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Lee HS, Dao TD, Huyen LTT, Bui VN, Bui AN, Ngo DT, Pham UB. Spatiotemporal Analysis and Assessment of Risk Factors in Transmission of African Swine Fever Along the Major Pig Value Chain in Lao Cai Province, Vietnam. Front Vet Sci 2022; 9:853825. [PMID: 35425836 PMCID: PMC9002011 DOI: 10.3389/fvets.2022.853825] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2022] [Accepted: 02/21/2022] [Indexed: 11/13/2022] Open
Abstract
African swine fever (ASF) is a contagious and lethal hemorrhagic disease with a case fatality rate approaching 100% in domestic pigs. The main objectives of this study were to describe the spatiotemporal analysis as well as to assess the potential risk factors along the pig value chain in Lao Cai province, Vietnam. A total of 925 outbreaks were reported from 2019 to 2020. The three clusters (primary, secondary and 5th) were observed near the Chinese border. The most temporal clusters were detected between May and August during the study period. In addition, we evaluated the association between ASF outbreak locations to the nearest main roads and elevation. For ASF outbreak locations to the nearest main roads, compared with the reference (<5,000 m), <1,000 m (10.22 times) and 1,000–2,000 m (1.98 times) were significantly higher occurrences of ASF. For elevation, compared to the reference (>1,500 m), the farm locations with <500 m (55.31 times) showed a significantly increased risk of ASF outbreaks. Farmers perceived that the highest risk of ASF transmission may come from collectors and slaughterers, intermediaries inside and outside the commune, feed agents and maize agents in the commune, and pig retailers. Both commercial and household pig producers considered minimizing the number of people going in and out of pig stables and improving healthcare and husbandry procedures to be both very important and feasible. There is a need for compliance by all pig producers and other actors in the pig value chain to adopt biosecurity practices. Therefore, awareness, knowledge and understanding of infection and risks of ASF need to be improved. Veterinary officials at the provincial and district levels need to improve capacity and resources to perform laboratory analysis for ASF and need to coordinate with local actors on the control and prevention of ASF in the community.
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Affiliation(s)
- Hu Suk Lee
- International Livestock Research Institute (ILRI), Animal and Human Health Program, Hanoi, Vietnam
- *Correspondence: Hu Suk Lee
| | - Tung Duy Dao
- Virology Department, National Institute of Veterinary Research, Hanoi, Vietnam
| | - Le Thi Thanh Huyen
- Livestock System and Environment Research Department, National Institute of Animal Science, Hanoi, Vietnam
| | - Vuong Nghia Bui
- Livestock System and Environment Research Department, National Institute of Animal Science, Hanoi, Vietnam
| | - Anh Ngoc Bui
- Livestock System and Environment Research Department, National Institute of Animal Science, Hanoi, Vietnam
| | - Dung Tien Ngo
- Lao Cai Animal Husbandry and Veterinary Branch, Lao Cai, Vietnam
| | - Uyen Ba Pham
- Lao Cai Animal Husbandry and Veterinary Branch, Lao Cai, Vietnam
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Ávila-Pérez G, Rejas MT, Chichón FJ, Guerra M, Fernández JJ, Rodríguez D. Architecture of torovirus replicative organelles. Mol Microbiol 2021; 117:837-850. [PMID: 34967475 DOI: 10.1111/mmi.14875] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2021] [Revised: 12/20/2021] [Accepted: 12/22/2021] [Indexed: 11/29/2022]
Abstract
Plus-stranded RNA viruses replicate in the cytosol of infected cells, in membrane-bound replication complexes. We previously identified double membrane vesicles (DMVs) in the cytoplasm of cells infected with Berne virus (BEV), the prototype member of Torovirus genus (Nidovirales Order). Our previous analysis by transmission electron microscopy suggested that the DMVs form a reticulovesicular network (RVN) analogous those described for the related severe acute respiratory syndrome coronavirus (SARS-CoV-1). Here, we used serial sectioning and electron tomography to characterize the architecture of torovirus replication organelles, and to learn about their biogenesis and dynamics during the infection. The formation of a RVN in BEV infected cells was confirmed, where the outer membranes of the DMVs are interconnected with each other and with the ER. Paired or zippered ER membranes connected with the DMVs were also observed, and likely represent early structures that evolve to give rise to DMVs. Also, paired membranes forming small spherule-like invaginations were observed at late time post-infection. Although resembling in size, the tomographic analysis show that these structures are clearly different from the true spherules described previously for coronaviruses. Hence, BEV shows important similarities, but also some differences, in the architecture of the replication organelles with other nidoviruses.
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Affiliation(s)
- Ginés Ávila-Pérez
- Department of Molecular and Cellular Biology, Centro de Biología Molecular Severo Ochoa, CSIC, C/Nicolás Cabrera 1, 28049, Madrid, Spain
| | - María Teresa Rejas
- Servicio de Microscopía Electrónica, Centro de Biología Molecular Severo Ochoa, CSIC, C/Nicolás Cabrera 1, 28049, Madrid, Spain
| | - Francisco Javier Chichón
- Servicio de Criomicroscopía Electrónica (cryoEM-CSIC) and Department of Macromolecular Structures, Centro Nacional de Biotecnología, CSIC, C/Darwin 3, 28049, Madrid, Spain
| | - Milagros Guerra
- Servicio de Microscopía Electrónica, Centro de Biología Molecular Severo Ochoa, CSIC, C/Nicolás Cabrera 1, 28049, Madrid, Spain
| | - José Jesús Fernández
- Instituto de Investigación Sanitaria del Principado de Asturias (ISPA), CINN-CSIC, Av Hospital Universitario s/n, 33011, Oviedo, Spain
| | - Dolores Rodríguez
- Department of Molecular and Cellular Biology, Centro de Biología Molecular Severo Ochoa, CSIC, C/Nicolás Cabrera 1, 28049, Madrid, Spain
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Lee HS, Thakur KK, Bui VN, Pham TL, Bui AN, Dao TD, Thanh VT, Wieland B. A stochastic simulation model of African swine fever transmission in domestic pig farms in the Red River Delta region in Vietnam. Transbound Emerg Dis 2021; 68:1384-1391. [PMID: 32810366 PMCID: PMC8246747 DOI: 10.1111/tbed.13802] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2020] [Revised: 08/12/2020] [Accepted: 08/14/2020] [Indexed: 12/11/2022]
Abstract
The main objectives of this study were to model various scenarios of African swine fever (ASF) virus transmission among farms in Vietnam and to evaluate the impact of control strategies using North American Animal Disease Spread Model (NAADSM). A total of 7,882 pig farms in the Red River Delta (RRD) region were obtained from the General Statistics Office, and then, random points corresponding to the number of farms in each province were generated as exact farm locations were not available. A total of 10 models were developed, including movement control scenarios. In addition, we conducted sensitivity analysis to assess the impact of indirect contact transmission probability (TP). Overall, the indirect contact exhibited an important role in transmitting the ASF virus. In order to minimize ASF transmission between farms, we found that movement restriction needed to reach a certain level (approximately between 50% and 75%) and that the restriction had to be applied in a timely manner. This study offers valuable insight into how ASF virus can be transmitted via direct and indirect contact and controlled among farms under the various simulation scenarios. Our results suggest that the enforcement of movement restriction was an effective control measure as soon as the outbreaks were reported. In addition, this study provided evidence that high standards of biosecurity can contribute to the reduction of disease spread.
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Affiliation(s)
- Hu Suk Lee
- International Livestock Research Institute (ILRI)HanoiVietnam
| | - Krishna K. Thakur
- Department of Health ManagementAtlantic Veterinary CollegeUniversity of Prince Edward IslandCharlottetownPEICanada
| | | | - Thanh Long Pham
- Department of Animal HealthEpidemiology DivisionHanoiVietnam
| | - Anh Ngoc Bui
- National Institute of Veterinary ResearchHanoiVietnam
| | - Tung Duy Dao
- National Institute of Veterinary ResearchHanoiVietnam
| | - Vu Thi Thanh
- National Institute of Veterinary ResearchHanoiVietnam
| | - Barbara Wieland
- International Livestock Research Institute (ILRI)Addis AbabaEthiopia
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4
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Lee HS, Thakur KK, Pham-Thanh L, Dao TD, Bui AN, Bui VN, Quang HN. A stochastic network-based model to simulate farm-level transmission of African swine fever virus in Vietnam. PLoS One 2021; 16:e0247770. [PMID: 33657173 PMCID: PMC7928462 DOI: 10.1371/journal.pone.0247770] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2020] [Accepted: 02/12/2021] [Indexed: 11/18/2022] Open
Abstract
African swine fever virus is highly contagious, and mortality rates reach up to 100% depending on the host, virus dose, and the transmission routes. The main objective of this study was to develop a network-based simulation model for the farm-level transmission of ASF virus to evaluate the impact of changes in farm connectivity on ASF spread in Vietnam. A hypothetical population of 1,000 pig farms was created and used for the network-based simulation, where each farm represented a node, and the connection between farms represented an edge. The three scenarios modelled in this way (baseline, low, and high) evaluated the impact of connectivity on disease transmission. The median number of infected farms was higher as the connectivity increased (low: 659, baseline: 968 and high: 993). In addition, we evaluated the impact of the culling strategy on the number of infected farms. A total of four scenarios were simulated depending on the timing of culling after a farm was infected. We found that the timing of culling at 16, 12, 8, and 6 weeks had resulted in a reduction of the number of median infected farms by 81.92%, 91.63%, 100%, and 100%, respectively. Finally, our evaluation of the implication of stability of ties between farms indicated that if the farms were to have the same trading partners for at least six months could significantly reduce the median number of infected farms to two (95th percentile: 413) than in the basic model. Our study showed that pig movements among farms had a significant influence on the transmission dynamics of ASF virus. In addition, we found that the either timing of culling, reduction in the number of trading partners each farm had, or decreased mean contact rate during the outbreaks were essential to prevent or stop further outbreaks.
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Affiliation(s)
- Hu Suk Lee
- International Livestock Research Institute (ILRI), Hanoi, Vietnam
- * E-mail:
| | - Krishna K. Thakur
- Department of Health Management, Atlantic Veterinary College, University of Prince Edward Island, Charlottetown, PE, Canada
| | - Long Pham-Thanh
- Epidemiology Division, Department of Animal Health, Hanoi, Vietnam
| | - Tung Duy Dao
- National Institute of Veterinary Research, Hanoi, Vietnam
| | - Anh Ngoc Bui
- National Institute of Veterinary Research, Hanoi, Vietnam
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Kedkovid R, Sirisereewan C, Thanawongnuwech R. Major swine viral diseases: an Asian perspective after the African swine fever introduction. Porcine Health Manag 2020; 6:20. [PMID: 32637149 PMCID: PMC7336096 DOI: 10.1186/s40813-020-00159-x] [Citation(s) in RCA: 32] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2020] [Accepted: 06/16/2020] [Indexed: 12/13/2022] Open
Abstract
Asia is a major pig producer of the world, and at present, African swine fever virus (ASFV) continues to significantly impact the Asian pig industry. Since more than 50% of the world’s pig population is in Asia, ASFV outbreaks in Asia will affect the global pig industry. Prior to the introduction of ASF, several outbreaks of major swine viruses occurred in Asia over the last two decades, including porcine reproductive and respiratory syndrome virus (PRRSV), porcine epidemic diarrhea virus (PEDV) and foot and mouth disease virus (FMDV). The rapid spreading of those viruses throughout Asia involve many factors such as the various pig production systems and supply chains ranging from back-yard to intensive industrial farms, animal movement and animal product trading within and among countries, and consumer behaviors. ASF has notoriously been known as a human-driven disease. Travelers and international trading are the major ASFV-carriers for the transboundary transmission and introduction to naïve countries. Globalization puts the entire pig industry at risk for ASF and other infectious diseases arising from Asian countries. Disease control strategies for the various pig production systems in Asia are challenging. In order to ensure future food security in the region and to prevent the deleterious consequences of ASF and other major viral disease outbreaks, disease control strategies and production systems must be improved and modernized.
