Bovine Herpesvirus Research Articles

Serum and Milk Levels of Antibodies to Bovine Viral Diarrhoea Virus, Bovine Herpesvirus-1 and -4, and Circulation of Different Bovine Herpesvirus-4 Genotypes in Dairy Cattle with Clinical Mastitis.

Bovine viral diarrhoea virus (BVDV) and bovine herpesvirus (BoHV)-1 and -4 are important causes of respiratory diseases and reproductive disorders of dairy cattle worldwide. Investigation of BVDV and BoHV-1 and -4 antibody levels in the serum and milk of dairy cattle in a group with clinical mastitis and a healthy group was undertaken using an indirect ELISA, and identification of the BoHV-4 genotypes in clinical mastitis cases was attempted by PCR and sequencing. Antibodies specific to BVDV, BoHV-1 and BoHV-4 were detected in the serum and milk of all dairy cattle with clinical mastitis. The cut-off values for BVDV and BoHV-1 in the sera and milk were extremely high in both healthy and mastitic animals. However, BoHV-4 antibodies were detected only in the clinically mastitic cattle, and BoHV-4 levels were higher in milk than in sera among these animals. Genotypes I and II of BoHV-4 were detected in the milk samples of four seropositive cows with clinical mastitis from the same herd. The results of this investigation demonstrate that clinical mastitis cases in the same herd may have aetiology in different BoHV-4 genotypes.

Neutralizing antibodies to bovine and bubaline alphaherpesviruses in water buffaloes (Bubalus bubalis).

Water buffaloes (Bubalus bubalis) have been introduced in many regions of the world as a source of animal protein. In many instances, bubaline cattle are reared close to or mixed with bovine or zebuine cattle. However, little is known about infectious diseases of bubaline and the interactions that may arise involving the microbiota of those species. Alphaherpesviruses of ruminants (bovine alphaherpesviruses types 1 and 5, BoHV-1, BoHV-5; bubaline alphaherpesvirus 1, BuHV-1) are highly cross-reactive in serological assays performed with bovine or zebuine sera. However, the profile of reactivity of bubaline cattle sera to alphaherpesviruses remains unknown. As such, it is not known which virus strain (or strains) would be most appropriate to be used as the challenge virus in the laboratory in search for alphaherpesvirus-neutralizing antibodies. In this study, the profile of neutralizing antibodies to alphaherpesviruses in bubaline sera was determined against different types/subtypes of bovine and bubaline alphaherpesviruses. Sera (n=339) were screened in a 24-h serum neutralization test (SN) against 100 TCID50 of each of the challenge viruses. From those, 159 (46.9 %) neutralized at least one of the viruses assayed; 131 (38.6%) sera neutralized the three viral strains used for screening. The viral strain that was neutralized by the largest number of sera was BoHV-5b A663 (149/159; 93.7%). A few sera neutralized only one of the challenge viruses: four sera neutralized BoHV-1 LA only; another neutralized BoHV-5 A663 only and four others neutralized BuHV-1 b6 only. SN testing with two additional strains gave rise to similar results, where maximum sensitivity (defined here as the largest number of sera that neutralized the challenge viruses) was obtained by adding positive results attained with three of the challenge strains. Differences in neutralizing antibody titers were not significant to allow inferences on which would be the most likely virus that induced the antibody responses detected here.

A method for the infectivity discrimination of enveloped DNA viruses using palladium compounds pre-treatment followed by real-time PCR.

Cultivation-based assays represent the gold standard for the assessment of virus infectivity; however, they are time-consuming and not suitable for every virus type. Pre-treatment with platinum (Pt) compounds followed by real-time PCR has been shown to discriminate between infectious and non-infectious RNA viruses. This study examined the effect of Pt and palladium (Pd) compounds on enveloped DNA viruses, paying attention to two significant pathogens of livestock - bovine herpesvirus-1 (BoHV-1) and African swine fever virus (ASFV). Native or heat-treated BoHV-1 suspension was incubated with the spectrum of Pt/Pd compounds. Bis(benzonitrile)palladium(II) dichloride (BB-PdCl 2) and dichloro(1,5-cyclooctadiene) palladium(II) (PdCl 2-COD) produced the highest differences found between native and heat- -treated viruses. Optimized pre-treatment conditions (1 mM of Pd compound, 15 min, 4°C) were applied on both virus genera and the heat inactivation profiles were assessed. A significant decrease in the detected quantity of BoHV-1 DNA and ASFV DNA after heat-treatment (60°C and 95°C) and consequent incubation with Pd compounds was observed. BB-PdCl 2 and PdCl 2-COD could help to distinguish between infectious and non-infectious enveloped DNA viruses such as BoHV-1 or ASFV.

