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Reactivity of Porcine Epidemic Diarrhea Virus Structural Proteins to Antibodies against Porcine Enteric Coronaviruses: Diagnostic Implications. J Clin Microbiol 2017; 55:1426-1436. [PMID: 28202790 DOI: 10.1128/jcm.02507-16] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2016] [Accepted: 02/10/2017] [Indexed: 12/25/2022] Open
Abstract
The development of porcine epidemic diarrhea virus (PEDV) antibody-based assays is important for detecting infected animals, confirming previous virus exposure, and monitoring sow herd immunity. However, the potential cross-reactivity among porcine coronaviruses is a major concern for the development of pathogen-specific assays. In this study, we used serum samples (n = 792) from pigs of precisely known infection status and a multiplex fluorescent microbead-based immunoassay and/or enzyme-linked immunoassay platform to characterize the antibody response to PEDV whole-virus (WV) particles and recombinant polypeptides derived from the four PEDV structural proteins, i.e., spike (S), nucleocapsid (N), membrane (M), and envelope (E). Antibody assay cutoff values were selected to provide 100% diagnostic specificity for each target. The earliest IgG antibody response, mainly directed against S1 polypeptides, was observed at days 7 to 10 postinfection. With the exception of nonreactive protein E, we observed similar antibody ontogenies and patterns of seroconversion for S1, N, M, and WV antigens. Recombinant S1 provided the best diagnostic sensitivity, regardless of the PEDV strain, with no cross-reactivity detected against transmissible gastroenteritis virus (TGEV), porcine respiratory coronavirus (PRCV), or porcine deltacoronavirus (PDCoV) pig antisera. The WV particles showed some cross-reactivity to TGEV Miller and TGEV Purdue antisera, while N protein presented some cross-reactivity to TGEV Miller. The M protein was highly cross-reactive to TGEV and PRCV antisera. Differences in the antibody responses to specific PEDV structural proteins have important implications in the development and performance of antibody assays for the diagnosis of PEDV enteric disease.
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Zhang Y, Tian Y, Lin SL, Sun SF, Chen J, Wang GS, Tian FL, Jiang SJ. Two Distinct Genotypes of Porcine Epidemic Diarrhoea Virus in Vaccinated Pig Flocks in Shandong Province of China, 2012-2015. Transbound Emerg Dis 2017; 64:1549-1556. [PMID: 28188693 PMCID: PMC7169864 DOI: 10.1111/tbed.12546] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2016] [Indexed: 11/10/2022]
Abstract
As one of the top pork producers in China, Shandong Province suffered frequent outbreaks of porcine epidemic diarrhoea virus (PEDV) on pig farms from January 2012 to July 2015, resulting in significant economic losses. To better understand the prevalence situation, we conducted molecular epidemiological analyses of 38 PEDV strains isolated from 13 cities in Shandong Province. The detection rate of PEDV was 71.2% (146/205) by reverse transcription polymerase chain reaction (RT‐PCR). The S genes of the 38 isolated samples were 4146 to 4161 nt in length and shared high levels of sequence identity (93.3–99.6% nt, 92.1–99.4% aa) with those of the 41 reference strains. Among the 38 strains, 31 strains that occupied 12 cities were classed into G3 genotype, while the other seven that only existed in four cities were classed into G2 genotype. In addition, the strains CH‐SDLY‐2‐2014 and CH‐SDLY‐3‐2014 isolated from Linyi were classed into the Gd subgenotype. Notably, there were multiple insertions or deletions in the S genes and several mutations in the neutralizing epitopes of the PEDV S protein. Overall, the results revealed that G2 and G3 are the predominant PEDV genotypes circulating in Shandong Province during 2012–2015, and Gd subgenotype in G3 group had already spread towards northern China in 2014.
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Affiliation(s)
- Y Zhang
- College of Veterinary Medicine, Shandong Agricultural University, Tai'an, China.,Shandong Provincial Center for Animal Disease Control and Prevention, Jinan, China
| | - Y Tian
- College of Veterinary Medicine, Shandong Agricultural University, Tai'an, China
| | - S-L Lin
- College of Veterinary Medicine, Shandong Agricultural University, Tai'an, China
| | - S-F Sun
- Shandong Provincial Center for Animal Disease Control and Prevention, Jinan, China
| | - J Chen
- Shandong Provincial Center for Animal Disease Control and Prevention, Jinan, China
| | - G-S Wang
- Shandong Provincial Center for Animal Disease Control and Prevention, Jinan, China
| | - F-L Tian
- College of Veterinary Medicine, Shandong Agricultural University, Tai'an, China.,Shandong Provincial Center for Animal Disease Control and Prevention, Jinan, China
| | - S-J Jiang
- College of Veterinary Medicine, Shandong Agricultural University, Tai'an, China
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103
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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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104
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Strandbygaard B, Lavazza A, Lelli D, Blanchard Y, Grasland B, Poder SL, Rose N, Steinbach F, van der Poel WHM, Widén F, Belsham GJ, Bøtner A. Inter-laboratory study to characterize the detection of serum antibodies against porcine epidemic diarrhoea virus. Vet Microbiol 2016; 197:151-160. [PMID: 27938678 PMCID: PMC7117164 DOI: 10.1016/j.vetmic.2016.11.020] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2016] [Revised: 11/17/2016] [Accepted: 11/20/2016] [Indexed: 10/25/2022]
Abstract
Porcine epidemic diarrhea virus (PEDV) has caused extensive economic losses to pig producers in many countries. It was recently introduced, for the first time, into North America and outbreaks have occurred again in multiple countries within Europe as well. To assess the properties of various diagnostic assays for the detection of PEDV infection, multiple panels of porcine sera have been shared and tested for the presence of antibodies against PEDV in an inter-laboratory ring trial. Different laboratories have used a variety of "in house" ELISAs and also one commercial assay. The sensitivity and specificity of each assay has been estimated using a Bayesian analysis applied to the ring trial results obtained with the different assays in the absence of a gold standard. Although different characteristics were found, it can be concluded that each of the assays used can detect infection of pigs at a herd level by either the early European strains of PEDV or the recently circulating strains (INDEL and non-INDEL). However, not all the assays seem suitable for demonstrating freedom from disease in a country. The results from individual animals, especially when the infection has occurred within an experimental situation, show more variation.
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Affiliation(s)
- Bertel Strandbygaard
- National Veterinary Institute, Technical University of Denmark, Lindholm, Kalvehave 4771, Denmark.
| | - Antonio Lavazza
- IZSLER - Virology Unit, Istituto Zooprofilattico Sperimentale della Lombardia e dell'Emilia Romagna "Bruno Ubertini" Via Bianchi 7/9, 25124 Brescia, Italy.
| | - Davide Lelli
- IZSLER - Virology Unit, Istituto Zooprofilattico Sperimentale della Lombardia e dell'Emilia Romagna "Bruno Ubertini" Via Bianchi 7/9, 25124 Brescia, Italy.
| | - Yannick Blanchard
- ANSES - Laboratory of Ploufragan-Plouzané - BP 53, 22440 Ploufragan, France; Université Bretagne Loire, Rennes, France.
| | - Béatrice Grasland
- ANSES - Laboratory of Ploufragan-Plouzané - BP 53, 22440 Ploufragan, France; Université Bretagne Loire, Rennes, France.
| | - Sophie Le Poder
- Université Paris-Est, Ecole Nationale Vétérinaire d'Alfort, UMR 1161 Virology, Maisons-Alfort, France; INRA, UMR 1161 Virology, Maisons-Alfort, France; ANSES - Laboratory of Animal Health of Maisons-Alfort - UMR 1161 Virology, 23 avenue du Général de Gaulle, France.
| | - Nicolas Rose
- ANSES - Laboratory of Ploufragan-Plouzané - BP 53, 22440 Ploufragan, France; Université Bretagne Loire, Rennes, France.
| | - Falko Steinbach
- APHA, Dept of Virology, Weybridge, Addlestone, Surrey. KT15 3NB, UK.
| | - Wim H M van der Poel
- Wageningen University and Research Centre, Edelhertweg 15, 8219PH, Lelystad, The Netherlands.
| | - Frederik Widén
- The National Veterinary Institute (SVA), 75189 Uppsala, Sweden.
| | - Graham J Belsham
- National Veterinary Institute, Technical University of Denmark, Lindholm, Kalvehave 4771, Denmark.
| | - Anette Bøtner
- National Veterinary Institute, Technical University of Denmark, Lindholm, Kalvehave 4771, Denmark.
