Search Results (44)

Classical swine fever (CSF), caused by the classical swine fever virus (CSFV), is an acute, febrile, and highly contagious disease that has led to significant economic losses in the global swine industry. Although the attenuated lapinized CSF vaccine (C-strain) has effectively controlled CSF outbreaks in China since the 1950s, it remains challenging to serologically differentiate infected from vaccinated animals (DIVA). Currently, the application of E2 subunit vaccines allows for DIVA by detecting antibodies against the E^rns protein. Therefore, this study aimed to develop a blocking ELISA for CSFV E^rns antibody detection using porcine monoclonal antibodies (mAbs) derived from single B cell technology. Peripheral blood mononuclear cells (PBMCs) were isolated from immunized pigs, and single CD21⁺IgM⁻E^rns-His tag⁺ B cells were sorted via flow cytometry. Using one-step PCR, full-length genes of porcine IgG heavy and light chains were amplified separately, yielding 11 porcine mAbs against the CSFV E^rns protein. Among these, three mAbs (E0S3, E0S5, and E0S10) exhibited broad reactivity, while two (E0S1, E0S4) showed no cross-reaction with bovine viral diarrhea virus (BVDV). Using mAb E0S4 as the blocking antibody, a blocking ELISA was established and optimized. The assay demonstrated a detection limit of 1:128, no cross-reactivity with other swine viruses or BVDV, and intra- and inter-assay coefficients of variation below 10%. ROC curve analysis determined an optimal cut-off value of 48.4%, with high sensitivity and specificity. In conclusion, the developed blocking ELISA provides a reliable tool for high-throughput serological surveillance, facilitating the DIVA strategy and contributing to CSF eradication programs. Full article

This study aimed to investigate the current epidemiology and genetic evolution of bovine viral diarrhea virus (BVDV) on cattle farms in Gansu Province, China, between 2021 and 2025. A total of 749 samples from 62 farms across 14 cities and prefectures in Gansu were tested. The overall BVDV positivity rate was 19.89%, determined by amplification of the 5′-UTR and N^pro regions. Seven subtypes were identified: BVDV-1a, -1b, -1d, -1m, -1v, -1u, and -2a. BVDV-1u was the predominant subtype (59.06%), followed by BVDV-1v (13.42%). The greatest subtype diversity was observed in Jinchang City and Gannan Tibetan Autonomous Prefecture. A non-cytopathic BVDV-1v strain, designated YC-2025-Gansu2 (GenBank accession no. PV945812.1), was isolated. This study expands the BVDV subtype database for Gansu and supports the development of subtype-specific prevention strategies in the region. Full article

Bovine viral diarrhea virus (BVDV) is a major cattle pathogen associated with significant economic losses worldwide. In Brazil, the high genetic diversity of circulating strains represents an additional challenge for disease control. To update the molecular epidemiology of BVDV in southern Brazil, 16,198 bovine serum samples collected in 2020 through a national surveillance program were screened for pestivirus RNA by RT-qPCR. Forty-nine samples (0.36%) were positive and subjected to partial sequencing of the 5′UTR and N^pro regions. Phylogenetic analysis identified BVDV-1a (25/49; 51%), BVDV-1b (1/49; 2%), BVDV-1d (7/49; 14%), and BVDV-2b (16/49; 33%), with no detection of HoBiPeV. When compared descriptively with data from 2010 in the same region, BVDV-1a remained the most frequent subgenotype, while BVDV-2b also represented a substantial proportion of detections, contrasting with other regions worldwide. Although the two datasets are not directly comparable, and no statistically significant differences were observed, these findings provide an updated overview of circulating BVDV subgenotypes in Rio Grande do Sul. The absence of HoBiPeV contrasts with reports from other regions of Brazil and suggests a distinct regional pattern of pestivirus circulation. Overall, the results reinforce the importance of continuous genomic surveillance to monitor changes in viral diversity and support control strategies in cattle populations. Full article