Immunogenicity of an inactivated vaccine for intravaginal application against bovine alphaherpesvirus type 5 (BoHV-5).

The present study was carried out to evaluate the intravaginal vaccine potential against bovine alphaherpesvirus type 5 (BoHV-5). Sixty three cows were divided into seven groups (n: 9) and inoculated intravaginally (VA) or intramuscularly (IM) with inactivated BoHV-5, associated with the recombinant B subunit of the heat-labile enterotoxin of E. coli (rLTB), 2-hydroxyethylcellulose (Drug Delivery System A - DDS-A) or Poloxamer 407 (Drug Delivery System B - DDS-B) as follows: G1 (DDS-A + BoHV-5+ rLTB), G2 (DDS-A + BoHV-5), G3 (DDS-B + BoHV-5+ rLTB), G4 (DDS-B + BoHV-5), G5 (BoHV-5+ rLTB), G6 (Negative control) e G7 (Positive control). The local and systemic humoral responses were measured by indirect ELISA (IgA and IgG) and serum neutralization tests, and the cellular response was measured by a quantitative direct ELISA (IL-2 and IFN-Gamma). The results showed the group inoculated by the IM route, G5, demonstrated the highest levels of IgG in the vaginal mucosa among the experimental groups (p<0.05). In the groups tested with polymers (G1 and G3) in the vaginal mucosa, even higher levels of IgG were seen in comparison to the positive control (G7; p<0.01). Higher levels of IgA were also noted in relation to the other groups (p<0.05) on days 30, 60 and 90 post-inoculations. The groups G1 and G3 also provided higher titers of neutralizing antibodies (Log2) in relation to other treatments (p<0.01) 90 days after inoculation. In the nasal mucosa, there was an increase in the levels of IgA and IgG with the use of vaccines from groups G1 and G3, in relation to the positive control, G7 (p<0.05) at 60 and 90 days after the first inoculation. Moreover, neutralizing antibodies titers were detected at 60 and 90 days by serum neutralization. The inclusion of the evaluated polymers resulted in a superior response (p<0.05) of immunoglobulins and IL-2 and IFN-Gamma in relation to the treatment using only rLTB (G5). This data demonstrates the capabilities of a vaccine with an intravaginal application in cattle to stimulate a local and systemic immune response.

A Qualitative PCR Assay for the Discrimination of Bubaline Herpesvirus 1, Bovine Herpesvirus 1 and Bovine Herpesvirus 5.

Bubaline herpesvirus 1 (BuHV-1), Bovine herpesvirus 1 (BoHV-1) and Bovine herpesvirus 5 (BoHV-5) are classified in the genus Varicellovirus, subfamily Alphaherpesvirinae. BoHV-1 is the causative agent of infectious bovine rhinotracheitis, BoHV-5 induces moderate disease in adult cattle while BuHV-1 has instead been associated with a decline in livestock production of water buffaloes. The aim of this study was to develop a qualitative PCR assay that allows the discrimination of BuHV-1, BoHV-1 and BoHV-5. The alignment of homologous genes identified specific nucleotide sequences of BuHV- 1, BoHV-1 and BoHV-5. The design of the primers and the optimization of the PCR assay were focused on the target sequences located on the portions of gD, gE and gG genes. This assay involved the use of three different PCR end-points: the PCR of a portion of the gD gene identified only the presence of BoHV-1; the PCR of a portion of the gE gene confirmed the presence of both BoHV-5 and BuHV-1; the PCR of a portion of the gG gene discriminated between BoHV-5 and BuHV-1, as the amplification product was observed only for BoHV-5. This qualitative PCR assay allowed the differentiation of BoHV-1 and BoHV-5 infections both in cattle and water buffaloes and heterologous BuHV-1 infections in bovine.