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105
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Bertolini F, Harding JCS, Mote B, Ladinig A, Plastow GS, Rothschild MF. Genomic investigation of piglet resilience following porcine epidemic diarrhea outbreaks. Anim Genet 2016; 48:228-232. [PMID: 27943331 PMCID: PMC7159462 DOI: 10.1111/age.12522] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/29/2016] [Indexed: 12/01/2022]
Abstract
Porcine epidemic diarrhea virus (PEDV) belongs to the Coronaviridae family and causes malabsorptive watery diarrhea, vomiting, dehydration and imbalanced blood electrolytes in pigs. Since the 1970s, PED outbreaks have become a source of problems in pig producing countries all over the world, causing large economic losses for pig producers. Although the infection in adults is not fatal, in naïve suckling piglets mortality is close to 100%. In this study, we investigated genome-wide differences between dead and recovered suckling piglets from commercial farms after PED outbreaks. Samples from 262 animals (156 dead and 106 recovered) belonging to several commercial lines were collected from five different farms in three different countries (USA, Canada and Germany) and genotyped with the porcine 80K SNP chip. Mean Fst value was calculated in 1-Mb non-overlapping windows between dead and recovered individuals, and the results were normalized to find differences within the comparison. Seven windows with high divergence between dead and recovered were detected-five on chromosome 2, one on chromosome 4 and one on chromosome 15-in total encompassing 152 genes. Several of these genes are either under- or overexpressed in many virus infections, including Coronaviridae (such as SARS-CoV). A total of 32 genes are included in one or more Gene Ontology terms that can be related to PED development, such as Golgi apparatus, as well as mechanisms generally linked to resilience or diarrhea development (cell proliferation, ion transport, ATPase activity). Taken together this information provides a first genomic picture of PEDV resilience in suckling piglets.
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Affiliation(s)
- F Bertolini
- Department of Animal Science, Iowa State University, Ames, IA, 50011-3150, USA
| | - J C S Harding
- Department of Large Animal Clinical Sciences, Western College of Veterinary Medicine, University of Saskatchewan, Saskatoon, SK, S7N 5B4, Canada
| | - B Mote
- Department of Animal Science, University of Nebraska, Lincoln, NE, 68583-0908, USA
| | - A Ladinig
- University Clinic for Swine, Department for Farm Animals and Veterinary Public Health, University of Veterinary Medicine Vienna, Wien, 1210, Austria
| | - G S Plastow
- Livestock Gentec, Department of Agricultural, Food and Nutritional Science, University of Alberta, Edmonton, AB, T6G 2R3, Canada
| | - M F Rothschild
- Department of Animal Science, Iowa State University, Ames, IA, 50011-3150, USA
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106
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Langel SN, Paim FC, Lager KM, Vlasova AN, Saif LJ. Lactogenic immunity and vaccines for porcine epidemic diarrhea virus (PEDV): Historical and current concepts. Virus Res 2016; 226:93-107. [PMID: 27212686 PMCID: PMC7111331 DOI: 10.1016/j.virusres.2016.05.016] [Citation(s) in RCA: 123] [Impact Index Per Article: 15.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2016] [Revised: 05/17/2016] [Accepted: 05/18/2016] [Indexed: 02/07/2023]
Abstract
Morbidity, mortality, and loss of productivity from enteric diseases in neonatal piglets cost swine producers millions of dollars annually. In 2013-2014, the porcine epidemic diarrhea virus (PEDV) outbreak led to $900 million to $1.8 billion in annual losses to US swine producers. Passive lactogenic immunity remains the most promising and effective way to protect neonatal suckling piglets from enteric diseases like PEDV. Protecting suckling piglets through lactogenic immunity is dependent on trafficking of pathogen-specific IgA plasmablasts to the mammary gland and accumulation of secretory IgA (sIgA) antibodies in milk, defined as the gut-mammary-sIgA axis. Due to an impermeable placenta, piglets are born agammaglobulinic, and are highly susceptible to a plethora of infectious agents. They rely solely on colostrum and milk antibodies for maternal lactogenic immunity. Previous advances in the development of live and attenuated vaccines for another devastating diarrheal virus of pigs, transmissible gastroenteritis virus (TGEV), provide insights into the mechanisms of maternal immunity and piglet protection. In this chapter, we will review previous research on TGEV-induced lactogenic immunity to provide a historical perspective on current efforts for PEDV control and vaccines in the swine industry. Identifying factors that influence lactogenic immunity and the gut-mammary-sIgA axis may lead to improved vaccine regimens for PEDV and other enteric pathogens in gestating swine and improved overall herd immunity, swine health and industry productivity.
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Affiliation(s)
- Stephanie N Langel
- Food Animal Health Research Program, Ohio Agricultural Research and Development Center, Department of Veterinary Preventive Medicine, The Ohio State University, Wooster, OH, USA
| | - Francine Chimelo Paim
- Food Animal Health Research Program, Ohio Agricultural Research and Development Center, Department of Veterinary Preventive Medicine, The Ohio State University, Wooster, OH, USA
| | - Kelly M Lager
- Virus and Prion Research Unit, National Animal Disease Center, USDA, Agricultural Research Service, Ames, IA 50010, USA
| | - Anastasia N Vlasova
- Food Animal Health Research Program, Ohio Agricultural Research and Development Center, Department of Veterinary Preventive Medicine, The Ohio State University, Wooster, OH, USA
| | - Linda J Saif
- Food Animal Health Research Program, Ohio Agricultural Research and Development Center, Department of Veterinary Preventive Medicine, The Ohio State University, Wooster, OH, USA.
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107
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Zhu Y, Liang L, Luo Y, Wang G, Wang C, Cui Y, Ai X, Cui S. A sensitive duplex nanoparticle-assisted PCR assay for identifying porcine epidemic diarrhea virus and porcine transmissible gastroenteritis virus from clinical specimens. Virus Genes 2016; 53:71-76. [PMID: 27815750 PMCID: PMC7089489 DOI: 10.1007/s11262-016-1405-z] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2016] [Accepted: 10/20/2016] [Indexed: 11/30/2022]
Abstract
In this study, a novel duplex nanoparticle-assisted polymerase chain reaction (nanoPCR) assay was developed to detect porcine epidemic diarrhea virus (PEDV) and porcine transmissible gastroenteritis virus (TGEV). Two pairs of primers were designed based on the conserved region within the N gene of PEDV and TGEV. In a screening of 114 clinical samples from four provinces in China for PEDV and TGEV, 48.2 and 3.5 % of the samples, respectively, tested positive. Under optimized conditions, the duplex nanoPCR assay had a detection limit of 7.6 × 101 and 8.5 × 101 copies μL−1 for PEDV and TGEV, respectively. The sensitivity of the duplex nanoPCR assay was ten times higher than that of a conventional PCR assay. Moreover, no fragments were amplified when the duplex nanoPCR assay was used to test samples containing other porcine viruses. Our results indicate that the duplex nanoPCR assay described here is useful for the rapid detection of PEDV and TGEV and can be applied in clinical diagnosis.
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Affiliation(s)
- Yu Zhu
- College of Animal Science and Technology, HLJ August First Land Reclamation University, Daqing, 163319, China
- Institute of Animal Science (IAS), Chinese Academy of Agricultural Sciences (CAAS), Yuanmingyuan West Road 2, Hai Dian District, Beijing, 100193, China
| | - Lin Liang
- Institute of Animal Science (IAS), Chinese Academy of Agricultural Sciences (CAAS), Yuanmingyuan West Road 2, Hai Dian District, Beijing, 100193, China
| | - Yakun Luo
- Institute of Animal Science (IAS), Chinese Academy of Agricultural Sciences (CAAS), Yuanmingyuan West Road 2, Hai Dian District, Beijing, 100193, China
| | - Guihua Wang
- Animal Medical Center DBN Technology Group, Beijing, 100195, China
| | - Chunren Wang
- College of Animal Science and Technology, HLJ August First Land Reclamation University, Daqing, 163319, China
| | - Yudong Cui
- College of Animal Science and Technology, HLJ August First Land Reclamation University, Daqing, 163319, China
| | - Xia Ai
- College of Animal Science and Veterinary Medicine, Tianjin Agricultural University, Tianjin, 300384, China.
| | - Shangjin Cui
- College of Animal Science and Technology, HLJ August First Land Reclamation University, Daqing, 163319, China.
- Institute of Animal Science (IAS), Chinese Academy of Agricultural Sciences (CAAS), Yuanmingyuan West Road 2, Hai Dian District, Beijing, 100193, China.
