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Gerber PF, Cao D, Xiao CT, Chen Q, Lager K, Bosch BJ, Meng XJ, Halbur PG, Opriessnig T. Failure to experimentally infect 10 days-old piglets with a cell culture-propagated infectious stock of a classical genotype 1a porcine epidemic diarrhea virus. Front Vet Sci 2023; 10:1279162. [PMID: 38046573 PMCID: PMC10693406 DOI: 10.3389/fvets.2023.1279162] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2023] [Accepted: 10/20/2023] [Indexed: 12/05/2023] Open
Abstract
Introduction Porcine epidemic diarrhea virus (PEDV) causes enteric disease in pigs of all ages. PEDV can be grouped into G1 (classical strains) and G2 (variant strains) based on sequence differences in the spike gene. Although several pathogenesis studies using contemporary strains of PEDV have been conducted to date, there is limited information on the pathogenesis of historical PEDV strains in contemporary pigs. This study aimed to investigate the clinical disease course of 10 days-old pigs infected with a classical European G1a PEDV strain from the 1980s which was last passaged in pigs in 1994. Methods Sequencing results confirmed that the virus inoculum was a PEDV strain closely related to the prototype CV777 strain. The PEDV stock was serially passaged three times in Vero cells, and the P3 infectious virus stock was used to inoculate the pigs. A total of 40 pigs were inoculated using the oral route. Results Pigs showed no enteric disease signs, and PEDV shedding was not detected for 44 days post-inoculation (dpi). At necropsy at 3 (5 pigs) or 7 dpi (5 pigs), no lesions were observed in intestinal sections, which were negative for PEDV antigen by immunohistochemistry. In addition, no IgG or IgA PEDV-specific antibodies in serum or fecal samples for 35 dpi further indicates a lack of infection. Titration of the leftover thawed and refrozen PEDV virus stock inoculum showed that the virus stock retained its infectivity in Vero cell culture and the porcine small intestine enterocytes cell line IPEC-J2. Discussion The reasons for the loss of infectivity in pigs are unknown. In conclusion, we showed that a classical G1a PEDV strain successfully propagated in cell cultures could not orally infect 40 piglets.
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Affiliation(s)
- Priscilla F. Gerber
- Department of Infectious Diseases and Public Health, City University of Hong Kong, Kowloon, Hong Kong SAR, China
| | - Dianjun Cao
- College of Veterinary Medicine, Long Island University, New York, NY, United States
| | - Chao-Ting Xiao
- Hunan Provincial Key Laboratory of Medical Virology, Institute of Pathogen Biology and Immunology, College of Biology, Hunan University, Changsha, China
| | - Qi Chen
- Department of Veterinary Diagnostic and Production Animal Medicine, College of Veterinary Medicine, Iowa State University, Ames, IA, United States
| | - Kelly Lager
- National Animal Disease Center, United States Department of Agriculture-Agricultural Research Services, Ames, IA, United States
| | - Berend Jan Bosch
- Virology Section, Infectious Diseases and Immunology Division, Department of Biomolecular Health Sciences, Faculty of Veterinary Medicine, Utrecht University, Utrecht, Netherlands
| | - Xiang-Jin Meng
- Department of Biomedical Sciences and Pathobiology, College of Veterinary Medicine, Virginia Polytechnic Institute and State University, Blacksburg, VA, United States
| | - Patrick G. Halbur
- Department of Veterinary Diagnostic and Production Animal Medicine, College of Veterinary Medicine, Iowa State University, Ames, IA, United States
| | - Tanja Opriessnig
- Department of Veterinary Diagnostic and Production Animal Medicine, College of Veterinary Medicine, Iowa State University, Ames, IA, United States
- Vaccines and Diagnostics Department, Moredun Research Institute, Penicuik, United Kingdom
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Li R, Wen Y, Yang L, Qian QS, Chen XX, Zhang JQ, Li X, Xing BS, Qiao S, Zhang G. Development of an enzyme-linked immunosorbent assay based on viral antigen capture by anti-spike glycoprotein monoclonal antibody for detecting immunoglobulin A antibodies against porcine epidemic diarrhea virus in milk. BMC Vet Res 2023; 19:46. [PMID: 36765329 PMCID: PMC9921583 DOI: 10.1186/s12917-023-03605-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2022] [Accepted: 02/03/2023] [Indexed: 02/12/2023] Open
Abstract
BACKGROUND Porcine epidemic diarrhea (PED), caused by PED virus (PEDV), is a severe enteric disease burdening the global swine industry in recent years. Especially, the mortality of PED in neonatal piglets approaches 100%. Maternal antibodies in milk, particularly immunoglobulin A (IgA) antibodies, are of great importance for protection neonatal suckling piglets against PEDV infection as passive lactogenic immunity. Therefore, appropriate detection methods are required for detecting PEDV IgA antibodies in milk. In the current study, we prepared monoclonal antibodies (mAbs) against PEDV spike (S) glycoprotein. An enzyme-linked immunosorbent assay (ELISA) was subsequently developed based on PEDV antigen capture by a specific anti-S mAb. RESULTS The developed ELISA showed high sensitivity (the maximum dilution of milk samples up to 1:1280) and repeatability (coefficient of variation values < 10%) in detecting PEDV IgA antibody positive and negative milk samples. More importantly, the developed ELISA showed a high coincidence rate with a commercial ELISA kit for PEDV IgA antibody detection in clinical milk samples. CONCLUSIONS The developed ELISA in the current study is applicable for PEDV IgA antibody detection in milk samples, which is beneficial for evaluating vaccination efficacies and neonate immune status against the virus.
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Affiliation(s)
- Rui Li
- grid.495707.80000 0001 0627 4537Key Laboratory of Animal Immunology of the Ministry of Agriculture, Henan Provincial Key Laboratory of Animal Immunology, Henan Academy of Agricultural Sciences, Zhengzhou, 450002 Henan China
| | - Ying Wen
- grid.495707.80000 0001 0627 4537Key Laboratory of Animal Immunology of the Ministry of Agriculture, Henan Provincial Key Laboratory of Animal Immunology, Henan Academy of Agricultural Sciences, Zhengzhou, 450002 Henan China
| | - Lei Yang
- grid.495707.80000 0001 0627 4537Key Laboratory of Animal Immunology of the Ministry of Agriculture, Henan Provincial Key Laboratory of Animal Immunology, Henan Academy of Agricultural Sciences, Zhengzhou, 450002 Henan China
| | - Qi-sheng Qian
- grid.495707.80000 0001 0627 4537Key Laboratory of Animal Immunology of the Ministry of Agriculture, Henan Provincial Key Laboratory of Animal Immunology, Henan Academy of Agricultural Sciences, Zhengzhou, 450002 Henan China
| | - Xin-xin Chen
- grid.495707.80000 0001 0627 4537Key Laboratory of Animal Immunology of the Ministry of Agriculture, Henan Provincial Key Laboratory of Animal Immunology, Henan Academy of Agricultural Sciences, Zhengzhou, 450002 Henan China
| | - Jia-qing Zhang
- grid.495707.80000 0001 0627 4537Institute of Animal Husbandry and Veterinary Science, Henan Academy of Agricultural Sciences, Zhengzhou, 450002 Henan China
| | - Xuewu Li
- grid.495707.80000 0001 0627 4537Key Laboratory of Animal Immunology of the Ministry of Agriculture, Henan Provincial Key Laboratory of Animal Immunology, Henan Academy of Agricultural Sciences, Zhengzhou, 450002 Henan China
| | - Bao-song Xing
- grid.495707.80000 0001 0627 4537Institute of Animal Husbandry and Veterinary Science, Henan Academy of Agricultural Sciences, Zhengzhou, 450002 Henan China
| | - Songlin Qiao
- Key Laboratory of Animal Immunology of the Ministry of Agriculture, Henan Provincial Key Laboratory of Animal Immunology, Henan Academy of Agricultural Sciences, Zhengzhou, 450002, Henan, China.
| | - Gaiping Zhang
- Key Laboratory of Animal Immunology of the Ministry of Agriculture, Henan Provincial Key Laboratory of Animal Immunology, Henan Academy of Agricultural Sciences, Zhengzhou, 450002, Henan, China.
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3
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Wang K, Hu Z, Fan M, Shao Z, Yu Q, Li X. Development of an indirect ELISA to detect PEDV specific IgA antibody based on a PEDV epidemic strain. BMC Vet Res 2022; 18:319. [PMID: 35982455 PMCID: PMC9386190 DOI: 10.1186/s12917-022-03419-w] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2022] [Accepted: 08/10/2022] [Indexed: 11/15/2022] Open
Abstract
Background Porcine epidemic diarrhea (PED), a swine epidemic disease caused by porcine epidemic diarrhea virus (PEDV), is characterized by severe watery diarrhea, vomiting, dehydration and high mortality in piglets, and has caused serious economic losses to the global porcine industry. The level of PEDV IgA antibody is a key marker to assess the extent of passive immunity of the resistance against PEDV infection. However, current commercial structure proteins-based kits for detection of PEDV antibody are not affordable, and those kits require complicated antigen preparation procedures, which cannot meet the scope of economic benefits of many large-scale pig companies in China. Therefore, there is an urgent need to develop an accurate, simple, and economical method for IgA detection in clinical samples. In this study, an indirect ELISA (i-ELISA) method was developed based on a purified PEDV epidemic strain (NH-TA2020). Results The results show that optimal working dilution ratios of PEDV antigen and HRP anti-swine IgA are at 1: 1000 and 1:15000 respectively. The sensitivity of this method is high with the maximum dilution of samples up to 1:160, and coefficients of variation (CV) of both the intra assays and inter assays were no more than 15%. In addition, the relative sensitivities of the i-ELISA were above 90% compared with values from commercial kits in both serum and oral fluid samples. Conclusions Our results suggested that the i-ELISA developed in this study was an accurate, simple, and economical method for PEDV-IgA detection in clinical samples. Supplementary Information The online version contains supplementary material available at 10.1186/s12917-022-03419-w.
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Affiliation(s)
- Kun Wang
- Shandong New Hope Liuhe Agriculture and Animal Husbandry Technology Co., Ltd (NHLH Academy of Swine Research), Dezhou, China
| | - Zhiqiang Hu
- Shandong New Hope Liuhe Agriculture and Animal Husbandry Technology Co., Ltd (NHLH Academy of Swine Research), Dezhou, China
| | - Mingyu Fan
- Shandong New Hope Liuhe Agriculture and Animal Husbandry Technology Co., Ltd (NHLH Academy of Swine Research), Dezhou, China
| | - Zhenwen Shao
- Shandong New Hope Liuhe Agriculture and Animal Husbandry Technology Co., Ltd (NHLH Academy of Swine Research), Dezhou, China
| | - Qiannan Yu
- Shandong New Hope Liuhe Agriculture and Animal Husbandry Technology Co., Ltd (NHLH Academy of Swine Research), Dezhou, China
| | - Xiaowen Li
- Shandong New Hope Liuhe Agriculture and Animal Husbandry Technology Co., Ltd (NHLH Academy of Swine Research), Dezhou, China. .,Shandong Swine Health Data and Intelligent Monitoring Project Laboratory, Dezhou University, Dezhou, China. .,Quality Control for Feed and Products of Livestock and Poultry Key Laboratory of Sichuan Province, New Hope Liuhe Co., Ltd, Chengdu, China.