Whole blood transcriptome analysis in dairy calves experimentally challenged with bovine herpesvirus 1 (BoHV-1) and comparison to a bovine respiratory syncytial virus (BRSV) challenge.

Bovine herpesvirus 1 (BoHV-1), is associated with several clinical syndromes in cattle, among which bovine respiratory disease (BRD) is of particular significance. Despite the importance of the disease, there is a lack of information on the molecular response to infection via experimental challenge with BoHV-1. The objective of this study was to investigate the whole-blood transcriptome of dairy calves experimentally challenged with BoHV-1. A secondary objective was to compare the gene expression results between two separate BRD pathogens using data from a similar challenge study with BRSV. Holstein-Friesian calves (mean age (SD) = 149.2 (23.8) days; mean weight (SD) = 174.6 (21.3) kg) were either administered BoHV-1 inoculate (1 × 107/mL × 8.5mL) (n = 12) or were mock challenged with sterile phosphate buffered saline (n = 6). Clinical signs were recorded daily from day (d) -1 to d 6 (post-challenge), and whole blood was collected in Tempus RNA tubes on d six post-challenge for RNA-sequencing. There were 488 differentially expressed (DE) genes (p < 0.05, False Discovery rate (FDR) < 0.10, fold change ≥2) between the two treatments. Enriched KEGG pathways (p < 0.05, FDR <0.05); included Influenza A, Cytokine-cytokine receptor interaction and NOD-like receptor signalling. Significant gene ontology terms (p < 0.05, FDR <0.05) included defence response to virus and inflammatory response. Genes that are highly DE in key pathways are potential therapeutic targets for the treatment of BoHV-1 infection. A comparison to data from a similar study with BRSV identified both similarities and differences in the immune response to differing BRD pathogens.

Cluster analysis of bovine respiratory disease (BRD)-associated pathogens shows the existence of two epidemiological patterns in BRD outbreaks

A hierarchical cluster analysis was used to classify outbreaks of bovine respiratory disease (BRD; n = 156) in natural groups according to the detection of nine pathogens (parainfluenza 3 virus (PI-3), bovine respiratory syncytial virus (BRSV), bovine coronavirus (BCV), bovine viral diarrhea virus (BVDV), and bovine herpesvirus 1 (BHV-1), Mannheimia haemolytica, Pasteurella multocida, Histophilus somni, and Mycoplasma bovis. Pathogens were detected by individual q-PCRs. Two clusters were identified. Cluster 1 was characterized by a relatively high frequency (40–72%) of four BRD-associated viruses, supporting their primary involvement in BRD. Cluster 2 was characterized by frequencies of PI-3, BRSV, or BVDV below 10% each. P. multocida and M. haemolytica were detected with high frequencies in both clusters (P > 0.05), while M. bovis and H. somni showed a significantly higher frequency in cluster 1and 2, respectively. Outbreaks in cluster 1 were associated with preweaning calves younger than 5 months (OR 2.2; 95% CI 1.1–4.5) and with cold months, whereas cluster 2 was associated with fattening calves older than 5 months after arrival to feedlots and without any seasonality. Thus, in addition to the classic epidemiological BRD pattern characterized by the primary involvement of viruses occurring preferably during winter and affecting young calves, there is a second pattern in which viruses would be less relevant, affecting mainly calves older than 5 months at any time of the year. This study allows a better understanding of the BRD epidemiology, which can be useful when implementing management and prophylaxis measures for a better control of this disease.

Oncolytic BHV-1 Is Sufficient to Induce Immunogenic Cell Death and Synergizes with Low-Dose Chemotherapy to Dampen Immunosuppressive T Regulatory Cells.