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108
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Jung K, Saif LJ. Goblet cell depletion in small intestinal villous and crypt epithelium of conventional nursing and weaned pigs infected with porcine epidemic diarrhea virus. Res Vet Sci 2016; 110:12-15. [PMID: 28159230 DOI: 10.1016/j.rvsc.2016.10.009] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2016] [Revised: 08/26/2016] [Accepted: 10/22/2016] [Indexed: 11/28/2022]
Abstract
Intestinal goblet cells secret mucins to form mucus layers critical for maintaining the integrity of the intestinal epithelium. Porcine epidemic diarrhea virus (PEDV) causes watery diarrhea and high mortality of suckling pigs. PEDV mainly infects villous epithelial cells of the small intestine, and infected cells undergo acute, massive necrosis, followed by severe villous atrophy. Conventional 9-day-old nursing pigs [PEDV-inoculated (n=9); Mock (n=11)] and 26-day-old weaned [PEDV-inoculated (n=11); Mock (n=9)] were inoculated orally [8.9 log10 genomic equivalents/pig] with PEDV strain PC21A or mock. We used alcian blue or Periodic-Acid-Schiff staining for the detection of acidic or neutral mucin-secreting goblet cells in the small intestine. We demonstrated that PEDV infection of the nursing pigs at post-inoculation days (PIDs) 1-5 and weaned pigs at PIDs 3-5 led to depletion or significant reduction in the number of goblet cells (and also the number of villous goblet cells normalized by jejunal villous crypt height to crypt depth ratios) in the villi or crypts. These findings coincided with the development of intestinal villous atrophy. By immunohistochemistry, a few PEDV antigen-positive goblet cells were identified in the jejunal or ileal villous epithelium of the infected nursing or weaned pigs. During the early stages of PEDV infection, goblet cell mucins in the small intestine may be decreased, possibly leading to an impaired mucus layer and increased susceptibility to secondary enteric bacterial infection.
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Affiliation(s)
- Kwonil Jung
- Food Animal Health Research Program, Ohio Agricultural Research and Development Center, Department of Veterinary Preventive Medicine, The Ohio State University, Wooster, Ohio, USA.
| | - Linda J Saif
- Food Animal Health Research Program, Ohio Agricultural Research and Development Center, Department of Veterinary Preventive Medicine, The Ohio State University, Wooster, Ohio, USA.
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109
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Characterization of a pathogenic full-length cDNA clone of a virulent porcine epidemic diarrhea virus strain AH2012/12 in China. Virology 2016; 500:50-61. [PMID: 27770703 PMCID: PMC7111662 DOI: 10.1016/j.virol.2016.10.011] [Citation(s) in RCA: 46] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2016] [Revised: 10/01/2016] [Accepted: 10/12/2016] [Indexed: 12/17/2022]
Abstract
Since 2010, outbreaks of variant porcine epidemic diarrhea virus (PEDV) have swept across the world causing substantial economic losses. The development of new, more effective vaccines has been hampered by difficulties in isolating strains and viral genome manipulation. In the present study, we successfully isolated a highly pathogenic field strain AH2012/12, from a pig farm reporting severe diarrhea in China. Phylogenetic analysis revealed that the new isolate belongs to group G2, which represents epidemic and pandemic field strains. Furthermore, we constructed an infectious cDNA clone of the newly isolated strain, rAH2012/12, and the rescued virus displayed phenotypic properties identical to the parental virus in vitro. In vivo experiments demonstrated that the rescued virus displayed similar pathogenicity to the parental isolate, causing high mortality rates in suckling pigs. This study provided a strong basis for the development of live attenuated vaccines and for research into the pathogenic mechanisms of this virus. We successfully isolated one epidemic PEDV strain AH2012/12 with high virulent in newborn pigs. We firstly generated the infectious cDNA clone of the virulent PEDV strain AH2012/12 in China. The rescued virus has similar biological characteristics with the parent virus in vitro and vivo.
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110
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Dong N, Fang L, Yang H, Liu H, Du T, Fang P, Wang D, Chen H, Xiao S. Isolation, genomic characterization, and pathogenicity of a Chinese porcine deltacoronavirus strain CHN-HN-2014. Vet Microbiol 2016; 196:98-106. [PMID: 27939164 PMCID: PMC7117368 DOI: 10.1016/j.vetmic.2016.10.022] [Citation(s) in RCA: 91] [Impact Index Per Article: 11.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2016] [Revised: 10/14/2016] [Accepted: 10/17/2016] [Indexed: 02/07/2023]
Abstract
Porcine deltacoronavirus (PDCoV) is an emerging swine coronavirus that causes diarrhea in piglets. Since the first outbreak of PDCoV in the United States in 2014, this novel porcine coronavirus has been detected in South Korea, Canada, Mexico, Thailand, and China. In this study, a Chinese PDCoV strain, designated CHN-HN-2014, was isolated from piglets with severe diarrhea on a pig farm in Henan Province, China, and examined with a specific immunofluorescence assay and electron microscopy. Genomic analysis showed that CHN-HN-2014 shares 91.6%-99.4% nucleotide identity with other known PDCoV strains. The pathogenicity of CHN-HN-2014 was further investigated in 5-day-old and 21-day-old piglets. Both kinds of piglets developed clear clinical symptoms, including vomiting, anorexia, lethargy, and severe diarrhea, by 2days postinoculation (DPI), and diarrhea persisted for about 5-6 days. Viral shedding was detected in rectal swabs until 14 DPI in challenged 5-day-old pigs and until 18 DPI in challenged 21-day-old pigs. At necropsy at 4 DPI, macroscopic and microscopic lesions were observed and viral antigen was detected in the small intestines with immunohistochemical staining. These data demonstrate that Chinese PDCoV strain CHN-HN-2014 shares high nucleotide identity with previously reported PDCoV strains and is pathogenic in 5-day-old and 21-day-old piglets.
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Affiliation(s)
- Nan Dong
- Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan 430070, China; The Cooperative Innovation Center for Sustainable Pig Production, Wuhan 430070, China
| | - Liurong Fang
- Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan 430070, China; The Cooperative Innovation Center for Sustainable Pig Production, Wuhan 430070, China
| | - Hao Yang
- Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan 430070, China; The Cooperative Innovation Center for Sustainable Pig Production, Wuhan 430070, China
| | - Han Liu
- Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan 430070, China; The Cooperative Innovation Center for Sustainable Pig Production, Wuhan 430070, China
| | - Ting Du
- Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan 430070, China
| | - Puxian Fang
- Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan 430070, China; The Cooperative Innovation Center for Sustainable Pig Production, Wuhan 430070, China
| | - Dang Wang
- Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan 430070, China; The Cooperative Innovation Center for Sustainable Pig Production, Wuhan 430070, China
| | - Huanchun Chen
- Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan 430070, China; The Cooperative Innovation Center for Sustainable Pig Production, Wuhan 430070, China
| | - Shaobo Xiao
- Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan 430070, China; The Cooperative Innovation Center for Sustainable Pig Production, Wuhan 430070, China.
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111
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Zentkovich MM, Nelson SW, Stull JW, Nolting JM, Bowman AS. Inactivation of porcine epidemic diarrhea virus using heated water. Vet Anim Sci 2016; 1:1-3. [PMID: 32289093 PMCID: PMC7103917 DOI: 10.1016/j.vas.2016.09.001] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2016] [Revised: 09/09/2016] [Accepted: 09/10/2016] [Indexed: 10/26/2022] Open
Abstract
Porcine epidemic diarrhea virus (PEDV) is a very contagious swine pathogen that spreads easily via the fecal-oral route, notably from contaminated fomites. The present study investigated heated water as a method for rapid thermal inactivation of PEDV. Cell-culture adapted PEDV was treated with water at varying temperatures and viral titers were measured at multiple time points post-treatment. Viable PEDV was not recovered after a ten second or longer treatment with water heated to ≥76 °C; however, PEDV nucleic acid was detected in all samples regardless of treatment. Hot water decontamination could be considered in settings where chemical disinfection is impractical.
