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Deb R, Sengar GS, Sonowal J, Pegu SR, Das PJ, Singh I, Chakravarti S, Selvaradjou A, Attupurum N, Rajkhowa S, Gupta VK. Transcriptome signatures of host tissue infected with African swine fever virus reveal differential expression of associated oncogenes. Arch Virol 2024; 169:54. [PMID: 38381218 DOI: 10.1007/s00705-023-05959-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2023] [Accepted: 11/27/2023] [Indexed: 02/22/2024]
Abstract
African swine fever (ASF) has emerged as a threat to swine production worldwide. Evasion of host immunity by ASF virus (ASFV) is well understood. However, the role of ASFV in triggering oncogenesis is still unclear. In the present study, ASFV-infected kidney tissue samples were subjected to Illumina-based transcriptome analysis. A total of 2463 upregulated and 825 downregulated genes were differentially expressed (p < 0.05). A literature review revealed that the majority of the differentially expressed host genes were key molecules in signaling pathways involved in oncogenesis. Bioinformatic analysis indicated the activation of certain oncogenic KEGG pathways, including basal cell carcinoma, breast cancer, transcriptional deregulation in cancer, and hepatocellular carcinoma. Analysis of host-virus interactions revealed that the upregulated oncogenic RELA (p65 transcription factor) protein of Sus scrofa can interact with the A238L (hypothetical protein of unknown function) of ASFV. Differential expression of oncogenes was confirmed by qRT-PCR, using the H3 histone family 3A gene (H3F3A) as an internal control to confirm the RNA-Seq data. The levels of gene expression indicated by qRT-PCR matched closely to those determined through RNA-Seq. These findings open up new possibilities for investigation of the mechanisms underlying ASFV infection and offer insights into the dynamic interaction between viral infection and oncogenic processes. However, as these investigations were conducted on pigs that died from natural ASFV infection, the role of ASFV in oncogenesis still needs to be investigated in controlled experimental studies.
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Affiliation(s)
- Rajib Deb
- ICAR-National Research Centre on Pig, Rani, Guwahati, Assam, 781131, India.
| | | | - Joyshikh Sonowal
- ICAR-National Research Centre on Pig, Rani, Guwahati, Assam, 781131, India
- Multidisciplinary Research Unit, Jorhat Medical College and Hospital, Jorhat, Assam, 785001, India
| | - Seema Rani Pegu
- ICAR-National Research Centre on Pig, Rani, Guwahati, Assam, 781131, India
| | - Pranab Jyoti Das
- ICAR-National Research Centre on Pig, Rani, Guwahati, Assam, 781131, India.
| | | | - Soumendu Chakravarti
- ICAR-Indian Veterinary Research Institute, Izatnagar, Bareilly, UP, 243122, India
- Pirbright Institute, Ash Road, Pirbright, Surrey, United Kingdom
| | | | - Nitin Attupurum
- ICAR-National Research Centre on Pig, Rani, Guwahati, Assam, 781131, India
| | - Swaraj Rajkhowa
- ICAR-National Research Centre on Pig, Rani, Guwahati, Assam, 781131, India
| | - Vivek Kumar Gupta
- ICAR-National Research Centre on Pig, Rani, Guwahati, Assam, 781131, India.
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A Novel Competitive ELISA for Specifically Measuring and Differentiating Immune Responses to Classical Swine Fever C-Strain Vaccine in Pigs. Viruses 2022; 14:v14071544. [PMID: 35891524 PMCID: PMC9315997 DOI: 10.3390/v14071544] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2022] [Revised: 07/07/2022] [Accepted: 07/13/2022] [Indexed: 11/17/2022] Open
Abstract
Classical swine fever can be controlled effectively by vaccination with C-strain vaccine. In this study, we developed a novel competitive enzyme-linked immunosorbent assay (cELISA) based on a C-strain Erns specific monoclonal antibody (mAb 1504), aiming to serologically measure immune responses to C-strain vaccine in pigs, and finally to make the C-strain become a DIVA-compatible vaccine. The cELISA system was established based on the strategy that mAb 1504 will compete with the C-strain induced antibodies in the pig serum to bind the C-strain Erns protein. The cELISA was optimized and was further evaluated by testing different categories of pig sera. It can efficiently differentiate C-strain immunized from wild-type CSFV-infected pigs and lacks cross-reaction with other common swine viruses and viruses in genus Pestivirus such as Bovine viral diarrhea virus (BVDV). The C-strain antibody can be tested in pigs 7-14 days post vaccination with this cELISA. The sensitivity and specificity of the established cELISA were 100% (95% confidence interval: 95.60 to 100%) and 100% (95% confidence interval: 98.30 to 100%), respectively. This novel cELISA is a reliable tool for specifically measuring and differentiating immune responses to C-strain vaccine in pigs. By combining with the wild-type CSFV-specific infection tests, it can make the C-strain have DIVA capability.
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Zhang Q, Yang F, Gao J, Zhang W, Xu X. Development of multiplex TaqMan qPCR for simultaneous detection and differentiation of eight common swine viral and bacterial pathogens. Braz J Microbiol 2021; 53:359-368. [PMID: 34709596 DOI: 10.1007/s42770-021-00633-w] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2021] [Accepted: 10/17/2021] [Indexed: 11/24/2022] Open
Abstract
It is laborious to diagnose the infections of classical swine fever virus (CSFV), porcine reproductive and respiratory syndrome virus (PRRSV), porcine circovirus type 2 (PCV2), and Suid herpesvirus 1 (SuHV-1) because of the similar clinical symptoms in piglets. Staphylococcus aureus (S. aureus), Streptococcus suis (S. suis), Salmonella choleraesuis (S. choleraesuis, serotype: 6,7:c:1,5), and Escherichia coli (E. coli) are common secondary bacterial pathogens in viral infections. Furthermore, the mixed infection of these viral and bacterial pathogens is more and more common in practical swine breeding. Therefore, a TaqMan multiplex qPCR method for simultaneous detection and differentiation of their pathogen was established in this study by designing specific primers and probes for the E2 gene of CSFV, the ORF7 gene of PRRSV, the ORF1 gene of PCV2 and the gE gene of SuHV-1, the nuc gene of S. aureus, the ef-tu gene of S. suis, the ivnA gene of S. choleraesuis, and the 23S rRNA gene of E. coli, and its specificity, sensitivity, and reproducibility were subsequently tested. The results showed that TaqMan multiplex qPCR method showed a high specificity with no cross reaction between different viruses, and a good repeatability with its coefficient of variation lower than 5%. Besides, the sensitivity of this method was also at least 10 times higher compared with conventional PCR. Overall, this study provided a reliable multiplex TaqMan qPCR method for the diagnosis and differentiation of the mentioned pathogens in pigs, laying a certain technical basis for disease prevention and control.