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Affiliation(s)
- Roongtham Kedkovid
- Department of Veterinary Medicine, Faculty of Veterinary Science, Chulalongkorn University, Bangkok, 10330 Thailand.,Swine Reproduction Research Unit, Chulalongkorn University, Bangkok, 10330 Thailand
| | - Chaitawat Sirisereewan
- Department of Veterinary Pathology, Faculty of Veterinary Science, Chulalongkorn University, Bangkok, 10330 Thailand
| | - Roongroje Thanawongnuwech
- Department of Veterinary Pathology, Faculty of Veterinary Science, Chulalongkorn University, Bangkok, 10330 Thailand
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Sun YF, Jiang X, Zhang A, Ma JF, Yu XX, Li LA, Yu H. Early infection of Streptococcus suis serotype 2 increases the virulence of highly pathogenic porcine reproductive and respiratory syndrome MLV-like virus in pigs. Res Vet Sci 2020; 130:68-72. [PMID: 32146377 DOI: 10.1016/j.rvsc.2020.02.010] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2019] [Revised: 01/20/2020] [Accepted: 02/18/2020] [Indexed: 11/19/2022]
Abstract
Modified-live virus (MLV) vaccines derived from highly pathogenic porcine reproductive and respiratory syndrome virus (HP-PRRSV) were wildly used in China, which resulted in the emergence of MLV-like strains in pigs. Previous studies demonstrated that secondary bacterial infection could enhance HP-PRRSV infection-mediated inflammatory responses, but it is unknown whether early bacterial infection could enhance the HP-PRRSV MLV-like infection-mediated pathological reaction. In this paper, to gain the evidence for infection of pigs with MLV-like strains in China, we firstly analyzed the genetic characterization of the HP-PRRSV MLV-like isolate (TJxq1701) and further evaluated whether the early Streptococcus suis infection synergizes HP-PRRSV MLV-like infection-mediated pathological reaction. Our results showed that the whole genome of TJxq1701 shared the highest homology with JXA1-P80 and a total of 16 amino acids residues unique to JXA1-P80 in ORF1a, ORF1b, GP2, GP3, GP4, and GP5 were found in the corresponding locations. The results of infection experiments in pigs revealed that TJxq1701 caused transitional fever, moderate respiratory clinical sign and microscopic lung lesions in piglets, but early infection with low virulence Streptococcus suis serotype 2 (SS2) exhibited seriously clinical signs, including high fever, anorexia, and respiratory distress, leading to 60% mortality within four weeks in comparison with alone infected group. Taken together, our findings reveal that early bacterial infection could enhance the HP-PRRSV MLV-like infection-mediated pathological reaction, which provide an important clue for understanding that streptococcus infection increases the pathogenicity of MLV-like virus and a new thought for prevention and control of PRRSV.
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Affiliation(s)
- Ying-Feng Sun
- Tianjin Key Laboratory of Agricultural Animal Breeding and Healthy Husbandry, College of Animal Science and Veterinary Medicine, Tianjin Agricultural University, Tianjin 300384, PR China
| | - Xuan Jiang
- Tianjin Key Laboratory of Agricultural Animal Breeding and Healthy Husbandry, College of Animal Science and Veterinary Medicine, Tianjin Agricultural University, Tianjin 300384, PR China
| | - Ao Zhang
- Tianjin Key Laboratory of Agricultural Animal Breeding and Healthy Husbandry, College of Animal Science and Veterinary Medicine, Tianjin Agricultural University, Tianjin 300384, PR China
| | - Ji-Fei Ma
- Tianjin Key Laboratory of Agricultural Animal Breeding and Healthy Husbandry, College of Animal Science and Veterinary Medicine, Tianjin Agricultural University, Tianjin 300384, PR China
| | - Xiao-Xue Yu
- Tianjin Key Laboratory of Agricultural Animal Breeding and Healthy Husbandry, College of Animal Science and Veterinary Medicine, Tianjin Agricultural University, Tianjin 300384, PR China
| | - Liu-An Li
- Tianjin Key Laboratory of Agricultural Animal Breeding and Healthy Husbandry, College of Animal Science and Veterinary Medicine, Tianjin Agricultural University, Tianjin 300384, PR China.
| | - Hai Yu
- Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Shanghai 200241, PR China; Jiangsu Co-Innovation Center for the Prevention and Control of Important Animal Infectious Disease and Zoonosis, Yangzhou University, Yangzhou 225009, PR China.
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7
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Do DT, Nguyen TT, Nguyen NTH, Nguyen MHP, Le HT, Nguyen NTT, Nguyen NTP, Chae C, Mah CK. The efficacy and performance impact of Fostera PRRS in a Vietnamese commercial pig farm naturally challenged by a highly pathogenic PRRS virus. Trop Anim Health Prod 2020; 52:1725-1732. [PMID: 31898019 DOI: 10.1007/s11250-019-02177-6] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2019] [Accepted: 12/03/2019] [Indexed: 11/25/2022]
Abstract
Highly pathogenic porcine reproductive and respiratory syndrome virus (HP-PRRSV) is characterized by high fever, respiratory distress, and high mortality in pigs of all ages and has severely affected the Vietnam pork industry in recent years. The study was conducted to compare the efficacy, safety, and overall performance of a modified live PRRSV-2 vaccine (Fostera PRRS) to an existing PRRSV modified live vaccine on a farm with a recent history of HP-PRRSV-associated respiratory diseases. A total of 351 pigs were randomly allocated to three treatment groups: (i) vaccinated with Fostera PRRS at 1 day of age (n = 118), (ii) vaccinated with Fostera PRRS (n = 118) at 21 days of age, and (iii) vaccinated with Amervac PRRS (n = 115) at 21 days of age. The Fostera PRRS vaccinated pigs had milder clinical symptoms, lower levels of HP-PRRSV viremia, fewer pathological changes in the lung, and higher body weight gain at the end of the study compared with the Amervac PRRS group. Vaccination of pigs with Fostera PRRS at 1 day of age also significantly reduced viral loads in their blood (P < 0.05) and induced higher anti-PRRSV antibody titers (P < 0.01) compared with pigs vaccinated with Amervac PRRS at 21 days of age. Fostera PRRS vaccination at 1 day of age can be useful in protecting young piglets from early HP-PRRSV infection because the immunized pigs were marketed 20 days earlier than their peers immunized at 21-day old as they reached the target market weight earlier in this study.
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Affiliation(s)
- Duy Tien Do
- Faculty of Animal Science and Veterinary Medicine, Nong Lam University, Thu Duc district, Hochiminh City, Vietnam.
| | - Toan Tat Nguyen
- Faculty of Animal Science and Veterinary Medicine, Nong Lam University, Thu Duc district, Hochiminh City, Vietnam
| | | | - Mai Ha Phuong Nguyen
- Faculty of Animal Science and Veterinary Medicine, Nong Lam University, Thu Duc district, Hochiminh City, Vietnam
| | - Hien Thanh Le
- Faculty of Animal Science and Veterinary Medicine, Nong Lam University, Thu Duc district, Hochiminh City, Vietnam
| | - Nam Thi Thu Nguyen
- Faculty of Animal Science and Veterinary Medicine, Nong Lam University, Thu Duc district, Hochiminh City, Vietnam
| | - Ninh Thi Phuoc Nguyen
- Faculty of Animal Science and Veterinary Medicine, Nong Lam University, Thu Duc district, Hochiminh City, Vietnam
| | - Chanhee Chae
- College of Veterinary Medicine, Seoul National University, 1 Gwanak-ro, Gwanak-gu, Seoul, 151-742, Republic of Korea
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The nsp2 Hypervariable Region of Porcine Reproductive and Respiratory Syndrome Virus Strain JXwn06 Is Associated with Viral Cellular Tropism to Primary Porcine Alveolar Macrophages. J Virol 2019; 93:JVI.01436-19. [PMID: 31554681 DOI: 10.1128/jvi.01436-19] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2019] [Accepted: 09/18/2019] [Indexed: 11/20/2022] Open
Abstract
Porcine reproductive and respiratory syndrome virus (PRRSV) poses a major threat to global pork production and has been notorious for its rapid genetic evolution in the field. The nonstructural protein 2 (nsp2) replicase protein represents the fastest evolving region of PRRSV, but the underlying biological significance has remained poorly understood. By deletion mutagenesis, we discovered that the nsp2 hypervariable region plays an important role in controlling the balance of genomic mRNA and a subset of subgenomic mRNAs. More significantly, we revealed an unexpected link of the nsp2 hypervariable region to viral tropism. Specifically, a mutant of the Chinese highly pathogenic PRRSV strain JXwn06 carrying a deletion spanning nsp2 amino acids 323 to 521 (nsp2Δ323-521) in its hypervariable region was found to lose infectivity in primary porcine alveolar macrophages (PAMs), although it could replicate relatively efficiently in the supporting cell line MARC-145. Consequently, this mutant failed to establish an infection in piglets. Further dissection of the viral life cycle revealed that the mutant had a defect (or defects) lying in the steps between virus penetration and negative-stranded RNA synthesis. Taken together, our results reveal novel functions of nsp2 in the PRRSV life cycle and provide important insights into the mechanisms of PRRSV RNA synthesis and cellular tropism.IMPORTANCE The PRRSV nsp2 replicase protein undergoes rapid and broad genetic variations in its middle region in the field, but the underlying significance has remained enigmatic. Here, we demonstrate that the nsp2 hypervariable region not only plays an important regulatory role in maintaining the balance of different viral mRNA species but also regulates PRRSV tropism to primary PAMs. Our results reveal novel functions for PRRSV nsp2 and have important implications for understanding the mechanisms of PRRSV RNA synthesis and cellular tropism.
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Chung CJ, Cha SH, Grimm AL, Ajithdoss D, Rzepka J, Chung G, Yu J, Davis WC, Ho CS. Pigs that recover from porcine reproduction and respiratory syndrome virus infection develop cytotoxic CD4+CD8+ and CD4+CD8- T-cells that kill virus infected cells. PLoS One 2018; 13:e0203482. [PMID: 30188946 PMCID: PMC6126854 DOI: 10.1371/journal.pone.0203482] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2018] [Accepted: 08/21/2018] [Indexed: 11/24/2022] Open
Abstract
Porcine reproductive and respiratory syndrome virus (PRRSV) infection is difficult to control because the virus undergoes antigenic variation during infection and also modulates the protective host immune response. Although current vaccines do not provide full protection, they have provided insight into the mechanisms of protection. Live PRRSV vaccines induce partial protection before the appearance of neutralizing antibody, suggesting cell-mediated immunity or other mechanisms may be involved. Herein, we demonstrate recovery from infection is associated with development of cytotoxic T-lymphocytes (CTL) that can kill PRRSV-infected target cells. Initial experiments showed survival of PRRSV-infected monocyte derived macrophage (MDM) targets is reduced when overlaid with peripheral blood mononuclear cells (PBMC) from gilts that had recovered from PRRSV infection. Further studies with PBMC depleted of either CD4+ or CD8+ T-cells and positively selected subpopulations of CD4+ and CD8+ T-cells showed that both CD4+ and CD8+ T-cells were involved in killing. Examination of killing at different time points revealed killing was biphasic and mediated by CTL of different phenotypes. CD4+CD8+high were associated with killing target cells infected for 3–6 hours. CD4+CD8- CTL were associated with killing at 16–24 hours. Thus, all the anti-PRRSV CTL activity in pigs was attributed to two phenotypes of CD4+ cells which is different from the anti-viral CD4-CD8+ CTL phenotype found in most other animals. These findings will be useful for evaluating CTL responses induced by current and future vaccines, guiding to a novel direction for future vaccine development.