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Successful Eradication of Porcine Epidemic Diarrhea in an Enzootically Infected Farm: A Two-Year Follow-Up Study. Pathogens 2021; 10:pathogens10070830. [PMID: 34357980 PMCID: PMC8308665 DOI: 10.3390/pathogens10070830] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2021] [Revised: 06/09/2021] [Accepted: 06/29/2021] [Indexed: 11/30/2022] Open
Abstract
Porcine epidemic diarrhea virus (PEDV) has negatively affected the welfare of animals and their productivity in South Korea for three decades. A shortage of effective control measures has led to the virus becoming endemic in domestic pig populations. This study aimed to describe how our intervention measures were implemented for PEDV elimination in an enzootically infected farm. We operated a risk assessment model of PEDV recurrence to obtain information about the virus itself, herd immunity, virus circulation, and biosecurity at the farm. Next, we conducted a four-pillar-based two-track strategy to heighten sow immunity and eradicate the virus, with longitudinal monitoring of immunity and virus circulation, involving strict biosecurity, prime-boost pre-farrow L/K/K immunization, all-in-all-out and disinfection practices in farrowing houses, and disinfection and gilt management in wean-to-finish barns. In particular, we observed a high prevalence and long-term survival of PEDV in slurries, posing a critical challenge to PED eradication and highlighting the necessity for consecutive testing of barn slurry samples and for the management of infected manure to control PEDV. Genetic analysis of PEDVs in this farm indicated that genetic drift continued in the spike gene, with a substitution rate of 1.683 × 10−4 substitutions/site/year. Our study underlines the need for active monitoring and surveillance of PEDV in herds and their environments, along with the coordinated means, to eliminate the virus and maintain a negative herd. The tools described in this study will serve as a framework for regional and national PED eradication programs.
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Jang G, Lee S, Lee C. Assessing the risk of recurrence of porcine epidemic diarrhea virus in affected farms on Jeju Island, South Korea. J Vet Sci 2021; 22:e48. [PMID: 34170089 PMCID: PMC8318795 DOI: 10.4142/jvs.2021.22.e48] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2021] [Revised: 05/17/2021] [Accepted: 05/25/2021] [Indexed: 11/20/2022] Open
Abstract
Background Porcine epidemic diarrhea virus (PEDV) is a swine enteropathogenic coronavirus that has devastated the swine industry in South Korea over the last 30 years. The lack of an effective method to control the endemics has led to a surge in PEDV recurrences in affected farms throughout the country. Objectives In the first step toward establishing systematic monitoring of and active control measures over the swine populations, we constructed an assessment model that evaluates the status of (1) biosecurity, (2) herd immunity, and (3) virus circulation in each of the PEDV-infected farms. Methods A total of 13 farrow-to-finish pig farms with a history of acute PEDV infection on Jeju Island were chosen for this study. The potential risk of the recurrence in these farms was estimated through on-site data collection and laboratory examination. Results Overall, the data indicated that a considerable number of the PEDV-infected farms had lax biosecurity, achieved incomplete protective immunity in the sows despite multi-dose vaccination, and served as incubators of the circulating virus; thus, they face an increased risk of recurrent outbreaks. Intriguingly, our results suggest that after an outbreak, a farm requires proactive tasks, including reinforcing biosecurity, conducting serological and virus monitoring to check the sows’ immunity and to identify the animals exposed to PEDV, and improving the vaccination scheme and disinfection practices if needed. Conclusions The present study highlights the significance of coordinated PEDV management in infected farms to reduce the risk of recurrence and further contribute towards the national eradication of PEDV.
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Affiliation(s)
- Guehwan Jang
- Animal Virology Laboratory, School of Life Sciences, BK21 FOUR KNU Creative BioResearch Group, Kyungpook National University, Daegu 41566, Korea
| | - Sunhee Lee
- Center for Convergent Research of Emerging Virus Infection, Korea Research Institute of Chemical Technology, Daejeon 34114, Korea
| | - Changhee Lee
- Animal Virology Laboratory, School of Life Sciences, BK21 FOUR KNU Creative BioResearch Group, Kyungpook National University, Daegu 41566, Korea.
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6
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Fast and accurate automated recognition of the dominant cells from fecal images based on Faster R-CNN. Sci Rep 2021; 11:10361. [PMID: 33990662 PMCID: PMC8121882 DOI: 10.1038/s41598-021-89863-4] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2020] [Accepted: 04/30/2021] [Indexed: 01/04/2023] Open
Abstract
Fecal samples can easily be collected and are representative of a person’s current health state; therefore, the demand for routine fecal examination has increased sharply. However, manual operation may pollute the samples, and low efficiency limits the general examination speed; therefore, automatic analysis is needed. Nevertheless, recognition exhaustion time and accuracy remain major challenges in automatic testing. Here, we introduce a fast and efficient cell-detection algorithm based on the Faster-R-CNN technique: the Resnet-152 convolutional neural network architecture. Additionally, a region proposal network and a network combined with principal component analysis are proposed for cell location and recognition in microscopic images. Our algorithm achieved a mean average precision of 84% and a 723 ms detection time per sample for 40,560 fecal images. Thus, this approach may provide a solid theoretical basis for real-time detection in routine clinical examinations while accelerating the process to satisfy increasing demand.
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Srijangwad A, Tripipat T, Saeng-Chuto K, Jermsujarit P, Tantituvanont A, Okabayashi T, Nilubol D. Development and validation of indirect ELISA for antibody detection against different protein antigens of porcine epidemic diarrhea virus in the colostrum and milk of sows. J Immunol Methods 2021; 494:113045. [PMID: 33781786 DOI: 10.1016/j.jim.2021.113045] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2021] [Revised: 03/20/2021] [Accepted: 03/20/2021] [Indexed: 11/29/2022]
Abstract
The objectives of this study are to develop and optimize indirect ELISA based on three coating antigens of porcine epidemic diarrhea virus (PEDV), recombinant spike (S12), nucleocapsid (N), and whole viral (WV) proteins, for the detection of IgG and IgA antibodies in colostrum and milk and to evaluate the diagnostic sensitivity (DSe) and diagnostic specificity (DSp) of the assay as a diagnostic method. Colostrum (n = 347) and milk (n = 272) samples from sows were employed in this assay. Indirect ELISA based on three coating antigens was assessed by receiver operating characteristic (ROC) curve analysis with a virus neutralization (VN) test as a reference method, and the cutoff value for calculating DSe and DSp was determined. S12-ELISA showed higher DSe and DSp of IgG and IgA detection compared to N- and WV-ELISA in both colostrum and milk samples. Moreover, S12-ELISA showed perfect agreement and a high correlation with the VN test, which was better than the N- and WV-ELISA for both IgG and IgA detection in colostrum and milk. In contrast, N-ELISA showed lower DSe and DSp compared to S12- and WV-ELISA, along with a correlation with VN and substantial agreement with the VN test. Nevertheless, our developed ELISAs have accuracy for repeatability in both inter- and intra-assay variation. Overall, this research demonstrates that S12-ELISA is more suitable than WV- and N-ELISA to detect IgG and IgA antibodies against PEDV from both colostrum and milk samples.
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Affiliation(s)
- Anchalee Srijangwad
- Department of Veterinary Microbiology, Faculty of Veterinary Science, Chulalongkorn University, Bangkok 10330, Thailand
| | - Thitima Tripipat
- Department of Veterinary Microbiology, Faculty of Veterinary Science, Chulalongkorn University, Bangkok 10330, Thailand
| | - Kepalee Saeng-Chuto
- Department of Veterinary Microbiology, Faculty of Veterinary Science, Chulalongkorn University, Bangkok 10330, Thailand
| | - Patumporn Jermsujarit
- Department of Veterinary Microbiology, Faculty of Veterinary Science, Chulalongkorn University, Bangkok 10330, Thailand
| | - Angkana Tantituvanont
- Department of Pharmaceutics and Industrial Pharmacy, Faculty of Pharmaceutical Sciences, Chulalongkorn University, Bangkok 10330, Thailand
| | - Tamaki Okabayashi
- Department of Veterinary Science, Faculty of Agriculture, University of Miyazaki, Miyazaki 889-2192, Japan
| | - Dachrit Nilubol
- Department of Veterinary Microbiology, Faculty of Veterinary Science, Chulalongkorn University, Bangkok 10330, Thailand.
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Díaz I, Pujols J, Cano E, Cortey M, Navarro N, Vidal A, Mateu E, Martín M. Immune response does not prevent homologous Porcine epidemic diarrhoea virus reinfection five months after the initial challenge. Transbound Emerg Dis 2021; 69:997-1009. [PMID: 33662178 DOI: 10.1111/tbed.14055] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2020] [Revised: 02/02/2021] [Accepted: 03/02/2021] [Indexed: 12/21/2022]
Abstract
The aim of the present study was to evaluate the duration of protective immunity against Porcine epidemic diarrhoea virus (PEDV). To do so, a two phases study was performed. In the first phase, 75 four-week-old pigs (group A) were orally inoculated (0 days post-inoculation; dpi) with a European PEDV G1b strain and 14 were kept as controls (group B). The second phase started five months later (154 dpi), when animals in group A were homologous challenged and animals in group B were challenged for first time. Clinical signs, viral shedding and immune responses were evaluated after each inoculation, including the determination of antibodies (ELISA and viral neutralization test, IgA and IgG ELISPOTs using peripheral blood mononuclear cells and lymph node cells) and the frequency of interferon-gamma (IFN-γ) secreting cells. During the first phase, loose stools/liquid faeces were observed in all group A animals. Faecal shedding of PEDV occurred mostly during the first 14 days but, in some animals, persisted until 42 dpi. All inoculated animals seroconverted for specific-PEDV IgG and IgA, and for neutralizing antibodies (NA). At 154 dpi, 77% of pigs were still positive for NA. After that, the homologous challenge resulted in a booster for IgG, IgA, NA, as well as specific-PEDV IgG, IgA and IFN-γ secreting cells. In spite of that, PEDV was detected in faeces of all pigs from group A, indicating that the immune response did not prevent reinfection, although the duration of the viral shedding and the total load of virus shed were significantly lower for previously challenged pigs (p < .05). Taken together, the results indicated that, potentially, maintenance of PEDV infection within an endemic farm may occur by transmission to and from previously infected animals and also indicates that sterilizing immunity is shorter than the productive life of pigs.