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Affiliation(s)
| | - Sarah W Nelson
- The Ohio State University, 1920 Coffey Road, Columbus, OH 43210, USA
| | - Jason W Stull
- The Ohio State University, 1920 Coffey Road, Columbus, OH 43210, USA
| | | | - Andrew S Bowman
- The Ohio State University, 1920 Coffey Road, Columbus, OH 43210, USA
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112
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Experimental infection of gnotobiotic pigs with the cell-culture-adapted porcine deltacoronavirus strain OH-FD22. Arch Virol 2016; 161:3421-3434. [PMID: 27619798 PMCID: PMC7087098 DOI: 10.1007/s00705-016-3056-8] [Citation(s) in RCA: 53] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2016] [Accepted: 09/07/2016] [Indexed: 11/12/2022]
Abstract
Porcine deltacoronavirus (PDCoV) is a novel enteropathogenic coronavirus in pigs. We have isolated and passaged the PDCoV strain OH-FD22 in an LLC porcine kidney (LLC-PK) cell line. Our study investigated the pathogenicity of the tissue-culture-grown PDCoV (TC-PDCoV) OH-FD22 at cell passages 5, 20 and 40 in LLC-PK cells, in eight 14-day-old gnotobiotic (Gn) pigs. Pigs (n = 3) were euthanized for pathologic examination at post-inoculation day (PID) 3, and the remainder were monitored for clinical signs, virus shedding, and serum antibody responses until PID 28. All inoculated pigs developed watery diarrhea and/or vomiting at PID 1-2 and shed the highest amount of viral RNA in feces at PID 3-5, accompanied by severe atrophic enteritis. They developed high titers of PDCoV-specific IgG/IgA and virus-neutralizing antibodies in serum at PID 23-24. Histologic lesions were limited to the villous epithelium of the jejunum and ileum at PID 3. Two inoculated pigs tested at PID 23-24 had small to moderate numbers of PDCoV antigen-positive cells in the intestinal lamina propria and mesenteric lymph nodes, but not in enterocytes. An analysis of full-length S and N genes of TC- and Gn-pig-passaged OH-FD22 revealed a high genetic stability in cell culture and pigs. TC-PDCoV OH-FD22 (cell passages 5, 20 and 40) was enteropathogenic, and the pathogenicity was similar to that of the original field virus. The TC-PDCoV OH-FD22 will be useful for further pathogenesis studies and for evaluating if higher-level cell-culture passaged virus becomes attenuated for vaccine development.
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113
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Wang L, Hayes J, Byrum B, Zhang Y. US variant porcine epidemic diarrhea virus: histological lesions and genetic characterization. Virus Genes 2016; 52:578-81. [PMID: 27059242 DOI: 10.1007/s11262-016-1334-x] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2015] [Accepted: 04/02/2016] [Indexed: 02/07/2023]
Abstract
Porcine epidemic diarrhea virus (PEDV) was first recognized in pigs in the United States (US) in May 2013. Since then, the virus has spread to over 30 states and caused significant economic losses in the US swine industry due to the high mortality in newborn piglets less than 2 weeks of age. A mild-variant strain OH851 of PEDV in the US was first reported in January 2014. Here, we report histological changes in the small intestines of five piglets infected with the variant strain OH851 of PEDV. The lesions observed were milder, compared to the US classical strain of PEDV. Our study, for the first time, reports the histological lesions caused by the variant PEDV OH851 strain from a field case. In addition, genomic characterization demonstrated that US variant PEDV is more closely related to European-like strains in the first 1170 nt of the 5' spike gene but to US classical PEDV strains in the remaining genome, suggesting that the variant PEDV strain may derive from a recombinant event between the US classical and European-like PEDV strains.
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Affiliation(s)
- Leyi Wang
- Animal Disease Diagnostic Laboratory, Ohio Department of Agriculture, 8995 East Main Street Building #6, Reynoldsburg, OH, 43068, USA.
| | - Jeff Hayes
- Animal Disease Diagnostic Laboratory, Ohio Department of Agriculture, 8995 East Main Street Building #6, Reynoldsburg, OH, 43068, USA
| | - Beverly Byrum
- Animal Disease Diagnostic Laboratory, Ohio Department of Agriculture, 8995 East Main Street Building #6, Reynoldsburg, OH, 43068, USA
| | - Yan Zhang
- Animal Disease Diagnostic Laboratory, Ohio Department of Agriculture, 8995 East Main Street Building #6, Reynoldsburg, OH, 43068, USA.
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114
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Pathological, Immunohistochemical and Molecular Findings Associated with Senecavirus A-Induced Lesions in Neonatal Piglets. J Comp Pathol 2016; 155:145-155. [PMID: 27473601 DOI: 10.1016/j.jcpa.2016.06.011] [Citation(s) in RCA: 44] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2016] [Revised: 06/10/2016] [Accepted: 06/22/2016] [Indexed: 11/21/2022]
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115
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Virulence factors in porcine coronaviruses and vaccine design. Virus Res 2016; 226:142-151. [PMID: 27397100 PMCID: PMC5159199 DOI: 10.1016/j.virusres.2016.07.003] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2016] [Revised: 07/04/2016] [Accepted: 07/05/2016] [Indexed: 11/23/2022]
Abstract
Engineered live attenuated vaccines may improve the control porcine CoVs infection. Porcine CoVs affect many host-cell pathways modulating pathogenesis. CoV genes acting as virulence factors should be modified for virus attenuation. To use attenuated CoVs as vaccine candidates several safety guards should be included.
Porcine enteric coronaviruses (CoVs) cause severe disease in the porcine herds worldwide, leading to important economic losses. Despite the knowledge of these viruses since the 1970s, vaccination strategies have not been implemented, leading to continuous re-emergence of novel virulent strains. Live attenuated vaccines historically have been the most efficient. We consider that the new trend is the development of recombinant vaccines by using reverse genetics systems to engineer attenuated viruses, which could be used as effective and safe modified live vaccine candidates. To this end, host cell signaling pathways influencing porcine CoV virulence should be identified. Similarly, the identity of viral proteins involved in the modulation of host cell pathways influencing CoV pathogenesis should be analyzed. With this information, and using reverse genetics systems, it is possible to design viruses with modifications in the viral proteins acting as virulence factors, which may lead to attenuated viruses and, therefore, vaccine candidates. In addition, novel antiviral drugs may be developed once the host cell pathways and the molecular mechanism affecting porcine CoV replication and virulence are known. This review is focused in the host cell responses to enteric porcine CoV infection and the viral proteins involved in pathogenesis.
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116
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Chung HC, Lee JH, Nguyen VG, Huynh TML, Lee GE, Moon HJ, Park SJ, Kim HK, Park BK. New emergence pattern with variant porcine epidemic diarrhea viruses, South Korea, 2012-2015. Virus Res 2016; 226:14-19. [PMID: 27345861 PMCID: PMC7114525 DOI: 10.1016/j.virusres.2016.06.013] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2015] [Revised: 06/16/2016] [Accepted: 06/17/2016] [Indexed: 11/21/2022]
Abstract
By the application of Bayesian phylogeographical analysis, this study demonstrated the spatial- temporal transmission of PEDVs within Korea. Of the recent emerged G2a viruses, J3142 strains showed potential recombination breakpoint (376–2,143nt) of S1 gene between KNU1303_Korea strain_G2a (KJ451046) and 45RWVCF0712_Thailand strain_G2b (KF724935). The pandemic G2a virus was partial neutralized by the antibodies invoked by the G1- based PED vaccine virus.
Since outbreaks of porcine epidemic diarrhea virus (PEDV) in the United States in 2013, explosive outbreaks of PED in South Korea have infected all age groups of pigs in 2014–2015 year. This study analyzed a large collection of the Spike protein coding gene to infer the spatial-temporal diffusion history of PEDV. The studying results suggested that PEDVs in Korea belonged to different genogroups. While classical G1 was continuingly circulating between provinces of Korea, the pandemic G2a were recently introduced from China and USA. By the application of Bayesian phylogeographical analysis, this study demonstrated the spatial-temporal transmission of PEDVs within Korea. Of the recent emerged G2a viruses, J3142 strains showed potential recombination breakpoint (376–2,143nt) of S1 gene between KNU1303_Korea strain_G2a (KJ451046) and 45RWVCF0712_Thailand strain_G2b (KF724935). The pandemic G2a virus was partial neutralized by the antibodies invoked by the G1- based PED vaccine virus.
