Detection of Pseudorabies Virus in Wild Boar Foetus

Pseudorabies, or Aujeszky’s disease, is a notifiable worldwide infection of domestic and feral swine that causes economic losses for the swine industry. In domestic pigs, the virus is responsible for nervous and/or respiratory symptoms; in pregnant sows, it is one of the major causes of stillbirth, mummification, embryonic death, and infertility (SMEDI). It is known that PRV infection in wild boar is associated with low pathogenicity and attenuated or absent symptomatology, but limited information is available about the ability of the virus to infect the foetuses of infected wild boar pregnant sows. Due to scarce information about the reproductive consequences, we investigate the possible intrauterine vertical transmission of the virus in wild boar pregnant sow living in a highly infected area. A number of 54 hunted wild boar were sampled during 2018–2019, and blood, genital and nasal swabs, placenta, and fetuses were collected for serological and molecular investigations. A seroprevalence of 74% (40/54) was detected, while 1/24 pregnant sow and 1/24 pooled foetuses tested positive by PCR (gene gB). This is the first evidence of viral detection in foetuses from seropositive pregnant wild boar. This finding suggests the possible pathogenetic role of PRV on pregnancy in wild boar and the existence of an additional transmission route.

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Development of Dual Fluorescent Microsphere Immunological Assay for Detection of Pseudorabies Virus gE and gB IgG Antibodies

10.21203/rs.3.rs-24925/v1 ◽

2020 ◽

Author(s):

chihai ji ◽

Jingyu Wang ◽

Yuchen Zeng ◽

Haoming Pan ◽

Yingfang Wei ◽

...

Keyword(s):

Pseudorabies Virus ◽

High Specificity ◽

Antibody Detection ◽

Economic Losses ◽

Igg Antibodies ◽

Wild Type ◽

Swine Industry ◽

Igg Antibody ◽

Fluorescent Microsphere ◽

Specificity And Sensitivity

Abstract Background Pseudorabies, also known as Aujezsky’s disease, is an acute viral infection caused by pseudorabies virus (PRV). Swine are one of the natural hosts of pseudorabies, therefore, the disease brings huge economic losses to the swine industry. Establishment of a differential diagnosis technique that can distinguish between wild-type infected and vaccinated pigs, and monitor vaccine-induced IgG is crucial for eventual eradication of pseudorabies.Results The aim of this study was to develop a rapid dual detection method for PRV gE and gB protein IgG antibodies with high specificity and sensitivity. PRV gE codons at amino acid residues (aa) 52–238 and gB codons at aa 539–741 were expressed to obtain recombinant PRV gE and gB proteins by pMAL-c5x vector. After purification with Qiagen Ni–NTA agarose affinity, the two proteins were analyzed by SDS-PAGE and immunoblotting assay. Two single fluorescent-microsphere immunoassays (FMIA) were established by coupling two recombinant proteins (gE and gB) with two magnetic microbeads and an effective dual FMIA was developed by integrating the two single assays. Optimal serum dilution for each assay, correlation with other common swine virus-positive sera and comparison with ELISA for two PRV antigens were tested for validation. Compared with ELISA, the specificity and sensitivity were 99.26% and 92.3% for gE IgG antibody detection and 95.74% and 96.3% for gB IgG antibody detection by dual-FMIA.Conclusion We provide a new method for monitoring PRV protective antibody in vaccinated pigs and differentiating wild-type-PRV-infected from vaccinated pigs

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Meclizine Inhibits Pseudorabies Virus Replication by Interfering With Virus Entry and Release

Frontiers in Microbiology ◽

10.3389/fmicb.2021.795593 ◽

2021 ◽

Vol 12 ◽

Author(s):

Panrao Liu ◽

Danhe Hu ◽

Lili Yuan ◽

Zhengmin Lian ◽

Xiaohui Yao ◽

...