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Affiliation(s)
- Chungwon J. Chung
- Department of Veterinary Microbiology and Pathology, Washington State University, Pullman, Washington, United States of America
- VMRD Inc., Pullman, Washington, United States of America
- * E-mail: (CJC); (SHC)
| | - Sang-Ho Cha
- Animal and Plant Quarantine Agency, Gimcheon, Republic of Korea
- * E-mail: (CJC); (SHC)
| | | | - Dharani Ajithdoss
- Department of Veterinary Microbiology and Pathology, Washington State University, Pullman, Washington, United States of America
| | - Joanna Rzepka
- VMRD Inc., Pullman, Washington, United States of America
| | - Grace Chung
- VMRD Inc., Pullman, Washington, United States of America
| | - Jieun Yu
- Animal and Plant Quarantine Agency, Gimcheon, Republic of Korea
| | - William C. Davis
- Department of Veterinary Microbiology and Pathology, Washington State University, Pullman, Washington, United States of America
| | - Chak-Sum Ho
- Gift of life Michigan, Ann Arbor, Michigan, United States of America
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10
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Zhang W, Chen K, Zhang X, Guo C, Chen Y, Liu X. An integrated analysis of membrane remodeling during porcine reproductive and respiratory syndrome virus replication and assembly. PLoS One 2018; 13:e0200919. [PMID: 30040832 PMCID: PMC6057628 DOI: 10.1371/journal.pone.0200919] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2018] [Accepted: 05/27/2018] [Indexed: 01/20/2023] Open
Abstract
Background Recently, three-dimensional (3D) imaging techniques have been used to detect viral invasion and the appearance of specialized structures established in virus-infected cells. These methods have had a positive impact in the field of virology and helped to further our knowledge of how viruses invade cells. Nearly all positive-strand RNA viruses propagate their viral genomes in part through intracellular membranes. Porcine reproductive and respiratory syndrome virus (PRRSV), an Arterivirus, accumulates viral RNA that forms replication complexes (RCs) in infected cells. In this study, using immunofluorescence and electron microscopy (EM), we dissected PRRSV-induced membrane structures in infected cells and determined the correlations between PRRSV particles and vesicles stimulated by PRRSV to understand the structural and dynamic aspects of PRRSV infection. Methods We identified the appropriate time point by determining the 50% tissue culture infectious dose (TCID50) and using qRT-PCR and Western blotting. The co-localization of viruses and organelles was determined by immunofluorescence and immune-electron microscopy (IEM). The ultrastructure of cells infected by PRRSV was observed using EM and electron tomography (ET). Results In our study, we found that PRRSV dsRNA was located at the endoplasmic reticulum (ER) and autophagosomes; in addition, the N protein was located at the mitochondria, ER and autophagosomes. Vesicles induced by PRRSV appeared at 16 hours post-infection (h.p.i.) and increased in size with time during the infection period. In addition, our findings demonstrated that the virus vesicles originated from the ER, and these two organelle structures connected with each other to form a reticulovesicular network (RVN) that provided a site for virus replication and assembly. Conclusion Our results revealed that membrane vesicles induced by PRRSV were derived from the ER. The vesicles may provide a location for PRRSV replication and assembly.
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Affiliation(s)
- Wei Zhang
- School of Life Sciences, Sun Yat-Sen University, Guangzhou, P. R. China
- State Key Laboratory of Biocontrol, School of Life Sciences, Sun Yat-Sen University, Guangzhou, P. R. China
| | - Keren Chen
- School of Life Sciences, Sun Yat-Sen University, Guangzhou, P. R. China
- State Key Laboratory of Biocontrol, School of Life Sciences, Sun Yat-Sen University, Guangzhou, P. R. China
| | - Xueqing Zhang
- School of Life Sciences, Sun Yat-Sen University, Guangzhou, P. R. China
- State Key Laboratory of Biocontrol, School of Life Sciences, Sun Yat-Sen University, Guangzhou, P. R. China
| | - Chunhe Guo
- School of Life Sciences, Sun Yat-Sen University, Guangzhou, P. R. China
- State Key Laboratory of Biocontrol, School of Life Sciences, Sun Yat-Sen University, Guangzhou, P. R. China
| | - Yaosheng Chen
- School of Life Sciences, Sun Yat-Sen University, Guangzhou, P. R. China
- State Key Laboratory of Biocontrol, School of Life Sciences, Sun Yat-Sen University, Guangzhou, P. R. China
| | - Xiaohong Liu
- School of Life Sciences, Sun Yat-Sen University, Guangzhou, P. R. China
- State Key Laboratory of Biocontrol, School of Life Sciences, Sun Yat-Sen University, Guangzhou, P. R. China
- * E-mail:
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11
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Rappe JCF, de Wilde A, Di H, Müller C, Stalder H, V'kovski P, Snijder E, Brinton MA, Ziebuhr J, Ruggli N, Thiel V. Antiviral activity of K22 against members of the order Nidovirales. Virus Res 2018; 246:28-34. [PMID: 29337162 PMCID: PMC7114538 DOI: 10.1016/j.virusres.2018.01.002] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2017] [Revised: 01/10/2018] [Accepted: 01/10/2018] [Indexed: 01/31/2023]
Abstract
Recently, a novel antiviral compound (K22) that inhibits replication of a broad range of animal and human coronaviruses was reported to interfere with viral RNA synthesis by impairing double-membrane vesicle (DMV) formation (Lundin et al., 2014). Here we assessed potential antiviral activities of K22 against a range of viruses representing two (sub)families of the order Nidovirales, the Arteriviridae (porcine reproductive and respiratory syndrome virus [PRRSV], equine arteritis virus [EAV] and simian hemorrhagic fever virus [SHFV]), and the Torovirinae (equine torovirus [EToV] and White Bream virus [WBV]). Possible effects of K22 on nidovirus replication were studied in suitable cell lines. K22 concentrations significantly decreasing infectious titres of the viruses included in this study ranged from 25 to 50 μM. Reduction of double-stranded RNA intermediates of viral replication in nidovirus-infected cells treated with K22 confirmed the anti-viral potential of K22. Collectively, the data show that K22 has antiviral activity against diverse lineages of nidoviruses, suggesting that the inhibitor targets a critical and conserved step during nidovirus replication.
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Affiliation(s)
- Julie Christiane Françoise Rappe
- Institute for Virology and Immunology IVI, Mittelhäusern and Bern, Switzerland; Graduate School for Cellular and Biomedical Sciences, University of Bern, Switzerland; Department of Infectious Diseases and Pathobiology, University of Bern, Switzerland.
| | - Adriaan de Wilde
- Molecular Virology Laboratory, Department of Medical Microbiology, Leiden University Medical Center, Leiden, The Netherlands.
| | - Han Di
- Department of Biology, 623 Petit Science Center, Georgia State University, 161 Jesse Hill Jr Drive, Atlanta, GA 30303, United States.
| | - Christin Müller
- Institute of Medical Virology, Justus Liebig University, Giessen, Germany.
| | - Hanspeter Stalder
- Institute for Virology and Immunology IVI, Mittelhäusern and Bern, Switzerland; Department of Infectious Diseases and Pathobiology, University of Bern, Switzerland.
| | - Philip V'kovski
- Institute for Virology and Immunology IVI, Mittelhäusern and Bern, Switzerland; Graduate School for Cellular and Biomedical Sciences, University of Bern, Switzerland; Department of Infectious Diseases and Pathobiology, University of Bern, Switzerland.
| | - Eric Snijder
- Molecular Virology Laboratory, Department of Medical Microbiology, Leiden University Medical Center, Leiden, The Netherlands.
| | - Margo A Brinton
- Department of Biology, 623 Petit Science Center, Georgia State University, 161 Jesse Hill Jr Drive, Atlanta, GA 30303, United States.
| | - John Ziebuhr
- Institute of Medical Virology, Justus Liebig University, Giessen, Germany.
| | - Nicolas Ruggli
- Institute for Virology and Immunology IVI, Mittelhäusern and Bern, Switzerland; Department of Infectious Diseases and Pathobiology, University of Bern, Switzerland.
| | - Volker Thiel
- Institute for Virology and Immunology IVI, Mittelhäusern and Bern, Switzerland; Department of Infectious Diseases and Pathobiology, University of Bern, Switzerland.
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12
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Investigating the financial impact of porcine reproductive and respiratory syndrome on smallholder pig farmers in Cambodia. Trop Anim Health Prod 2017; 49:791-806. [PMID: 28316000 DOI: 10.1007/s11250-017-1264-1] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2016] [Accepted: 03/06/2017] [Indexed: 10/19/2022]
Abstract
Porcine reproductive and respiratory syndrome (PRRS) was first identified in Cambodia in 2010, causing serious problems on affected farms, although the costs of the disease have not been well defined. The household financial impact of a PRRS outbreak in Cambodia was investigated using partial budget analysis, examining the economic benefit of three proposed interventions: (i) quarterly PRRS vaccine use, (ii) biosecurity implementation, and (iii) implementation of vaccination and biosecurity. The analyses were applied to three farm models: (i) a two-sow breeder; (ii) a five-pig fattener; and (iii) a single-sow, three-pig farrow-to-finish/breeder. Data was derived from a knowledge, attitude, and practice survey of 240 smallholder farmers (61 with pigs) from 16 villages across 5 provinces, plus case studies of 12 farmers selected for more detailed financial analysis. The study indicated that financial losses associated with PRRS were severe, with a 25% mean loss to the annual household income of 61 interviewed farmers. Partial budget analysis identified a strongly positive incentive for vaccination and biosecurity to be implemented in combination, with the highest annual net benefit of USD 357.10 realised by the breeder system. However, due to current scarcity of the PRRS vaccine and its high cost to smallholders, biosecurity interventions may be more cost-effective, especially for low PRRS incidence regions. It was concluded that PRRS critically constrains the profitability of smallholder pig farms and that these findings will assist development of village-level livestock disease risk management programmes that encourage adoption of vaccination and biosecurity practices to enhance farmer livelihoods in Cambodia.
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Han J, Zhou L, Ge X, Guo X, Yang H. Pathogenesis and control of the Chinese highly pathogenic porcine reproductive and respiratory syndrome virus. Vet Microbiol 2017; 209:30-47. [PMID: 28292547 DOI: 10.1016/j.vetmic.2017.02.020] [Citation(s) in RCA: 90] [Impact Index Per Article: 12.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2016] [Revised: 02/22/2017] [Accepted: 02/27/2017] [Indexed: 12/24/2022]
Abstract
Porcine reproductive and respiratory syndrome virus (PRRSV) has remained a major threat to the worldwide swine industry ever since its first discovery in the early 1990s. Under the selective pressures in the field, this positive-stranded RNA virus undergoes rapid genetic evolution that eventually leads to emergence in 2006 of the devastating Chinese highly pathogenic PRRSV (HP-PRRSV). The atypical nature of HP-PRRSV has caused colossal economic losses to the swine producers in China and the surrounding countries. In this review, we summarize the recent advances in our understanding of the pathogenesis, evolution and ongoing field practices on the control of this troubling virus in China.
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Affiliation(s)
- Jun Han
- Key Laboratory of Animal Epidemiology and Zoonosis of Ministry of Agriculture, College of Veterinary Medicine and State Key Laboratory of Agrobiotechnology, China Agricultural University, Beijing, PR China
| | - Lei Zhou
- Key Laboratory of Animal Epidemiology and Zoonosis of Ministry of Agriculture, College of Veterinary Medicine and State Key Laboratory of Agrobiotechnology, China Agricultural University, Beijing, PR China
| | - Xinna Ge
- Key Laboratory of Animal Epidemiology and Zoonosis of Ministry of Agriculture, College of Veterinary Medicine and State Key Laboratory of Agrobiotechnology, China Agricultural University, Beijing, PR China
| | - Xin Guo
- Key Laboratory of Animal Epidemiology and Zoonosis of Ministry of Agriculture, College of Veterinary Medicine and State Key Laboratory of Agrobiotechnology, China Agricultural University, Beijing, PR China
| | - Hanchun Yang
- Key Laboratory of Animal Epidemiology and Zoonosis of Ministry of Agriculture, College of Veterinary Medicine and State Key Laboratory of Agrobiotechnology, China Agricultural University, Beijing, PR China.