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Affiliation(s)
- Ivan Díaz
- IRTA, Centre de Recerca en Sanitat Animal (CReSA, IRTA-UAB), Campus de la Universitat Autònoma de Barcelona, Bellaterra, Spain.,OIE Collaborating Centre for the Research and Control of Emerging and Re-Emerging Swine Diseases in Europe (IRTA-CReSA), Bellaterra, Spain
| | - Joan Pujols
- IRTA, Centre de Recerca en Sanitat Animal (CReSA, IRTA-UAB), Campus de la Universitat Autònoma de Barcelona, Bellaterra, Spain.,OIE Collaborating Centre for the Research and Control of Emerging and Re-Emerging Swine Diseases in Europe (IRTA-CReSA), Bellaterra, Spain
| | - Esmeralda Cano
- IRTA, Centre de Recerca en Sanitat Animal (CReSA, IRTA-UAB), Campus de la Universitat Autònoma de Barcelona, Bellaterra, Spain.,OIE Collaborating Centre for the Research and Control of Emerging and Re-Emerging Swine Diseases in Europe (IRTA-CReSA), Bellaterra, Spain
| | - Martí Cortey
- Departament de Sanitat i Anatomia Animals, Universitat Autònoma de Barcelona (UAB), Bellaterra, Spain
| | - Núria Navarro
- IRTA, Centre de Recerca en Sanitat Animal (CReSA, IRTA-UAB), Campus de la Universitat Autònoma de Barcelona, Bellaterra, Spain.,OIE Collaborating Centre for the Research and Control of Emerging and Re-Emerging Swine Diseases in Europe (IRTA-CReSA), Bellaterra, Spain
| | - Anna Vidal
- Departament de Sanitat i Anatomia Animals, Universitat Autònoma de Barcelona (UAB), Bellaterra, Spain
| | - Enric Mateu
- IRTA, Centre de Recerca en Sanitat Animal (CReSA, IRTA-UAB), Campus de la Universitat Autònoma de Barcelona, Bellaterra, Spain.,OIE Collaborating Centre for the Research and Control of Emerging and Re-Emerging Swine Diseases in Europe (IRTA-CReSA), Bellaterra, Spain.,Departament de Sanitat i Anatomia Animals, Universitat Autònoma de Barcelona (UAB), Bellaterra, Spain
| | - Marga Martín
- IRTA, Centre de Recerca en Sanitat Animal (CReSA, IRTA-UAB), Campus de la Universitat Autònoma de Barcelona, Bellaterra, Spain.,OIE Collaborating Centre for the Research and Control of Emerging and Re-Emerging Swine Diseases in Europe (IRTA-CReSA), Bellaterra, Spain.,Departament de Sanitat i Anatomia Animals, Universitat Autònoma de Barcelona (UAB), Bellaterra, Spain
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Suda Y, Miyazaki A, Miyazawa K, Shibahara T, Ohashi S. Systemic and intestinal porcine epidemic diarrhea virus-specific antibody response and distribution of antibody-secreting cells in experimentally infected conventional pigs. Vet Res 2021; 52:2. [PMID: 33397461 PMCID: PMC7780908 DOI: 10.1186/s13567-020-00880-z] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2020] [Accepted: 12/15/2020] [Indexed: 01/03/2023] Open
Abstract
Porcine epidemic diarrhea (PED) is a coronavirus disease characterized by the rapid spread of severe diarrhea among pigs. PED virus (PEDV) infects and replicates mainly in the epithelial cells of the duodenum, jejunum, ileum and colon. Serum or mucosal IgA antibody levels have been used to predict both vaccine efficacy and the level of protective immunity to enteric infectious diseases in individuals or herds. Details of the B-cell immune response upon PEDV infection, such as the systemic and mucosal PEDV IgA antibody response, the distribution of IgA antibody-secreting cells (ASCs), and their role in virus clearance are not yet clear. In this experimental infection study, we observed similar fluctuations in PEDV IgA antibody levels in serum and intestinal contents of the upper and lower jejunum and ileum, but not fecal samples, over the 4-week experimental course. ASCs that actively secrete PEDV IgA antibody without in vitro stimulation were distributed mainly in the upper jejunum, whereas memory B cells that showed enhanced PEDV IgA antibody production upon in vitro stimulation were observed in mesenteric lymph nodes and the ileum. Our findings will contribute to the development of effective vaccines and diagnostic methods for PEDV.
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Affiliation(s)
- Yuto Suda
- Kyushu Research Station, National Institute of Animal Health (NIAH), National Agriculture and Food Research Organization (NARO), 2702 Chuzan, Kagoshima, Kagoshima, 891-0105, Japan. .,Division of Viral Disease and Epidemiology, NIAH, NARO, 3-1-5 Kannondai, Tsukuba, Ibaraki, 305-0856, Japan.
| | - Ayako Miyazaki
- Division of Viral Disease and Epidemiology, NIAH, NARO, 3-1-5 Kannondai, Tsukuba, Ibaraki, 305-0856, Japan
| | - Kohtaro Miyazawa
- Division of Viral Disease and Epidemiology, NIAH, NARO, 3-1-5 Kannondai, Tsukuba, Ibaraki, 305-0856, Japan
| | - Tomoyuki Shibahara
- Division of Pathology and Pathophysiology, NIAH, NARO, 3-1-5 Kannondai, Tsukuba, Ibaraki, 305-0856, Japan.,Department of Veterinary Science, Graduate School of Life and Environmental Sciences, Osaka Prefecture University, 1-58 Rinku-oraikita, Izumisano, Osaka, 598-8531, Japan
| | - Seiichi Ohashi
- Division of Viral Disease and Epidemiology, NIAH, NARO, 3-1-5 Kannondai, Tsukuba, Ibaraki, 305-0856, Japan
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10
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Evaluation of Cross-Protection between G1a- and G2a-Genotype Porcine Epidemic Diarrhea Viruses in Suckling Piglets. Animals (Basel) 2020; 10:ani10091674. [PMID: 32957461 PMCID: PMC7552732 DOI: 10.3390/ani10091674] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2020] [Revised: 08/31/2020] [Accepted: 09/14/2020] [Indexed: 12/12/2022] Open
Abstract
Simple Summary Porcine epidemic diarrhea (PED), caused by PED virus (PEDV), is a devastating enteric disease in pigs worldwide. At least two genotypes (G1 and G2) and five subgenotypes (G1a, G1b, G2a, G2b, andG2c) of PEDV strains have been identified. To date, the reports on the antigenicity and immunogenicity of those viruses are limited and the results documented on cross-neutralization among different genotypes and/or subgenotypes of PEDV were inconsistent. This study aimed to observe the comparative pathogenicity and cross-protection between G1a and G2a PEDVs, and thus find a new insight into the antigenicity and immunogenicity of PEDVs. The results of the present study demonstrated that the G2a-based inactivated vaccine could provide sterilizing immunity against both highly virulent homologous and heterologous PEDV challenges. In contrast, the G1a-based inactivated vaccine could induce a sterilizing immune response against challenge of homologous strain CV777 and only provide partial protection for the challenge of a heterologous G2a PEDV CH/JX/01. The findings of this study might explain the underlying mechanism that severe PED and deaths still occurred among the neonatal piglets of which CV777-based PEDV vaccine were administered in China, and imply G2a-based PEDV vaccine used in this study might be a good vaccine candidate for PEDV which may provide solid protection against circulating highly virulent PEDVs. Abstract To date, two genotypes, i.e., genotype 1 (G1) and genotype 2 (G2), of porcine epidemic diarrhea virus (PEDV) have been identified in swine, while the cross protection between the G2a and G1a subgenotypes is undetermined. Hence, in the present study, we attempted to observe a comparative pathogenicity and cross protection of G1a (CV777) and G2a (CH/JX/01) PEDVs. Initially pregnant sows were vaccinated twice with the two kinds of inactivated G1a- and G2a-based PEDV vaccines, respectively and the delivered neonatal piglets were challenged with prototype isolates of G1a and G2a PEDVs, and then the pathogenicity and cross-protection in neonatal piglets were observed. The results showed that CH/JX/01, a highly virulent and dominant G2a PEDV strain currently circulating in China had more severe pathogenicity in vitro and in vivo, and induced more strong immune responses, including higher titers of sIgA in maternal milk than that induced by CV777 PEDV, a prototype of G1a PEDV strain. All piglets from the sows immunized with CH/JX/01 could not only survive when challenged with the homologous PEDV, but also be fully protected when challenged with heterogenous G1a PEDV. In contrast, the piglets from the sows immunized with CV777 could be protected when challenged with homologous PEDV and only partially protected when challenged with heterologous G2a strain of PEDV (CH/JX/01). The findings of this study provide new insights into the pathogenicity, antigenicity, and immunogenicity of currently circulating wild type G2a PEDV, which might be valuable for the development of novel PEDV vaccine candidates with improved efficacy.
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Humoral immune responses in piglets experimentally infected with a field strain of porcine epidemic diarrhea virus. Vet Microbiol 2020; 246:108742. [PMID: 32605747 DOI: 10.1016/j.vetmic.2020.108742] [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: 03/19/2020] [Revised: 05/27/2020] [Accepted: 05/28/2020] [Indexed: 11/22/2022]
Abstract
Porcine epidemic diarrhea virus (PEDV) causes severe clinical diarrhea in neonatal piglets, with reported mortality rates between 70-100%. The humoral immunity, especially the local intestinal IgA responses, plays an important role in the immune protection against PEDV infection. In this study, we evaluated the isotype antibody responses against the PEDV nucleocapsid (N) protein and the spike (S) protein subunits 1 (S1) and 2 (S2) in the serum and intestine of piglets. We also determined its serum neutralizing activity against the PEDV field strain HBMC2012 in 21-day-old piglets. Enzyme-linked immunosorbent assays (ELISA) revealed that the production of IgM against the N protein and S1 subunit was higher compared to the S2 subunit. The anti-S2 IgA antibodies were higher than the anti-N protein and anti-S1 IgA at 3 days post-infection (dpi). The specific IgA responses to the S2 subunit were higher than the responses observed in S1. The specific IgG responses against S1 and S2 subunits exceeded those of N protein. The serum neutralizing activities against PEDV were relatively low with a tendency to decline over time. No isotype-specific antibodies were found in the intestinal contents from infected pigs, except the one with weak IgA responses against N protein at 28 dpi. Immunohistochemical staining showed that a few IgM, IgA, and IgG antibody-secreting cells were mainly located in the mucosa of the duodenum and ileum of PEDV-infected pigs at 3 dpi. This study suggests poor systemic and intestinal isotype-specific antibody responses, especially those of IgA, and weak serum neutralizing activities against the field PEDV strain in piglets.
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Liu J, Gao R, Shi H, Cong G, Chen J, Zhang X, Shi D, Cao L, Wang X, Zhang J, Ji Z, Jing Z, Feng L. Development of a rapid immunochromatographic strip test for the detection of porcine epidemic diarrhea virus specific SIgA in colostrum. J Virol Methods 2020; 279:113855. [PMID: 32173373 PMCID: PMC7151449 DOI: 10.1016/j.jviromet.2020.113855] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2019] [Revised: 03/06/2020] [Accepted: 03/09/2020] [Indexed: 12/24/2022]
Abstract
A rapid immunochromatographic strip test for the detection of porcine epidemic diarrhea virus specific SIgA in colostrum was established. The rapid immunochromatographic strip test is sensitive as compared with ELISA. The rapid immunochromatographic strip test can be used to epidemiological surveillance as well as vaccine immunity assessment.