Keyword(s):

Viral Entry ◽

Pseudorabies Virus ◽

Molecular Mechanisms ◽

Clinical Symptoms ◽

Antiviral Effect ◽

Inhibitory Effect ◽

Economic Losses ◽

Swine Industry ◽

Viral Attachment ◽

Viral Loads

Pseudorabies virus (PRV) is a pathogen that causes substantial economic losses to the swine industry. With the emergence and widespread of PRV variants since 2011 in China, current commercial vaccines cannot provide complete protection against PRV infection. Therefore, antiviral drugs may work as an alternative way to control and prevent PRV. In this study, the inhibitory effects and underlying molecular mechanisms of meclizine against PRV were studied. Meclizine displayed a significant inhibitory effect against PRV when it was added before, simultaneously with, or after virus infection. The inhibitory effect of meclizine occurred during viral entry and cell-to-cell spreading but not at viral attachment into PK-15 cells. Meclizine also inhibited viral particle release at the late stage of infection. The antiviral effect of meclizine was tested in mice, and the results showed that meclizine reduced the severity of clinical symptoms and the viral loads in tissues, and delayed the death, after PRV challenge. The above results indicated that meclizine had an inhibitory effect on PRV. Our findings will contribute to the development of potential therapeutic drugs against PRV infection.

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Major Vault Protein Inhibits Porcine Reproductive and Respiratory Syndrome Virus Infection in CRL2843CD163 Cell Lines and Primary Porcine Alveolar Macrophages

Viruses ◽

10.3390/v13112267 ◽

2021 ◽

Vol 13 (11) ◽

pp. 2267

Author(s):

Xiaoping Wu ◽

Junyang Fang ◽

Qiuping Huang ◽

Xu Chen ◽

Zhongyi Guo ◽

...

Keyword(s):

Cell Lines ◽

Alveolar Macrophages ◽

Economic Losses ◽

Respiratory Syndrome Virus ◽

Major Vault Protein ◽

Swine Industry ◽

Effective Prevention ◽

Viral Infectious Disease ◽

Sirna Knockdown

Porcine reproductive and respiratory syndrome (PRRS), a significant viral infectious disease that commonly occurs among farmed pigs, leads to considerable economic losses to the swine industry worldwide. Major vault protein (MVP) is a host factor that induces type Ⅰ interferon (IFN) production. In this study, we evaluated the effect of MVP on PRRSV infection in CRL2843CD163 cell lines and porcine alveolar macrophages (PAMs). Our results showed that MVP expression was downregulated by PRRSV infection. Adenoviral overexpression of MVP inhibited PRRSV replication, whereas the siRNA knockdown of MVP promoted PRRSV replication. In addition, MVP knockdown has an adverse effect on the inhibitive role of MVP overexpression on PRRSV replication. Moreover, MVP could induce the expression of type Ⅰ IFNs and IFN-stimulated gene 15 (ISG15) in PRRSV-infected PAMs. Based on these results, MVP may be a potential molecular target of drugs for the effective prevention and treatment of PRRSV infection.

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Mathematical Approach to Estimating the Main Epidemiological Parameters of African Swine Fever in Wild Boar

Vaccines ◽

10.3390/vaccines8030521 ◽

2020 ◽

Vol 8 (3) ◽

pp. 521 ◽

Cited By ~ 1

Author(s):

Federica Loi ◽

Stefano Cappai ◽

Alberto Laddomada ◽

Francesco Feliziani ◽

Annalisa Oggiano ◽

...

Keyword(s):

Wild Boar ◽

African Swine Fever ◽

Economic Losses ◽

Mathematical Approach ◽

Swine Industry ◽

Domestic Pig ◽

The North ◽

Reproduction Numbers ◽

Pig Farms ◽

Epidemiological Parameters

African swine fever (ASF) severely threatens the swine industry worldwide, given its spread and the absence of an available licensed vaccine, and has caused severe economic losses. Its persistence in wild boar (WB), longer than in domestic pig farms, and the knowledge gaps in ASF epidemiology hinder ASF virus (ASFV) eradication. Even in areas where disease is effectively controlled and ASFV is no longer detected, declaring eradication is difficult as seropositive WBs may still be detected. The aim of this work was to estimate the main ASF epidemiological parameters specific for the north of Sardinia, Italy. The estimated basic (R0) and effective (Re) reproduction numbers demonstrate that the ASF epidemic is declining and under control with an R0 of 1.139 (95% confidence interval (CI) = 1.123–1.153) and Re of 0.802 (95% CI = 0.612–0.992). In the last phases of an epidemic, these estimates are crucial tools for identifying the intensity of interventions required to definitively eradicate the disease. This approach is useful to understand if and when the detection of residual seropositive WB is no longer associated with any further ASFV circulation.