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Affiliation(s)
- Qi Zhang
- College of Veterinary Medicine, Northwest A&F University, Yangling, 712100, Shaanxi, China
| | - Feng Yang
- College of Veterinary Medicine, Northwest A&F University, Yangling, 712100, Shaanxi, China
| | - Jie Gao
- College of Veterinary Medicine, Northwest A&F University, Yangling, 712100, Shaanxi, China
| | - Weimin Zhang
- College of Veterinary Medicine, Northwest A&F University, Yangling, 712100, Shaanxi, China.
| | - Xingang Xu
- College of Veterinary Medicine, Northwest A&F University, Yangling, 712100, Shaanxi, China.
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Tu F, Yang X, Xu S, Chen D, Zhou L, Ge X, Han J, Zhang Y, Guo X, Yang H. Development of a fluorescent probe-based real-time reverse transcription recombinase-aided amplification assay for the rapid detection of classical swine fever virus. Transbound Emerg Dis 2020; 68:2017-2027. [PMID: 32979245 DOI: 10.1111/tbed.13849] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2020] [Revised: 09/05/2020] [Accepted: 09/17/2020] [Indexed: 11/29/2022]
Abstract
Classical swine fever (CSF), which is caused by the CSF virus (CSFV), remains one of the most economically important diseases of the global swine industry. Rapid and reliable detection of CSFV is critical for controlling CSF. In this study, a novel fluorescent probe-based real-time reverse transcription recombinase-aided amplification (rRT-RAA) assay, targeting a highly conserved position within the 5' non-translated region (5'NTR) among all CSFV genotypes, was developed for the detection of CSFV. The assay is highly specific to CSFV and does not cross react with other important viruses. Sensitivity analysis revealed that the assay could detect two 50% tissue culture infectious dose (TCID50 ) of CSFV RNA per reaction at 95% probability, which is comparable to that of a documentary reverse transcription quantitative PCR (RT-qPCR) assay for CSFV. The rRT-RAA assay exhibited good reproducibility, with intra- and inter-assay coefficient of variation values of <8.0%. Of the 135 samples (including 102 clinical tissue samples and 33 different cell culture isolates of CSFV), 50 and 52 samples were tested positive for CSFV by rRT-RAA and RT-qPCR, respectively. The coincidence rate between the two assays was 98.5% (133/135). Further linear regression analysis showed a significant correlation between the rRT-RAA and RT-qPCR assays with an R2 value of 0.8682. Interestingly, the amplification products of the rRT-RAA assay could be directly observed with naked eyes under a portable blue light imager, making it possible for an on-site testing. Our results indicate that the rRT-RAA assay is a robust diagnostic tool for the rapid detection of CSFV.
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Affiliation(s)
- Fei Tu
- Key Laboratory of Animal Epidemiology of Ministry of Agriculture and Rural Affairs, College of Veterinary Medicine, China Agricultural University, Beijing, People's Republic of China
| | - Xintan Yang
- Key Laboratory of Animal Epidemiology of Ministry of Agriculture and Rural Affairs, College of Veterinary Medicine, China Agricultural University, Beijing, People's Republic of China
| | - Shengkui Xu
- Key Laboratory of Animal Epidemiology of Ministry of Agriculture and Rural Affairs, College of Veterinary Medicine, China Agricultural University, Beijing, People's Republic of China
| | - Dengjin Chen
- Key Laboratory of Animal Epidemiology of Ministry of Agriculture and Rural Affairs, College of Veterinary Medicine, China Agricultural University, Beijing, People's Republic of China
| | - Lei Zhou
- Key Laboratory of Animal Epidemiology of Ministry of Agriculture and Rural Affairs, College of Veterinary Medicine, China Agricultural University, Beijing, People's Republic of China
| | - Xinna Ge
- Key Laboratory of Animal Epidemiology of Ministry of Agriculture and Rural Affairs, College of Veterinary Medicine, China Agricultural University, Beijing, People's Republic of China
| | - Jun Han
- Key Laboratory of Animal Epidemiology of Ministry of Agriculture and Rural Affairs, College of Veterinary Medicine, China Agricultural University, Beijing, People's Republic of China
| | - Yongning Zhang
- Key Laboratory of Animal Epidemiology of Ministry of Agriculture and Rural Affairs, College of Veterinary Medicine, China Agricultural University, Beijing, People's Republic of China
| | - Xin Guo
- Key Laboratory of Animal Epidemiology of Ministry of Agriculture and Rural Affairs, College of Veterinary Medicine, China Agricultural University, Beijing, People's Republic of China
| | - Hanchun Yang
- Key Laboratory of Animal Epidemiology of Ministry of Agriculture and Rural Affairs, College of Veterinary Medicine, China Agricultural University, Beijing, People's Republic of China
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Wang L, Madera R, Li Y, McVey DS, Drolet BS, Shi J. Recent Advances in the Diagnosis of Classical Swine Fever and Future Perspectives. Pathogens 2020; 9:pathogens9080658. [PMID: 32824178 PMCID: PMC7460108 DOI: 10.3390/pathogens9080658] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2020] [Revised: 08/09/2020] [Accepted: 08/13/2020] [Indexed: 11/16/2022] Open
Abstract
Classical swine fever (CSF) is a highly contagious viral disease of pigs, including wild boar. It is regarded as one of the major problems in the pig industry as it is still endemic in many regions of the world and has the potential to cause devastating epidemics, particularly in countries free of the disease. Rapid and reliable diagnosis is of utmost importance in the control of CSF. Since clinical presentations of CSF are highly variable and may be confused with other viral diseases in pigs, laboratory diagnosis is indispensable for an unambiguous diagnosis. On an international level, well-established diagnostic tests of CSF such as virus isolation, fluorescent antibody test (FAT), antigen capture antibody enzyme-linked immunosorbent assay (ELISA), reverse-transcription polymerase chain reaction (RT-PCR), virus neutralization test (VNT), and antibody ELISA have been described in detail in the OIE Terrestrial Manual. However, improved CSF diagnostic methods or alternatives based on modern technologies have been developed in recent years. This review thus presents recent advances in the diagnosis of CSF and future perspectives.