Porcine epidemic diarrhea virus (PEDV) causes very high mortality in newborn piglets. The mucosal immune system in the gut must eliminate potential pathogens while maintaining a mutually beneficial relationship with the commensal microbiota. Antibodies derived from the secretory immunoglobulin A (SIgA) class, act as the first line of antigen-specific immunity in the gut by recognizing both pathogens and commensals. Therefore, the measurement of SIgA levels is an important index in evaluating PEDV infections and immune status. A simple and rapid method for the detection of PEDV-specific SIgA using an immunochromatographic test strip has been developed; incorporating a colloidal gold-labeled anti-SIgA secretory component (SC) mAb probe for the detection of anti-PEDV-specific SIgA in swine. On the strip, a gold-labeled anti-SIgA SC mAb was applied to a conjugate pad; purified PEDV particles and goat anti-mouse antibodies were blotted onto a nitrocellulose membrane to form the test and control lines, respectively. Results showed that the immunochromatographic test strip had high sensitivity and specificity. When compared with enzyme-linked immunosorbent assay, kappa value suggesting that the strip could be used to detect PEDV specific SIgA in colostrum samples. Furthermore, the strip assay is rapid and easy to perform with no requirement for professional-level skills or equipment. We found that the immunochromatographic test strip was a rapid, sensitive, and reliable method for the identification of PEDV specific SIgA, indicating its suitability for epidemiological surveillance as well as vaccine immunity when studying PEDV.
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Affiliation(s)
- Jianbo Liu
- State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute of the Chinese Academy of Agricultural Sciences, Harbin 150069, China
| | - Ran Gao
- State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute of the Chinese Academy of Agricultural Sciences, Harbin 150069, China
| | - Hongyan Shi
- State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute of the Chinese Academy of Agricultural Sciences, Harbin 150069, China
| | - Guangyi Cong
- State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute of the Chinese Academy of Agricultural Sciences, Harbin 150069, China
| | - Jianfei Chen
- State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute of the Chinese Academy of Agricultural Sciences, Harbin 150069, China
| | - Xin Zhang
- State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute of the Chinese Academy of Agricultural Sciences, Harbin 150069, China
| | - Da Shi
- State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute of the Chinese Academy of Agricultural Sciences, Harbin 150069, China
| | - Liyan Cao
- State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute of the Chinese Academy of Agricultural Sciences, Harbin 150069, China
| | - Xiaobo Wang
- State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute of the Chinese Academy of Agricultural Sciences, Harbin 150069, China
| | - Jialin Zhang
- State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute of the Chinese Academy of Agricultural Sciences, Harbin 150069, China
| | - Zhaoyang Ji
- State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute of the Chinese Academy of Agricultural Sciences, Harbin 150069, China
| | - Zhaoyang Jing
- State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute of the Chinese Academy of Agricultural Sciences, Harbin 150069, China
| | - Li Feng
- State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute of the Chinese Academy of Agricultural Sciences, Harbin 150069, China.
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Luo L, Chen J, Li X, Qiao D, Wang Z, Wu X, Du Q, Tong D, Huang Y. Establishment of method for dual simultaneous detection of PEDV and TGEV by combination of magnetic micro-particles and nanoparticles. J Infect Chemother 2020; 26:523-526. [PMID: 32147375 PMCID: PMC7128872 DOI: 10.1016/j.jiac.2020.01.008] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2019] [Revised: 01/16/2020] [Accepted: 01/22/2020] [Indexed: 11/18/2022]
Abstract
Transmissible gastroenteritis virus (TGEV) and porcine epidemic diarrhea virus (PEDV) are the main pathogens causing viral diarrhea in pig, mixed infections of these two viruses are very common in intensive pig rearing. However, there is a lack of a method to simultaneously detect and distinguish PEDV and TGEV in preclinical levels. In this study, we aimed to establish a dual ultrasensitive nanoparticle DNA probe-based PCR assay (dual UNDP-PCR) based on functionalized magnetic bead enrichment and specific nano-technology amplification for simultaneous detection and distinguish diagnosis of PEDV and TGEV. The detection limit of dual UNDP-PCR for single or multiple infections of PEDV and TGEV is 25 copies/g, which is 400 times more sensitive than the currently known duplex RT-PCR, showing better specificity and sensitivity without cross-reaction with other viruses. For pre-clinical fecal samples, the dual UNDP-PCR showed a markedly higher positive detection rate (52.08%) than conventional duplex RT-PCR (13.21%), can rapidly and accurately identify targeted pathogens whenever simple virus infection or co-infection. In summary, this study provides a technique for detecting and distinguishing PEDV and TGEV in preclinical levels, which is high sensitivity, specificity, repeatability, low cost and broad application prospect.
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Affiliation(s)
- Le Luo
- College of Veterinary Medicine, Northwest A&F University, Yangling, Shaanxi 712100, PR China
| | - Jing Chen
- College of Veterinary Medicine, Northwest A&F University, Yangling, Shaanxi 712100, PR China
| | - Xiaomin Li
- College of Veterinary Medicine, Northwest A&F University, Yangling, Shaanxi 712100, PR China
| | - Dan Qiao
- College of Veterinary Medicine, Northwest A&F University, Yangling, Shaanxi 712100, PR China
| | - Zhenyu Wang
- College of Veterinary Medicine, Northwest A&F University, Yangling, Shaanxi 712100, PR China
| | - Xingchen Wu
- College of Veterinary Medicine, Northwest A&F University, Yangling, Shaanxi 712100, PR China
| | - Qian Du
- College of Veterinary Medicine, Northwest A&F University, Yangling, Shaanxi 712100, PR China
| | - Dewen Tong
- College of Veterinary Medicine, Northwest A&F University, Yangling, Shaanxi 712100, PR China.
| | - Yong Huang
- College of Veterinary Medicine, Northwest A&F University, Yangling, Shaanxi 712100, PR China.
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Malik YS, Singh RK, Yadav MP, Langel SN, Malik YS, Saif LJ. Porcine Coronaviruses. EMERGING AND TRANSBOUNDARY ANIMAL VIRUSES 2020. [PMCID: PMC7123000 DOI: 10.1007/978-981-15-0402-0_4] [Citation(s) in RCA: 27] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/03/2022]
Abstract
Transmissible gastroenteritis virus (TGEV), porcine epidemic diarrhoea virus (PEDV), and porcine deltacoronavirus (PDCoV) are enteropathogenic coronaviruses (CoVs) of swine. TGEV appearance in 1946 preceded identification of PEDV (1971) and PDCoV (2009) that are considered as emerging CoVs. A spike deletion mutant of TGEV associated with respiratory tract infection in piglets appeared in 1984 in pigs in Belgium and was designated porcine respiratory coronavirus (PRCV). PRCV is considered non-pathogenic because the infection is very mild or subclinical. Since PRCV emergence and rapid spread, most pigs have become immune to both PRCV and TGEV, which has significantly reduced the clinical and economic importance of TGEV. In contrast, PDCoV and PEDV are currently expanding their geographic distribution, and there are reports on the circulation of TGEV-PEDV recombinants that cause a disease clinically indistinguishable from that associated with the parent viruses. TGEV, PEDV and PDCoV cause acute gastroenteritis in pigs (most severe in neonatal piglets) and matches in their clinical signs and pathogenesis. Necrosis of the infected intestinal epithelial cells causes villous atrophy and malabsorptive diarrhoea. Profuse diarrhoea frequently combined with vomiting results in dehydration, which can lead to the death of piglets. Strong immune responses following natural infection protect against subsequent homologous challenge; however, these viruses display no cross-protection. Adoption of advance biosecurity measures and effective vaccines control and prevent the occurrence of diseases due to these porcine-associated CoVs. Recombination and reversion to virulence are the risks associated with generally highly effective attenuated vaccines necessitating further research on alternative vaccines to ensure their safe application in the field.
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Affiliation(s)
- Yashpal Singh Malik
- grid.417990.20000 0000 9070 5290Biological Standardization, Indian Veterinary Research Institute, Izatnagar, Uttar Pradesh India
| | - Raj Kumar Singh
- grid.417990.20000 0000 9070 5290ICAR-Indian Veterinary Research Institute, Izatnagar, Uttar Pradesh India
| | - Mahendra Pal Yadav
- grid.444573.5ICAR-Indian Veterinary Research Institute, Izatnagar, Uttar Pradesh, India, Sardar Vallabhbhai Patel University of Agriculture & Technology, Meerut, Uttar Pradesh India
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Host Factors Affecting Generation of Immunity Against Porcine Epidemic Diarrhea Virus in Pregnant and Lactating Swine and Passive Protection of Neonates. Pathogens 2020; 9:pathogens9020130. [PMID: 32085410 PMCID: PMC7168134 DOI: 10.3390/pathogens9020130] [Citation(s) in RCA: 27] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/26/2019] [Revised: 02/13/2020] [Accepted: 02/14/2020] [Indexed: 02/08/2023] Open
Abstract
Porcine epidemic diarrhea virus (PEDV) is a highly virulent re-emerging enteric coronavirus that causes acute diarrhea, dehydration, and up to 100% mortality in neonatal suckling piglets. Despite this, a safe and effective PEDV vaccine against highly virulent strains is unavailable, making PEDV prevention and control challenging. Lactogenic immunity induced via the gut-mammary gland-secretory IgA (sIgA) axis, remains the most promising and effective way to protect suckling piglets from PEDV. Therefore, a successful PEDV vaccine must induce protective maternal IgA antibodies that passively transfer into colostrum and milk. Identifying variables that influence lymphocyte migration and IgA secretion during gestation and lactation is imperative for designing maternal immunization strategies that generate the highest amount of lactogenic immune protection against PEDV in suckling piglets. Because pregnancy-associated immune alterations influence viral pathogenesis and adaptive immune responses in many different species, a better understanding of host immune responses to PEDV in pregnant swine may translate into improved maternal immunization strategies against enteric pathogens for multiple species. In this review, we discuss the role of host factors during pregnancy on antiviral immunity and their implications for generating protective lactogenic immunity in suckling neonates.