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Construction of a Quadruple Gene-deleted Vaccine Confers Complete Protective Immunity Against Emerging PRV Variant Challenge in Piglets

10.21203/rs.3.rs-985687/v1 ◽

2021 ◽

Author(s):

Leqiang Sun ◽

Yajie Tang ◽

Keji Yan ◽

Huawei Zhang

Keyword(s):

Pseudorabies Virus ◽

Clinical Signs ◽

Economic Losses ◽

Swine Industry ◽

Live Attenuated Vaccine ◽

Specific Antibodies ◽

Variant Strain ◽

Attenuated Vaccine ◽

Suckling Piglets ◽

Full Protection

Abstract Background: Pseudorabies virus (PRV) causes Aujeszky’s disease or pseudorabies (PR) in pigs worldwide, which leads to heavy economic losses to the swine industry. Pigs are the natural host, meanwhile, animals such as dogs, cats, foxes, rabbits, cattle and sheep are susceptible to infection. In 2011, the emerging PRV variant led to the outbreak of PR in Bar-tha-K61-vaccinated pigs. The PR outbreaks demonstrated that the Bartha-K61 vaccine did not provide full protection against the emerging PRV variant. It is widely believed that PRV live-attenuated vaccines could control PRV infection. Methods: In this study, we developed a novel PRV live-attenuated vaccine by deleting its gI, gE, US9, and US2 genes through CRISPR/Cas9, which was named PRV GDFS-delgI/gE/US9/US2.Results: Safety experiments confirmed that PRV GDFS-delgI/gE/US9/US2 was safe for 5 to 7-day-old suckling piglets. Piglets immunized with the PRV GDFS-delgI/gE/US9/US2 vaccine did not produce PRV gE-specific antibodies but could generate PRV gB-specific antibodies and high neutralizing titers against the PRV GDFS strain (variant PRV strain) or PRV Ea strain (older PRV strain). After challenge with the emerging PRV GDFS variant, none of the piglets immunized with the PRV GDFS-delgI/gE/US9/US2 vaccine showed any clinical signs, and their rectal temperatures were normal. Moreover, the autopsy and histopathological analyses revealed that the piglets in the PRV GDFS-delgI/gE/US9/US2 vaccine group did not show apparent gross or pathological lesions. Furthermore, the piglets in the PRV GDFS-delgI/gE/US9/US2 vaccine groups did not present weight loss. According to the criteria of the OIE terrestrial manual, the results of the experiment confirmed that the PRV GDFS-delgI/gE/US9/US2 vaccine could provide full protection against the emerging PRV variant strain in piglets. Conclusions: The PRV GDFS-delgI/gE/US9/US2 strain is a potential new live-attenuated vaccine against emerging PRV variant strain infections in China.

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Occurrence of Mycoplasma hyopneumoniae in slaughter pigs from Southern Brazil

Brazilian Journal of Veterinary Research and Animal Science ◽

10.11606/issn.1678-4456.bjvras.2019.150072 ◽

2019 ◽

Vol 56 (1) ◽

pp. e150072

Author(s):

Violetta Dias Pacce ◽

Natasha Rodrigues de Oliveira ◽

Sérgio Jorge ◽

Odir Antônio Dellagostin

Keyword(s):