This study investigated the in vitro replication kinetics and molecular characteristics of five field isolates of bovine viral diarrhea virus (BVDV) representing subgenotypes 1b, 1d, and 1f, currently circulating in Hungary. We compared cytopathogenic (cp) and non-cytopathogenic (ncp) biotype pairs using digital PCR (dPCR) and virus titration. While dPCR showed higher genome copy numbers for cp isolates, virus titration revealed comparable or lower infectious titers, suggesting the accumulation of replication-incompetent viral particles during the infection cycle. Molecular analysis identified (novel) amino acid substitutions in Npro, capsid, and NS4B regions, although typical large-scale genome rearrangements were absent. These findings demonstrate that biotype differences are molecularly complex and subgenotype-dependent. Our results emphasize that relying on a few genetic markers is insufficient for biotype categorization, necessitating comprehensive characterization in BVDV surveillance programs. This complexity must be considered when designing vaccines or control programs, especially in regions with diverse circulating strains. Full article

Bovine viral diarrhea virus (BVDV) causes severe mucosal inflammation in cattle, and effective treatment options remain limited. Dysregulated activation of the NLRP3 inflammasome, driven by NF-κB and STAT3 signaling, may exacerbate disease pathogenesis, highlighting this axis as a potential therapeutic target. Although traditional Chinese medicine has shown promise in antiviral and anti-inflammatory applications, it remains unclear whether it can inhibit BVDV replication via the NF-κB/STAT3-NLRP3 pathway. The present study aimed to clarify the inhibitory effect of luteolin on bovine viral diarrhea virus (BVDV) replication, and to elucidate its underlying mechanisms from two perspectives: interference with viral internalization and replication processes, as well as regulation of the NF-κB/STAT3-NLRP3 inflammasome pathway. Collectively, this work intended to provide experimental evidence and theoretical support for the development of luteolin as a natural anti-BVDV agent. To this end, BVDV-infected MDBK cells were treated with gradient concentrations of luteolin, followed by quantification of viral load using qRT-PCR and Western blot assays. Meanwhile, the activation status of the NF-κB/STAT3-NLRP3 signaling pathway was evaluated via immunofluorescence staining and luciferase reporter gene assays. Our results demonstrate that luteolin exhibits potent dual antiviral activity against cytopathic BVDV-1m in MDBK (Madin-Darby Bovine Kidney) cells, effectively suppressing both viral replication and inflammatory responses. At non-cytotoxic concentrations, luteolin specifically inhibited the internalization and replication stages of the viral lifecycle, accompanied by reduced NS5B polymerase activity. Importantly, luteolin disrupted the NF-κB/STAT3-NLRP3 axis by suppressing phosphorylation of p65 (Ser536) and STAT3 (Ser727), downregulating NLRP3 and pro-caspase-1 expression, and inhibiting caspase-1 cleavage (p20) as well as maturation of IL-1β and IL-18. Consequently, it attenuated the overexpression of TNF-α and IL-8. To our knowledge, this is the first report of a single compound simultaneously targeting multiple stages of the BVDV lifecycle and counteracting NLRP3-mediated immunopathology, offering a strategic basis for developing flavonoid-based therapies against Flavivirus infections. Full article

Bovine viral diarrhea virus (BVDV) primarily causes bovine viral diarrhea/mucosal disease, an infectious disease having a significant economic impact on the cattle-farming industry globally. Comprehensive monitoring and in-depth studies of the pathological characteristics of viruses are crucial in formulating effective prevention and control strategies. The isolation, identification, molecular characterization, and pathogenicity analysis of a BVDV strain isolated from persistently infected cattle ear tissue samples are reported in this study. This newly isolated strain is a noncytopathogenic BVDV, which we named HB2411. Homology between the HB2411 and U63479 strains was determined to be 96.7%, and the phylogenetic tree indicated that HB2411 belongs to the BVDV-1b subtype. Genetic variation analysis of the E2 protein of the HB2411 strain revealed multiple amino-acid mutation sites. Recombination analysis of the newly isolated HB2411 strain suggested a potential cross-geographical transmission event. BALB/c mice were intraperitoneally inoculated with the BVDV strain to evaluate the pathogenicity and virulence of BVDV-1b HB2411. BVDV was detected in multiple organs of BALB/c mice, with the highest viral load in the liver. BVDV infection promoted the expression of inflammatory cytokines in mice livers, necessitating further studies on the virulence and pathogenic mechanisms of this new strain to reduce economic losses caused to the animal husbandry industry. Full article