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Lei XM, Yang YL, He YQ, Peng L, Zhao P, Xu SY, Cao H, Fang P, Qiu W, Qin P, Wang B, Huang YW. Specific recombinant proteins of porcine epidemic diarrhea virus are immunogenic, revealing their potential use as diagnostic markers. Vet Microbiol 2019; 236:108387. [PMID: 31500721 PMCID: PMC7117304 DOI: 10.1016/j.vetmic.2019.108387] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2019] [Revised: 08/04/2019] [Accepted: 08/08/2019] [Indexed: 01/03/2023]
Abstract
Given the highly contagious and acute nature of porcine epidemic diarrhea (PED), especially in piglets, there is an urgent need for the development of rapid and sensitive diagnostic assays. The diagnostic potentials of specific porcine epidemic diarrhea virus (PEDV) accessory and nonstructural proteins, if any, have not yet been investigated. In order to determine and compare which of the viral proteins may be useful as diagnostic antigens, whole virus (WV) particles and a panel of structural and nonstructural PEDV proteins [spike subunit 1 (S1), the C-terminal part of ORF3 (ORF3C), envelope (E), nonstructural protein 1 (Nsp1), Nsp2, Ac (acidic domain of Nsp3), and ADRP (ADP-ribose-1-monophosphatase domain of Nsp3), expressed individually in bacterial and/or mammalian cells] were tested for reactivity with sera from PEDV-infected pigs by ELISA and/or western blot analysis. According to western blots, serum antibody interactions with the S1 protein were relatively more sensitive and specific than ORF3C, E and Ac. Furthermore, a total of 851 serum samples from diarrheal pigs of different ages were analyzed by ELISA, with most showing immune-reactivity towards the WV, S1, ORF3C, and E proteins. The earliest IgG antibody response was observed in the one-week-old piglets, with similar antibody ontogeny and patterns of seroconversion for S1, ORF3C, E, and WV antigens. In addition, the pattern of neutralizing antibody was more similar to that of IgA in weaning piglets after PEDV infection. Collectively, these data provide more reliable information on the host immune response to different viral proteins, which will be useful for development of novel serological assays and for design of vaccines that better stimulate protective immunity.
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Affiliation(s)
- Xi-Mei Lei
- Institute of Preventive Veterinary Medicine and Key Laboratory of Animal Virology of Ministry of Agriculture, College of Animal Sciences, Zhejiang University, Hangzhou 310058, China
| | - Yong-Le Yang
- Institute of Preventive Veterinary Medicine and Key Laboratory of Animal Virology of Ministry of Agriculture, College of Animal Sciences, Zhejiang University, Hangzhou 310058, China
| | - Yong-Qiang He
- The Technical Center of Zhejiang Entry-exit Inspection and Quarantine Bureau of The P.R. China, Hangzhou 310016, China
| | - Lei Peng
- Institute of Preventive Veterinary Medicine and Key Laboratory of Animal Virology of Ministry of Agriculture, College of Animal Sciences, Zhejiang University, Hangzhou 310058, China
| | - Pengwei Zhao
- Institute of Preventive Veterinary Medicine and Key Laboratory of Animal Virology of Ministry of Agriculture, College of Animal Sciences, Zhejiang University, Hangzhou 310058, China
| | - Shu-Ya Xu
- Institute of Preventive Veterinary Medicine and Key Laboratory of Animal Virology of Ministry of Agriculture, College of Animal Sciences, Zhejiang University, Hangzhou 310058, China
| | - Hongwei Cao
- College of Life Science and Technology, Hei Long Jiang Bayi Agricultural University, Daqing 163319, China
| | - Pengfei Fang
- Huapai Bioengineering Group Co., Ltd, Jianyang 641423, China
| | - Wenying Qiu
- Huapai Bioengineering Group Co., Ltd, Jianyang 641423, China
| | - Pan Qin
- Institute of Preventive Veterinary Medicine and Key Laboratory of Animal Virology of Ministry of Agriculture, College of Animal Sciences, Zhejiang University, Hangzhou 310058, China
| | - Bin Wang
- Institute of Preventive Veterinary Medicine and Key Laboratory of Animal Virology of Ministry of Agriculture, College of Animal Sciences, Zhejiang University, Hangzhou 310058, China
| | - Yao-Wei Huang
- Institute of Preventive Veterinary Medicine and Key Laboratory of Animal Virology of Ministry of Agriculture, College of Animal Sciences, Zhejiang University, Hangzhou 310058, China.
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Luise D, Lauridsen C, Bosi P, Trevisi P. Methodology and application of Escherichia coli F4 and F18 encoding infection models in post-weaning pigs. J Anim Sci Biotechnol 2019; 10:53. [PMID: 31210932 PMCID: PMC6567477 DOI: 10.1186/s40104-019-0352-7] [Citation(s) in RCA: 63] [Impact Index Per Article: 12.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2018] [Accepted: 04/04/2019] [Indexed: 02/06/2023] Open
Abstract
The enterotoxigenic Escherichia coli (ETEC) expressing F4 and F18 fimbriae are the two main pathogens associated with post-weaning diarrhea (PWD) in piglets. The growing global concern regarding antimicrobial resistance (AMR) has encouraged research into the development of nutritional and feeding strategies as well as vaccination protocols in order to counteract the PWD due to ETEC. A valid approach to researching effective strategies is to implement piglet in vivo challenge models with ETEC infection. Thus, the proper application and standardization of ETEC F4 and F18 challenge models represent an urgent priority. The current review provides an overview regarding the current piglet ETEC F4 and F18 challenge models; it highlights the key points for setting the challenge protocols and the most important indicators which should be included in research studies to verify the effectiveness of the ETEC challenge. Based on the current review, it is recommended that the setting of the model correctly assesses the choice and preconditioning of pigs, and the timing and dosage of the ETEC inoculation. Furthermore, the evaluation of the ETEC challenge response should include both clinical parameters (such as the occurrence of diarrhea, rectal temperature and bacterial fecal shedding) and biomarkers for the specific expression of ETEC F4/F18 (such as antibody production, specific F4/F18 immunoglobulins (Igs), ETEC F4/F18 fecal enumeration and analysis of the F4/F18 receptors expression in the intestinal brush borders). On the basis of the review, the piglets’ response upon F4 or F18 inoculation differed in terms of the timing and intensity of the diarrhea development, on ETEC fecal shedding and in the piglets’ immunological antibody response. This information was considered to be relevant to correctly define the experimental protocol, the data recording and the sample collections. Appropriate challenge settings and evaluation of the response parameters will allow future research studies to comply with the replacement, reduction and refinement (3R) approach, and to be able to evaluate the efficiency of a given feeding, nutritional or vaccination intervention in order to combat ETEC infection.
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Affiliation(s)
- Diana Luise
- 1Department of Agricultural and Food Sciences (DISTAL), Alma Mater Studiorum - University of Bologna, Bologna, Italy
| | - Charlotte Lauridsen
- 2Faculty of Science and Technology, Department of Animal Science, Aarhus University, Tjele, Denmark
| | - Paolo Bosi
- 1Department of Agricultural and Food Sciences (DISTAL), Alma Mater Studiorum - University of Bologna, Bologna, Italy
| | - Paolo Trevisi
- 1Department of Agricultural and Food Sciences (DISTAL), Alma Mater Studiorum - University of Bologna, Bologna, Italy
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Jang G, Won H, Lee DU, Noh YH, Lee SC, Choi HW, Yoon IJ, Lee YJ, Sang Yoo H, Lee C. Assessment of the safety and efficacy of an attenuated live vaccine based on highly virulent genotype 2b porcine epidemic diarrhea virus in nursing piglets. Vet Microbiol 2019; 231:120-128. [PMID: 30955799 PMCID: PMC7117296 DOI: 10.1016/j.vetmic.2019.03.009] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2019] [Revised: 03/07/2019] [Accepted: 03/10/2019] [Indexed: 11/19/2022]
Abstract
We have previously reported the generation of the attenuated KNU-141112-S DEL5/ORF3 virus by continuous propagation of highly virulent G2b porcine epidemic diarrhea virus (PEDV) in Vero cells. The present study aimed to assess the safety of S DEL5/ORF3 and to evaluate its effectiveness as a live vaccine for prime-booster vaccinations. Reversion to virulence experiments revealed that the S DEL5/ORF3 strain retains its attenuated phenotype and genetic stability after five successive passages in susceptible piglets. Pregnant sows were primed orally with an S DEL5/ORF3 live vaccine and boosted intramuscularly twice with a commercial killed vaccine at 2-week intervals prior to parturition. This sow vaccination regimen completely protected nursing piglets against virulent G2b challenge, as evidenced by the increase in survival rate from 0% to 100% and the significant reduction in diarrhea intensity, including the amount and duration of PEDV fecal shedding. In addition, despite a 2-3 day period of weight loss in piglets from vaccinated sows after challenge, their daily weight gain was recovered at 7 days post-challenge and became similar to that of unchallenged pigs from unvaccinated sows over the course of the experiment. Furthermore, strong antibody responses to PEDV were verified in the sera and colostrum of immunized sows with the prime-boost treatment and their offspring. Altogether, our data demonstrated that the attenuated S DEL5/ORF3 strain guarantees the safety to host animals with no reversion to virulence and is suitable as an effective primary live vaccine providing durable maternal lactogenic immunity for passive piglet protection.
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Affiliation(s)
- Guehwan Jang
- Animal Virology Laboratory, School of Life Sciences, BK21 plus KNU Creative BioResearch Group, Kyungpook National University, Daegu, 41566, Republic of Korea
| | - Hokeun Won
- ChoongAng Vaccine Laboratories, Daejeon, 34055, Republic of Korea; Department of Infectious Diseases, College of Veterinary Medicine, Seoul National University, Seoul, 08826, Republic of Korea
| | - Dong-Uk Lee
- ChoongAng Vaccine Laboratories, Daejeon, 34055, Republic of Korea
| | - Yun-Hee Noh
- ChoongAng Vaccine Laboratories, Daejeon, 34055, Republic of Korea
| | - Seung-Chul Lee
- ChoongAng Vaccine Laboratories, Daejeon, 34055, Republic of Korea
| | - Hwan-Won Choi
- ChoongAng Vaccine Laboratories, Daejeon, 34055, Republic of Korea
| | - In-Joong Yoon
- ChoongAng Vaccine Laboratories, Daejeon, 34055, Republic of Korea
| | - Yoo Jin Lee
- Department of Neural Development and Disease, Korea Brain Research Institute, Daegu, 41068, Republic of Korea
| | - Han Sang Yoo
- Department of Infectious Diseases, College of Veterinary Medicine, Seoul National University, Seoul, 08826, Republic of Korea
| | - Changhee Lee
- Animal Virology Laboratory, School of Life Sciences, BK21 plus KNU Creative BioResearch Group, Kyungpook National University, Daegu, 41566, Republic of Korea.
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Shan Y, Liu Y, Liu Z, Li G, Chen C, Luo H, Chen Y, Guo N, Shi X, Zhang X, Fang W, Li X. Development and application of an indirect enzyme-linked immunosorbent assay using recombinant S1 for serological testing of porcine epidemic diarrhea virus. Can J Microbiol 2019; 65:343-352. [PMID: 30707600 DOI: 10.1139/cjm-2018-0240] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Porcine epidemic diarrhea virus (PEDV) causes severe infectious diseases in all ages of swine and leads to serious economic losses. Serologic tests are widely accepted and used to detect anti-PEDV antibodies that could indicate PEDV infection or vaccination. In this study, PEDV recombinant S1 protein (rS1) was expressed with the Bac-to-Bac system and purified by nickel-affinity chromatography. An indirect enzyme-linked immunosorbent assay based on rS1 (rS1-ELISA) was then developed and optimized by checkerboard assays with serial dilutions of antigen and serum. Serum samples from 453 domestic pigs and 42 vaccinated pigs were analyzed by the indirect fluorescent antibody (IFA) test and rS1-ELISA. Taking IFA as a gold standard, rS1-ELISA produced a high sensitivity (90.7%) and specificity (94.6%) by a receiver operating characteristic (ROC) curve. In addition, ROC analysis also revealed that rS1-ELISA was consistent with IFA (area under the curve 0.9583 ± 0.0082). This rS1-ELISA was then applied to antibody detection in inactivated PEDV vaccinated pigs. The antibody could be detected 2-4 weeks after the first inoculation. These results indicated that the rS1-ELISA established in this study provides a promising and reliable tool for serologic detection of anti-PEDV IgG antibodies in infected or vaccinated pigs.