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Affiliation(s)
- Lihua Wang
- Department of Anatomy and Physiology, College of Veterinary Medicine, Kansas State University, Manhattan, KS 66506, USA; (R.M.); (Y.L.)
- Correspondence: (L.W.); (J.S.); Tel.: +1-785-532-4397 (L.W.); +1-785-532-4506 (J.S.)
| | - Rachel Madera
- Department of Anatomy and Physiology, College of Veterinary Medicine, Kansas State University, Manhattan, KS 66506, USA; (R.M.); (Y.L.)
| | - Yuzhen Li
- Department of Anatomy and Physiology, College of Veterinary Medicine, Kansas State University, Manhattan, KS 66506, USA; (R.M.); (Y.L.)
| | - David Scott McVey
- United States Department of Agriculture, Arthropod-Borne Animal Diseases Research Unit, Center for Grain and Animal Health Research, Manhattan, KS 66502, USA; (D.S.M.); (B.S.D.)
| | - Barbara S. Drolet
- United States Department of Agriculture, Arthropod-Borne Animal Diseases Research Unit, Center for Grain and Animal Health Research, Manhattan, KS 66502, USA; (D.S.M.); (B.S.D.)
| | - Jishu Shi
- Department of Anatomy and Physiology, College of Veterinary Medicine, Kansas State University, Manhattan, KS 66506, USA; (R.M.); (Y.L.)
- Correspondence: (L.W.); (J.S.); Tel.: +1-785-532-4397 (L.W.); +1-785-532-4506 (J.S.)
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6
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Blome S, Wernike K, Reimann I, König P, Moß C, Beer M. A decade of research into classical swine fever marker vaccine CP7_E2alf (Suvaxyn ® CSF Marker): a review of vaccine properties. Vet Res 2017; 48:51. [PMID: 28915927 PMCID: PMC5603031 DOI: 10.1186/s13567-017-0457-y] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2017] [Accepted: 09/04/2017] [Indexed: 11/29/2022] Open
Abstract
Due to its impact on animal health and pig industry, classical swine fever (CSF) is still one of the most important viral diseases of pigs. To control the disease, safe and highly efficacious live attenuated vaccines exist for decades. However, until recently, the available live vaccines did not allow a serological marker concept that is essentially important to circumvent long-term trade restrictions. In 2014, a new live attenuated marker vaccine, Suvaxyn® CSF Marker (Zoetis), was licensed by the European Medicines Agency. This vaccine is based on pestivirus chimera “CP7_E2alf” that carries the main immunogen of CSF virus “Alfort/187”, glycoprotein E2, in a bovine viral diarrhea virus type 1 backbone (“CP7”). This review summarizes the available data on design, safety, efficacy, marker diagnostics, and its possible integration into control strategies.
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Affiliation(s)
- Sandra Blome
- Institute of Diagnostic Virology, Friedrich-Loeffler-Institut, Suedufer 10, 17493, Greifswald-Insel Riems, Germany.
| | - Kerstin Wernike
- Institute of Diagnostic Virology, Friedrich-Loeffler-Institut, Suedufer 10, 17493, Greifswald-Insel Riems, Germany
| | - Ilona Reimann
- Institute of Diagnostic Virology, Friedrich-Loeffler-Institut, Suedufer 10, 17493, Greifswald-Insel Riems, Germany
| | - Patricia König
- Institute of Diagnostic Virology, Friedrich-Loeffler-Institut, Suedufer 10, 17493, Greifswald-Insel Riems, Germany
| | - Claudia Moß
- Institute of Diagnostic Virology, Friedrich-Loeffler-Institut, Suedufer 10, 17493, Greifswald-Insel Riems, Germany
| | - Martin Beer
- Institute of Diagnostic Virology, Friedrich-Loeffler-Institut, Suedufer 10, 17493, Greifswald-Insel Riems, Germany
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7
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Postel A, Austermann-Busch S, Petrov A, Moennig V, Becher P. Epidemiology, diagnosis and control of classical swine fever: Recent developments and future challenges. Transbound Emerg Dis 2017; 65 Suppl 1:248-261. [PMID: 28795533 DOI: 10.1111/tbed.12676] [Citation(s) in RCA: 81] [Impact Index Per Article: 11.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2017] [Indexed: 12/31/2022]
Abstract
Classical swine fever (CSF) represents a major health and trade problem for the pig industry. In endemic countries or those with a wild boar reservoir, CSF remains a priority for Veterinary Services. Surveillance as well as stamping out and/or vaccination are the principle tools of prevention and control, depending on the context. In the past decades, marker vaccines and accompanying diagnostic tests allowing the discrimination of infected from vaccinated animals have been developed. In the European Union, an E2 subunit and a chimeric live vaccine have been licensed and are available for the use in future disease outbreak scenarios. The implementation of commonly accepted and globally harmonized concepts could pave the way to replace the ethically questionable stamping out policy by a vaccination-to-live strategy and thereby avoid culling of a large number of healthy animals and save food resources. Although a number of vaccines and diagnostic tests are available worldwide, technological advancement in both domains is desirable. This work provides a summary of an analysis undertaken by the DISCONTOOLS group of experts on CSF. Details of the analysis can be downloaded from the web site at http://www.discontools.eu/.
