEF.

Prevalence of bovine respiratory viruses in cattle calves in Kangra district of Himachal Pradesh

Respiratory diseases causing pneumonia are the 2nd leading cause of mortality in bovine calves and are primarily caused by viral pathogens. The present study was undertaken in cattle calves under twelve months of age for detecting four respiratory viruses, viz. bovine herpes virus-1 (BoHV-1), bovine viral diarrhoea virus (BVDV), bovine respiratory syncytial virus (BRSV), and bovine parainfluenza virus type 3 (BPI3), using a commercially available multiscreen antigen ELISA kit. A total of 30 cattle calves necropsied at the Department of Veterinary Pathology, DGCN COVAS, CSKHPKV, Palampur, from June 2021 to June 2022 were screened. The samples of lung tissues and nasal turbinates were collected and stored at –20°C until further processing. The collected tissue samples were homogenised and processed as per the standard protocol. Among the 30 necropsied samples, BoHV-1 and BRSV were detected in 17/30 (56.67%) samples, BPI3 was detected in 14/30 (46.67%) samples, and BVDV was detected in 8/30 (26.67%) samples. 5/30 (16.67%) samples were found positive for all four viruses. Moreover, three viruses were concurrently detected in 4/30 samples (13.33%), and two viruses were present in 10/30 samples (33.33%). Additionally, a single virus was detected in 4/30 samples (13.33%). In conclusion, the present investigation reveals the substantial presence of respiratory viruses in the respiratory tract of cattle calves. The result indicates a complex pattern of co-infections of different viruses, emphasising the need for effective surveillance and management strategies to address the diverse viral dynamics affecting bovine respiratory health.

Bovine H5N1 influenza virus binds poorly to human-type sialic acid receptors.

Clade 2.3.4.4b highly pathogenic H5N1 avian influenza (HPAI) viruses started circulating widely in lactating dairy cattle in the United States at the end of 2023. Avian influenza viruses enter cells after binding to glycan receptors with terminally linked α2-3 sialic acid, whereas human influenza viruses typically bind to glycan receptors terminally linked α2-6 sialic acid in the upper respiratory tract. Here, we evaluated the receptor binding properties of hemagglutinin (HA) trimers from a clade 2.3.4.4b avian isolate (A/American Wigeon/South Carolina/22-000345-001/2021) and a cattle isolate (A/dairy cattle/Texas/24-008749-002-v/2024). Using two different methods, we found that both of the 2.3.4.4b H5s bound efficiently to glycan receptors with terminally linked α2-3 sialic acid with no detectable binding to glycan receptors with terminally linked α2-6 sialic acid. Our data suggest that clade 2.3.4.4b H5N1 viruses bind poorly to human receptors. It will be important to continue evaluating receptor binding properties of these viruses as they evolve in cattle.

Receptor Binding Specificity of a Bovine A(H5N1) Influenza Virus.

Outbreaks in the US of highly pathogenic avian influenza virus (H5N1) in dairy cows have been occurring for months creating new possibilities for direct contact between the virus and humans. Eisfeld et al. examined the pathogenicity and transmissibility of a bovine HPAI H5N1 virus isolated from New Mexico in a series of in vitro and in vivo assays. They found the virus has a dual human- and avian virus-like receptor-binding specificity as measured in a solid phase glycan binding assay. Here, we examined the receptor specificity of a bovine HPAI H5N1 virus (A/bovine/OH/B24OSU-432/2024, H5N1, clade 2.3.4.4b) employing four different assays including glycan array technology, bio-layer interferometry (BLI), a solid phase capture assay and hemagglutination of glycan remodeled erythrocytes. As controls, well characterized avian (A/Vietnam/1203/2004, H5N1, clade 1) and human (A/CA/04/2009, H1N1) IAVs were included that bind α2,3- and α2,6-sialosides, respectively. We found that A/bovine/OH/B24OSU-432/2024 preferentially binds to "avian type" receptors (α2,3-sialosides). Furthermore, sequence alignments showed that A/bovine has maintained amino acids in its HA associated with α2,3-sialoside (avian) receptor specificity. We conclude that while we find no evidence that A/bovine has acquired human virus receptor binding specificity, ongoing efforts must be placed on monitoring for this trait.

Bovine Ephemeral Fever Viruses in Israel 2014-2023: Genetic Characterization of Local and Emerging Strains.

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.