Nested Pcr ◽

Mycoplasma Hyopneumoniae ◽

Economic Losses ◽

Limited Information ◽

Southern Brazil ◽

Feed Conversion ◽

Swine Industry ◽

Lung Lesions ◽

Slaughter Pigs ◽

Gross Lesions

Mycoplasma hyopneumoniae is the causative agent of enzootic pneumonia (EP), a disease that is highly prevalent and globally distributed, causing significant economic losses to the swine industry. Disease progression is characterized by reduced feed conversion and the development of lung lesions. Considering the limited information about the epidemiology of EP in Southern Brazil, the main objective of this study was to determine the occurrence of M. hyopneumoniae in swine lung samples and to evaluate the scores of lung lesions caused by local strains. A total of 120 samples was randomly collected and processed. DNA was extracted from lung tissue to perform nested-PCR and lungs were inspected to evaluate the presence of the pneumonia-like gross lesions of M. hyopneumoniae. The results showed 95.8% positive samples, while the lung lesion score analysis showed suggestive lesions in 60% of samples. The detection of positive samples in nested-PCR was associated with the presence of pneumonia-like gross lesions (P < 0.01). The results demonstrate a high occurrence of EP in slaughter pigs from southern Brazil.

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Porcine Reproductive and Respiratory Syndrome Virus Evades Antiviral Innate Immunity via MicroRNAs Regulation

Frontiers in Microbiology ◽

10.3389/fmicb.2021.804264 ◽

2021 ◽

Vol 12 ◽

Author(s):

Xuan Zhang ◽

Wen-Hai Feng

Keyword(s):

Innate Immunity ◽

Immune Evasion ◽

Economic Losses ◽

Respiratory Syndrome Virus ◽

Swine Industry ◽

Gene Expressions ◽

Non Coding Rnas ◽

New Treatments ◽

Antiviral Innate Immunity

Porcine reproductive and respiratory syndrome (PRRS) is one of the most important diseases in pigs, leading to significant economic losses in the swine industry worldwide. MicroRNAs (miRNAs) are small single-stranded non-coding RNAs involved in regulating gene expressions at the post-transcriptional levels. A variety of host miRNAs are dysregulated and exploited by PRRSV to escape host antiviral surveillance and help virus infection. In addition, PRRSV might encode miRNAs. In this review, we will summarize current progress on how PRRSV utilizes miRNAs for immune evasions. Increasing knowledge of the role of miRNAs in immune evasion will improve our understanding of PRRSV pathogenesis and help us develop new treatments for PRRSV-associated diseases.

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Isatis root polysaccharide promotes maturation and secretory function of monocyte-derived dendritic cells

BMC Complementary Medicine and Therapies ◽

10.1186/s12906-020-03103-2 ◽

2020 ◽

Vol 20 (1) ◽

Author(s):

Xuebing Wang ◽

Zewen Chen ◽

Tong Chen ◽

Xiao Li ◽

Shucheng Huang ◽

...

Keyword(s):

Dendritic Cells ◽

Pseudorabies Virus ◽

Molecular Mechanisms ◽

Peripheral Blood Monocyte ◽

Economic Losses ◽

Enzyme Linked Immunosorbent Assay ◽

Swine Industry ◽

Chinese Medicinal Herb ◽

Animal Virus ◽

Immature Dendritic Cells

Abstract Background Pseudorabies virus (PRV) is an animal virus that is globally responsible for the high economic losses in the swine industry. Isatis root is a traditional Chinese medicinal herb that possesses immune-enhancing and antiviral properties. However, the molecular mechanisms underlying the effects of the active component of the isatis root polysaccharide (IRPS) extract on immature dendritic cells remain elusive. Methods In this study, we investigated the molecular changes in primary porcine peripheral blood monocyte-derived dendritic cells (MoDCs) during PRV infection, using enzyme-linked immunosorbent assay (ELISA) and quantitative reverse transcription-polymerase chain reaction. Additionally, we studied the effect of IRPS on PRV-infected DCs. Results The results showed that IRPS stimulated the maturation of MoDCs, induced IL-12 secretion, and downregulated IL-6 expression. Conclusions Collectively, these results suggest that IRPS is a promising candidate for promoting maturation of DCs and enhancing their secretory potential after PRV infection.