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Affiliation(s)
- Alexander Postel
- EU and OIE Reference Laboratory for Classical Swine Fever, Department of Infectious Diseases, Institute of Virology, University of Veterinary Medicine Hannover, Hannover, Germany
| | - Sophia Austermann-Busch
- EU and OIE Reference Laboratory for Classical Swine Fever, Department of Infectious Diseases, Institute of Virology, University of Veterinary Medicine Hannover, Hannover, Germany
| | - Anja Petrov
- EU and OIE Reference Laboratory for Classical Swine Fever, Department of Infectious Diseases, Institute of Virology, University of Veterinary Medicine Hannover, Hannover, Germany
| | - Volker Moennig
- EU and OIE Reference Laboratory for Classical Swine Fever, Department of Infectious Diseases, Institute of Virology, University of Veterinary Medicine Hannover, Hannover, Germany
| | - Paul Becher
- EU and OIE Reference Laboratory for Classical Swine Fever, Department of Infectious Diseases, Institute of Virology, University of Veterinary Medicine Hannover, Hannover, Germany
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8
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Classical Swine Fever-An Updated Review. Viruses 2017; 9:v9040086. [PMID: 28430168 PMCID: PMC5408692 DOI: 10.3390/v9040086] [Citation(s) in RCA: 160] [Impact Index Per Article: 22.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2017] [Revised: 04/11/2017] [Accepted: 04/13/2017] [Indexed: 01/03/2023] Open
Abstract
Classical swine fever (CSF) remains one of the most important transboundary viral diseases of swine worldwide. The causative agent is CSF virus, a small, enveloped RNA virus of the genus Pestivirus. Based on partial sequences, three genotypes can be distinguished that do not, however, directly correlate with virulence. Depending on both virus and host factors, a wide range of clinical syndromes can be observed and thus, laboratory confirmation is mandatory. To this means, both direct and indirect methods are utilized with an increasing degree of commercialization. Both infections in domestic pigs and wild boar are of great relevance; and wild boars are a reservoir host transmitting the virus sporadically also to pig farms. Control strategies for epidemic outbreaks in free countries are mainly based on classical intervention measures; i.e., quarantine and strict culling of affected herds. In these countries, vaccination is only an emergency option. However, live vaccines are used for controlling the disease in endemically infected regions in Asia, Eastern Europe, the Americas, and some African countries. Here, we will provide a concise, updated review on virus properties, clinical signs and pathology, epidemiology, pathogenesis and immune responses, diagnosis and vaccination possibilities.
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Luo Y, Ji S, Liu Y, Lei JL, Xia SL, Wang Y, Du ML, Shao L, Meng XY, Zhou M, Sun Y, Qiu HJ. Isolation and Characterization of a Moderately Virulent Classical Swine Fever Virus Emerging in China. Transbound Emerg Dis 2016; 64:1848-1857. [PMID: 27658930 DOI: 10.1111/tbed.12581] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2016] [Indexed: 11/29/2022]
Abstract
Classical swine fever (CSF) is a devastating infectious disease of pigs caused by classical swine fever virus (CSFV). In China, CSF has been under control owing to extensive vaccination with the lapinized attenuated vaccine (C-strain) since 1950s, despite sporadic or endemic in many regions. However, recently, CSF outbreaks occurred in a large number of swine herds in China. Here, we isolated 15 CSFV strains from diverse C-strain-vaccinated pig farms in China and characterized the genetic variations and antigenicity of the new isolates. The new strains showed unique variations in the E2 protein and were clustered to the subgenotype 2.1d of CSFV recently emerging in China in the phylogenetic tree. Cross-neutralization test showed that the neutralizing titres of porcine anti-C-strain sera against the new isolates were substantially lower than those against both the highly virulent Shimen strain and the subgenotype 2.1b strains that were isolated in China in 2006 and 2009, respectively. In addition, experimental animal infection showed that the HLJZZ2014 strain-infected pigs displayed lower mortality and less severe clinical signs and pathological changes compared with the Shimen strain-infected pigs. The HLJZZ2014 strain was defined to be moderately virulent based on a previously established assessment system for CSFV virulence evaluation, and the virus shedding and the viral load in various tissues of the CSFV HLJZZ2014 strain-infected pigs were significantly lower than those of the Shimen strain-infected pigs. Taken together, the subgenotype 2.1d isolate of CSFV is a moderately virulent strain with molecular variations and antigenic alterations.
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Affiliation(s)
- Y Luo
- State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin, China
| | - S Ji
- State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin, China.,Department of Animal Medicine, Agricultural College of Yanbian University, Yanji, Jilin, China
| | - Y Liu
- State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin, China
| | - J-L Lei
- State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin, China
| | - S-L Xia
- State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin, China
| | - Y Wang
- State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin, China
| | - M-L Du
- State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin, China
| | - L Shao
- State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin, China
| | - X-Y Meng
- State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin, China
| | - M Zhou
- State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin, China
| | - Y Sun
- State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin, China
| | - H-J Qiu
- State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin, China
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Rossi S, Staubach C, Blome S, Guberti V, Thulke HH, Vos A, Koenen F, Le Potier MF. Controlling of CSFV in European wild boar using oral vaccination: a review. Front Microbiol 2015; 6:1141. [PMID: 26557109 PMCID: PMC4615961 DOI: 10.3389/fmicb.2015.01141] [Citation(s) in RCA: 73] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2015] [Accepted: 10/05/2015] [Indexed: 11/24/2022] Open
Abstract
Classical swine fever (CSF) is among the most detrimental diseases for the swine industry worldwide. Infected wild boar populations can play a crucial role in CSF epidemiology and controlling wild reservoirs is of utmost importance for preventing domestic outbreaks. Oral mass vaccination (OMV) has been implemented to control CSF in wild boars and limit the spill over to domestic pigs. This retrospective overview of vaccination experiences illustrates the potential for that option. The C-strain live vaccine was confirmed to be highly efficacious and palatable baits were developed for oral delivery in free ranging wild boars. The first field trials were performed in Germany in the 1990’s and allowed deploying oral baits at a large scale. The delivery process was further improved during the 2000’s among different European countries. Optimal deployment has to be early regarding disease emergence and correctly designed regarding the landscape structure and the natural food sources that can compete with oral baits. OMV deployment is also highly dependent on a local veterinary support working closely with hunters, wildlife and forestry agencies. Vaccination has been the most efficient strategy for CSF control in free ranging wild boar when vaccination is wide spread and lasting for a sufficient period of time. Alternative disease control strategies such as intensified hunting or creating physical boundaries such as fences have been, in contrast, seldom satisfactory and reliable. However, monitoring outbreaks has been challenging during and after vaccination deployment since OMV results in a low probability to detect virus-positive animals and the live-vaccine currently available does not allow serological differentiation of infected from vaccinated animals. The development of a new marker vaccine and companion test is thus a promising option for better monitoring outbreaks during OMV deployment as well as help to better determine when to stop vaccination efforts. After rabies in red fox, the use of OMV against CSF in European wild boar can be considered as a second example of successful disease control in wildlife. The 30 years of disease control experience included in this review may provide options for improving future disease management within wild populations.