Immunogenic cell death (ICD) can switch immunologically "cold" tumors "hot", making them sensitive to immune checkpoint inhibitor (ICI) therapy. Many therapeutic platforms combine multiple modalities such as oncolytic viruses (OVs) and low-dose chemotherapy to induce ICD and improve prognostic outcomes. We previously detailed many unique properties of oncolytic bovine herpesvirus type 1 (oBHV) that suggest widespread clinical utility. Here, we show for the first time, the ability of oBHV monotherapy to induce bona fide ICD and tumor-specific activation of circulating CD8+ T cells in a syngeneic murine model of melanoma. The addition of low-dose mitomycin C (MMC) was necessary to fully synergize with ICI through early recruitment of CD8+ T cells and reduced infiltration of highly suppressive PD-1+ Tregs. Cytokine and gene expression analyses within treated tumors suggest that the addition of MMC to oBHV therapy shifts the immune response from predominantly anti-viral, as evidenced by a high level of interferon-stimulated genes, to one that stimulates myeloid cells, antigen presentation and adaptive processes. Collectively, these data provide mechanistic insights into how oBHV-mediated therapy modalities overcome immune suppressive tumor microenvironments to enable the efficacy of ICI therapy.

The Bovine Herpesvirus 1 Latency-Reactivation Cycle, a Chronic Problem in the Cattle Industry.

Bovine alphaherpesvirus 1 (BoHV-1) is a persistent and recurring disease that affects cattle worldwide. It is a major contributor to bovine respiratory disease and reproductive failure in the US. A major complication of BoHV-1 arises from the lifelong latent infection established in the sensory ganglia of the peripheral nervous system following acute infection. Lifelong latency is marked by periodic reactivation from latency that leads to virus transmission and transient immunosuppression. Physiological and environmental stress, along with hormone fluctuations, can drive virus reactivation from latency, allowing the virus to spread rapidly. This review discusses the mechanisms of the latency/reactivation cycle, with particular emphasis on how different hormones directly regulate BoHV-1 gene expression and productive infection. Glucocorticoids, including the synthetic corticosteroid dexamethasone, are major effectors of the stress response. Stress directly regulates BoHV-1 gene expression through multiple pathways, including β-catenin dependent Wnt signaling, and the glucocorticoid receptor. Related type 1 nuclear hormone receptors, the androgen and progesterone receptors, also drive BoHV-1 gene expression and productive infection. These receptors form feed-forward transcription loops with the stress-induced Krüppel-like transcription factors KLF4 and KLF15. Understanding these molecular pathways is critical for developing novel therapeutics designed to block reactivation and reduce virus spread and disease.

Histophilus somni disease conditions with simultaneous infections by ovine gammaherpesvirus 2 in cattle herds from Southern Brazil.

This report investigated the cause of cattle mortality in two farms in Southern Brazil. The tissues of one animal from each farm (animals #1 and #2) respectively were used inpathological and molecular investigations to determine the possible cause of death. The principal pathological findings observed in animal #1 were pulmonary, myocardial, and encephalitic hemorrhages with vasculitis, and lymphoplasmacytic interstitial pneumonia with proliferative vascular lesions (PVL). The main pathological findings observed in animal #2 were purulent bronchopneumonia, hemorrhagic myocarditis, and lymphoplasmacytic interstitial pneumonia with PVL. An immunohistochemical assay detected intralesional antigens of a malignant catarrhal fever virus (MCFV) from multiple tissues of animal #2 while PCR confirmed that the MCFV amplified was ovine gammaherpesvirus 2 (OvGHV2), genus Macavirus, subfamily Gammaherpesvirinae; OvGHV2 was also amplified from multiple tissues of animal #1. Furthermore, PCR assays amplified Histophilus somni DNA from multiple fragments of both animals. However, the nucleic acids of Mannheimia haemolytica, Pasteurella multocida, Mycoplasma bovis, bovine respiratory syncytial virus, bovine alphaherpesvirus virus 1 and 5, bovine coronavirus,and bovine parainfluenza virus 3 were not amplified from any of the tissues analyzed, suggesting that these pathogens did not participate in the development of the lesions herein described. These findings demonstrated that both animals were concomitantly infected by H. somni and OvGHV2 and developed the septicemic and encephalitic manifestations of H. somni. Furthermore, theinterstitial pneumonia observed in cow #2 was more likely associated with infection by OvGHV2.