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Iseki H, Kawashima K, Tung N, Inui K, Ikezawa M, Shibahara T, Yamakawa M. Efficacy of Type 2 porcine reproductive and respiratory syndrome virus (PRRSV) vaccine against the 2010 isolate of Vietnamese highly pathogenic PRRSV challenge in pigs. J Vet Med Sci 2017; 79:765-773. [PMID: 28239040 PMCID: PMC5402200 DOI: 10.1292/jvms.16-0536] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
Abstract
The efficacy of a commercial attenuated live type 2 porcine reproductive and respiratory
syndrome (PRRS) vaccine was tested under experimental infection with a highly virulent
Vietnamese virus isolated from a diseased pig affected with highly pathogenic PRRS
(HP-PRRS) using specific pathogen-free (SPF) pigs. Twenty-five 4-week-old SPF pigs were
divided into three groups as follows: pigs vaccinated with a single dose of the vaccine
(Group 1, n=10), unvaccinated pigs (Group 2, n=10) and unvaccinated and non-infectious
control pigs (Group 3, n=5). Four weeks later, Groups 1 and 2 were challenged with a 1
ml inoculum containing 1 × 105.5 50% tissue culture
infectious dose (TCID50)/ml of a Vietnamese HP-PRRS virus
isolated in 2010 via the intranasal route. Animals were monitored during the subsequent
two-week period post-challenge and necropsied for virological and pathological assays.
Results showed a significant reduction in viral replication and shedding in vaccinated
pigs compared to unvaccinated pigs. The non-vaccinated pigs showed severe pyrogenic and
respiratory illness with marked systematic lesions including interstitial pneumonia and
thymic atrophy. In contrast, vaccinated pigs recovered quickly from fever with only mild
pathological manifestations. Therefore, although viral shedding was still noted,
immunization with the live PRRS vaccine did indeed reduce viral replication and disease
severity, suggesting its utility in minimizing outbreaks of HP-PRRS.
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Affiliation(s)
- Hiroshi Iseki
- Viral Disease and Epidemiology Research Division, National Institute of Animal Health, National Agriculture and Food Research Organization, 3-1-5 Kannondai, Tsukuba, Ibaraki 305-0856 Japan
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15
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Comparison of Asian porcine high fever disease isolates of porcine reproductive and respiratory syndrome virus to United States isolates for their ability to cause disease and secondary bacterial infection in swine. Vet Microbiol 2017; 203:6-17. [PMID: 28619168 DOI: 10.1016/j.vetmic.2017.02.003] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2016] [Revised: 02/07/2017] [Accepted: 02/08/2017] [Indexed: 11/21/2022]
Abstract
Epidemiologic data from Asian outbreaks of highly-pathogenic (HP) porcine reproductive and respiratory syndrome virus (PRRSV) suggest that disease severity was associated with both the virulence of the PRRSV isolates and secondary bacterial infections. Previous reports have indicated that U.S. isolates of PRRSV predispose to secondary bacterial infections as well, but the severity of disease that occurred in Asia in pigs infected with these HP-PRRSV strains has not been reported in the U.S. The objectives of this research were to compare the pathogenesis of Asian and U.S. PRRSV isolates with regard to their ability to cause disease and predispose to secondary bacterial infections in swine. To address these objectives groups of pigs were infected with 1 of 2 Asian HP-PRRSV strains (rJXwn06 or rSRV07) or 1 of 2 U.S. PRRSV strains (SDSU73 or VR-2332) alone or in combination with Streptococcus suis, Haemophilus parasuis, and Actinobacillus suis. Pigs infected with rJXwn06 exhibited the most severe clinical disease while the pigs infected with rSRV07 and SDSU73 exhibited moderate clinical disease, and pigs infected with VR-2332 exhibited minimal clinical signs. The frequency of secondary bacterial pneumonia was associated with the clinical severity induced by the PRRSV strains evaluated. The levels of proinflammatory cytokines in the serum were often lower for pigs coinfected with virus and bacteria compared to pigs infected with PRRSV alone indicating an alteration in the immune response in coinfected pigs. Combined our results demonstrate that severity of disease appears to be dependent on virulence of the PRRSV strain, and development of secondary bacterial infection.
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King SJ, Ooi PT, Phang LY, Allaudin ZNB, Loh WH, Tee CY, How SP, Yip LS, Choo PY, Lim BK. Phylogenetic characterization of genes encoding for viral envelope glycoprotein (ORF5) and nucleocapsid protein (ORF7) of porcine reproductive & respiratory syndrome virus found in Malaysia in 2013 and 2014. BMC Vet Res 2017; 13:3. [PMID: 28056965 PMCID: PMC5217455 DOI: 10.1186/s12917-016-0933-z] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2016] [Accepted: 12/17/2016] [Indexed: 11/30/2022] Open
Abstract
Background Porcine reproductive and respiratory syndrome (PRRS) is one of the most expensive diseases of modern swine production & results in annual economic losses and cost the industry over 600 million USD in U.S. alone and billions of dollars worldwide. Two atypical PRRS cases were observed in 2013 and 2014 characterized by late-term abortion, fever and sudden increase in sow mortality which persisted for a prolonged period of time. Methods Lungs, lymph nodes and other samples were collected for disease investigation. Sequencing of the viral envelope glycoprotein (ORF5) and nucleocapsid protein (ORF7) of PRRSV was done using the BigDye Terminator v3.1 cycle sequencing kit chemistry. The phylogenetic tree was constructed by using the Maximum Likelihood method, generated by Mega 6.06®. Results Analysis of the ORF5 and ORF7 showed high degree of sequence homology to PRRSV parent vaccine strain VR-2332, RespPRRSV and other mutant/chimeric virus strains. Conclusions Our study suggests that recombination events between vaccine strains and field isolates may contribute to PRRSV virulence in the field.
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Affiliation(s)
- Seetha Jaganathan King
- Department of Clinical Studies, Faculty of Veterinary Medicine, Universiti Putra Malaysia, UPM, Serdang, Selangor, 43400, Malaysia.,Asia-Pacific Special Nutrients Sdn. Bhd, Lot 18B, Jalan 241, Section 51A, Petaling Jaya, Selangor, 46100, Malaysia
| | - Peck Toung Ooi
- Department of Clinical Studies, Faculty of Veterinary Medicine, Universiti Putra Malaysia, UPM, Serdang, Selangor, 43400, Malaysia.
| | - Lai Yee Phang
- Department of Biotechnology, Faculty of Biotechnology & Molecular Science, Universiti Putra Malaysia, UPM, Serdang, Selangor, 43400, Malaysia
| | | | - Wei Hoong Loh
- Vet Food Agro Diagnostic (M) Sdn. Bhd, Lot 18B, Jalan 241, Section 51A, Petaling Jaya, Selangor, 46100, Malaysia
| | - Chiou Yan Tee
- Vet Food Agro Diagnostic (M) Sdn. Bhd, Lot 18B, Jalan 241, Section 51A, Petaling Jaya, Selangor, 46100, Malaysia
| | - Shiao Pau How
- Vet Food Agro Diagnostic Sdn. Bhd, Lot 18B, Jalan 241, Section 51A, Petaling Jaya, Selangor, 46100, Malaysia
| | - Lai Siong Yip
- Vet Food Agro Diagnostic (M) Sdn. Bhd, Lot 18B, Jalan 241, Section 51A, Petaling Jaya, Selangor, 46100, Malaysia
| | - Pow Yoon Choo
- Vet Food Agro Diagnostic (M) Sdn. Bhd, Lot 18B, Jalan 241, Section 51A, Petaling Jaya, Selangor, 46100, Malaysia
| | - Ban Keong Lim
- Vet Food Agro Diagnostic (M) Sdn. Bhd, Lot 18B, Jalan 241, Section 51A, Petaling Jaya, Selangor, 46100, Malaysia
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Diseases Primarily Affecting the Reproductive System. Vet Med (Auckl) 2017. [PMCID: PMC7150237 DOI: 10.1016/b978-0-7020-5246-0.00018-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Do HQ, Trinh DT, Nguyen TL, Vu TTH, Than DD, Van Lo T, Yeom M, Song D, Choe S, An DJ, Le VP. Molecular evolution of type 2 porcine reproductive and respiratory syndrome viruses circulating in Vietnam from 2007 to 2015. BMC Vet Res 2016; 12:256. [PMID: 27855667 PMCID: PMC5112882 DOI: 10.1186/s12917-016-0885-3] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2016] [Accepted: 11/10/2016] [Indexed: 11/24/2022] Open
Abstract
Background Porcine respiratory and reproductive syndrome (PRRS) virus is one of the most economically significant pathogens in the Vietnamese swine industry. ORF5, which participates in many functional processes, including virion assembly, entry of the virus into the host cell, and viral adaptation to the host immune response, has been widely used in molecular evolution and phylogeny studies. Knowing of molecular evolution of PRRSV fields strains might contribute to PRRS control in Vietnam. Results The results showed that phylogenetic analysis indicated that all strains belonged to sub-lineages 8.7 and 5.1. The nucleotide and amino acid identities between strains were 84.5–100% and 82–100%, respectively. Furthermore, the results revealed differences in nucleotide and amino acid identities between the 2 sub-lineage groups. N-glycosylation prediction identified 7 potential N-glycosylation sites and 11 glycotypes. Analyses of the GP5 sequences, revealed 7 sites under positive selective pressure and 25 under negative selective pressure. Conclusions Phylogenetic analysis based on ORF5 sequence indicated the diversity of PRRSV in Vietnam. Furthermore, the variance of N-glycosylation sites and position under selective pressure were demonstrated. This study expands existing knowledge on the genetic diversity and evolution of PRRSV in Vietnam and assists the effective strategies for PRRS vaccine development in Vietnam. Electronic supplementary material The online version of this article (doi:10.1186/s12917-016-0885-3) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Hai Quynh Do
- Faculty of Veterinary Medicine, Vietnam National University of Agriculture, Hanoi, Vietnam
| | - Dinh Thau Trinh
- Faculty of Veterinary Medicine, Vietnam National University of Agriculture, Hanoi, Vietnam
| | - Thi Lan Nguyen
- Faculty of Veterinary Medicine, Vietnam National University of Agriculture, Hanoi, Vietnam
| | - Thi Thu Hang Vu
- Research and Development Laboratory, Avac Vietnam Company Limited (AVAC), Hung Yen, Vietnam
| | - Duc Duong Than
- Research and Development Laboratory, Avac Vietnam Company Limited (AVAC), Hung Yen, Vietnam
| | - Thi Van Lo
- Research and Development Laboratory, Avac Vietnam Company Limited (AVAC), Hung Yen, Vietnam
| | - Minjoo Yeom
- College of Pharmacy, Korea University, Sejong, Republic of Korea
| | - Daesub Song
- College of Pharmacy, Korea University, Sejong, Republic of Korea
| | - SeEun Choe
- Animal and Plant Quarantine Agency, Gyeonggi-do, Gimcheon, Gyeongsangbukdo, Republic of Korea
| | - Dong-Jun An
- Animal and Plant Quarantine Agency, Gyeonggi-do, Gimcheon, Gyeongsangbukdo, Republic of Korea
| | - Van Phan Le
- Faculty of Veterinary Medicine, Vietnam National University of Agriculture, Hanoi, Vietnam.