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Affiliation(s)
- Sophie Rossi
- Unité Sanitaire de la Faune, Office National de la Chasse et de la Faune Sauvage Gap, France
| | - Christoph Staubach
- Friedrich-Loeffler-Institut, Federal Research Institute for Animal Health Greifswald, Germany
| | - Sandra Blome
- Friedrich-Loeffler-Institut, Federal Research Institute for Animal Health Greifswald, Germany
| | - Vittorio Guberti
- Instituto Superiore per la Protezione e la Ricerca Ambientale Ozzano dell'Emilia, Italy
| | - Hans-Hermann Thulke
- Department of Ecological Modelling, Helmholtz Centre for Environmental Research-UFZ Leipzig, Germany
| | - Ad Vos
- Development Vaccines Technologies, IDT Biologika GmbH Dessau-Rosslau, Germany
| | - Frank Koenen
- Operational Direction Interactions and Surveillance, Centrum voor Onderzoek in Diergeneeskunde en Agrochemie-Centre d'Etude et de Recherches Vétérinaires et Agrochimiques Ukkel, Belgium
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11
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Zeng Z, Liu Z, Wang W, Tang D, Liang H, Liu Z. Establishment and application of a multiplex PCR for rapid and simultaneous detection of six viruses in swine. J Virol Methods 2014; 208:102-6. [PMID: 25116201 DOI: 10.1016/j.jviromet.2014.08.001] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2014] [Revised: 07/28/2014] [Accepted: 08/01/2014] [Indexed: 10/24/2022]
Abstract
A multiplex PCR assay was developed and evaluated subsequently for its effectiveness in simultaneously detecting mixed viral infections of swine. Specific primers were designed and used for testing the six swine viruses: three DNA viruses, including pseudorabies virus (PRV), porcine parvovirus (PPV), and porcine circovirus type 2 (PCV2); three common RNA viruses, including porcine reproductive and respiratory syndrome virus (PRRSV), classical swine fever virus (CSFV), and Japanese encephalitis virus (JEV). This technique has shown to be highly sensitive in that the minimum detection amounts of nucleic acids from PRV, PPV, PCV2, PRRSV, CSFV, and JEV were 6.6, 96, 12.9, 10.5, 51, and 46 pg, respectively. It also was effective for detecting one or multiple viruses in the specimens, such as the lungs, spleens, lymph nodes, and tonsils collected from clinically ill pigs. The multiplex PCR method can detect simultaneously not only infection of the six viruses, but also other swine DNA and RNA viruses. Given its rapidity, specificity, and sensitivity, the multiplex PCR is a useful tool for diagnosing clinically the mixed infections of swine DNA and RNA viruses.
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Affiliation(s)
- Zhiyong Zeng
- College of Animal Sciences, Guizhou University, Guiyang 550025, China; Key Laboratory of Animal Epidemic Disease and Veterinary Public Health in Guizhou Province, Guiyang 550025, China.
| | - Zhijie Liu
- College of Animal Sciences, Guizhou University, Guiyang 550025, China
| | - Weicheng Wang
- College of Animal Sciences, Guizhou University, Guiyang 550025, China
| | - Deyuan Tang
- College of Animal Sciences, Guizhou University, Guiyang 550025, China
| | - Haiying Liang
- Teaching and Experimental Farms, Guizhou University, Guiyang 550025, China
| | - Zhao Liu
- College of Animal Sciences, Guizhou University, Guiyang 550025, China
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12
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Luo Y, Li S, Sun Y, Qiu HJ. Classical swine fever in China: a minireview. Vet Microbiol 2014; 172:1-6. [PMID: 24793098 DOI: 10.1016/j.vetmic.2014.04.004] [Citation(s) in RCA: 109] [Impact Index Per Article: 10.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2014] [Revised: 03/26/2014] [Accepted: 04/01/2014] [Indexed: 11/30/2022]
Abstract
Classical swine fever (CSF), caused by Classical swine fever virus (CSFV), is an OIE-listed, highly contagious, often fatal disease of swine worldwide. Currently, the disease is controlled by prophylactic vaccination in China and many other countries using the modified live vaccines derived from C-strain, which was developed in China in the mid-1950s. This minireview summarizes the epidemiology, diagnostic assays, control and challenges of CSF in China. Though CSF is essentially under control, complete eradication of CSF in China remains a challenging task and needs long-term, joint efforts of stakeholders.
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Affiliation(s)
- Yuzi Luo
- State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, No. 427 Maduan Street, Harbin 150001, PR China
| | - Su Li
- State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, No. 427 Maduan Street, Harbin 150001, PR China
| | - Yuan Sun
- State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, No. 427 Maduan Street, Harbin 150001, PR China
| | - Hua-Ji Qiu
- State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, No. 427 Maduan Street, Harbin 150001, PR China.