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Affiliation(s)
- Hee-Chun Chung
- Department of Veterinary Medicine Virology Lab, College of Veterinary Medicine and Research Institute for Veterinary Science, Seoul National University, DaeHakRo 1, GwanAk-Gu, Seoul, 151-742, Republic of Korea
| | - Jee-Hoon Lee
- Department of Veterinary Medicine Virology Lab, College of Veterinary Medicine and Research Institute for Veterinary Science, Seoul National University, DaeHakRo 1, GwanAk-Gu, Seoul, 151-742, Republic of Korea
| | - Van Giap Nguyen
- Department of Veterinary Microbiology and Infectious Diseases, Faculty of Veterinary Medicine, Vietnam National University of Agriculture, Hanoi, Vietnam
| | - Thi My Le Huynh
- Department of Veterinary Microbiology and Infectious Diseases, Faculty of Veterinary Medicine, Vietnam National University of Agriculture, Hanoi, Vietnam
| | - Ga-Eun Lee
- Department of Veterinary Medicine Virology Lab, College of Veterinary Medicine and Research Institute for Veterinary Science, Seoul National University, DaeHakRo 1, GwanAk-Gu, Seoul, 151-742, Republic of Korea
| | - Hyoung-Joon Moon
- Research Unit, Green Cross Veterinary Products, Yongin, Republic of Korea
| | - Seong-Jun Park
- Forensic Medicine Division, Daegu Institute, National Forensic Service, Chilgok 718-803, Republic of Korea
| | - Hye-Kwon Kim
- Viral Infectious Disease Research Center, Korea Research Institute of Bioscience and Biotechnology, Daejeon 305-806, Republic of Korea
| | - Bong Kyun Park
- Department of Veterinary Medicine Virology Lab, College of Veterinary Medicine and Research Institute for Veterinary Science, Seoul National University, DaeHakRo 1, GwanAk-Gu, Seoul, 151-742, Republic of Korea.
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117
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Pensaert MB, Martelli P. Porcine epidemic diarrhea: A retrospect from Europe and matters of debate. Virus Res 2016; 226:1-6. [PMID: 27317168 PMCID: PMC7132433 DOI: 10.1016/j.virusres.2016.05.030] [Citation(s) in RCA: 65] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2016] [Revised: 05/05/2016] [Accepted: 05/05/2016] [Indexed: 11/27/2022]
Abstract
A retrospect is given on the emergence of porcine epidemic diarrhea (PED) during the early seventies in Europe. While, at first, it appeared as a disease affecting feeder pigs, fattening- and adult swine, it later also became pathogenic for neonatal and suckling pigs hereby drastically increasing its economic impact. Isolation of the causative virus revealed a new porcine coronavirus, the origin of which has never been clarified. Pathogenesis studies with the prototype strain CV777 showed severe villous atrophy in neonatal pigs and the virus-animal interactions showed many similarities with transmissible gastro-enteritis virus (TGEV), another porcine coronavirus. Disease patterns in field outbreaks showed muchvariation but, while farm related factors played a role, possible genetic variations of virus strains in Europe have not been examined and are thus unknown. CV777 in experimental pigs caused diarrheal disease and mortality rates similar to those later encountered in Asia and more recently with the "original" US strains even though genomic typing of the prototype European strain have shown that it belongs to the S-INDEL strains. In Europe, PED has become endemic during the eighties and nineties and subsequently regressed so that, after 2000, swine populations in many countries have largely become seronegative. Sporadic outbreaks have recently reappeared showing a large variety of clinical outcomes.
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Affiliation(s)
- Maurice B Pensaert
- Laboratory of Virology, Faculty of Veterinary Medicine, Ghent University, Salisburylaan, 133, 9820, Merelbeke, Belgium.
| | - Paolo Martelli
- Department of Veterinary Science, University of Parma, Via del taglio, 10, 43126 Parma, Italy.
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118
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Lin CM, Saif LJ, Marthaler D, Wang Q. Evolution, antigenicity and pathogenicity of global porcine epidemic diarrhea virus strains. Virus Res 2016; 226:20-39. [PMID: 27288724 PMCID: PMC7111424 DOI: 10.1016/j.virusres.2016.05.023] [Citation(s) in RCA: 178] [Impact Index Per Article: 22.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2016] [Revised: 05/21/2016] [Accepted: 05/21/2016] [Indexed: 12/16/2022]
Abstract
Evolution of global PEDV strains. Cross-reactivity between PEDV and other coronaviruses and antigenic variations among different PEDV strains. Pathologic features of different PEDV strains. Considerations for vaccine strain selection: PEDV virulence attenuation and in vivo cross-protection among PEDV variants.
Emerging and re-emerging coronaviruses cause morbidity and mortality in human and animal populations, resulting in serious public and animal health threats and economic losses. The ongoing outbreak of a highly contagious and deadly porcine epidemic diarrhea virus (PEDV) in Asia, the Americas and Europe is one example. Genomic sequence analyses of PEDV variants have revealed important insights into the evolution of PEDV. However, the antigenic variations among different PEDV strains are less explored, although they may contribute to the failure of PEDV vaccines in Asian countries. In addition, the evolution of PEDV results in variants with distinct genetic features and virulence differences; thus PEDV can serve as a model to explore the molecular mechanisms of coronavirus evolution and pathogenesis. In this article, we review the evolution, antigenic relationships and pathologic features of PEDV strains. This information and review of researches will aid in the development of strategies for control and prevention of PED.
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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.
| | - 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.
| | - Douglas Marthaler
- Department of Veterinary Population Medicine and Veterinary Diagnostic Laboratory, University of Minnesota, 1333 Gortner Avenue, St. Paul, MN 55108, United States.
| | - 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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119
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Zhang Q, Yoo D. Immune evasion of porcine enteric coronaviruses and viral modulation of antiviral innate signaling. Virus Res 2016; 226:128-141. [PMID: 27212682 PMCID: PMC7111337 DOI: 10.1016/j.virusres.2016.05.015] [Citation(s) in RCA: 84] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2016] [Revised: 05/16/2016] [Accepted: 05/17/2016] [Indexed: 12/15/2022]
Abstract
Enteric coronaviruses have evolved to modulate the host innate immunity. Viral IFN antagonists have been identified and they are mostly redundant. For protection of intestinal epithelia from enteric viruses, type III IFN plays a major role.
Porcine epidemic diarrhea virus (PEDV) and porcine deltacoronavirus (PDCoV) are emerged and reemerging viruses in pigs, and together with transmissible gastroenteritis virus (TGEV), pose significant economic concerns to the swine industry. These viruses infect epithelial cells of the small intestine and cause watery diarrhea, dehydration, and a high mortality in neonatal piglets. Type I interferons (IFN-α/β) are major antiviral cytokines forming host innate immunity, and in turn, these enteric coronaviruses have evolved to modulate the host innate immune signaling during infection. Accumulating evidence however suggests that IFN induction and signaling in the intestinal epithelial cells differ from other epithelial cells, largely due to distinct features of the gut epithelial mucosal surface and commensal microflora, and it appears that type III interferon (IFN-λ) plays a key role to maintain the antiviral state in the gut. This review describes the recent understanding on the immune evasion strategies of porcine enteric coronaviruses and the role of different types of IFNs for intestinal antiviral innate immunity.
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Affiliation(s)
- Qingzhan Zhang
- Department of Pathobiology, University of Illinois at Urbana-Champaign, Urbana IL, United States
| | - Dongwan Yoo
- Department of Pathobiology, University of Illinois at Urbana-Champaign, Urbana IL, United States.
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120
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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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121
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Liu X, Wang Q. Reverse transcription-PCR assays for the differentiation of various US porcine epidemic diarrhea virus strains. J Virol Methods 2016; 234:137-41. [PMID: 27134071 PMCID: PMC7173223 DOI: 10.1016/j.jviromet.2016.04.018] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2016] [Revised: 04/03/2016] [Accepted: 04/27/2016] [Indexed: 11/07/2022]
Abstract
Concurrently, several porcine epidemic diarrhea virus (PEDV) variants are circulating in US swine farms, including the original US and the spike insertion-deletion (S-INDEL) strains. In this study, reverse transcription (RT)-PCR assays for the detection and differentiation of different US PEDV variants were developed based on the differences in the S1 domain of the spike (S) gene. This assay successfully differentiated three PEDV strains: PC22A (the original US virulent), Iowa106 (S-INDEL), and PC177 (S-197DEL) that was derived from cell culture adaptation and has a 197 amino acid-deletion in the S1 domain. The assays did not amplify the porcine deltacoronavirus OH-FD22 strain or transmissible gastroenteritis virus Miller strain. It is the first report on the development of RT-PCR assays allowing the detection and differentiation of all major types of US PEDV variants.
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Affiliation(s)
- Xinsheng Liu
- 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, China; 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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122
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Porcine deltacoronavirus infection: Etiology, cell culture for virus isolation and propagation, molecular epidemiology and pathogenesis. Virus Res 2016; 226:50-59. [PMID: 27086031 PMCID: PMC7114557 DOI: 10.1016/j.virusres.2016.04.009] [Citation(s) in RCA: 149] [Impact Index Per Article: 18.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2016] [Revised: 04/07/2016] [Accepted: 04/08/2016] [Indexed: 11/21/2022]
Abstract
Porcine deltacoronavirus (PDCoV) is a novel swine enteropathogenic coronavirus. The etiology and molecular epidemiology of PDCoV are described. The cell culture for PDCoV isolation and propagation are demonstrated. The disease mechanisms and pathogenesis of PDCoV are reviewed.