Bovine viral diarrhea (BVD) is a highly infectious disease with a global distribution caused by the bovine viral diarrhea virus (BVDV), primarily affecting cattle. Dairy farms play a central role in the persistence and spread of BVDV in Italy, making control strategies and genetic studies essential to reduce its circulation. This work aimed to identify and characterize the genotype and subgenotype of BVDV infecting cattle in a specific area of Sardinia. Ten BVDV Sardinian strains were isolated and sequenced from the blood of infected cattle collected into EDTA tubes during outbreaks between 2018 and 2024. Then, to characterize the isolates, phylogenetic and variant analyses were performed on the entire collection of BVDV genomes available to date in GenBank. All Sardinian isolates were assigned to the BVDV-1b subgenotype. Except for two divergent strains, the isolates clustered into a distinct monophyletic clade characterized by 61 exclusive variants absent in all other analyzed sequences. These findings point to the existence of a distinct Sardinian genomic signature. Moreover, among these mutations, 19 missenses distributed on genes encoding the E1, E2, Core, NS3, NS4B and NS5A proteins could have a relevant functional impact, given the role these proteins play in the virus life cycle and in interaction with the host. Full article

Bovine viral diarrhea virus (BVDV) is a pathogen of worldwide economic importance. In Uruguay, BVDV is endemic, with seroprevalence >80% at the farm level. This study analyzed 912 samples collected from January 2018 to October 2024 by reverse transcription PCR and sequencing, from calves with diarrhea, aborted fetuses, heifers with a history of abortions, and animals exhibiting symptoms of Mucosal Disease. This work summarizes ten years (2014–2024) of molecular epidemiology and evolution of BVDV. Analysis of the BVDV 5′UTR/N^pro genomic region revealed that the BVDV-1a, 1e, 1i, and 2b subtypes circulate in Uruguay. BVDV-1a remains the most prevalent subtype, followed by BVDV-2b, whose prevalence has been increasing. Our previous studies revealed that BVDV-1a showed geographical diversification in Uruguay. In this work, evolutionary studies conducted with N^pro genomic region showed that BVDV-2b is evolving at a substitution rate of 6.09 × 10⁻⁴ substitutions/site/year and has been introduced from Brazil in six separate events between 1870 and 1928, showing no geographical diversification. This work demonstrates that BVDV-1a and BVDV-2b are evolving differently in Uruguay. This evolutionary divergence is notable when comparing patterns observed in other countries where these subtypes circulate. Our findings provide crucial knowledge that should be considered for developing effective BVDV control measures in Uruguay. Full article

Bovine viral diarrhea virus (BVDV) is an important pathogen in cattle and causes considerable economic losses worldwide. In Argentina, where there is no national control program, BVDV remains endemic. In this retrospective study, the epidemiological, clinical and pathological features of postnatal BVDV-associated diseases in 50 outbreaks in central Argentina (1995–2024) were analyzed. Data were obtained from field reports, necropsies, and virological results (virus isolation, RT-nPCR, immunochromatography). No seasonal pattern was found. Acute infections (AIs) and mucosal disease (MD) occurred with similar frequency. Clinical signs included salivation, weakness, emaciation and diarrhea. The lesions were widespread and involved the gastrointestinal tract, skin, lymphoid tissues and spleen. Although MD cases has more extensive tissue involvement, no significant differences in morbidity, mortality or distribution of lesions were observed between AIs and MD. BVDV-1b was the most frequently detected subtype. These results highlight the challenges of BVDV control in extensive production systems. Strengthening diagnostic surveillance, implementing targeted vaccination and eliminating persistently infected animals are essential to reduce BVDV impact in endemic regions such as Argentina. Full article