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13
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Wang X, Dang E, Gao J, Guo S, Li Z. Development of a gold nanoparticle-based oligonucleotide microarray for simultaneous detection of seven swine viruses. J Virol Methods 2013; 191:9-15. [DOI: 10.1016/j.jviromet.2013.03.023] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2012] [Revised: 02/28/2013] [Accepted: 03/14/2013] [Indexed: 02/06/2023]
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14
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Development of a triplex TaqMan real-time RT-PCR assay for differential detection of wild-type and HCLV vaccine strains of classical swine fever virus and bovine viral diarrhea virus 1. Res Vet Sci 2012; 92:512-8. [DOI: 10.1016/j.rvsc.2011.03.029] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2010] [Revised: 03/25/2011] [Accepted: 03/30/2011] [Indexed: 11/30/2022]
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15
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Xu XG, Chen GD, Huang Y, Ding L, Li ZC, Chang CD, Wang CY, Tong DW, Liu HJ. Development of multiplex PCR for simultaneous detection of six swine DNA and RNA viruses. J Virol Methods 2012; 183:69-74. [PMID: 22575688 DOI: 10.1016/j.jviromet.2012.03.034] [Citation(s) in RCA: 51] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2011] [Revised: 03/21/2012] [Accepted: 03/26/2012] [Indexed: 11/19/2022]
Abstract
Uniplex and multiplex reverse transcription-polymerase chain reaction (RT-PCR) and PCR protocols were developed and evaluated subsequently for its effectiveness in detecting simultaneously single and mixed infections in swine. Specific primers for three DNA viruses and three RNA viruses, including classical swine fever virus (CSFV), porcine reproductive and respiratory syndrome virus (PRRSV), Japanese encephalitis virus (JEV), porcine circovirus type 2 (PCV2), porcine pseudorabies virus (PRV) and porcine parvovirus (PPV) were used for testing procedure. A single nucleic acid extraction protocol was adopted for the simultaneous extraction of both RNA and DNA viruses. The multiplex PCR consisted with two-step procedure which included reverse transcription of RNA virus and multiplex PCR of viral cDNA and DNA. The multiplex PCR assay was shown to be sensitive detecting at least 450pg of viral genomic DNA or RNA from a mixture of six viruses in a reaction. The assay was also highly specific in detecting one or more of the same viruses in various combinations in specimens. Thirty clinical samples and aborted fetuses collected from 4- to 12-week-old piglets were detected among 39 samples tested by both uniplex and multiplex PCR, showing highly identification. Because of the sensitivity and specificity, the multiplex PCR is a useful approach for clinical diagnosis of mixed infections of DNA and RNA viruses in swine.
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Affiliation(s)
- Xin-Gang Xu
- College of Veterinary Medicine, Northwest A&F University, Yangling, Shaanxi 712100, China
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16
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Zhang XJ, Han QY, Sun Y, Belák S, Liu L, Qiu HJ. Development of a loop-mediated isothermal amplification for visual detection of the HCLV vaccine against classical swine fever in China. J Virol Methods 2010; 171:200-5. [PMID: 21055419 DOI: 10.1016/j.jviromet.2010.10.025] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2010] [Revised: 10/21/2010] [Accepted: 10/26/2010] [Indexed: 11/17/2022]
Abstract
A loop-mediated isothermal amplification (LAMP) assay was developed and evaluated for the rapid and specific detection of HCLV vaccine strain against classical swine fever. Four primers were designed for amplification of NS5B gene region with Bst DNA polymerase at a constant temperature of 65°C. The products showed ladder-like pattern on 2% agarose gel, and can be visualised after addition of SYBR Green I dye. The detection limit of the assay was 5 copies of the HCLV genome per reaction. No cross-reaction with other porcine viruses including different wild-type CSFV strains and the bovine viral diarrhoea virus was observed. The agreement between the LAMP and TaqMan real-time RT-PCR assays was 94.4% for the detection of 72 batches of HCLV vaccine. The assay provides a rapid tool for the control of vaccine quality and can be an accompanying assay of the LAMP for wild-type CSFV described previously for differential diagnosis.
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Affiliation(s)
- Xing-Juan Zhang
- Division of Swine Infectious Diseases, National Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin, China
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17
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Zhang XJ, Sun Y, Liu L, Belák S, Qiu HJ. Validation of a loop-mediated isothermal amplification assay for visualised detection of wild-type classical swine fever virus. J Virol Methods 2010; 167:74-8. [PMID: 20304010 DOI: 10.1016/j.jviromet.2010.03.013] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2009] [Revised: 03/04/2010] [Accepted: 03/10/2010] [Indexed: 11/17/2022]
Abstract
Loop-mediated isothermal amplification (LAMP) is a nucleic acid amplification method applied and adapted to the detection of a number of pathogens. A LAMP assay was developed for the specific detection of wild-type classical swine fever virus (CSFV). Based on an alignment of genomic sequences of pestiviruses available in GenBank, four primers were selected targeting six positions in the NS5B gene region of the viral genome. The assay was performed in a simple water bath at a constant temperature of 62 degrees C, and after adding SYBR Green I, the results were visualised by the naked eye. This assay allowed easy applicability in a laboratory that is equipped simply, or even on site, close to the outbreaks and under field conditions. For confirmation, the results could also be visualised under UV light or by separation of the amplified products on 2% agarose gels. The detection limit of the assay was 2.5 medium tissue culture infectious dose (TCID(50)). The assay was validated with 116 clinical samples from vaccinated swineherds and 53 blood samples from experimental infections, and the results were comparable to a real-time RT-PCR assay. In summary, the LAMP assay provides a simple, rapid, and sensitive tool for the detection of wild-type CSFV under field conditions.
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Affiliation(s)
- Xing-Juan Zhang
- Division of Swine Infectious Diseases, National Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin 150001, Heilongjiang, China
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18
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Chen N, Li D, Yuan X, Li X, Hu H, Zhu B, Wan X, Fang W. Genetic characterization of E2 gene of classical swine fever virus by restriction fragment length polymorphism and phylogenetic analysis. Virus Genes 2010; 40:389-96. [PMID: 20217206 DOI: 10.1007/s11262-010-0465-8] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2009] [Accepted: 02/23/2010] [Indexed: 11/26/2022]
Abstract
An RT-nested PCR (RT-nPCR)-based restriction fragment length polymorphism (RFLP) analyses of the E2 gene were developed for genetic subtyping and differentiation of vaccinated and infected classical swine fever virus (CSFV) strains. RT-nPCR identified 96 CSFV-positive samples from 321 clinical specimens from southeastern China during 2003-2008. The PCR products of positive samples were further differentiated using MspI digestion, 23 were identified as the C-strain, 62 as field strains, and 11 as mixture of the vaccine strain and field ones. RFLP with BglI, DdeI, DraI, and PstI were then used for subtyping of the field CSFV isolates. Thirty-eight field isolates phylogenetically classified as subgroup 2.1 based on E2 were divided into 11 subtypes by this RFLP scheme. Both RFLP profiling and sequence-based phylogenetic analysis revealed genetic diversity of CSFV in the field. Three novel substitutions at amino acid positions 17, 93, and 286 were identified in the predominant subtype VI strains isolated in 2008 as compared to other strains including historical subtype VI strains. These results suggest that CSFV in China experienced gradual variations and evolutionary accumulation progress. Thus, the RFLP methods targeting on the CSFV E2 gene are suitable for epidemiological survey in endemic area where the C-strain is applied for vaccination. Combination of the RFLP schemes with sequence-based phylogenetic analysis could provide more detailed information on transmission of CSFV in the region or even its evolution.