Porcine deltacoronavirus (PDCoV) (family Coronaviridae, genus Deltacoronavirus) is a novel swine enteropathogenic coronavirus that causes acute diarrhea/vomiting, dehydration and mortality in seronegative neonatal piglets. PDCoV diarrhea was first reported in the US in early 2014, concurrently with co-circulation of porcine epidemic diarrhea virus (PEDV) (family Coronaviridae, genus Alphacoronavirus). The origin of PDCoV in pigs and also its sudden emergence or route of introduction into the US still remains unclear. In the US, since 2013–2014, the newly emerged PDCoV and PEDV have spread nationwide, causing a high number of pig deaths and significant economic impacts. The current US PDCoV strains are enteropathogenic and infect villous epithelial cells of the entire small and large intestines although the jejunum and ileum are the primary sites of infection. Similar to PEDV infections, PDCoV infections also cause acute, severe atrophic enteritis accompanied by transient viremia (viral RNA) that leads to severe diarrhea and/or vomiting, followed by dehydration as the potential cause of death in nursing piglets. At present, differential diagnosis of PDCoV, PEDV, and transmissible gastroenteritis virus (TGEV) is essential to control viral diarrheas in US swine. Cell culture-adapted US PDCoV (TC-PDCoV) strains have been isolated and propagated by us and in several other laboratories. TC-PDCoV strains will be useful to develop serologic assays and to evaluate if serial cell-culture passage attenuates TC-PDCoV as a potential vaccine candidate strain. A comprehensive understanding of the pathogenesis and epidemiology of epidemic PDCoV strains is currently needed to prevent and control the disease in affected regions and to develop an effective vaccine. This review focuses on the etiology, cell culture isolation and propagation, molecular epidemiology, disease mechanisms and pathogenesis of PDCoV infection.
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123
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Poonsuk K, Giménez-Lirola LG, Zhang J, Arruda P, Chen Q, Correa da Silva Carrion L, Magtoto R, Pineyro P, Sarmento L, Wang C, Sun Y, Madson D, Johnson J, Yoon KJ, Zimmerman J, Main R. Does Circulating Antibody Play a Role in the Protection of Piglets against Porcine Epidemic Diarrhea Virus? PLoS One 2016; 11:e0153041. [PMID: 27050556 PMCID: PMC4822964 DOI: 10.1371/journal.pone.0153041] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2015] [Accepted: 03/22/2016] [Indexed: 01/23/2023] Open
Abstract
The contribution of circulating antibody to the protection of naïve piglets against porcine epidemic diarrhea virus (PEDV) was evaluated using a passive antibody transfer model. Piglets (n = 62) derived from 6 sows were assigned to one of 6 different treatments using a randomized block design which provided for allocation of all treatments to all sows' litters. Each treatment was designed to achieve a different level of circulating anti-PEDV antibody via intraperitoneally administration of concentrated serum antibody. Piglets were orally inoculated with PEDV (USA/IN/2013/19338E, 1 x 103 TCID50 per piglet) 24 hours later and then monitored for 14 days. Piglets remained with their dam throughout the experiment. Sow milk samples, piglet fecal samples, and data on piglet clinical signs, body weight, and body temperature were collected daily. Fecal samples were tested by PEDV real-time reverse transcriptase PCR. Serum, colostrum, and milk were tested for PEDV IgG, IgA, and virus-neutralizing antibody. The data were evaluated for the effects of systemic PEDV antibody levels on growth, body temperature, fecal shedding, survival, and antibody response. The analysis showed that circulating antibody partially ameliorated the effect of PEDV infection. Specifically, antibody-positive groups returned to normal body temperature faster and demonstrated a higher rate of survivability than piglets without PEDV antibody. When combined with previous literature on PEDV, it can be concluded that both systemic antibodies and maternal secretory IgA in milk contribute to the protection of the neonatal pig against PEDV infections. Overall, the results of this experiment suggested that passively administered circulating antibodies contributed to the protection of neonatal piglets against PEDV infection.
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Affiliation(s)
- Korakrit Poonsuk
- Department of Veterinary Diagnostic and Production Animal Medicine, College of Veterinary Medicine, Iowa State University, Ames, Iowa, 50011, United States of America
| | - Luis Gabriel Giménez-Lirola
- Department of Veterinary Diagnostic and Production Animal Medicine, College of Veterinary Medicine, Iowa State University, Ames, Iowa, 50011, United States of America
| | - Jianqiang Zhang
- Department of Veterinary Diagnostic and Production Animal Medicine, College of Veterinary Medicine, Iowa State University, Ames, Iowa, 50011, United States of America
| | - Paolo Arruda
- Department of Veterinary Diagnostic and Production Animal Medicine, College of Veterinary Medicine, Iowa State University, Ames, Iowa, 50011, United States of America
| | - Qi Chen
- Department of Veterinary Diagnostic and Production Animal Medicine, College of Veterinary Medicine, Iowa State University, Ames, Iowa, 50011, United States of America
| | - Lucas Correa da Silva Carrion
- Department of Veterinary Diagnostic and Production Animal Medicine, College of Veterinary Medicine, Iowa State University, Ames, Iowa, 50011, United States of America
| | - Ronaldo Magtoto
- Department of Veterinary Diagnostic and Production Animal Medicine, College of Veterinary Medicine, Iowa State University, Ames, Iowa, 50011, United States of America
| | - Pablo Pineyro
- Department of Veterinary Diagnostic and Production Animal Medicine, College of Veterinary Medicine, Iowa State University, Ames, Iowa, 50011, United States of America
| | - Luciana Sarmento
- Department of Veterinary Diagnostic and Production Animal Medicine, College of Veterinary Medicine, Iowa State University, Ames, Iowa, 50011, United States of America
| | - Chong Wang
- Department of Veterinary Diagnostic and Production Animal Medicine, College of Veterinary Medicine, Iowa State University, Ames, Iowa, 50011, United States of America
- Department of Statistics, College of Liberal Arts and Sciences, Iowa State University, Ames, Iowa, 50011, United States of America
| | - Yaxuan Sun
- Department of Veterinary Diagnostic and Production Animal Medicine, College of Veterinary Medicine, Iowa State University, Ames, Iowa, 50011, United States of America
- Department of Statistics, College of Liberal Arts and Sciences, Iowa State University, Ames, Iowa, 50011, United States of America
| | - Darin Madson
- Department of Veterinary Diagnostic and Production Animal Medicine, College of Veterinary Medicine, Iowa State University, Ames, Iowa, 50011, United States of America
| | - John Johnson
- Department of Veterinary Diagnostic and Production Animal Medicine, College of Veterinary Medicine, Iowa State University, Ames, Iowa, 50011, United States of America
| | - Kyoung-Jin Yoon
- Department of Veterinary Diagnostic and Production Animal Medicine, College of Veterinary Medicine, Iowa State University, Ames, Iowa, 50011, United States of America
| | - Jeffrey Zimmerman
- Department of Veterinary Diagnostic and Production Animal Medicine, College of Veterinary Medicine, Iowa State University, Ames, Iowa, 50011, United States of America
| | - Rodger Main
- Department of Veterinary Diagnostic and Production Animal Medicine, College of Veterinary Medicine, Iowa State University, Ames, Iowa, 50011, United States of America
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Zhang J, Tsai YL, Lee PYA, Chen Q, Zhang Y, Chiang CJ, Shen YH, Li FC, Chang HFG, Gauger PC, Harmon KM, Wang HTT. Evaluation of two singleplex reverse transcription-Insulated isothermal PCR tests and a duplex real-time RT-PCR test for the detection of porcine epidemic diarrhea virus and porcine deltacoronavirus. J Virol Methods 2016; 234:34-42. [PMID: 27060624 PMCID: PMC7113669 DOI: 10.1016/j.jviromet.2016.03.016] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2015] [Revised: 03/02/2016] [Accepted: 03/28/2016] [Indexed: 11/30/2022]
Abstract
A new PEDV RT-iiPCR method could detect PEDV sensitively and specifically. A new PDCoV RT-iiPCR method could detect PDCoV sensitively and specifically. A new duplex rRT-PCR could detect and differentiate PEDV and PDCoV simultaneously. A portable automatic extraction method worked well with PEDV and PDCoV RT-iiPCRs. The RT-iiPCRs are potentially useful tools for on-site PEDV and PDCoV detection.