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Chung CJ, Cha SH, Grimm AL, Chung G, Gibson KA, Yoon KJ, Parish SM, Ho CS, Lee SS. Recognition of Highly Diverse Type-1 and -2 Porcine Reproductive and Respiratory Syndrome Viruses (PRRSVs) by T-Lymphocytes Induced in Pigs after Experimental Infection with a Type-2 PRRSV Strain. PLoS One 2016; 11:e0165450. [PMID: 27798650 PMCID: PMC5087905 DOI: 10.1371/journal.pone.0165450] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2016] [Accepted: 10/12/2016] [Indexed: 11/18/2022] Open
Abstract
Background/Aim Live attenuated vaccines confer partial protection in pigs before the appearance of neutralizing antibodies, suggesting the contribution of cell-mediated immunity (CMI). However, PRRSV-specific T-lymphocyte responses and protective mechanisms need to be further defined. To this end, the hypothesis was tested that PRRSV-specific T-lymphocytes induced by exposure to type-2 PRRSV can recognize diverse isolates. Methods An IFN-gamma ELISpot assay was used to enumerate PRRSV-specific T-lymphocytes from PRRSVSD23983-infected gilts and piglets born after in utero infection against 12 serologically and genetically distinct type-1 and -2 PRRSV isolates. The IFN-gamma ELISpot assay using synthetic peptides spanning all open reading frames of PRRSVSD23983 was utilized to localize epitopes recognized by T-lymphocytes. Virus neutralization tests were carried out using the challenge strain (type-2 PRRSVSD23983) and another strain (type-2 PRRSVVR2332) with high genetic similarity to evaluate cross-reactivity of neutralizing antibodies in gilts after PRRSVSD23983 infection. Results At 72 days post infection, T-lymphocytes from one of three PRRSVSD23983-infected gilts recognized all 12 diverse PRRSV isolates, while T-lymphocytes from the other two gilts recognized all but one isolate. Furthermore, five of nine 14-day-old piglets infected in utero with PRRSVSD23983 had broadly reactive T-lymphocytes, including one piglet that recognized all 12 isolates. Overlapping peptides encompassing all open reading frames of PRRSVSD23983 were used to identify ≥28 peptides with T-lymphocyte epitopes from 10 viral proteins. This included one peptide from the M protein that was recognized by T-lymphocytes from all three gilts representing two completely mismatched MHC haplotypes. In contrast to the broadly reactive T-lymphocytes, neutralizing antibody responses were specific to the infecting PRRSVSD23983 isolate. Conclusion These results demonstrated that T-lymphocytes recognizing antigenically and genetically diverse isolates were induced by infection with a type 2 PRRSV strain (SD23983). If these reponses have cytotoxic or other protective functions, they may help overcome the suboptimal heterologous protection conferred by conventional vaccines.
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Affiliation(s)
- Chungwon J. Chung
- VMRD Inc., Pullman, WA 99163, United States of America
- Department of Veterinary Microbiology and Pathology, Washington State University, Pullman, WA 99163, United States of America
- * E-mail:
| | - Sang-Ho Cha
- Department of Virology, Animal and Plant Quarantine Agency, Anyang, Republic of Korea
| | | | - Grace Chung
- VMRD Inc., Pullman, WA 99163, United States of America
- Department of Veterinary Microbiology and Pathology, Washington State University, Pullman, WA 99163, United States of America
| | - Kathleen A. Gibson
- Department of Veterinary Diagnostic and Production Animal Medicine, College of Veterinary Medicine, Iowa State University, Ames, IA 50011, United States of America
| | - Kyoung-Jin Yoon
- Department of Veterinary Diagnostic and Production Animal Medicine, College of Veterinary Medicine, Iowa State University, Ames, IA 50011, United States of America
| | - Steven M. Parish
- Department of Veterinary Clinical Sciences, College of Veterinary Medicine, Washington State University, Pullman, WA 99163, United States of America
| | - Chak-Sum Ho
- Gift of Life Michigan, Ann Arbor, MI 48108, United States of America
| | - Stephen S. Lee
- Department of Statistics, University of Idaho, Moscow, ID 83844, United States of America
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van der Hoeven B, Oudshoorn D, Koster AJ, Snijder EJ, Kikkert M, Bárcena M. Biogenesis and architecture of arterivirus replication organelles. Virus Res 2016; 220:70-90. [PMID: 27071852 PMCID: PMC7111217 DOI: 10.1016/j.virusres.2016.04.001] [Citation(s) in RCA: 58] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2016] [Accepted: 04/01/2016] [Indexed: 02/06/2023]
Abstract
Arterivirus RNA synthesis presumably is associated with double-membrane vesicles (DMVs). Putative intermediates in DMV formation were detected in infected cells. Arterivirus-induced DMVs form a highly interconnected reticulovesicular network (RVN). Expression of the nsp2-3 replicase polyprotein fragment induces a comparable RVN. Nsp2-7 expression results in smaller DMVs, closer in size to DMVs found in infection.
All eukaryotic positive-stranded RNA (+RNA) viruses appropriate host cell membranes and transform them into replication organelles, specialized micro-environments that are thought to support viral RNA synthesis. Arteriviruses (order Nidovirales) belong to the subset of +RNA viruses that induce double-membrane vesicles (DMVs), similar to the structures induced by e.g. coronaviruses, picornaviruses and hepatitis C virus. In the last years, electron tomography has revealed substantial differences between the structures induced by these different virus groups. Arterivirus-induced DMVs appear to be closed compartments that are continuous with endoplasmic reticulum membranes, thus forming an extensive reticulovesicular network (RVN) of intriguing complexity. This RVN is remarkably similar to that described for the distantly related coronaviruses (also order Nidovirales) and sets them apart from other DMV-inducing viruses analysed to date. We review here the current knowledge and open questions on arterivirus replication organelles and discuss them in the light of the latest studies on other DMV-inducing viruses, particularly coronaviruses. Using the equine arteritis virus (EAV) model system and electron tomography, we present new data regarding the biogenesis of arterivirus-induced DMVs and uncover numerous putative intermediates in DMV formation. We generated cell lines that can be induced to express specific EAV replicase proteins and showed that DMVs induced by the transmembrane proteins nsp2 and nsp3 form an RVN and are comparable in topology and architecture to those formed during viral infection. Co-expression of the third EAV transmembrane protein (nsp5), expressed as part of a self-cleaving polypeptide that mimics viral polyprotein processing in infected cells, led to the formation of DMVs whose size was more homogenous and closer to what is observed upon EAV infection, suggesting a regulatory role for nsp5 in modulating membrane curvature and DMV formation.
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Affiliation(s)
- Barbara van der Hoeven
- Electron Microscopy Section, Department of Molecular Cell Biology, Leiden University Medical Center, Leiden, The Netherlands
| | - Diede Oudshoorn
- Molecular Virology Laboratory, Department of Medical Microbiology, Leiden University Medical Center, Leiden, The Netherlands
| | - Abraham J Koster
- Electron Microscopy Section, Department of Molecular Cell Biology, Leiden University Medical Center, Leiden, The Netherlands
| | - Eric J Snijder
- Molecular Virology Laboratory, Department of Medical Microbiology, Leiden University Medical Center, Leiden, The Netherlands
| | - Marjolein Kikkert
- Molecular Virology Laboratory, Department of Medical Microbiology, Leiden University Medical Center, Leiden, The Netherlands.
| | - Montserrat Bárcena
- Electron Microscopy Section, Department of Molecular Cell Biology, Leiden University Medical Center, Leiden, The Netherlands.
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Faisal F, Widayanti R, Haryanto A, Tabu CR. Molecular identification and genetic diversity of open reading frame 7 field isolated porcine reproductive and respiratory syndrome in North Sumatera, Indonesia, in the period of 2008-2014. Vet World 2016; 8:875-80. [PMID: 27047168 PMCID: PMC4774680 DOI: 10.14202/vetworld.2015.875-880] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2015] [Revised: 06/13/2015] [Accepted: 06/22/2015] [Indexed: 11/16/2022] Open
Abstract
AIM Molecular identification and genetic diversity of open reading frame 7 (ORF7) of field isolated porcine reproductive and respiratory syndrome virus (PRRSV) in North Sumatera, Indonesia, in the period of 2008-2014. MATERIALS AND METHODS A total of 47 PRRSV samples were collected from the death case of pigs. The samples were collected from different districts in the period of 2008-2014 from North Sumatera province. Two pairs of primer were designed to amplify ORF7 of Type 1 and 2 PRRSV based on the sequence of reference viruses VR2332 and Lelystad. Viral RNAs were extracted from samples using PureLink™ micro-to-Midi total RNA purification system (Invitrogen). To amplify the ORF7 of PRRSV, the synthesis cDNA and DNA amplification were performed by reverse transcription polymerase chain reaction (RT-PCR) and nested PCR method. Then the DNA sequencing of PCR products and phylogenetic analysis were accomplished by molecular evolutionary genetics analysis version 6.0 software program. RESULTS RT-: PCR and nested PCR used in this study had successfully detected of 18 samples positive PRRS virus with the amplification products at 703bp and 508bp, respectively. Sequencing of the ORF7 shows that 18 PRRS viruses isolated from North Sumatera belonged to North American (NA). JXA1 Like and classic NA type viruses. Several mutations were detected, particularly in the area of nuclear localization signal (NLS1) and in NLS2. In the local viruses, which were related closed to JXA1 virus; there are two differences in amino acids in position 12 and 43 of ORF7. Our tested viruses showed that the amino acid positions 12 and 43 are Asparagine and Arginine, while the reference virus (VR2332, Lelystad, and JXA1) occupied both by Lysine. Based on differences in two amino acids at position 12 and 43 showed that viruses from North Sumatera has its own uniqueness and related closed to highly pathogenic PRRS (HP-PRRS) virus (JXA1). CONCLUSION The results demonstrated that North Sumatera type PRRS virus has caused PRRS outbreaks in pig in North Sumatera between 2008 and 2014. The JAX1 like viruses had unique amino acid residue in position 12 and 43 of asparagine and lysine, and these were genetic determinants of North Sumatera viruses compared to other PRRS viruses.
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Affiliation(s)
- Faisal Faisal
- Department of Veterinary Science, Faculty of Veterinary Medicine, Gadjah Mada University, Yogyakarta, Indonesia; Department of Molecular Biology, Animal Disease Investigation Centre of Medan, North Sumatera, Indonesia
| | - Rini Widayanti
- Department of Biochemistry, Faculty of Veterinary Medicine, Gadjah Mada University, Yogyakarta, Indonesia
| | - Aris Haryanto
- Department of Biochemistry, Faculty of Veterinary Medicine, Gadjah Mada University, Yogyakarta, Indonesia
| | - Charles Rangga Tabu
- Department of Pathology, Faculty of Veterinary Medicine, Gadjah Mada University, Yogyakarta, Indonesia
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Huong Giang N, Lan N, Nam N, Hirai T, Yamaguchi R. Pathological Characterization of an Outbreak of Porcine Reproductive and Respiratory Syndrome in Northern Vietnam. J Comp Pathol 2016; 154:135-49. [DOI: 10.1016/j.jcpa.2015.11.004] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2015] [Revised: 11/18/2015] [Accepted: 11/23/2015] [Indexed: 11/29/2022]
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23
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Ge M, Zhang Y, Liu Y, Liu T, Zeng F. Propagation of field highly pathogenic porcine reproductive and respiratory syndrome virus in MARC-145 cells is promoted by cell apoptosis. Virus Res 2016; 213:322-331. [DOI: 10.1016/j.virusres.2015.12.023] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2015] [Revised: 12/22/2015] [Accepted: 12/23/2015] [Indexed: 02/04/2023]
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24
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Kang R, Ji G, Yang X, Lv X, Zhang Y, Ge M, Pan Y, Li Q, Wang H, Zeng F. Investigation on host susceptibility of Tibetan pig to infection of porcine reproductive and respiratory syndrome virus through viral challenge study. Vet Microbiol 2015; 183:62-8. [PMID: 26790936 DOI: 10.1016/j.vetmic.2015.11.035] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2015] [Revised: 11/26/2015] [Accepted: 11/27/2015] [Indexed: 11/15/2022]
Abstract
Previous reports showed that infection of porcine reproductive and respiratory syndrome virus (PRRSV) stimulated a variable host response and pig susceptibility to PRRSV was largely dependent on its genetic composition. In the present study, host susceptibility of Tibetan pig to PRRSV was compared with other two pig breeds, ZangMei black and Large White, by challenge of them with highly pathogenic PRRSV (HP-PRRSV). In the first challenge test, each eight piglets of the three breeds were inoculated with HP-PRRSV and clinical symptoms, viremia and animal mortality were examined up to 28 days post inoculation (DPI). In the secondary pathological study, each twelve piglets of the three breeds were challenged and three pigs of each breed were sacrificed on 4, 7, and 14 DPI for examination of gross damage and lung microscopic lesions. The results showed that no typical clinical signs such as cough, diarrhea and high fever were observed in challenged Tibetan pigs, which however all occurred in Large White accompanied with ∼40% mortality (3/8). In addition, a significant low and short viremia was detected specifically in Tibetan pigs. Based on histopathological analysis of lung sections, a mild to moderate interstitial pneumonia in Tibetan pigs and a much severe pneumonia in Large White were identified on 7-14 DPI. In summary, the study demonstrated that three genetically different pig breeds exhibited a differential host susceptibility to HP-PRRSV and Tibetan pig was much less susceptible to the virus in the three tested pig breeds.