Bovine viral diarrhea virus (BVDV) is the most prevalent pathogen in cattle and causes significant economic losses due to its severe clinical manifestations. It belongs to the family Flaviviridae and is distributed in species A, B, and H within the genus Pestivirus. The objective of this study was to detect and characterize BVDV using molecular techniques (RT-PCR) in semen and aborted fetuses samples that were sent to the CEDIVEP (Veterinary Diagnostic Center of Paraguay) laboratory. Seventy-three samples of semen from bulls were analyzed, and 54.7% of the samples were positive for Pestivirus A. The presence of Pestivirus A and H was detected in 2/8 spontaneously aborted fetuses. The genotypes of four individual samples of type A and four samples of type H organs were confirmed by partial sequencing of the 5-UTR region. The presence of BVDV was confirmed by molecular techniques for the first time in our country through its detection in different types of samples, as well as the presence of two genotypes. This suggests that the circulation of this virus can cause significant losses in cattle production in Paraguay. Full article

Bovine respiratory disease complex (BRDC) is one of the primary causes of morbidity, mortality, and economic loss in cattle worldwide. Accurate and rapid identification of causative pathogenic agents is essential for effective disease management and control. In this study, a novel multiplex fluorescence-based quantitative polymerase chain reaction (qPCR) assay was developed for the simultaneous detection of eight major pathogens associated with BRDC. The targeted pathogens included the following: bovine viral diarrhea virus (BVDV), bovine parainfluenza virus type 3 (BPIV3), bovine respiratory syncytial virus (BRSV), bovine coronavirus (BcoV), Mycoplasma bovis (M.bovis), Pasteurella multocida (PM), Mannheimia haemolytica (MH), and infectious bovine rhinotracheitis virus (IBRV). The assay was rigorously optimized to ensure high specificity with no cross-reactivity among targets. The limit of detection (LOD) was determined to be as low as 5 copies per reaction for all target pathogens. The coefficient of variation (CVs) for both intra-assay and inter-assay measurements were consistently below 2%, demonstrating excellent reproducibility. To validate the clinical utility of the assay, a total of 1012 field samples were tested, including 504 nasal swabs from Farm A and 508 from Farm B in Jiangsu Province. BVDV, BcoV, PM, and MH were detected from Farm A, with a BVDV-positive rate of 21.63% (109/504), BcoV-positive rate of 26.79% (135/504), PM-positive rate of 28.77% (145/504), and MH-positive rate of 15.08% (76/504). Also, BcoV, PM, MH, and IBRV were detected from Farm B, with a BcoV-positive rate of 2.36% (12/508), PM-positive rate of 1.38% (7/508), MH-positive rate of 14.76% (75/508), and IBRV-positive rate of 5.51% (28/508). Notably, a significant proportion of samples showed evidence of mixed infections, underscoring the complexity of BRDC etiology and the importance of a multiplex diagnostic approach. In conclusion, the developed multiplex qPCR assay provides a reliable, rapid, and cost-effective tool for simultaneous detection of multiple BRDC-associated pathogens, which will hold great promise for enhancing disease surveillance, early diagnosis, and targeted intervention strategies, ultimately contributing to improved BRDC management and cattle health outcomes. Full article

Background/Objectives: Bovine viral diarrhea virus (BVDV) causes significant economic losses in the cattle industry worldwide. The current vaccines have limited efficacy against diverse BVDV genotypes. Currently, multi-antigen target design and nanocarrier display technologies can provide ideas for broad-spectrum and efficient BVDV vaccine design. Methods: Here we developed a trivalent mRNA vaccine encoding the domains I-II of envelope glycoprotein E2 from three BVDV genotypes (3E2), introduced with bovine IgG1 Fc (bFc), STABILON (hStab), and artificial virus-like particle (ARVLP) containing CD80 transmembrane (TM) domain, FcγRII cytoplasmic domain, and WW domain of ITCH. Then, in vitro expression, in vivo immunogenicity and neutralizing antibody analysis were performed to evaluate the vaccines. Results: The in vitro expression results showed that bFc and hStab dramatically enhanced antigen expression and immunogenicity. In addition, the ARVLP further enhanced the secretion and potency of neutralizing antibodies. Finally, the immunogenicity of the bFc_BVDV_3E2_ARVLP_hStab mRNA vaccine was evaluated in mice, guinea pigs, and lactating goats and high levels of neutralizing antibodies against all three BVDV genotypes were detected. Conclusions: Our trivalent design strategy with bFc, hStab, and ARVLP shows highly efficient expression as well as strong immunogenicity and provides a promising approach for next-generation BVDV vaccines with broader and stronger protection. Full article