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Affiliation(s)
- Ying Shan
- a Zhejiang Provincial Key Lab of Preventive Veterinary Medicine, Institute of Preventive Veterinary Medicine, College of Animal Sciences, Zhejiang University, Hangzhou, P.R. China
| | - Yajie Liu
- a Zhejiang Provincial Key Lab of Preventive Veterinary Medicine, Institute of Preventive Veterinary Medicine, College of Animal Sciences, Zhejiang University, Hangzhou, P.R. China
| | - Ziqi Liu
- a Zhejiang Provincial Key Lab of Preventive Veterinary Medicine, Institute of Preventive Veterinary Medicine, College of Animal Sciences, Zhejiang University, Hangzhou, P.R. China
| | - Guowei Li
- a Zhejiang Provincial Key Lab of Preventive Veterinary Medicine, Institute of Preventive Veterinary Medicine, College of Animal Sciences, Zhejiang University, Hangzhou, P.R. China
| | - Cong Chen
- a Zhejiang Provincial Key Lab of Preventive Veterinary Medicine, Institute of Preventive Veterinary Medicine, College of Animal Sciences, Zhejiang University, Hangzhou, P.R. China
| | - Hao Luo
- a Zhejiang Provincial Key Lab of Preventive Veterinary Medicine, Institute of Preventive Veterinary Medicine, College of Animal Sciences, Zhejiang University, Hangzhou, P.R. China
| | - Yunlu Chen
- a Zhejiang Provincial Key Lab of Preventive Veterinary Medicine, Institute of Preventive Veterinary Medicine, College of Animal Sciences, Zhejiang University, Hangzhou, P.R. China
| | - Ningning Guo
- a Zhejiang Provincial Key Lab of Preventive Veterinary Medicine, Institute of Preventive Veterinary Medicine, College of Animal Sciences, Zhejiang University, Hangzhou, P.R. China.,b Xiazhuhu Wetland Scenic Management Committee, Deqing, Huzhou, P.R. China
| | - Xingfen Shi
- c Animal Products Quality Testing Center of Zhejiang Province, Hangzhou, P.R. China
| | - Xian Zhang
- a Zhejiang Provincial Key Lab of Preventive Veterinary Medicine, Institute of Preventive Veterinary Medicine, College of Animal Sciences, Zhejiang University, Hangzhou, P.R. China.,d College of Animal Sciences and Technology, Zhejiang A&F University, Hangzhou, P.R. China
| | - Weihuan Fang
- a Zhejiang Provincial Key Lab of Preventive Veterinary Medicine, Institute of Preventive Veterinary Medicine, College of Animal Sciences, Zhejiang University, Hangzhou, P.R. China
| | - Xiaoliang Li
- a Zhejiang Provincial Key Lab of Preventive Veterinary Medicine, Institute of Preventive Veterinary Medicine, College of Animal Sciences, Zhejiang University, Hangzhou, P.R. China
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20
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Poonsuk K, Giménez-Lirola LG, Magtoto RL, Ji J, Baum DH, Rademacher CJ, Brown JT, Zhang J, Wang C, Main RG, Zimmerman JJ. The effect of chemical clarification of oral fluids on porcine epidemic diarrhea virus antibody responses. J Vet Diagn Invest 2018; 30:937-941. [PMID: 30204059 DOI: 10.1177/1040638718798672] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
Routine testing of breeding herd oral fluid (OF) samples for porcine epidemic diarrhea virus (PEDV) IgG and/or IgA is used to track levels of PEDV immunity over time. However, OFs contain particles of feed, feces, and inorganic material that detract from the quality of the sample. We clarified swine OF samples using lyophilized chitosan-based formulas (A-C) tested by PEDV IgG and IgA ELISAs. To evaluate both the immediate and residual effects of treatment on antibody detection, samples were tested immediately post-treatment, then stored at 4°C and retested at 2, 4, and 6 days post-treatment (DPT). Formulations were shown to effectively clarify samples. Statistical analysis comparing treated to untreated OF samples at 0 DPT found that neither chitosan nor Tween 20 affected the OF ELISA IgA and IgG sample-to-positive (S/P) ratio results ( p > 0.05). Furthermore, pairwise comparisons of 0 DPT to 2, 4, and 6 DPT results detected no significant differences ( p > 0.05) in IgA and IgG S/P ratios (i.e., treated OF samples were stable over time). Therefore, chitosan efficiently clarified OF specimens without affecting the results of the PEDV IgG and IgA antibody ELISAs.
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Affiliation(s)
- Korakrit Poonsuk
- Department of Veterinary Diagnostic and Production Animal Medicine, College of Veterinary Medicine (Poonsuk, Giménez-Lirola, Magtoto, Baum, Rademacher, Brown, Zhang, Main, Zimmerman), Iowa State University, Ames, IA.,Department of Statistics, College of Liberal Arts and Sciences (Ji, Wang), Iowa State University, Ames, IA
| | - Luis G Giménez-Lirola
- Department of Veterinary Diagnostic and Production Animal Medicine, College of Veterinary Medicine (Poonsuk, Giménez-Lirola, Magtoto, Baum, Rademacher, Brown, Zhang, Main, Zimmerman), Iowa State University, Ames, IA.,Department of Statistics, College of Liberal Arts and Sciences (Ji, Wang), Iowa State University, Ames, IA
| | - Ronaldo L Magtoto
- Department of Veterinary Diagnostic and Production Animal Medicine, College of Veterinary Medicine (Poonsuk, Giménez-Lirola, Magtoto, Baum, Rademacher, Brown, Zhang, Main, Zimmerman), Iowa State University, Ames, IA.,Department of Statistics, College of Liberal Arts and Sciences (Ji, Wang), Iowa State University, Ames, IA
| | - Ju Ji
- Department of Veterinary Diagnostic and Production Animal Medicine, College of Veterinary Medicine (Poonsuk, Giménez-Lirola, Magtoto, Baum, Rademacher, Brown, Zhang, Main, Zimmerman), Iowa State University, Ames, IA.,Department of Statistics, College of Liberal Arts and Sciences (Ji, Wang), Iowa State University, Ames, IA
| | - David H Baum
- Department of Veterinary Diagnostic and Production Animal Medicine, College of Veterinary Medicine (Poonsuk, Giménez-Lirola, Magtoto, Baum, Rademacher, Brown, Zhang, Main, Zimmerman), Iowa State University, Ames, IA.,Department of Statistics, College of Liberal Arts and Sciences (Ji, Wang), Iowa State University, Ames, IA
| | - Christopher J Rademacher
- Department of Veterinary Diagnostic and Production Animal Medicine, College of Veterinary Medicine (Poonsuk, Giménez-Lirola, Magtoto, Baum, Rademacher, Brown, Zhang, Main, Zimmerman), Iowa State University, Ames, IA.,Department of Statistics, College of Liberal Arts and Sciences (Ji, Wang), Iowa State University, Ames, IA
| | - Justin T Brown
- Department of Veterinary Diagnostic and Production Animal Medicine, College of Veterinary Medicine (Poonsuk, Giménez-Lirola, Magtoto, Baum, Rademacher, Brown, Zhang, Main, Zimmerman), Iowa State University, Ames, IA.,Department of Statistics, College of Liberal Arts and Sciences (Ji, Wang), Iowa State University, Ames, IA
| | - Jianqiang Zhang
- Department of Veterinary Diagnostic and Production Animal Medicine, College of Veterinary Medicine (Poonsuk, Giménez-Lirola, Magtoto, Baum, Rademacher, Brown, Zhang, Main, Zimmerman), Iowa State University, Ames, IA.,Department of Statistics, College of Liberal Arts and Sciences (Ji, Wang), Iowa State University, Ames, IA
| | - Chong Wang
- Department of Veterinary Diagnostic and Production Animal Medicine, College of Veterinary Medicine (Poonsuk, Giménez-Lirola, Magtoto, Baum, Rademacher, Brown, Zhang, Main, Zimmerman), Iowa State University, Ames, IA.,Department of Statistics, College of Liberal Arts and Sciences (Ji, Wang), Iowa State University, Ames, IA
| | - Rodger G Main
- Department of Veterinary Diagnostic and Production Animal Medicine, College of Veterinary Medicine (Poonsuk, Giménez-Lirola, Magtoto, Baum, Rademacher, Brown, Zhang, Main, Zimmerman), Iowa State University, Ames, IA.,Department of Statistics, College of Liberal Arts and Sciences (Ji, Wang), Iowa State University, Ames, IA
| | - Jeffrey J Zimmerman
- Department of Veterinary Diagnostic and Production Animal Medicine, College of Veterinary Medicine (Poonsuk, Giménez-Lirola, Magtoto, Baum, Rademacher, Brown, Zhang, Main, Zimmerman), Iowa State University, Ames, IA.,Department of Statistics, College of Liberal Arts and Sciences (Ji, Wang), Iowa State University, Ames, IA
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21
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Duffy MA, Chen Q, Zhang J, Halbur PG, Opriessnig T. Impact of dietary spray-dried bovine plasma addition on pigs infected with porcine epidemic diarrhea virus. Transl Anim Sci 2018; 2:349-357. [PMID: 32289108 PMCID: PMC7107225 DOI: 10.1093/tas/txy088] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2018] [Accepted: 07/09/2018] [Indexed: 01/15/2023] Open
Abstract
Experimental data suggest that the addition of spray-dried plasma (SDP) to pig feed may enhance antibody responses against certain pathogens and negatively impact virus survival. The benefit of SDP on Escherichia coli infection is well documented. The aim of this study was to determine the effect of bovine SDP (BovSDP) in the pig diet on acute porcine epidemic diarrhea virus (PEDV) infection. A total of 16 3-wk-old conventional crossbred pigs were used and divided into three groups. Treatments included 1) a negative control group fed a commercial diet and sham inoculated with commercial liquid porcine plasma (n = 3), 2) a positive control group fed a commercial diet and inoculated with PEDV-spiked porcine plasma (PEDV; n = 8), and 3) a third group of pigs fed the commercial diet with inclusion of 5% spray-dried bovine plasma and inoculated with PEDV-spiked porcine plasma (BovSDP; n = 5). Although clinical signs associated with PEDV infection were mild in the BovSDP group, two of eight pigs in the PEDV group developed moderate clinical disease and had to be euthanized. The PEDV IgG and IgA antibody levels and prevalence rates were significantly (P < 0.05) higher in the PEDV–BovSDP group compared with the PEDV group at 7 d postinoculation. The average fecal PEDV RNA shedding time was 7.2 ± 1.0 d for the PEDV–BovSDP group and 9.3 ± 1.1 d for the PEDV group with an overall time to clearance of PEDV shedding of 11 d for PEDV–BovSDP pigs and at least 14 d for PEDV pigs, which was not different (P = 0.215). The results indicate that addition of BovSDP induced an earlier anti-PEDV antibody response in pigs experimentally infected with PEDV thereby reducing clinical disease and the amount and duration of viral shedding during acute PEDV infection.