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Affiliation(s)
- Runmin Kang
- College of Life Sciences, Animal Disease Prevention and Food Safety Key Laboratory of Sichuan Province, Key Laboratory of Bio-resources and Eco-environment of Ministry of Education, Sichuan University, Chengdu, PR China; Sichuan Animal Science Academy, Chengdu, PR China
| | - Gaosheng Ji
- College of Life Sciences, Animal Disease Prevention and Food Safety Key Laboratory of Sichuan Province, Key Laboratory of Bio-resources and Eco-environment of Ministry of Education, Sichuan University, Chengdu, PR China
| | - Xin Yang
- College of Life Sciences, Animal Disease Prevention and Food Safety Key Laboratory of Sichuan Province, Key Laboratory of Bio-resources and Eco-environment of Ministry of Education, Sichuan University, Chengdu, PR China
| | - Xuebing Lv
- Sichuan Animal Science Academy, Chengdu, PR China
| | - Yi Zhang
- College of Life Sciences, Animal Disease Prevention and Food Safety Key Laboratory of Sichuan Province, Key Laboratory of Bio-resources and Eco-environment of Ministry of Education, Sichuan University, Chengdu, PR China
| | - Mengyun Ge
- College of Life Sciences, Animal Disease Prevention and Food Safety Key Laboratory of Sichuan Province, Key Laboratory of Bio-resources and Eco-environment of Ministry of Education, Sichuan University, Chengdu, PR China
| | - Yun Pan
- College of Life Sciences, Animal Disease Prevention and Food Safety Key Laboratory of Sichuan Province, Key Laboratory of Bio-resources and Eco-environment of Ministry of Education, Sichuan University, Chengdu, PR China
| | - Qingzhou Li
- College of Life Sciences, Animal Disease Prevention and Food Safety Key Laboratory of Sichuan Province, Key Laboratory of Bio-resources and Eco-environment of Ministry of Education, Sichuan University, Chengdu, PR China
| | - Hongning Wang
- College of Life Sciences, Animal Disease Prevention and Food Safety Key Laboratory of Sichuan Province, Key Laboratory of Bio-resources and Eco-environment of Ministry of Education, Sichuan University, Chengdu, PR China.
| | - Fanya Zeng
- College of Life Sciences, Animal Disease Prevention and Food Safety Key Laboratory of Sichuan Province, Key Laboratory of Bio-resources and Eco-environment of Ministry of Education, Sichuan University, Chengdu, PR China.
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25
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Investigations of selected pathogens among village pigs in Central Papua, Indonesia. Trop Anim Health Prod 2015; 48:29-36. [DOI: 10.1007/s11250-015-0913-5] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2015] [Accepted: 09/07/2015] [Indexed: 10/23/2022]
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26
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Temporal and spatial association of Streptococcus suis infection in humans and porcine reproductive and respiratory syndrome outbreaks in pigs in northern Vietnam. Epidemiol Infect 2015; 144:35-44. [PMID: 25997360 PMCID: PMC4697300 DOI: 10.1017/s0950268815000990] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
Abstract
Porcine reproductive and respiratory syndrome (PRRS) outbreaks in pigs are associated with increased susceptibility of pigs to secondary bacterial infections, including Streptococcus suis – an important zoonotic pathogen causing bacterial meningitis in humans. This case-control study examined the association between human S. suis infection and PRRS outbreaks in pigs in northern Vietnam. We included 90 S. suis case-patients and 183 non-S. suis sepsis controls from a referral hospital in Hanoi in 2010, a period of major PRRS epizootics in Vietnam. PRRS exposure was determined using data from the National Centre of Veterinary Diagnosis. By univariate analysis, significantly more S. suis patients were reported residing in or adjacent to a PRRS district compared to controls [odds ratio (OR) 2·82, 95% confidence interval (CI) 1·35–5·89 and OR 3·15, 95% CI 1·62–6·15, respectively]. Only residency in adjacent districts remained significantly associated with risk of S. suis infection after adjusting for sex, occupation, and eating practices. SaTScan analysis showed a possible cluster of S. suis infection in humans around PRRS confirmed locations during the March–August period. The findings indicate an epidemiological association between PRRS in pigs and S. suis infections in humans. Effective strategies to strengthen control of PRRS in pigs may help reduce transmission of S. suis infection to humans.
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Salguero FJ, Frossard JP, Rebel JMJ, Stadejek T, Morgan SB, Graham SP, Steinbach F. Host-pathogen interactions during porcine reproductive and respiratory syndrome virus 1 infection of piglets. Virus Res 2015; 202:135-43. [PMID: 25559070 PMCID: PMC7172408 DOI: 10.1016/j.virusres.2014.12.026] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2014] [Revised: 12/18/2014] [Accepted: 12/22/2014] [Indexed: 01/26/2023]
Abstract
Porcine reproductive and respiratory syndrome (PRRS) is a major disease affecting pigs worldwide and resulting in considerable economic losses. While PRRS is a global phenomenon, the causative viruses PRRSV-1 (first detected in Europe) and PRRSV-2 (isolated in North America) are genetically and biologically distinct. In addition, the disease outcome is directly linked to co-infections associated with the porcine respiratory disease complex and the host response is variable between different breeds of pigs. It is therefore warranted when studying the pathogenesis of PRRS to consider each viral genotype separately and apply careful consideration to the disease model studied. We here review the respiratory pig model for PRRSV-1, with a focus on a recent set of studies conducted with carefully selected virus strains and pigs, which may serve as both a baseline and benchmark for future investigation.
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Affiliation(s)
- Francisco J Salguero
- Virology Department, Animal and Plant Health Agency, Weybridge, Addlestone, United Kingdom; Department of Pathology and Infectious Diseases, School of Veterinary Medicine, University of Surrey, Guildford, United Kingdom
| | - Jean-Pierre Frossard
- Virology Department, Animal and Plant Health Agency, Weybridge, Addlestone, United Kingdom.
| | - Johanna M J Rebel
- Department of Infection Biology, Central Veterinary Institute, Lelystad, The Netherlands
| | - Tomasz Stadejek
- Department of Pathology and Veterinary Diagnostics, Faculty of Veterinary Medicine, Warsaw University of Life, Poland
| | - Sophie B Morgan
- Virology Department, Animal and Plant Health Agency, Weybridge, Addlestone, United Kingdom
| | - Simon P Graham
- Virology Department, Animal and Plant Health Agency, Weybridge, Addlestone, United Kingdom; Department of Pathology and Infectious Diseases, School of Veterinary Medicine, University of Surrey, Guildford, United Kingdom
| | - Falko Steinbach
- Virology Department, Animal and Plant Health Agency, Weybridge, Addlestone, United Kingdom; Department of Pathology and Infectious Diseases, School of Veterinary Medicine, University of Surrey, Guildford, United Kingdom
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28
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Do TD, Park C, Choi K, Jeong J, Nguyen TT, Nguyen DQ, Le TH, Chae C. Comparison of experimental infection with northern and southern Vietnamese strains of highly pathogenic porcine reproductive and respiratory syndrome virus. J Comp Pathol 2015; 152:227-37. [PMID: 25678425 DOI: 10.1016/j.jcpa.2014.12.002] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2014] [Revised: 10/15/2014] [Accepted: 12/08/2014] [Indexed: 11/18/2022]
Abstract
The aim of this study was to compare the virulence of northern and southern Vietnamese strains of highly pathogenic porcine reproductive and respiratory syndrome virus (HP-PRRSV) as assessed by the level of viral replication, gross and microscopical lung lesions and virus distribution in experimentally infected pigs. The northern and southern Vietnamese HP-PRRSV strains share 96.7% (non-structural protein 2) and 99.3% (open reading frame 5) nucleotide identity. On experimental challenge, approximately 50% of pigs infected with northern Vietnamese HP-PRRSV died, while death was not observed in any pigs infected with southern Vietnamese HP-PRRSV. Mean viral titres (expressed as log(10)TCID(50)/ml) were significantly (P <0.05) higher in sera and lungs from pigs infected with the northern Vietnamese HP-PRRSV than from those infected with the southern Vietnamese strain at multiple time points. Lung lesion scores and PRRSV antigen within pulmonary and lymphoid lesions were significantly (P <0.05) higher in pigs infected with northern Vietnamese HP-PRRSV than in those receiving southern Vietnamese HP-PRRSV at multiple time points. PRRSV antigens were observed in cardiac myocytes, gastric and renal tubular epithelial cells and astrocytes and microglia of white matter in the brain from pigs infected with the northern Vietnamese HP-PRRSV strain only. Thus, genetic similarity did not predict the degree of virulence of these strains. Northern Vietnamese HP-PRRSV was more virulent and had extended tissue tropism when compared with southern Vietnamese HP-PRRSV.
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Affiliation(s)
- T D Do
- Seoul National University, Department of Veterinary Pathology, College of Veterinary Medicine, Seoul National University, 1 Gwanak-ro, Gwanak-gu, Seoul, Republic of Korea; Faculty of Animal Husbandry and Veterinary Medicine, Nonglam University, Thu Duc District, Ho Chi Minh City, Vietnam
| | - C Park
- Seoul National University, Department of Veterinary Pathology, College of Veterinary Medicine, Seoul National University, 1 Gwanak-ro, Gwanak-gu, Seoul, Republic of Korea
| | - K Choi
- Seoul National University, Department of Veterinary Pathology, College of Veterinary Medicine, Seoul National University, 1 Gwanak-ro, Gwanak-gu, Seoul, Republic of Korea
| | - J Jeong
- Seoul National University, Department of Veterinary Pathology, College of Veterinary Medicine, Seoul National University, 1 Gwanak-ro, Gwanak-gu, Seoul, Republic of Korea
| | - T T Nguyen
- Faculty of Animal Husbandry and Veterinary Medicine, Nonglam University, Thu Duc District, Ho Chi Minh City, Vietnam
| | - D Q Nguyen
- Faculty of Animal Husbandry and Veterinary Medicine, Nonglam University, Thu Duc District, Ho Chi Minh City, Vietnam
| | - T H Le
- Faculty of Animal Husbandry and Veterinary Medicine, Nonglam University, Thu Duc District, Ho Chi Minh City, Vietnam
| | - C Chae
- Seoul National University, Department of Veterinary Pathology, College of Veterinary Medicine, Seoul National University, 1 Gwanak-ro, Gwanak-gu, Seoul, Republic of Korea.
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29
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Tornimbene B, Frossard JP, Chhim V, Sorn S, Guitian J, Drew T. Emergence of highly pathogenic porcine reproductive and respiratory syndrome (HP-PRRS) in medium-scale swine farms in southeastern Cambodia. Prev Vet Med 2015; 118:93-103. [DOI: 10.1016/j.prevetmed.2014.08.009] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2014] [Revised: 08/12/2014] [Accepted: 08/13/2014] [Indexed: 11/16/2022]
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30
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Morgan SB, Frossard JP, Pallares FJ, Gough J, Stadejek T, Graham SP, Steinbach F, Drew TW, Salguero FJ. Pathology and Virus Distribution in the Lung and Lymphoid Tissues of Pigs Experimentally Inoculated with Three Distinct Type 1 PRRS Virus Isolates of Varying Pathogenicity. Transbound Emerg Dis 2014; 63:285-95. [PMID: 25382098 DOI: 10.1111/tbed.12272] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2014] [Indexed: 12/22/2022]
Abstract
Porcine reproductive and respiratory syndrome (PRRS) continues to be the most economically important disease of swine worldwide. The appearance of highly pathogenic PRRS virus (PRRSV) strains in Europe and Asia has raised concerns about this disease and initiated increased efforts to understand the pathogenesis. In this study, we have compared the pathology and the virus distribution in tissues of pigs experimentally inoculated with three different genotype 1 PRRSV isolates. Sixty 5-week-old pigs were inoculated intranasally with a) the Lelystad virus (LV), b) a field strain from the UK causing respiratory clinical signs (UK) or c) a highly pathogenic strain from Belarus (BE). Sixteen animals were mock-infected and used as controls. The animals were euthanized at 3, 7 and 35 days post-infection (dpi), and lung and lymphoid tissues collected for histopathological examination and PRRSV detection by immunohistochemistry (IHC). Histopathological lesions consisted of interstitial pneumonia with mononuclear cell infiltrates in the lungs, lymphoid depletion, apoptosis and follicular hyperplasia in the spleen, lymph nodes and tonsil and lymphoid depletion in the thymus. Porcine reproductive and respiratory syndrome virus was detected mainly in monocytes-macrophages. BE-infected animals showed the highest pathological scores and the highest presence of virus at 3 and 7 dpi, followed by the UK field strain and then LV. Moderate lesions were observed at 35 dpi with lesser detection of PRRSV by IHC in each infected group. The highly pathogenic BE strain induced more severe pathology in both lungs and lymphoid organs of pigs compared with the classic field isolate and the prototype LV. The increased severity of pathology was in correlation with the presence of a higher number of PRRSV-infected cells in the tissues.