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G-Quadruplexes Formation at the Upstream Region of Replication Origin (OriL) of the Pseudorabies Virus: Implications for Antiviral Targets

Viruses ◽

10.3390/v13112219 ◽

2021 ◽

Vol 13 (11) ◽

pp. 2219

Author(s):

Yance Zhu ◽

Wenhao Liu ◽

Chao Zhang

Keyword(s):

Pseudorabies Virus ◽

Resonance Energy Transfer ◽

Resonance Energy ◽

Cd Spectroscopy ◽

Host Cells ◽

Upstream Region ◽

Economic Losses ◽

Swine Industry ◽

Taq Polymerase

Pseudorabies virus (PRV) is the causative agent of Aujeszky’s disease, which still causes large economic losses for the swine industry. Therefore, it is urgent to find a new strategy to prevent and control PRV infection. Previous studies have proven that guanine (G)-rich DNA or RNA sequences in some other viruses’ genomes have the potential to form G-quadruplex (G4), which serve as promising antivirus targets. In this study, we identified two novel G4-forming sequences, OriL-A and OriL-S, which are located at the upstream origin of replication (OriL) in the PRV genome and conserved across 32 PRV strains. Circular dichroism (CD) spectroscopy and a gel electrophoresis assay showed that the two G-rich sequences can fold into parallel G4 structures in vitro. Moreover, fluorescence resonance energy transfer (FRET) melting and a Taq polymerase stop assay indicated that the G4 ligand PhenDC3 has the capacity to bind and stabilize the G4. Notably, the treatment of PRV-infected cells with G4-stabilizer PhenDC3 significantly inhibited PRV DNA replication in host cells but did not affect PRV’s attachment and entry. These results not only expand our knowledge about the G4 characteristics in the PRV genome but also suggest that G4 may serve as an innovative therapeutic target against PRV.

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Recombinant pseudorabies virus with gI/gE deletion generated by overlapping polymerase chain reaction and homologous recombination technology induces protection against the PRV variant PRV-GD2013

BMC Veterinary Research ◽

10.1186/s12917-021-02861-6 ◽

2021 ◽

Vol 17 (1) ◽

Author(s):

Wenhui Li ◽

Dijing Zhuang ◽

Hong Li ◽

Mengpo Zhao ◽

Erpeng Zhu ◽

...

Keyword(s):

Homologous Recombination ◽

Vaccine Strain ◽

Recombinant Virus ◽

Pseudorabies Virus ◽

Clinical Symptoms ◽

Growth Curves ◽

Economic Losses ◽

Plaque Morphology ◽

Swine Industry ◽

Antigenic Variant

Abstract Background Since 2011, numerous highly virulent and antigenic variant viral strains have been reported in pigs that were vaccinated against the swine pseudorabies virus. These infections have led to substantial economic losses in the Chinese swine industry. Results This study, constructed a novel recombinant vaccine strain with gI/gE deletion (PRV-GD2013-ΔgI/gE) by overlapping PCR and homologous recombination technology. The growth curves and plaque morphology of the recombinant virus were similar to those of the parental strain. However, PRV-GD2013-ΔgI/gE infection was significantly attenuated in mice compared with that of PRV-GD2013. Two-week-old piglets had normal rectal temperatures and displayed no clinical symptoms after being inoculated with 105 TCID50 PRV-GD2013-ΔgI/gE, indicating that the recombinant virus was avirulent in piglets. Piglets were immunized with different doses of PRV-GD2013-ΔgI/gE, or a single dose of Bartha-K61 or DMEM, and infected with PRV-GD2013 at 14 days post-vaccination. Piglets given high doses of PRV-GD2013-ΔgI/gE showed no obvious clinical symptoms, and their antibody levels were higher than those of other groups, indicating that the piglets were completely protected from PRV-GD2013. Conclusions The PRV-GD2013-ΔgI/gE vaccine strain could be effective for immunizing Chinese swine herds against the pseudorabies virus (PRV) strain.

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