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Affiliation(s)
- Mark A Duffy
- Department of Veterinary Diagnostic and Production Animal Medicine, College of Veterinary Medicine, Iowa State University, Ames, IA
| | - Qi Chen
- Department of Veterinary Diagnostic and Production Animal Medicine, College of Veterinary Medicine, Iowa State University, Ames, IA
| | - Jianqiang Zhang
- Department of Veterinary Diagnostic and Production Animal Medicine, College of Veterinary Medicine, Iowa State University, Ames, IA
| | - Patrick G Halbur
- Department of Veterinary Diagnostic and Production Animal Medicine, College of Veterinary Medicine, Iowa State University, Ames, IA
| | - Tanja Opriessnig
- Department of Veterinary Diagnostic and Production Animal Medicine, College of Veterinary Medicine, Iowa State University, Ames, IA.,The Roslin Institute and The Royal (Dick) School of Veterinary Studies, University of Edinburgh, Easter Bush, Midlothian, UK
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22
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Opriessnig T, Gerber PF, Shen H, de Castro AMMG, Zhang J, Chen Q, Halbur P. Evaluation of the efficacy of a commercial inactivated genogroup 2b-based porcine epidemic diarrhea virus (PEDV) vaccine and experimental live genogroup 1b exposure against 2b challenge. Vet Res 2017; 48:69. [PMID: 29073936 PMCID: PMC5659040 DOI: 10.1186/s13567-017-0472-z] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2017] [Accepted: 10/10/2017] [Indexed: 11/10/2022] Open
Abstract
Porcine epidemic diarrhea virus strains from the G1b cluster are considered less pathogenic compared to the G2b cluster. The aim of this study was to compare the ability of G1b-based live virus exposure against use of a commercial G2b–based inactivated vaccine to protect growing pigs against G2b challenge. Thirty-nine PEDV naïve pigs were randomly divided into five groups: EXP-IM-1b (intramuscular G1b exposure; G2b challenge), EXP-ORAL-1b (oral G1b exposure; G2b challenge), VAC-IM-2b (intramuscular commercial inactivated G2b vaccination; G2b challenge), POS-CONTROL (sham-vaccination; G2b challenge) and NEG-CONTROL (sham-vaccination; sham-challenge). Pigs were vaccinated/exposed at 3 weeks of age (day post-vaccination 0, dpv 0), VAC-IM-2b pigs were revaccinated at dpv 14, and the pigs were challenged at dpv 28. Among all groups, VAC-IM-2b pigs had significantly higher anti-PEDV IgG levels on dpv 21 and 28 while EXP-ORAL-1b pigs had significantly higher anti-PEDV IgA levels on dpv 14, 21, 28 and 35. EXP-ORAL-1b also had detectable IgA in feces. Intramuscular PEDV exposure did not result in a detectable antibody response in EXP-IM-1b pigs. The fecal PEDV RNA levels in VAC-IM-2b pigs were significantly lower 5–7 days after challenge compared to the POS-CONTROL group. Under the study conditions a commercial inactivated G2b-based vaccine protected pigs against G2b challenge, as evidenced by reduction of PEDV RNA in feces for 3–4 logs during peak shedding and a shorter viral shedding duration. The oral, but not the intramuscular, experimental G1b-based live virus exposure induced a high anti-PEDV IgA response prior to challenge, which apparently did not impact PEDV shedding compared to POS-CONTROL pigs.
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Affiliation(s)
- Tanja Opriessnig
- The Roslin Institute and The Royal (Dick) School of Veterinary Studies, University of Edinburgh, Midlothian, Scotland, UK. .,Department of Veterinary Diagnostic and Production Animal Medicine, College of Veterinary Medicine, Iowa State University, Ames, IA, USA.
| | - Priscilla F Gerber
- The Roslin Institute and The Royal (Dick) School of Veterinary Studies, University of Edinburgh, Midlothian, Scotland, UK.,Animal Science, School of Environmental and Rural Science, University of New England, Armidale, NSW, 2351, Australia
| | - Huigang Shen
- Department of Veterinary Diagnostic and Production Animal Medicine, College of Veterinary Medicine, Iowa State University, Ames, IA, USA
| | - Alessandra Marnie M G de Castro
- Department of Veterinary Diagnostic and Production Animal Medicine, College of Veterinary Medicine, Iowa State University, Ames, IA, USA.,Complexo Educacional Faculdades Metropolitana Unidas, Veterinária, Rua Ministro Nelson Hungria, 541, Real Parque, Morumbi, São Paulo, SP, Brazil
| | - Jianqiang Zhang
- Department of Veterinary Diagnostic and Production Animal Medicine, College of Veterinary Medicine, Iowa State University, Ames, IA, USA
| | - Qi Chen
- Department of Veterinary Diagnostic and Production Animal Medicine, College of Veterinary Medicine, Iowa State University, Ames, IA, USA
| | - Patrick Halbur
- Department of Veterinary Diagnostic and Production Animal Medicine, College of Veterinary Medicine, Iowa State University, Ames, IA, USA
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23
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Lin CM, Hou Y, Marthaler DG, Gao X, Liu X, Zheng L, Saif LJ, Wang Q. Attenuation of an original US porcine epidemic diarrhea virus strain PC22A via serial cell culture passage. Vet Microbiol 2017; 201:62-71. [PMID: 28284624 PMCID: PMC7117544 DOI: 10.1016/j.vetmic.2017.01.015] [Citation(s) in RCA: 42] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2016] [Revised: 01/12/2017] [Accepted: 01/14/2017] [Indexed: 01/06/2023]
Abstract
An original US PEDV strain PC22A was attenuated via Vero cell culture passages. Attenuated PEDV PC22A strain elicited protective immunity in pigs. Genomic changes of PEDV PC22A at high passage levels were identified. Various molecular changes are related to PEDV attenuation in pigs. PEDV PC22A at high passage levels can be live, attenuated vaccine candidates.
Although porcine epidemic diarrhea (PED) has caused huge economic losses in the pork industry worldwide, an effective live, attenuated vaccine is lacking. In this study, an original US, highly virulent PED virus (PEDV) strain PC22A was serially passaged in Vero CCL81 and Vero BI cells. The virus growth kinetics in cell culture, virulence in neonatal pigs and the whole genomic sequences of selected passages were examined. Increased virus titers and sizes of syncytia were observed at the 65th passage level (P65) and P120, respectively. Based on the severity of clinical signs, histopathological lesions and the distribution of PEDV antigens in the gut, the virulence of P100 and above, but not P95C13 (CCL81), was markedly reduced in 4-day-old, caesarian-derived, colostrum-deprived piglets. Subsequently, the attenuation of P120 and P160 was confirmed in 4-day-old, conventional suckling piglets. Compared with P120, P160 replicated less efficiently in the intestine of pigs and induced a lower rate of protection after challenge. Sequence analysis revealed that the virulent viruses [P3 and P95C13 (CCL81)] had one, one, sixteen (including an early termination of nine amino acids) and two amino acid differences in non-structure protein 1 (nsp1), nsp4, spike and membrane proteins, respectively, from the fully attenuated P160. However, the overall pattern of attenuation-related genetic changes in PC22A differed from those of the other four pairs of PEDV wild type strains and their attenuated derivatives. These results suggest that PEDV attenuation can occur through multiple molecular mechanisms. The knowledge provides insights into potential molecular mechanisms of PEDV attenuation.
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Affiliation(s)
- Chun-Ming Lin
- Food Animal Health Research Program, Ohio Agricultural Research and Development Center, College of Food, Agricultural and Environmental Sciences, Department of Veterinary Preventive Medicine, The Ohio State University, Wooster, OH, USA
| | - Yixuan Hou
- Food Animal Health Research Program, Ohio Agricultural Research and Development Center, College of Food, Agricultural and Environmental Sciences, Department of Veterinary Preventive Medicine, The Ohio State University, Wooster, OH, USA
| | - Douglas G Marthaler
- Department of Veterinary Population Medicine and Veterinary Diagnostic Laboratory, University of Minnesota,1333 Gortner Avenue, St. Paul, MN 55108, United States
| | - Xiang Gao
- Food Animal Health Research Program, Ohio Agricultural Research and Development Center, College of Food, Agricultural and Environmental Sciences, Department of Veterinary Preventive Medicine, The Ohio State University, Wooster, OH, USA
| | - Xinsheng Liu
- Food Animal Health Research Program, Ohio Agricultural Research and Development Center, College of Food, Agricultural and Environmental Sciences, Department of Veterinary Preventive Medicine, The Ohio State University, Wooster, OH, USA; State Key Laboratory of Veterinary Etiological Biology, OIE/National Foot-and-Mouth Disease Reference Laboratory of China, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Lanzhou, China
| | - Lanlan Zheng
- Food Animal Health Research Program, Ohio Agricultural Research and Development Center, College of Food, Agricultural and Environmental Sciences, Department of Veterinary Preventive Medicine, The Ohio State University, Wooster, OH, USA; College of Animal Science and Veterinary Medicine, Henan Agricultural University, Zhengzhou, China
| | - Linda J Saif
- Food Animal Health Research Program, Ohio Agricultural Research and Development Center, College of Food, Agricultural and Environmental Sciences, Department of Veterinary Preventive Medicine, The Ohio State University, Wooster, OH, USA.
| | - Qiuhong Wang
- Food Animal Health Research Program, Ohio Agricultural Research and Development Center, College of Food, Agricultural and Environmental Sciences, Department of Veterinary Preventive Medicine, The Ohio State University, Wooster, OH, USA.
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24
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Xing N, Guan X, An B, Cui B, Wang Z, Wang X, Zhang X, Du Q, Zhao X, Huang Y, Tong D. Ultrasensitive Detection of Porcine Epidemic Diarrhea Virus from Fecal Samples Using Functionalized Nanoparticles. PLoS One 2016; 11:e0167325. [PMID: 27936019 PMCID: PMC5147876 DOI: 10.1371/journal.pone.0167325] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2016] [Accepted: 11/13/2016] [Indexed: 12/02/2022] Open
Abstract
Porcine epidemic diarrhea virus (PEDV) is the main causative agent of porcine diarrhea, which has resulted in devastating damage to swine industry and become a perplexed global problem. PEDV infection causes lesions and clinical symptoms, and infected pigs often succumb to severe dehydration. If there is not a timely and effective method to control its infection, PEDV will spread rapidly across the whole swine farm. Therefore, preclinical identification of PEDV is of great significance for preventing the outbreak and spread of this disease. In this study, a functionalized nanoparticles-based PCR method (UNDP-PCR) specific for PEDV was developed through systematic optimization of functionalized magnetic beads and gold nanoparticles which were further used to specifically enrich viral RNA from the lysate of PEDV stool samples, forming a MMPs-RNA-AuNPs complex. Then, oligonucleotides specific for PEDV coated on AuNPs were eluted from the complex and were further amplified and characterized by PCR. The detection limitation of the established UNDP-PCR method for PEDV was 25 copies in per gram PEDV stool samples, which is 400-fold more sensitive than conventional RT-PCR for stool samples. The UNDP-PCR for PEDV exhibited reliable reproducibility and high specificity, no cross-reaction was observed with other porcine viruses. In 153 preclinical fecal samples, the positive detection rate of UNDP-PCR specific for PEDV (30.72%) was much higher than that of conventional RT-PCR (5.88%) and SYBR Green real-time RT-PCR. In a word, this study provided a RNA extraction and transcription free, rapid and economical method for preclinical PEDV infection, which showed higher sensitivity, specificity and reproducibility, and exhibited application potency for evaluating viral loads of preclinical samples.