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Affiliation(s)
- Ning Chen
- Zhejiang Provincial Key Laboratory of Preventive Veterinary Medicine, Institute of Preventive Veterinary Medicine, Zhejiang University, 268 Kaixuan Road, 310029 Hangzhou, Zhejiang, People's Republic of China
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19
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Uttenthal A, Parida S, Rasmussen TB, Paton DJ, Haas B, Dundon WG. Strategies for differentiating infection in vaccinated animals (DIVA) for foot-and-mouth disease, classical swine fever and avian influenza. Expert Rev Vaccines 2010; 9:73-87. [PMID: 20021307 DOI: 10.1586/erv.09.130] [Citation(s) in RCA: 50] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
The prophylactic use of vaccines against exotic viral infections in production animals is undertaken exclusively in regions where the disease concerned is endemic. In such areas, the infection pressure is very high and so, to assure optimal protection, the most efficient vaccines are used. However, in areas considered to be free from these diseases and in which there is the possibility of only limited outbreaks, the use of Differentiation of Infected from Vaccinated Animals (DIVA) or marker vaccines allows for vaccination while still retaining the possibility of serological surveillance for the presence of infection. This literature review describes the current knowledge on the use of DIVA diagnostic strategies for three important transboundary animal diseases: foot-and-mouth disease in cloven-hoofed animals, classical swine fever in pigs and avian influenza in poultry.
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Affiliation(s)
- Ase Uttenthal
- National Veterinary Institute, Technical University of Denmark, Lindholm, DK-4771 Kalvehave, Denmark.
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20
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Animal health safety of fresh meat derived from pigs vaccinated against Classic Swine Fever. EFSA J 2009. [DOI: 10.2903/j.efsa.2009.933] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
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21
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Leifer I, Depner K, Blome S, Le Potier MF, Le Dimna M, Beer M, Hoffmann B. Differentiation of C-strain “Riems” or CP7_E2alf vaccinated animals from animals infected by classical swine fever virus field strains using real-time RT-PCR. J Virol Methods 2009; 158:114-22. [DOI: 10.1016/j.jviromet.2009.02.002] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2008] [Revised: 01/24/2009] [Accepted: 02/05/2009] [Indexed: 10/21/2022]
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22
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23
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Jiang Y, Shang H, Xu H, Zhu L, Chen W, Zhao L, Fang L. Simultaneous detection of porcine circovirus type 2, classical swine fever virus, porcine parvovirus and porcine reproductive and respiratory syndrome virus in pigs by multiplex polymerase chain reaction. Vet J 2009; 183:172-5. [PMID: 19131259 DOI: 10.1016/j.tvjl.2008.11.016] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2008] [Revised: 11/04/2008] [Accepted: 11/28/2008] [Indexed: 11/18/2022]
Abstract
A multiplex polymerase chain reaction (PCR) was designed for the simultaneous detection of four viruses involved in reproductive and respiratory failure in pigs: porcine circovirus type 2 (PCV-2), porcine parvovirus (PPV), classical swine fever virus (CSFV) and porcine reproductive and respiratory syndrome virus (PRRSV). Each of the four pairs of oligonucleotide primers exclusively amplified the targeted fragment of the specific viruses. The sensitivity of the multiplex PCR using purified plasmid constructs containing the specific viral target fragments was 2.58x10(7), 2.64x10(5), 2.66x10(7) and 2.73x10(5) copies for PRRSV, PCV-2, CSFV and PPV, respectively. Using the multiplex PCR, co-infections with these four viruses were identified in 26/76 (34.2%) piglets born from sows with reproductive failure in China. This method is a rapid, sensitive and cost-effective diagnostic tool for the routine surveillance of viral infections in pigs.
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Affiliation(s)
- Yonghou Jiang
- College of Life Sciences, Zhejiang Sci-Tech University, Hangzhou, China.
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24
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Pan CH, Jong MH, Huang YL, Huang TS, Chao PH, Lai SS. Rapid detection and differentiation of wild-type and three attenuated lapinized vaccine strains of classical swine fever virus by reverse transcription polymerase chain reaction. J Vet Diagn Invest 2008; 20:448-56. [PMID: 18599849 DOI: 10.1177/104063870802000406] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
A simple one-step reverse transcription polymerase chain reaction (RT-PCR) method was developed based on T-rich insertions in the viral genome for simultaneous detection and differentiation of wild type and vaccine strains of Classical swine fever virus (CSFV). The CSFV-specific primers were designed to contain the sequences of the T-rich insertion sites that exist uniquely in the 3' nontranslated regions (3' NTR) of the genome of lapinized CSFV vaccine strains. By using a one-step RT-PCR or a nested PCR followed by an agarose gel electrophoresis or a multicapillary electrophoresis, the wild-type and lapinized vaccine strains of CSFV in clinical samples could be detected and accurately distinguished. These assays can be applied to at least 3 attenuated lapinized vaccine strains, lapinized Philippines Coronel (LPC), hog cholera lapinized virus (HCLV), and Chinese strain (C strain). The detection limit of the wild-type virus was 6.3 TCID(50) (50% tissue culture infective dose)/ml for RT-PCR and 0.63 TCID(50)/ml for nested PCR. In previous studies, notable T-rich insertions of 12-13 nucleotides (nt) were found in the 3' NTR of the genome of lapinized vaccine strains of CSFV. However, this study discovered that 2 T-rich insertions, 42 and 36 nt in length, are present in the viral genome of lapinized vaccine strains LPC/PRK (primary rabbit kidney) and LPC/TS (Tam-Sui), respectively. These T-rich insertions of 12, 36, and 42 nt length increases the size of PCR fragments, which are favorable genetic markers for rapid detection of and differentiation between wild-type and different lapinized vaccine strains of CSFV.