Cell entry of Bovine herpesvirus-1 through clathrin- and caveolin-mediated endocytosis requires activation of PI3K-Akt-NF-κB and Ras-p38 MAPK pathways as well as the interaction of BoHV-1 gD with cellular receptor nectin-1

Bovine herpesvirus-1 (BoHV-1) can infect all breeds of cattle and cause severe respiratory organs and genital tract diseases. However, the mechanism of BoHV-1 entering the cells remains unclear. In this study, we explored the mechanism of BoHV-1 entering MDBK cells. We found that the entry of BoHV-1 was blocked by NH4Cl and bafilomycin A1, indicating that BoHV-1 entry is dependent on the acidic environment of endosome. Specific inhibitor dynasore and small interfering RNA (siRNA) knockdown of dynamin-2 inhibited BoHV-1 entry, showing that dynamin is required in BoHV-1 entry. The results of specific inhibitor, siRNA knockdown and co-localization indicating clathrin- and caveolin- mediated endocytosis play a role in BoHV-1 entry. BoHV-1 infection was not affected by EIPA which is a specific inhibitor of macropinocytosis. In addition, we found that BoHV-1 triggered PI3K-Akt-NF-κB and Ras-p38 MAPK signaling pathways to induce clathrin-mediated and caveolin-mediated endocytosis at the early stage of BoHV-1 infection. BoHV-1 binding was sufficient to activate the endocytic signaling pathways and promote viral entry. These two signaling pathways were activated by transfection of viral gD protein, and were inhibited by deletion of viral gD protein and the siRNA knockdown of cellular receptor nectin-1. The results of co-localization indicating the entered BoHV-1 is traced to late endosomes via early endosomes. Our results suggested the interaction of viral gD protein and cellular receptor nectin-1 triggered the PI3K-Akt-NF-κB and Ras-p38 MAPK signaling pathways and induced clathrin-mediated and caveolin-mediated endocytosis to promote BoHV-1 entry into MDBK cells at the early stage of BoHV-1 infection.

An ELISA to Detect Antibodies to Bovine Alphaherpesviruses 1 and 5 and Bubaline Alphaherpesvirus 1 in Cattle Sera

Bovine alphaherpesvirus 1 (subtypes 1.1, 1.2a, and 1.2b), type 5 (subtypes 5a, 5b, and 5c), and bubaline herpesvirus 1 (BuHV-1) induce highly, though not fully cross-reactive serological responses. Most types and subtypes of these viruses circulate particularly in countries of the southern hemisphere, notably Brazil and Argentina. Therefore, the detection of infected animals is important in defining prevention and control strategies, particularly when flocks are destined for international trade. Identification of infected herds is most often achieved by assays that detect antibodies, such as enzyme immunoassays (ELISAs). However, to date, no ELISA has been evaluated in its capacity to detect antibodies to these alphaherpesviruses. Here, an ELISA was developed to detect antibodies to all currently recognized BoAHV-1, BoAHV-5, and BuAHV-1 types/subtypes, and its sensitivity and specificity were determined. Six hundred bovine sera were screened in serum neutralization tests (SN) against the seven viruses. ELISAs prepared with each of the viruses were compared to SN. Subsequently, a combined assay with multiple antigens LISA was prepared by mixing five viral antigens, chosen for their highest sensitivity in the preparative assays. In comparison to SN, the mAgELISA sensitivity was 96.5% with 96.1% specificity (κ = 0.93; PPV = 95.0%; NPV = 97.3%). The findings reveal that the mAgELISA developed here is highly suitable for the detection of antibodies, comparable in sensitivity and specificity to that of SN when performed with all known types and subtypes of bovine and bubaline alphaherpesviruses.

Assessing pregnancy outcomes in cow-calf operations after administration of modified-live or killed virus vaccinations at the initiation of synchronization for fixed-time AI