Recent outbreaks of porcine epidemic diarrhea virus (PEDV) and porcine deltacoronavirus (PDCoV) in multiple countries have caused significant economic losses and remain a serious challenge to the swine industry. Rapid diagnosis is critical for the implementation of efficient control strategies before and during PEDV and PDCoV outbreaks. Insulated isothermal PCR (iiPCR) on the portable POCKIT™ device is user friendly for on-site pathogen detection. In the present study, a singleplex PEDV RT-iiPCR, a singleplex PDCoV RT-iiPCR, and a duplex PEDV/PDCoV real-time RT-PCR (rRT-PCR) commercial reagents targeting the M gene were compared to an N gene-based PEDV rRT-PCR and an M gene-based PDCoV rRT-PCR that were previously published and used as reference PCRs. All PCR assays were highly specific and did not cross react with other porcine enteric pathogens. Analytical sensitivities of the PEDV RT-iiPCR, PDCoV RT-iiPCR and duplex PEDV/PDCoV rRT-PCR were determined using in vitro transcribed RNA as well as viral RNA extracted from ten-fold serial dilutions of PEDV and PDCoV cell culture isolates. Performance of each PCR assay was further evaluated using 170 clinical samples (86 fecal swabs, 24 feces, 19 intestines, and 41 oral fluids). Compared to the reference PEDV rRT-PCR, the sensitivity, specificity and accuracy of the PEDV RT-iiPCR were 97.73%, 98.78%, and 98.24%, respectively, and those of the duplex PEDV/PDCoV rRT-PCR were 98.86%, 96.34%, and 97.65%, respectively. Compared to the reference PDCoV rRT-PCR, the sensitivity, specificity and accuracy of the PDCoV RT-iiPCR were 100%, 100%, and 100%, respectively, and those of the PEDV/PDCoV duplex rRT-PCR were 96.34%, 100%, and 98.24%, respectively. Overall, all three new PCR assays were comparable to the reference rRT-PCRs for detection of PEDV and/or PDCoV. The PEDV and PDCoV RT-iiPCRs are potentially useful tools for on-site detection and the duplex PEDV/PDCoV rRT-PCR provides a convenient method to simultaneously detect the two viruses and differentiate PEDV from PDCoV.
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Affiliation(s)
- Jianqiang Zhang
- Department of Veterinary Diagnostic and Production Animal Medicine, Iowa State University, Ames, IA, USA.
| | | | | | - Qi Chen
- Department of Veterinary Diagnostic and Production Animal Medicine, Iowa State University, Ames, IA, USA
| | - Yan Zhang
- Animal Disease Diagnostic Laboratory, Ohio Department of Agriculture, Reynoldsburg, OH, USA
| | | | | | | | | | - Phillip C Gauger
- Department of Veterinary Diagnostic and Production Animal Medicine, Iowa State University, Ames, IA, USA
| | - Karen M Harmon
- Department of Veterinary Diagnostic and Production Animal Medicine, Iowa State University, Ames, IA, USA
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125
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Perez AM, Alba A, Goede D, McCluskey B, Morrison R. Monitoring the Spread of Swine Enteric Coronavirus Diseases in the United States in the Absence of a Regulatory Framework. Front Vet Sci 2016; 3:18. [PMID: 27014703 PMCID: PMC4789556 DOI: 10.3389/fvets.2016.00018] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2015] [Accepted: 02/17/2016] [Indexed: 11/13/2022] Open
Abstract
The reporting and monitoring of swine enteric coronavirus diseases (SECD), including porcine epidemic diarrhea virus and porcine delta coronavirus, in the United States have been challenging because of the initial absence of a regulatory framework and the emerging nature of these diseases. The National Animal Health Laboratory Network, the Emergency Management and Response System, and the Swine Health Monitoring Project were used to monitor the disease situation between May 2013 and March 2015. Important differences existed between and among them in terms of nature and extent of reporting. Here, we assess the implementation of these systems from different perspectives, including a description and comparison of collected data, disease metrics, usefulness, simplicity, flexibility, acceptability, representativeness, timeliness, and stability. This assessment demonstrates the limitations that the absence of premises identification imposes on certain animal health surveillance and response databases, and the importance of federally regulated frameworks in collecting accurate information in a timely manner. This study also demonstrates the value that the voluntary and producer-organized systems may have in monitoring emerging diseases. The results from all three data sources help to establish the baseline information on SECD epidemiological dynamics after almost 3 years of disease occurrence in the country.
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Affiliation(s)
- Andres M Perez
- Department of Veterinary Population Medicine, College of Veterinary Medicine, University of Minnesota , St. Paul, MN , USA
| | - Anna Alba
- Department of Veterinary Population Medicine, College of Veterinary Medicine, University of Minnesota , St. Paul, MN , USA
| | - Dane Goede
- Department of Veterinary Population Medicine, College of Veterinary Medicine, University of Minnesota , St. Paul, MN , USA
| | - Brian McCluskey
- Veterinary Services, Animal and Plant Health Inspection Service, U.S. Department of Agriculture , Fort Collins, CO , USA
| | - Robert Morrison
- Department of Veterinary Population Medicine, College of Veterinary Medicine, University of Minnesota , St. Paul, MN , USA
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126
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O’Dea EB, Snelson H, Bansal S. Using heterogeneity in the population structure of U.S. swine farms to compare transmission models for porcine epidemic diarrhoea. Sci Rep 2016; 6:22248. [PMID: 26947420 PMCID: PMC4780089 DOI: 10.1038/srep22248] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2015] [Accepted: 02/10/2016] [Indexed: 11/09/2022] Open
Abstract
In 2013, U.S. swine producers were confronted with the disruptive emergence of porcine epidemic diarrhoea (PED). Movement of animals among farms is hypothesised to have played a role in the spread of PED among farms. Via this or other mechanisms, the rate of spread may also depend on the geographic density of farms and climate. To evaluate such effects on a large scale, we analyse state-level counts of outbreaks with variables describing the distribution of farm sizes and types, aggregate flows of animals among farms, and an index of climate. Our first main finding is that it is possible for a correlation analysis to be sensitive to transmission model parameters. This finding is based on a global sensitivity analysis of correlations on simulated data that included a biased and noisy observation model based on the available PED data. Our second main finding is that flows are significantly associated with the reports of PED outbreaks. This finding is based on correlations of pairwise relationships and regression modeling of total and weekly outbreak counts. These findings illustrate how variation in population structure may be employed along with observational data to improve understanding of disease spread.
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Affiliation(s)
- Eamon B. O’Dea
- Georgetown University, Department of Biology, Washington, District of Columbia, 20057, United States
| | - Harry Snelson
- American Association of Swine Veterinarians, Perry, Iowa, 50220, United States
| | - Shweta Bansal
- Georgetown University, Department of Biology, Washington, District of Columbia, 20057, United States
- National Institutes of Health, Fogarty International Center, Bethesda, Maryland, 20892, United States
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Ma Y, Zhang Y, Liang X, Oglesbee M, Krakowka S, Niehaus A, Wang G, Jia A, Song H, Li J. Two-way antigenic cross-reactivity between porcine epidemic diarrhea virus and porcine deltacoronavirus. Vet Microbiol 2016; 186:90-6. [PMID: 27016762 PMCID: PMC7117190 DOI: 10.1016/j.vetmic.2016.02.004] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2015] [Revised: 01/26/2016] [Accepted: 02/08/2016] [Indexed: 11/26/2022]
Abstract
No cross-neutralization was detected between PEDV and PdCV. A two-way cross-reactivity was detected between PEDV and PdCV. Conserved epitope(s) in viral N proteins may contribute to antigenic cross-reactivity. Prevention of PEDV and PdCV will require the development of separate virus-specific vaccine products.
Porcine epidemic diarrhea virus (PEDV) and porcine deltacoronavirus (PdCV) cause indistinguishable clinical signs and pathological changes in swine. Here we investigated the antigenic relationship between PEDV and PdCV. We provide the first evidence that conserved epitope(s) on the respective viral nucleocapsid proteins cross-react with each other although virus neutralization cross-reactivity was not observed. As a practical matter, prevention of these two very similar diseases of swine will require the development of separate virus-specific vaccine products.