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Affiliation(s)
- Chu-Hsiang Pan
- Division of Hog Cholera Research, Animal Health Rsearch Institute, Council of Agriculture, Tamsui, Taipei, Taiwan
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25
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Monoclonal Antibody 4A4 Against E2 Swine Fever Virus. Hybridoma (Larchmt) 2008. [DOI: 10.1089/hyb.2008.0038.mab] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
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26
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Cheng D, Zhao JJ, Li N, Sun Y, Zhou YJ, Zhu Y, Tian ZJ, Tu C, Tong GZ, Qiu HJ. Simultaneous detection of Classical swine fever virus and North American genotype Porcine reproductive and respiratory syndrome virus using a duplex real-time RT-PCR. J Virol Methods 2008; 151:194-199. [PMID: 18582953 DOI: 10.1016/j.jviromet.2008.05.011] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2008] [Revised: 04/16/2008] [Accepted: 05/12/2008] [Indexed: 11/29/2022]
Abstract
Classical swine fever and porcine reproductive and respiratory syndrome are both notifiable diseases of the World Organization for Animal Health (OIE). The two diseases exhibit indistinguishable clinical symptoms and sometimes co-exist in swine herds. In this study, a duplex real-time RT-PCR for simultaneous detection of Classical swine fever virus (CSFV) and North American (NA) genotype Porcine reproductive and respiratory syndrome virus (PRRSV) based on two differently labeled TaqMan probes was developed and evaluated. The detection limit of the assay was 3.2 TCID(50) or 13 RNA copies for CSFV and 1.8 TCID(50) or 10 RNA copies for PRRSV, about 50 times more sensitive than conventional RT-PCRs. The duplex real-time RT-PCR was capable of specifically detecting different subgroups of wild-type CSFV and different strains of NA-genotype PRRSV, whereas a number of non-CSFV/PRRSV porcine viruses and bovine pestivirus were tested negative. Out of 155 field samples, 16 were tested positive for CSFV, 73 were positive for PRRSV, and 13 were co-infected with the two viruses. These results were 99.4% in agreement with those using conventional RT-PCRs. Therefore, the assay provides sensitive and simultaneous detection and differentiation of CSFV and PRRSV.
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Affiliation(s)
- Dan Cheng
- Division of Swine Infectious Diseases, National Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute, The Chinese Academy of Agricultural Sciences, 427 Maduan Street, Harbin 150001, Heilongjiang, China
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Li N, Zhao JJ, Zhao HP, Sun Y, Zhu QH, Tong GZ, Qiu HJ. Protection of pigs from lethal challenge by a DNA vaccine based on an alphavirus replicon expressing the E2 glycoprotein of classical swine fever virus. J Virol Methods 2007; 144:73-8. [PMID: 17499369 DOI: 10.1016/j.jviromet.2007.03.018] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2007] [Revised: 03/21/2007] [Accepted: 03/28/2007] [Indexed: 10/23/2022]
Abstract
In a previous study, it has been shown that a Semliki Forest virus (SFV) replicon vectored DNA vaccine (pSFV1CS-E2) expressing the E2 glycoprotein of classical swine fever virus (CSFV) conferred full protection for pigs immunized three times with 600 microg of the vaccine. This study was designed to evaluate further the efficacy of the vaccine with lower dosage and fewer inoculations. Pigs were immunized twice with 100 microg of pSFV1CS-E2 (n=5) or control plasmid pSFV1CS (n=3), respectively, and challenged with virulent Shimen strain 6 weeks following the booster immunization. Pigs immunized with pSFV1CS-E2 developed high titers of specific neutralizing antibodies against CSFV after the booster, and the antibody titers increased rapidly upon challenge. The immunized animals showed no clinical symptoms except short-term fever and low-level viremia, whereas, the control pigs immunized with the control plasmid produced no detectable antibody prior to challenge, and showed obvious clinical signs following challenge, and two pigs died of illness. All control animals developed extended viremia as detected by nested RT-PCR and real-time RT-PCR. Severe pathologic lesions typical of CSFV infection were observed at necropsy. It is concluded that the alphavirus replicon-vectored DNA-based vaccine can be a potential marker vaccine against CSFV.
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Affiliation(s)
- Na Li
- National Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin 150001, China
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28
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Zhao JJ, Cheng D, Li N, Sun Y, Shi Z, Zhu QH, Tu C, Tong GZ, Qiu HJ. Evaluation of a multiplex real-time RT-PCR for quantitative and differential detection of wild-type viruses and C-strain vaccine of Classical swine fever virus. Vet Microbiol 2007; 126:1-10. [PMID: 17658704 DOI: 10.1016/j.vetmic.2007.04.046] [Citation(s) in RCA: 97] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2007] [Revised: 04/18/2007] [Accepted: 04/25/2007] [Indexed: 11/23/2022]
Abstract
Classical swine fever virus (CSFV) is the causative agent of classical swine fever (CSF), one of OIE listed diseases. Most of the currently available detection methods do not allow discrimination between wild-type CSF viruses and the vaccine strains. This study was designed to develop a multiplex real-time RT-PCR for the quantitative and differential detection of wild-type viruses and C-strain vaccine widely used in China. CSFV specific primers and two differently labeled TaqMan probes for the differentiation of wild-type viruses from C-strain vaccine were designed in the 5'-untranslated region of the viral genome of CSFV. The two TaqMan probes specifically hybridize wild-type viruses of different subgroups and C-strain vaccine, respectively, in the multiplex real-time RT-PCR, with no cross-reaction to a number of non-CSFV porcine viruses. The sensitivity of the assay for detecting wild-type and C-strain-type vaccine viruses was determined to be 41.8 and 81.5copies/microL viral RNA, respectively. Completely correct differentiation of wild-type viruses from C-strain vaccine was achieved when testing reference strains and characterized field isolates of CSFV in China. The multiplex real-time RT-PCR was able to detect the viral RNA in the whole blood samples of experimentally infected pigs as early as 2 days post-infection, 3 to 4 days prior to the onset of clinical signs in co-housed pigs. The agreements between the multiplex real-time RT-PCR and a multiplex RT-nested PCR for detection of wild-type and C-strain-type viruses were 96.9% and 100%, respectively, when detecting 106 different field samples. There is a positive correlation between the titers of C-strain vaccines titrated in rabbits and RNA copies quantitated by the multiplex real-time RT-PCR. The novel assay described here is rapid and sensitive, and is useful for differentiating field strains and C-strain of CSFV in China.
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Affiliation(s)
- Jian-Jun Zhao
- Division of Swine Infectious Diseases, Harbin Veterinary Research Institute, The Chinese Academy of Agricultural Sciences, 427 Maduan Street, Harbin 150001, Heilongjiang, China
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