The objective of this study was to compare the reproductive outcomes (artificial insemination [AI] pregnancy rates, season pregnancy rates, AI pregnancy losses) and calf traits (birth and weaning weights) after vaccination of suckled beef cows against bovine herpesvirus 1 and bovine viral diarrhea virus using commercially-available modified-live virus (MLV) or killed virus (KV) vaccine at the initiation of a fixed-time AI program. Previously-vaccinated cows (n = 2138) on 14 farms throughout Virginia were enrolled in the study during the Fall 2017 and Spring 2018 breeding seasons. Animals received a single vaccination injection at 10 d pre-breeding, corresponding with time of CIDR insertion at initiation of the 7-d CO-Synch + CIDR synchronization protocol. Cows were inseminated at a fixed time (60–66 h after removal of the CIDR insert) and subsequently turned out with bulls approximately 1 wk after insemination for a natural service. Cows treated with the MLV vaccine had greater AI pregnancy rates than cows treated with the KV vaccine during the fall (P = 0.008; 54% vs. 46%, respectively), but not during the spring breeding season (P = 0.62; 48 vs. 49%). Season pregnancy rates were greater (P = 0.01) in the fall (95–96%) than in the spring breeding season (89–90%), but were not affected by vaccine treatment (P = 0.49) or treatment by season (P = 0.30) interactions. Percentage of AI pregnancy losses was not affected by season (P = 0.85), vaccine treatment (P = 0.83), or treatment by season interactions (P = 0.68). The number of cycles it took for cows to become pregnant by natural service differed by season (P = 0.006) but not treatment (P = 0.87) or treatment by season interaction (P = 0.997). Cows treated with the MLV vaccine gave birth earlier in the calving season (8.36 ± 0.6 d) than those treated with the KV vaccine (10.31 ± 0.6 d; P = 0.02). There was a main effect of season on birth weights (P = 0.008), weaning weights (P < 0.001), and ADG at weaning (P < 0.001), but no effects of treatment (P ≥ 0.26) or treatment by season interaction (P ≥ 0.10) on any of these parameters. Overall, this study demonstrated that the administration of an MLV vaccine at 10 d before fixed-time AI did not have any adverse effects on pregnancy or calf outcomes compared with KV vaccine administration.

Characterization and expression of domains of Alphaherpesvirus bovine 1/5 envelope glycoproteins B in Komagataella phaffi

BackgroundBovine herpes virus (BoHV 1 and BoHV-5) are the causative agents of infectious bovine rhinotracheitis (IBR). IBR is responsible for important economic losses in the cattle industry. The envelope glycoprotein B (gB) is essential for BoHV infection of cattle's upper respiratory and genital tract. gB is one of the main candidate antigens for a potential recombinant vaccine since it induces a strong and persistent immune response.ResultsIn this study, gB of BoHV-1 and BoHV-5 was characterized in terms of function, structure, and antigenicity through bioinformatics tools. gB showed conserved sequence and structure, so, both domains named PH Like 1 and 2 domains of each virus were selected for the design of a bivalent vaccine candidate. The immunoinformatic study showed that these two domains have epitopes recognizable by B and T lymphocytes, followed by this, the cDNA domains from BoHV-1/5 gB (Domains-gB) were transformed into the yeast Komagataella phaffii GS115 (previously known as Pichia pastoris). A recombinant protein with molecular weight of about 110 kDa was obtained from the culture media. The vaccine candidate protein (Domains-gB) was recognized by a monoclonal antibody from a commercial ELISA kit used for IBR diagnostic, which may suggest that the epitopes are conserved of the entire infectious virus.ConclusionOverall, it was shown that the recombinant domains of BoHV-1/5 gB have antigenic and immunogenic properties similar to the native gB. This vaccine candidate is promising to be used in future studies to assess its immunogenicity in an animal model.

The N-terminal Proline Hinge Motif Controls the Structure of Bovine Herpesvirus 1-encoded Inhibitor of the Transporter Associated with Antigen Processing Required for its Immunomodulatory Function

Due to unique features, proline residues may control protein structure and function. Here, we investigated the role of 52PPQ54 residues, indicated by the recently established experimental 3D structure of bovine herpesvirus 1-encoded UL49.5 protein as forming a characteristic proline hinge motif in its N-terminal domain. UL49.5 acts as a potent inhibitor of the transporter associated with antigen processing (TAP), which alters the antiviral immune response. Mechanisms employed by UL49.5 to affect TAP remain undetermined on a molecular level. We found that mutations in the 52PPQ54 region had a vast impact on its immunomodulatory function, increasing cell surface MHC class I expression, TAP levels, and peptide transport efficiency. This inhibitory effect was specific for UL49.5 activity towards TAP but not towards the viral glycoprotein M. To get an insight into the impact of proline hinge modifications on structure and dynamics, we performed all-atom and coarse-grained molecular dynamics studies on the native protein and PPQ mutants. The results demonstrated that the proline hinge sequence with its highly rigid conformation served as an anchor into the membrane. This anchor was responsible for the structural and dynamical behavior of the whole protein, constraining the mobility of the C-terminus, increasing the mobility of the transmembrane region, and controlling the accessibility of the C-terminal residues to the cytoplasmic environment. Those features appear crucial for TAP binding and inhibition. Our findings significantly advance the structural understanding of the UL49.5 protein and its functional regions and support the importance of proline motifs for the protein structure.