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Affiliation(s)
- Na Xing
- College of Veterinary Medicine, Northwest A&F University, Yangling, Shaanxi, P. R. China
| | - Xiaoxiao Guan
- College of Veterinary Medicine, Northwest A&F University, Yangling, Shaanxi, P. R. China
| | - Bin An
- College of Veterinary Medicine, Northwest A&F University, Yangling, Shaanxi, P. R. China
| | - Beibei Cui
- College of Veterinary Medicine, Northwest A&F University, Yangling, Shaanxi, P. R. China
| | - Zengguo Wang
- College of Veterinary Medicine, Northwest A&F University, Yangling, Shaanxi, P. R. China
| | - Xiaoya Wang
- College of Veterinary Medicine, Northwest A&F University, Yangling, Shaanxi, P. R. China
| | - Xiujuan Zhang
- College of Veterinary Medicine, Northwest A&F University, Yangling, Shaanxi, P. R. China
| | - Qian Du
- College of Veterinary Medicine, Northwest A&F University, Yangling, Shaanxi, P. R. China
| | - Xiaomin Zhao
- College of Veterinary Medicine, Northwest A&F University, Yangling, Shaanxi, P. R. China
| | - Yong Huang
- College of Veterinary Medicine, Northwest A&F University, Yangling, Shaanxi, P. R. China
- * E-mail: (DT); (YH)
| | - Dewen Tong
- College of Veterinary Medicine, Northwest A&F University, Yangling, Shaanxi, P. R. China
- * E-mail: (DT); (YH)
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25
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Gerber PF, Xiao CT, Lager K, Crawford K, Kulshreshtha V, Cao D, Meng XJ, Opriessnig T. Increased frequency of porcine epidemic diarrhea virus shedding and lesions in suckling pigs compared to nursery pigs and protective immunity in nursery pigs after homologous re-challenge. Vet Res 2016; 47:118. [PMID: 27871312 PMCID: PMC5118895 DOI: 10.1186/s13567-016-0402-5] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2016] [Accepted: 11/08/2016] [Indexed: 11/17/2022] Open
Abstract
Porcine epidemic diarrhea virus (PEDV) causes enteric disease in pigs and spreads rapidly after entering naïve pig populations. The objectives were to (1) compare the disease course following inoculation with PEDV isolate US/Colorado/2013 in naïve 10 day and 8 week-old pigs, and (2) contrast the naïve response to homologous challenge in 8 week-old pigs. Pigs were randomly assigned into group 1 (n = 40, no PEDV exposure), group 2 (n = 43, PEDV inoculation at 10 days of age) and group 3 (n = 48, PEDV inoculation at 8 weeks of age). Thirty-three group 2 pigs received a homologous challenge at 8 weeks of age. Following primary or secondary inoculation, 3–10 pigs were euthanized at days post-inoculation (dpi) 1, 2, 3, 7 or 14. Clinical signs were more pronounced in 10 day-old pigs compared to 8 week-old pigs at dpi 2 and 3, a higher number of 10 day-old pigs shed PEDV RNA in feces compared to 8 week-old pigs. Typical severe atrophic enteritis of PEDV infection was observed at dpi 3 in both age groups, and at dpi 4 and 14 fecal shedding patterns were also similar. While both age groups had seroconverted to PEDV by dpi 14, IgG levels were higher in 8 week-old pigs. PEDV IgA antibodies were detected in feces of approximately 50% of the pigs at dpi 44. In homologous challenged pigs, no clinical signs or lesions were found, and PEDV fecal shedding was restricted to less than 10% of the pigs indicating the existence of homologous protection 44 days after initial PEDV exposure.
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Affiliation(s)
- Priscilla F Gerber
- The Roslin Institute and the Royal (Dick) School of Veterinary Studies, University of Edinburgh, Midlothian, Scotland, UK
| | - Chao-Ting Xiao
- Department of Veterinary Diagnostic and Production Animal Medicine, Iowa State University, Ames, IA, USA.,College of Biology, Hunan University, Changsha, China
| | - Kelly Lager
- National Animal Disease Center, United States Department of Agriculture-Agricultural Research Services, Ames, IA, USA
| | - Kimberly Crawford
- National Animal Disease Center, United States Department of Agriculture-Agricultural Research Services, Ames, IA, USA
| | - Vikas Kulshreshtha
- National Animal Disease Center, United States Department of Agriculture-Agricultural Research Services, Ames, IA, USA
| | - Dianjun Cao
- Department of Biomedical Sciences and Pathobiology, College of Veterinary Medicine, Virginia Polytechnic Institute and State University, Blacksburg, VA, USA
| | - Xiang-Jin Meng
- Department of Biomedical Sciences and Pathobiology, College of Veterinary Medicine, Virginia Polytechnic Institute and State University, Blacksburg, VA, USA
| | - Tanja Opriessnig
- The Roslin Institute and the Royal (Dick) School of Veterinary Studies, University of Edinburgh, Midlothian, Scotland, UK. .,Department of Veterinary Diagnostic and Production Animal Medicine, Iowa State University, Ames, IA, USA.
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26
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Porcine deltacoronavirus: Overview of infection dynamics, diagnostic methods, prevalence and genetic evolution. Virus Res 2016; 226:71-84. [PMID: 27270129 PMCID: PMC7114555 DOI: 10.1016/j.virusres.2016.05.028] [Citation(s) in RCA: 125] [Impact Index Per Article: 15.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2016] [Revised: 05/27/2016] [Accepted: 05/30/2016] [Indexed: 12/25/2022]
Abstract
Porcine deltacoronavirus (PDCoV) was first reported in Hong Kong, China in 2012 and reported in United States swine in February 2014. PDCoV has subsequently been detected in South Korea, mainland China, and Thailand. PDCoV has been experimentally confirmed to cause diarrhea in inoculated pigs and need to be differentially diagnosed from porcine epidemic diarrhea virus and transmissible gastroenteritis virus in the field. Rapid diagnosis is critical for the implementation of efficient control strategies against PDCoV. Developing high-quality diagnostic methods and understanding PDCoV infection dynamics to collect appropriate specimens at the appropriate time window are important to obtain reliable diagnostic results. Among the virological methods, PDCoV-specific RT-PCR remains the method of choice for the detection of PDCoV; immunohistochemistry combined with hematoxylin and eosin staining has also been commonly used to examine histopathological lesions caused by PDCoV. Serological assays can provide information about previous exposure to PDCoV and also determine antibody responses to infection or vaccination. Prevalence of PDCoV is lower compared to that of PEDV. However, among PDCoV-positive samples, co-infection with other enteric pathogen e.g. PEDV is common. It is also important to understand molecular epidemiology of PDCoV and genetic relationships of global PDCoVs. This review discusses PDCoV infection dynamics and appropriate sample collection for diagnostic testing, the commonly used virological and serological methods for PDCoV diagnosis, prevalence and genetic evolution of PDCoVs.
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27
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Diel DG, Lawson S, Okda F, Singrey A, Clement T, Fernandes MHV, Christopher-Hennings J, Nelson EA. Porcine epidemic diarrhea virus: An overview of current virological and serological diagnostic methods. Virus Res 2016; 226:60-70. [PMID: 27189041 PMCID: PMC7172987 DOI: 10.1016/j.virusres.2016.05.013] [Citation(s) in RCA: 35] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2016] [Revised: 05/06/2016] [Accepted: 05/09/2016] [Indexed: 12/30/2022]
Abstract
Molecular assays such as rRT-PCR are the method of choice for PEDV diagnosis. Multiplex rRT-PCR allow simultaneous testing for PEDV, TGEV and PDCoV. Serological assays provide valuable information on previous exposure to PEDV and population immunity.
Porcine epidemic diarrhea virus (PEDV) is the causative agent of an acute, highly contagious, and severe enteric disease that leads to high mortality rates in suckling piglets. Therefore, accurate diagnosis of PEDV infection is critical for the implementation of control measures for the virus. Many diagnostic tests have been recently developed and are currently available for the detection of PEDV, its proteins or nucleic acid, including virus isolation, immunofluorescence (IF) or immunohistochemistry (IHC), polymerase chain reaction (PCR) and isothermal amplification assays. Additionally, several serological assays have been developed and are currently used for the detection of antibodies against PEDV. Molecular assays such as real-time reverse transcriptase-PCR (rRT-PCR) became the methods of choice for the diagnosis of PEDV infection, providing sensitive, specific and rapid detection of the virus RNA in clinical samples. Whereas serological assays have been widely used to monitor prior exposure to the virus and to evaluate the efficacy of novel vaccine candidates or vaccination strategies. Here we discuss the properties of current PEDV diagnostic assays and prospects for improving diagnostic strategies in the future.
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Affiliation(s)
- D G Diel
- Animal Disease Research and Diagnostic Laboratory, Department of Veterinary and Biomedical Sciences, South Dakota State University, Brookings, SD 57007, USA.
| | - S Lawson
- Animal Disease Research and Diagnostic Laboratory, Department of Veterinary and Biomedical Sciences, South Dakota State University, Brookings, SD 57007, USA
| | - F Okda
- Animal Disease Research and Diagnostic Laboratory, Department of Veterinary and Biomedical Sciences, South Dakota State University, Brookings, SD 57007, USA
| | - A Singrey
- Animal Disease Research and Diagnostic Laboratory, Department of Veterinary and Biomedical Sciences, South Dakota State University, Brookings, SD 57007, USA
| | - T Clement
- Animal Disease Research and Diagnostic Laboratory, Department of Veterinary and Biomedical Sciences, South Dakota State University, Brookings, SD 57007, USA
| | - M H V Fernandes
- Animal Disease Research and Diagnostic Laboratory, Department of Veterinary and Biomedical Sciences, South Dakota State University, Brookings, SD 57007, USA
| | - J Christopher-Hennings
- Animal Disease Research and Diagnostic Laboratory, Department of Veterinary and Biomedical Sciences, South Dakota State University, Brookings, SD 57007, USA
| | - E A Nelson
- Animal Disease Research and Diagnostic Laboratory, Department of Veterinary and Biomedical Sciences, South Dakota State University, Brookings, SD 57007, USA
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