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Affiliation(s)
- S B Morgan
- Virology Department, Animal Health and Veterinary Laboratories Agency, Addlestone, UK.,Department of Microbial and Cellular Sciences, Faculty of Health and Medical Sciences, University of Surrey, Guildford, UK
| | - J P Frossard
- Virology Department, Animal Health and Veterinary Laboratories Agency, Addlestone, UK
| | - F J Pallares
- Department of Anatomy and Comparative Pathology, Faculty of Veterinary Medicine, Murcia University, Murcia, Spain.,Department of Pathology, Animal Health and Veterinary Laboratories Agency, Addlestone, UK
| | - J Gough
- Department of Pathology, Animal Health and Veterinary Laboratories Agency, Addlestone, UK
| | - T Stadejek
- Faculty of Veterinary Medicine, Warsaw University of Life Sciences, Warsaw, Poland
| | - S P Graham
- Virology Department, Animal Health and Veterinary Laboratories Agency, Addlestone, UK
| | - F Steinbach
- Virology Department, Animal Health and Veterinary Laboratories Agency, Addlestone, UK
| | - T W Drew
- Virology Department, Animal Health and Veterinary Laboratories Agency, Addlestone, UK
| | - F J Salguero
- Department of Pathology, Animal Health and Veterinary Laboratories Agency, Addlestone, UK.,School of Veterinary Medicine, Faculty of Health and Medical Sciences, University of Surrey, Guildford, UK
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31
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Mokhtar H, Eck M, Morgan SB, Essler SE, Frossard JP, Ruggli N, Graham SP. Proteome-wide screening of the European porcine reproductive and respiratory syndrome virus reveals a broad range of T cell antigen reactivity. Vaccine 2014; 32:6828-37. [DOI: 10.1016/j.vaccine.2014.04.054] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2013] [Revised: 04/11/2014] [Accepted: 04/17/2014] [Indexed: 01/06/2023]
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32
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Lager KM, Schlink SN, Brockmeier SL, Miller LC, Henningson JN, Kappes MA, Kehrli ME, Loving CL, Guo B, Swenson SL, Yang HC, Faaberg KS. Efficacy of Type 2 PRRSV vaccine against Chinese and Vietnamese HP-PRRSV challenge in pigs. Vaccine 2014; 32:6457-62. [PMID: 25285886 DOI: 10.1016/j.vaccine.2014.09.046] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2013] [Revised: 09/19/2014] [Accepted: 09/21/2014] [Indexed: 11/26/2022]
Abstract
Porcine reproductive and respiratory syndrome virus (PRRSV) causes significant reproductive losses in the sow herd and respiratory disease in growing pigs. The virus belongs to the family Arteriviridae and there are two major genotypes. Type 1 is represented by Lelystad virus, the European prototype virus, and Type 2 is represented by the North American prototype virus, VR-2332. Depending on husbandry, immune status of the herd, and virulence of the isolate, the severity of disease and magnitude of economic loss can be variable. Vaccine use is not always successful indicating a lack of cross-protection between vaccine strains and circulating wild-type viruses. To date, there is no clear method to demonstrate if a vaccine confers protection against a specific isolate except for empirical animal studies. In 2006, a new lineage of Type 2 PRRSV emerged in Chinese swine herds that were suffering dramatic losses resulting in those viruses being described as "Highly Pathogenic PRRSV" (HP-PRRSV). Experimental reproduction of severe disease with HP-PRRSV isolates and virus derived from HP-PRRSV clones demonstrated the causal role of this virus. Recently, partial heterologous protection has been reported for Type 1 and Type 2 attenuated PRRSV vaccines against challenge by different Chinese HP-PRRSV isolates providing some hope for reducing economic loss. This paper reports the efficacy of a commercially available Type 2 attenuated vaccine in young pigs against heterologous challenge with a Chinese and Vietnamese HP-PRRSV isolate. When compared to unvaccinated pigs, vaccination decreased the length of viremia and viral titer, diminished the time of high fever and reduced macroscopic lung scores following homologous and heterologous PRRSV challenge. These results demonstrate the potential use of vaccine as an aid in the control of HP-PRRSV outbreaks.
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Affiliation(s)
- Kelly M Lager
- Virus and Prion Research Unit, National Animal Disease Center, Agricultural Research Service, USDA, Ames, IA, USA.
| | - Sarah N Schlink
- Virus and Prion Research Unit, National Animal Disease Center, Agricultural Research Service, USDA, Ames, IA, USA
| | - Susan L Brockmeier
- Virus and Prion Research Unit, National Animal Disease Center, Agricultural Research Service, USDA, Ames, IA, USA
| | - Laura C Miller
- Virus and Prion Research Unit, National Animal Disease Center, Agricultural Research Service, USDA, Ames, IA, USA
| | - Jamie N Henningson
- Diagnostic Medicine Pathobiology, Kansas State University, Manhattan, KS, USA
| | - Matthew A Kappes
- Virus and Prion Research Unit, National Animal Disease Center, Agricultural Research Service, USDA, Ames, IA, USA
| | - Marcus E Kehrli
- Virus and Prion Research Unit, National Animal Disease Center, Agricultural Research Service, USDA, Ames, IA, USA
| | - Crystal L Loving
- Virus and Prion Research Unit, National Animal Disease Center, Agricultural Research Service, USDA, Ames, IA, USA
| | - Baoquing Guo
- Veterinary Diagnostic & Production Animal Medicine, Iowa State University, Ames, IA, USA
| | - Sabrina L Swenson
- National Veterinary Service Laboratories, Animal Plant Health Inspection Service, USDA, Ames, IA, USA
| | | | - Kay S Faaberg
- Virus and Prion Research Unit, National Animal Disease Center, Agricultural Research Service, USDA, Ames, IA, USA
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Truong VM, Gummow B. Risk factors for porcine reproductive and respiratory syndrome outbreaks in Vietnamese small stock farms. N Z Vet J 2014; 62:199-207. [PMID: 24483988 DOI: 10.1080/00480169.2014.888640] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Abstract
AIM To examine risk factors that could have played a role in the 2010 porcine reproductive and respiratory syndrome (PRRS) outbreak in Yenhung district, Quangninh province, North-Vietnam, with the purpose of establishing why existing control measures implemented after previous outbreaks had failed to prevent further outbreaks. METHODS A case-control study was carried out in Yenhung district. Data were obtained by an interview-based questionnaire survey. The sampling unit was households, which equated to small-scale pig farms. A total of 150 case and 150 control households were selected at communes affected by the 2010 PRRS epidemic during April to June. Risk factors were analysed using binary logistic regression and unconditional multiple logistic regression. RESULTS Households infected with PRRS were significantly associated with multiple variables belonging to three main groups: (1) location of the farms: i.e. farms positioned <1,000 m from a pig abattoir or within 500 m of local markets or 100 m of main roads; (2) farm management: i.e. where there was non-application of weekly farm disinfection, feeding uncooked swill, new introduction of purchased pigs without isolation, or usage of water from irrigation systems for raising pigs; (3) people and animal contact: i.e. where households kept animals with either no confinement or partial confinement, had visits by family members to other affected farms or had frequent visits by neighbours. The use of water from irrigation systems was found to be the risk factor most strongly associated with infected households in the 2010 outbreak (OR=22; 95% CI=12-42). CONCLUSIONS The results show that the epidemiology of PRRS in Quangninh province was linked to sociological and cultural practices, and that effective PRRS control needs an integrated approach coupled with behavioural changes in the pig raising practices of the general public. Failure to recognise this could explain why further outbreaks have occurred.
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Affiliation(s)
- V M Truong
- a School of Veterinary and Biomedical Sciences , James Cook University , Townsville , Queensland 4811 , Australia
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34
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Lin HX, Ma Z, Yang XQ, Fan HJ, Lu CP. A novel vaccine against Porcine circovirus type 2 (PCV2) and Streptococcus equi ssp. zooepidemicus (SEZ) co-infection. Vet Microbiol 2014; 171:198-205. [PMID: 24726504 DOI: 10.1016/j.vetmic.2014.03.018] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2013] [Revised: 03/07/2014] [Accepted: 03/10/2014] [Indexed: 12/22/2022]
Abstract
To develop a vaccine against Porcine circovirus type 2 (PCV2) and Streptococcus equi ssp. zooepidemicus (SEZ) co-infection, the genes of porcine IL-18, capsid protein (Cap) of PCV2 and M-like protein (SzP) of SEZ were inserted into the swinepox virus (SPV) genome by homologous recombination. The recombinant swinepox virus rSPV-ICS was verified by PCR and indirect immunofluorescence assays. To evaluate the immunogenicity of rSPV-ICS, 28 PCV2 and SEZ seronegative Bama minipigs were immunized with rSPV-ICS (n=8), commercial PCV2 vaccine and SEZ vaccine (n=8) or wild type SPV (n=8). The results showed that SzP-specific antibody and PCV2 neutralizing antibody of the rSPV-ICS immunized group increased significantly compared to the wild type SPV treated group after vaccination and increased continuously over time. The levels of IL-4 and IFN-γ in the rSPV-ICS immunized group were significantly higher than the other three groups, respectively. After been co-challenged with PCV2 and SEZ, 87.5% piglets in rSPV-ICS immunized group were survived. Significant reductions in gross lung lesion score, histopathological lung lesion score, and lymph node lesion score were noticed in the rSPV-ICS immunized group compared with the wtSPV treated group. The results suggested that the recombinant rSPV-ICS provided piglets with significant protection against PCV2-SEZ co-infection; thus, it offers proof-of-principle for the development of a vaccine for the prevention of these swine diseases.