Bakery waste supplementation to late gestating Bos indicus-influenced beef cows successfully impacted offspring postnatal performance.

This study evaluated the growth and immune function of beef calves born to cows supplemented with bakery waste containing two concentrations of crude fat. On day 0 (~90 d before calving), 108 multiparous Brangus crossbred cows were stratified by body weight (BW; 551 ± 65 kg) and body condition score (BCS, 5.5 ± 0.9) and randomly allocated into 1 of 18 bahiagrass (Paspalum notatum) pastures (6 cows and 4.3 ha per pasture). Treatments were randomly assigned to pastures (6 pastures per treatment) and consisted of no prepartum supplementation (NOSUP) and isocaloric and isonitrogenous supplementation of low-fat (LFAT; 6.4% crude fat) or high-fat (HFAT; 10.7% crude fat) bakery waste from days 0 to 70 (1 kg DM per cow per day). Calves were weaned on day 292 (201 ± 17 d of age). Then, 15 heifers per treatment were randomly selected and assigned to drylot pens from days 300 to 345 and vaccinated against respiratory pathogens on days 300 and 315. Cow BCS near calving (day 70) was the least (P ≤ 0.05) for NOSUP cows and did not differ (P = 0.12) between LFAT and HFAT cows. Cow BCS at the start of the breeding season (day 140) was greater (P = 0.05) for HFAT vs. NOSUP cows and intermediate (P ≥ 0.35) for LFAT cows. Plasma concentrations of total polyunsaturated fatty acids in HFAT cows did not differ (P ≥ 0.76) compared with LFAT cows but were greater (P ≤ 0.05) compared to NOSUP cows on day 70. Final pregnancy percentage did not differ (P ≥ 0.26) among treatments, but a greater percentage of HFAT cows calved (P ≤ 0.05) their second offspring during the first 21 d of the calving season compared to NOSUP and LFAT cows (bred by natural service). Weaning BW was the greatest (P ≤ 0.05) for LFAT and least for NOSUP calves. Maternal treatments did not impact (P ≥ 0.11) postweaning growth and total DM intake of calves. Average plasma cortisol concentrations were greater (P = 0.03) for NOSUP vs. HFAT calves and intermediate for LFAT calves (P ≥ 0.26). Serum titers against infectious bovine rhinotracheitis and bovine respiratory syncytial virus were greater or tended to be greater (P ≤ 0.08) for HFAT vs. LFAT calves and intermediate (P ≥ 0.27) for NOSUP calves at the end of preconditioning. Thus, supplemental fat concentration fed to late-gestating beef cows had variable effects on calf performance. Low-fat bakery waste led to the greatest calf preweaning growth, whereas high-fat bakery waste enhanced maternal reproduction and had minor benefits to calf humoral immune function.

Cepa de alfaherpesvírus bovino 1 com deleção do gene da glicoproteína E é atenuada e imunogênica para bezerros com imunidade passiva após imunização intranasal