Bovine viral diarrhea virus (BVDV) is a globally prevalent pathogen causing severe detriment to the cattle industry. Vertical infection occurring before the development of the fetal adaptive immune response, before 125 days of gestation, results in an immunotolerant, persistently infected (PI) calf. It was hypothesized that epigenetic alterations observed in the splenic tissue of PI fetuses at gestational day 245 would persist into the postnatal period. White blood cell DNA from five PI and five control heifers at 4 months of age was subjected to reduced representation bisulfite sequencing and interpreted within the context of complete blood count and flow cytometry data herein. Analysis revealed 8367 differentially methylated sites contained within genes associated with the immune and cardiac system, as well as hematopoiesis. Differences observed in the complete blood counts of PI heifers include increased monocytes, microcytic anemia, and elevated platelets with decreased mean platelet volume. Flow cytometry revealed increased classical monocytes, B cells, and CD4⁺/CD8B⁺ and CD25⁺/CD127⁻ T cells, as well as decreased γδ⁺, CD4⁺, and CD4⁻/CD8B⁻ T cells. Investigation of the PI methylome provides a new perspective on the mechanisms of pathologies and provides potential biomarkers for the rapid identification of PI cattle. Full article

(1) Background: Bovine viral diarrhea virus (BVDV) causes calf diarrhea, bovine respiratory syndrome, and cow abortion, resulting in substantial economic losses in the cattle industry. Owing to its persistent infection mechanism, BVDV is a major challenge in the treatment of cattle. (2) Methods: To determine how metformin (Met) inhibits the interaction between BVDV and host cells, we treated BVDV-infected cells with Met. We then performed an RNA sequencing (RNA-seq) analysis of Met-treated cells infected with BVDV to identify differentially expressed genes (DEGs). Consequently, the RNA-seq results were validated through real-time quantitative PCR (qPCR). (3) Results: Our analysis revealed 3169 DEGs in the Met-treated cells (Met group) vs. the negative controls (NC group) and 2510 DEGs in the BVDV-infected cells after pretreatment with Met (MetBVDV group) vs. the BVDV-infected cells (BVDV group). The DEGs were involved in MDBK interactions during BVDV infection, as indicated by Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analyses. The potential interactions of the DEGs were confirmed via a protein–protein interaction (PPI) network. Met treatment induced autophagy signaling activity and the expression of the autophagy-related genes ATG2A, ATG4B, ATG10, and ATG12 in BVDV-infected Met-pretreated cells. (4) Conclusions: We found that the host transcriptomic profile was affected by BVDV infection and Met pretreatment. These findings offer valuable new insights and provide support for future studies on the inhibition of BVDV replication by Met. Full article

Multivalent live-attenuated or inactivated vaccines are often used to control the bovine viral diarrhea disease (BVD). Still, they retain inherent disadvantages and do not provide the expected protection. This study developed a new vaccine prototype, including the external segment of the E2 viral protein from five different subgenotypes selected after a massive screening. The E2 proteins of every subgenotype (1aE2, 1bE2, 1cE2, 1dE2, and 1eE2) were produced in mammalian cells and purified by IMAC. An equimolar mixture of E2 proteins formulated in an oil-in-water adjuvant made up the vaccine candidate, inducing a high humoral response at 50, 100, and 150 µg doses in sheep. A similar immune response was observed in bovines at 50 µg. The cellular response showed a significant increase in the transcript levels of relevant Th1 cytokines, while those corresponding to the Th2 cytokine IL-4 and the negative control were similar. High levels of neutralizing antibodies against the subgenotype BVDV1a demonstrated the effectiveness of our vaccine candidate, similar to that observed in the sera of animals vaccinated with the commercial vaccine. These results suggest that our vaccine prototype could become an effective recombinant vaccine against the BVD. Full article