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Affiliation(s)
- Hui-xing Lin
- College of Veterinary Medicine, Nanjing Agricultural University, Nanjing, China
| | - Zhe Ma
- College of Veterinary Medicine, Nanjing Agricultural University, Nanjing, China
| | - Xu-qiu Yang
- College of Veterinary Medicine, Nanjing Agricultural University, Nanjing, China
| | - Hong-jie Fan
- College of Veterinary Medicine, Nanjing Agricultural University, Nanjing, China; Jiangsu Co-innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou, China.
| | - Cheng-ping Lu
- College of Veterinary Medicine, Nanjing Agricultural University, Nanjing, China
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35
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Tornimbene B, Chhim V, Sorn S, Drew TW, Guitian J. Knowledge, attitudes and practices of Cambodian swine producers in relation to porcine reproductive and respiratory syndrome (PRRS). Prev Vet Med 2014; 116:252-67. [PMID: 24472214 DOI: 10.1016/j.prevetmed.2013.12.009] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2013] [Revised: 11/19/2013] [Accepted: 12/20/2013] [Indexed: 10/25/2022]
Abstract
Porcine reproductive and respiratory syndrome (PRRS) was first detected in Cambodia in 2010. The disease was responsible for high morbidity and high mortality in adult pigs and the outbreak had a costly impact on those farmers affected. The aim of this study was to generate a better understanding of Cambodian swine producers' behaviour, in relation to PRRS and its control, in areas that have previously been affected by the disease. A survey of the knowledge, attitude and practices (KAPs) of pig owners with regard to PRRS was conducted in semi-commercial and backyard farms in Takeo province in southeast Cambodia. The survey was designed to assess knowledge of PRRS disease and its transmission, farmers' attitudes and practices related to preventive and control measures, knowledge on vaccination and perception towards local veterinary authority activities. Descriptive statistics were used to summarise qualitative data, while multivariate regression analyses were used to assess the association between selected outcomes and a number of hypothetical predictors. When presented with clinical signs typical of PRRS, most farmers identified an infectious disease as the most likely explanation for the listed clinical conditions. Farmers were also confident in recognising direct contact between pigs as one of the main ways of disease transmission; however, other viral transmission patterns typical of PRRS were mostly unknown or ignored. In general, male farmers and farmers with a higher level of education were more likely to have a better knowledge of transmission routes between pigs. In terms of attitude towards control measures, vaccination and disinfection were perceived as the most effective control practices. Farmers with a better knowledge of vaccine protocols were more likely to find vaccination effective. Village animal health workers (VAHWs) were generally in contact more with backyard farmers, while semi-commercial farmers were more prone to treat pigs themselves, raising the issue of easy and uncontrolled access to medication and vaccination. In general, farmers had a positive attitude towards local veterinarians, and lack of contact between farmers and the veterinary authority was associated more with logistic constraints than with farmers' mistrust towards the authority.
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Affiliation(s)
- B Tornimbene
- Department of Veterinary Clinical Sciences, Royal Veterinary College, Hatfield AL9 7TA, United Kingdom; Virology Department, Animal Health and Veterinary Laboratories Agency (AHVLA), Weybridge KT15 3NB, United Kingdom.
| | - V Chhim
- National Institute of Veterinary Research (NaVRI), Animal Health and Production Office, Ministry of Agriculture Food and Fishery, Phnom Penh, Cambodia
| | - S Sorn
- National Institute of Veterinary Research (NaVRI), Animal Health and Production Office, Ministry of Agriculture Food and Fishery, Phnom Penh, Cambodia
| | - T W Drew
- Virology Department, Animal Health and Veterinary Laboratories Agency (AHVLA), Weybridge KT15 3NB, United Kingdom
| | - J Guitian
- Department of Veterinary Clinical Sciences, Royal Veterinary College, Hatfield AL9 7TA, United Kingdom
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Guo B, Lager KM, Schlink SN, Kehrli ME, Brockmeier SL, Miller LC, Swenson SL, Faaberg KS. Chinese and Vietnamese strains of HP-PRRSV cause different pathogenic outcomes in United States high health swine. Virology 2013; 446:238-50. [PMID: 24074587 DOI: 10.1016/j.virol.2013.08.008] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2013] [Revised: 06/24/2013] [Accepted: 08/09/2013] [Indexed: 01/12/2023]
Abstract
An infectious clone of a highly pathogenic PRRSV strain from Vietnam (rSRV07) was prepared and was demonstrated to contain multiple amino acid differences throughout the genome when compared to Chinese highly pathogenic PRRSV strain rJXwn06. Virus rescued from the rSRV07 infectious clone was compared to rJXwn06 and US Type 2 prototype strain VR-2332 to examine the effects of virus genotype and phenotype on in vitro growth, and virus challenge dose on in vivo pathogenicity and host response. After swine inoculation at high- and low-doses of virus, rSRV07 was shown to replicate to an approximately 10-fold lower level in serum than rJXwn06, produced lower body temperatures than rJXwn06 and resulted in decreased mortality. Furthermore, a 9-plex cytokine panel revealed that the cytokine responses varied between different strains of PRRSV, as well as between tissues examined and by inoculum dose.
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Affiliation(s)
- Baoqing Guo
- Veterinary Diagnostic & Production Animal Medicine, Iowa State University, Ames, IA, USA
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Ni J, Yang S, Bounlom D, Yu X, Zhou Z, Song J, Khamphouth V, Vatthana T, Tian K. Emergence and pathogenicity of highly pathogenic Porcine reproductive and respiratory syndrome virus in Vientiane, Lao People's Democratic Republic. J Vet Diagn Invest 2012; 24:349-54. [PMID: 22379051 DOI: 10.1177/1040638711434111] [Citation(s) in RCA: 53] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
Highly pathogenic porcine reproductive and respiratory syndrome (HP-PRRS) characterized by high fever, high morbidity, and high mortality in pigs of all ages emerged in China in 2006 and spread rapidly throughout Southeast Asia. In July 2010, a highly contagious swine disease with clinical signs similar to those of HP-PRRS was observed in the Lao People's Democratic Republic (Lao PDR). A field investigation covering 8 pig farms and 1 slaughterhouse in 7 different districts in the capital city of Vientiane was conducted to identify the disease. Total mortality rates ranged from 6.02% in boars to 91.28% in piglets (mean 54.15%) across the farms investigated. Emergence of the HP-PRRS virus (HP-PRRSV) in Lao PDR was confirmed using real-time reverse transcription polymerase chain reaction as well as virus isolation and identification. An animal inoculation study was performed to characterize the HP-PRRSV responsible for this outbreak. Isolate Laos 1.13 was inoculated into 70-day-old specific pathogen-free pigs to study pathogenicity. Clinical signs of high fever, rubefaction, respiratory distress, nervous symptoms, and diarrhea were observed in inoculated pigs, as well as pathological hemorrhagic lesions consolidated in the lungs. Morbidity and mortality were 100% and 60%, respectively, in inoculated pigs. HP-PRRSV was re-isolated from the inoculated pigs. Results suggested that the newly emerged HP-PRRSV was responsible for recent outbreaks of the swine disease in Lao PDR. The current report highlights the importance of continuous surveillance in neighboring countries to prevent introduction of PRRS to new regions.
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Affiliation(s)
- Jianqiang Ni
- China Animal Disease Control Center, Beijing, Republic of China
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Wei Z, Fu Q, Liu X, Chen Y. Attenuated Streptococcus equi ssp. zooepidemicus as a bacterial vector for expression of porcine circovirus type 2 capsid protein. FEMS Microbiol Lett 2012; 332:20-6. [PMID: 22489773 DOI: 10.1111/j.1574-6968.2012.02569.x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2012] [Revised: 03/19/2012] [Accepted: 03/30/2012] [Indexed: 11/30/2022] Open
Abstract
Porcine circovirus type 2 (PCV2) infection and other concurrent factors is associated with post-weaning multisystemic wasting syndrome, which is becoming a major problem for the swine industry worldwide. Coinfection of Streptococcus equi ssp. zooepidemicus (SEZ) and PCV2 in swine has necessitated demand for a recombinant vaccine against these two pathogens. A recombinant SEZ-Cap strain expressing the major immunogenic capsid protein of PCV2 in place of the szp gene of acapsular SEZ C55138 ΔhasB was constructed. Fluorescence-activated cell sorting and immunofluorescence microscopy analyses indicated that the capsid protein is expressed on the surface of the recombinant strain. Experiments in mice demonstrated that strain SEZ-Cap was less virulent than the parental strain and that it induced significant anti-PCV2 antibodies when administered intraperitoneally, which is worthy of further investigation in swine.
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Affiliation(s)
- Zigong Wei
- State Key Laboratory of Biocontrol, School of Life Sciences, Sun Yat-sen University, Guangzhou, Guangdong, China
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Yu X, Chen N, Wang L, Wu J, Zhou Z, Ni J, Li X, Zhai X, Shi J, Tian K. New genomic characteristics of highly pathogenic porcine reproductive and respiratory syndrome viruses do not lead to significant changes in pathogenicity. Vet Microbiol 2012; 158:291-9. [PMID: 22525010 DOI: 10.1016/j.vetmic.2012.02.036] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2011] [Revised: 02/16/2012] [Accepted: 02/23/2012] [Indexed: 11/25/2022]
Abstract
Highly pathogenic porcine reproductive and respiratory syndrome (HP-PRRS) initially emerged in China and currently prevails in other Asian countries as well, resulting in immense economic losses. HP-PRRS virus (HP-PRRSV) has undergone rapid evolution since its first recognition in 2006. To analyze the genomic and pathogenic characteristics of 2010 HP-PRRSV, we tested 919 clinical samples collected from China, Laos and Vietnam, sequenced 29 complete genomes of HP-PRRSV isolates, and determined the pathogenicity of seven HP-PRRS viruses isolated from 2006 to 2010. HP-PRRSV was detected from 45.2% (415/919) samples, while only 0.1% (1/919) was classical PRRSV, indicating that HP-PRRSV isolates with a unique discontinuous deletion of 30 amino acids (aa) in non-structural protein 2 (Nsp2) are still the predominant viruses. 2010 HP-PRRSV together with 2009 HP-PRRSV isolates form a new evolutionary branch based on phylogenetic analyses. The numbers of potential N-glycosylation sites are variable in major glycoprotein GP5 but are conserved in minor glycoproteins GP2, GP3 and GP4. Pathogenicity studies showed that HP-PRRS viruses isolated from 2006 to 2010 maintain similar level of high pathogenicity, which caused high fever (>41°C for at least four days), 100% morbidity, and 40-100% mortality in 4-10 weeks old pigs. Real time monitoring information from this study could help to understand the genetic and pathogenic evolution of HP-PRRSV and assist in the control of HP-PRRS in Asia.
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Affiliation(s)
- Xiuling Yu
- Veterinary Diagnostic Lab, China Animal Disease Control Center, No. 2 Yuanmingyuan West Rd., Haidian District, Beijing 100193, PR China
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Gauger PC, Faaberg KS, Guo B, Kappes MA, Opriessnig T. Genetic and phenotypic characterization of a 2006 United States porcine reproductive and respiratory virus isolate associated with high morbidity and mortality in the field. Virus Res 2011; 163:98-107. [PMID: 21920393 DOI: 10.1016/j.virusres.2011.08.017] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2011] [Revised: 08/26/2011] [Accepted: 08/30/2011] [Indexed: 11/28/2022]
Abstract
The objective of this study was to characterize a porcine reproductive and respiratory syndrome virus (PRRSV) isolated from United States pigs experiencing high morbidity (50%) and mortality (20%). The PRRSV isolate, designated NC16845b, was characterized through phenotypic analysis and genomic sequencing and compared to Type 2 PRRSV isolates VR-2332, MN184 and VR-2385. NC16845b demonstrated slower replication in vitro compared to the three other isolates and grew to a peak titer of 5.4×10(5) plaque forming units (PFU) per ml at 60 h post inoculation, which was 4- to 13-fold less than the peak titer of the other three viruses. NC16845b plaques were intermediate size averaging 3.3mm in diameter that was larger than MN184 plaques and smaller than VR-2385 and VR-2332. Using Northern blot analysis, viral and subgenomic RNA were detected that demonstrated variable levels of hybridization in some open reading frames (ORF) compared to the other viruses. NC16845b is 15,389 nucleotides in length and ORF 5 restriction fragment length polymorphism (RFLP) analysis demonstrated a 1-18-2 pattern. Among all available Type 2 complete genome sequences, NC16845b showed the highest nucleotide homology (91.2%) to atypical PRRSV strain JA142. Compared to prototype VR-2332, NC16845b demonstrated marked nucleotide variability within non-structural protein (nsp) 1β and nsp2, and a nucleotide deletion of 24 bases in nsp2. Sequence homology with VR-2332 and MN184 was 88.4% and 82.9%, respectively; homology with the ORF2-7 of VR-2385 was 90.4%. Collectively, these data indicate that, compared to prototype Type 2 PRRSV isolates, NC16845b exhibited slower in vitro growth properties, had regions of heterogeneity within ORF1a that corresponded to at least two individual virus quasispecies, and also contained a continuous 8 amino acid deletion in the nsp2 protein.
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Affiliation(s)
- Phillip C Gauger
- Department of Veterinary Diagnostic and Production Animal Medicine, College of Veterinary Medicine, Iowa State University, Ames, IA 50011, USA
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