ABSTRACT: Vaccination has been used to prevent the losses associated with Bovine alphaherpesvirus 1 (BoHV-1) infection but passively acquired antibodies may compromise vaccine efficacy. Intranasal immunization (IN) of calves with modified live viral BoHV-1 vaccines has proven to overcome the acquired passive antibodies and confer adequate protection. Herein, we evaluated the safety and immunogenicity of a glycoprotein E-deleted Brazilian BoHV-1 strain (BoHV-1gEΔ) for IN immunization of calves. Ten 1-to-2 months-old calves with virus-neutralizing titers (VN) ranging from 2-64 were immunized IN with viable BoHV-1gEΔ (107.1 TCID50) and four remained as unvaccinated controls (VN titers 8-32). After IN immunization, calves presented a transient (2-6 days) mild nasal secretion and shed the vaccine virus in nasal secretions in low titers (&lt;102.6TCID50/mL) for 4-8 days. Interestingly, the vaccinated calves did not show an increase in VN titers after vaccination. Rather, they presented a gradual reduction in serum VN antibodies in the following weeks - similarly to unvaccinated controls. Upon IN challenge with a virulent heterologous BoHV-1 strain at day 55 post-immunization (107.63TCID50), vaccinated calves shed significantly less virus from day 6 post-challenge onwards (p &lt; 0.07) and for a shorter period of time than the controls (p &lt; 0.0024). Importantly, both the duration and intensity of clinical signs were reduced in vaccinated animals. In addition, vaccinated calves showed an abrupt raise in VN titers post-challenge, indicating adequate immunological priming by vaccination. In summary, immunization of calves harboring passive antibodies with BoHV-1gEΔ by the IN route was able to prime the immunity to afford partial virological and clinical protection upon challenge.

Assessment of BoHV-4-based vector vaccine intranasally administered in a hamster challenge model of lung disease.

Bovine herpesvirus 4 (BoHV-4) is a bovine Rhadinovirus not associated with a specific pathological lesion or disease and experimentally employed as a viral vector vaccine. BoHV-4-based vector (BoHV-4-BV) has been shown to be effective in immunizing and protecting several animal species when systemically administrated through intramuscular, subcutaneous, intravenous, or intraperitoneal routes. However, whether BoHV-4-BV affords respiratory disease protection when administered intranasally has never been tested. In the present study, recombinant BoHV-4, BoHV-4-A-S-ΔRS-HA-ΔTK, was constructed to deliver an expression cassette for the SARS-CoV-2 spike glycoprotein, and its immunogenicity, as well as its capability to transduce cells of the respiratory tract, were tested in mice. The well-established COVID-19/Syrian hamster model was adopted to test the efficacy of intranasally administered BoHV-4-A-S-ΔRS-HA-ΔTK in protecting against a SARS-CoV-2 challenge. The intranasal administration of BoHV-4-A-S-ΔRS-HA-ΔTK elicited protection against SARS-CoV-2, with improved clinical signs, including significant reductions in body weight loss, significant reductions in viral load in the trachea and lungs, and significant reductions in histopathologic lung lesions compared to BoHV-4-A-S-ΔRS-HA-ΔTK administered intramuscularly. These results suggested that intranasal immunization with BoHV-4-BV induced protective immunity and that BoHV-4-BV could be a potential vaccine platform for the protection of other animal species against respiratory diseases.

Seropositivity of infectious bovine rhinotracheitis (IBR) in cattle of Chhattisgarh state of India

Seropositivity of infectious bovine rhinotracheitis (IBR) in cattle of Chhattisgarh state of India

Investigations on bovine herpesvirus 4 infections in cattle in Bulgaria

Cattle infected with BHV 4 show respiratory symptoms, gastrointestinal and postnatal genital disorders. The virus is a cofactor of bacterial infections. This paper reflects data on the prevalence of BHV 4 infections in several herds, among breeding animals and bulls from artificial insemination stations (AIS). One hundred and twenty six serum samples from bulls were investigated by MVNT and 45 (35.7%) were positive. Epizootiological and clinical studies on the prevalence of BHV 4 infections were limited to bovine farms with suspected infection with this virus. To establish seroconversion to the virus, double serum samples from 264 cattle – 165 native-born cows and 99 imported pregnant heifers were investigated by the microvirus neutralisation test (MVNT) and commercial ELISA for the detection of antibodies against BHV 4. Ninety-nine samples (37.5%) were positive in the MVNT and 110 samples (41.6%) – in ELISA. One out of the seven milk samples from cows with signs of mammary glands involvement was positive in the polymerase chain reaction (PCR) performed to detect the gB and Tk virus genes. Four of the ten whole blood samples from acutely ill animals were positive for BHV 4 DNA by PCR. The results of the present study confirmed that the BHV 4 circulated within the Bulgarian cattle population.