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Affiliation(s)
- Yuanmei Ma
- Department of Veterinary Biosciences, College of Veterinary Medicine, The Ohio State University, Columbus, OH 43210, USA.
| | - Yu Zhang
- Department of Veterinary Biosciences, College of Veterinary Medicine, The Ohio State University, Columbus, OH 43210, USA
| | - Xueya Liang
- Department of Veterinary Biosciences, College of Veterinary Medicine, The Ohio State University, Columbus, OH 43210, USA
| | - Michael Oglesbee
- Department of Veterinary Biosciences, College of Veterinary Medicine, The Ohio State University, Columbus, OH 43210, USA
| | - Steven Krakowka
- Department of Veterinary Biosciences, College of Veterinary Medicine, The Ohio State University, Columbus, OH 43210, USA
| | - Andrew Niehaus
- Department of Veterinary Clinical Sciences, College of Veterinary Medicine, The Ohio State University, Columbus, OH 43210, USA
| | - Guiping Wang
- Guangdong Haid Institute of Animal Husbandry & Veterinary, PanYu, Guangdong 511400, PR China
| | - Aiqing Jia
- Guangdong Haid Institute of Animal Husbandry & Veterinary, PanYu, Guangdong 511400, PR China
| | - Houhui Song
- College of Animal Science and Technology, Zhejiang Agriculture and Forestry University, Lin-An, Zhejiang 311300, PR China
| | - Jianrong Li
- Department of Veterinary Biosciences, College of Veterinary Medicine, The Ohio State University, Columbus, OH 43210, USA.
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Chen Q, Gauger PC, Stafne MR, Thomas JT, Madson DM, Huang H, Zheng Y, Li G, Zhang J. Pathogenesis comparison between the United States porcine epidemic diarrhoea virus prototype and S-INDEL-variant strains in conventional neonatal piglets. J Gen Virol 2016; 97:1107-1121. [PMID: 26841768 DOI: 10.1099/jgv.0.000419] [Citation(s) in RCA: 72] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
At least two genetically different porcine epidemic diarrhoea virus (PEDV) strains have been identified in the USA: US PEDV prototype and S-INDEL-variant strains. The objective of this study was to compare the pathogenicity differences of the US PEDV prototype and S-INDEL-variant strains in conventional neonatal piglets under experimental infections. Fifty PEDV-negative 5-day-old pigs were divided into five groups of ten pigs each and were inoculated orogastrically with three US PEDV prototype isolates (IN19338/2013, NC35140/2013 and NC49469/2013), an S-INDEL-variant isolate (IL20697/2014), and virus-negative culture medium, respectively, with virus titres of 104 TCID50 ml- 1, 10 ml per pig. All three PEDV prototype isolates tested in this study, regardless of their phylogenetic clades, had similar pathogenicity and caused severe enteric disease in 5-day-old pigs as evidenced by clinical signs, faecal virus shedding, and gross and histopathological lesions. Compared with pigs inoculated with the three US PEDV prototype isolates, pigs inoculated with the S-INDEL-variant isolate had significantly diminished clinical signs, virus shedding in faeces, gross lesions in small intestines, caeca and colons, histopathological lesions in small intestines, and immunohistochemistry staining in ileum. However, the US PEDV prototype and the S-INDEL-variant strains induced similar viraemia levels in inoculated pigs. Whole genome sequences of the PEDV prototype and S-INDEL-variant strains were determined, but the molecular basis of virulence differences between these PEDV strains remains to be elucidated using a reverse genetics approach.
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Affiliation(s)
- Qi Chen
- Department of Veterinary Diagnostic and Production Animal Medicine, Iowa State University, Ames, IA, USA
| | - Phillip C Gauger
- Department of Veterinary Diagnostic and Production Animal Medicine, Iowa State University, Ames, IA, USA
| | - Molly R Stafne
- Department of Veterinary Diagnostic and Production Animal Medicine, Iowa State University, Ames, IA, USA
| | - Joseph T Thomas
- Department of Veterinary Diagnostic and Production Animal Medicine, Iowa State University, Ames, IA, USA
| | - Darin M Madson
- Department of Veterinary Diagnostic and Production Animal Medicine, Iowa State University, Ames, IA, USA
| | - Haiyan Huang
- Department of Veterinary Diagnostic and Production Animal Medicine, Iowa State University, Ames, IA, USA
| | - Ying Zheng
- Department of Veterinary Diagnostic and Production Animal Medicine, Iowa State University, Ames, IA, USA
| | - Ganwu Li
- Department of Veterinary Diagnostic and Production Animal Medicine, Iowa State University, Ames, IA, USA
| | - Jianqiang Zhang
- Department of Veterinary Diagnostic and Production Animal Medicine, Iowa State University, Ames, IA, USA
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Yamamoto T, Suzuki T, Ohashi S, Miyazaki A, Tsutsui T. Genomic Motifs as a Novel Indicator of the Relationship between Strains Isolated from the Epidemic of Porcine Epidemic Diarrhea in 2013-2014. PLoS One 2016; 11:e0147994. [PMID: 26808527 PMCID: PMC4726493 DOI: 10.1371/journal.pone.0147994] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2015] [Accepted: 01/10/2016] [Indexed: 11/18/2022] Open
Abstract
Porcine epidemic diarrhea virus (PEDV) is a positive-sense RNA virus that causes infectious gastroenteritis in pigs. Following a PED outbreak that occurred in China in 2010, the disease was identified for the first time in the United States in April 2013, and was reported in many other countries worldwide from 2013 to 2014. As a novel approach to elucidate the epidemiological relationship between PEDV strains, we explored their genome sequences to identify the motifs that were shared within related strains. Of PED outbreaks reported in many countries during 2013–2014, 119 PEDV strains in Japan, USA, Canada, Mexico, Germany, and Korea were selected and used in this study. We developed a motif mining program, which aimed to identify a specific region of the genome that was exclusively shared by a group of PEDV strains. Eight motifs were identified (M1–M8) and they were observed in 41, 9, 18, 6, 10, 14, 2, and 2 strains, respectively. Motifs M1–M6 were shared by strains from more than two countries, and seemed to originate from one PEDV strain, Indiana12.83/USA/2013, among the 119 strains studied. BLAST search for motifs M1–M6 revealed that M3–M5 were almost identical to the strain ZMDZY identified in 2011 in China, while M1 and M2 were similar to other Chinese strains isolated in 2011–2012. Consequently, the PED outbreaks in these six countries may be closely related, and multiple transmissions of PEDV strains between these countries may have occurred during 2013–2014. Although tools such as phylogenetic tree analysis with whole genome sequences are increasingly applied to reveal the connection between isolates, its interpretation is sometimes inconclusive. Application of motifs as a tool to examine the whole genome sequences of causative agents will be more objective and will be an explicit indicator of their relationship.
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Affiliation(s)
- Takehisa Yamamoto
- Virology and Epidemiology Research Division, National Institute of Animal Health, National Agriculture and Research Organization, Tsukuba, Ibaraki 305–0856, Japan
- * E-mail:
| | - Tohru Suzuki
- Virology and Epidemiology Research Division, National Institute of Animal Health, National Agriculture and Research Organization, Tsukuba, Ibaraki 305–0856, Japan
| | - Seiichi Ohashi
- Virology and Epidemiology Research Division, National Institute of Animal Health, National Agriculture and Research Organization, Tsukuba, Ibaraki 305–0856, Japan
| | - Ayako Miyazaki
- Virology and Epidemiology Research Division, National Institute of Animal Health, National Agriculture and Research Organization, Tsukuba, Ibaraki 305–0856, Japan
| | - Toshiyuki Tsutsui
- Virology and Epidemiology Research Division, National Institute of Animal Health, National Agriculture and Research Organization, Tsukuba, Ibaraki 305–0856, Japan
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Beall A, Yount B, Lin CM, Hou Y, Wang Q, Saif L, Baric R. Characterization of a Pathogenic Full-Length cDNA Clone and Transmission Model for Porcine Epidemic Diarrhea Virus Strain PC22A. mBio 2016; 7:e01451-15. [PMID: 26733065 PMCID: PMC4724997 DOI: 10.1128/mbio.01451-15] [Citation(s) in RCA: 74] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2015] [Accepted: 11/10/2015] [Indexed: 01/18/2023] Open
Abstract
UNLABELLED Porcine epidemic diarrhea virus (PEDV) is a highly pathogenic alphacoronavirus. In the United States, highly virulent PEDV strains cause between 80 and 100% mortality in suckling piglets and are rapidly transmitted between animals and farms. To study the genetic factors that regulate pathogenesis and transmission, we developed a molecular clone of PEDV strain PC22A. The infectious-clone-derived PEDV (icPEDV) replicated as efficiently as the parental virus in cell culture and in pigs, resulting in lethal disease in vivo. Importantly, recombinant PEDV was rapidly transmitted to uninoculated pigs via indirect contact, demonstrating virulence and efficient transmission while replicating phenotypes seen in the wild-type virus. Using reverse genetics, we removed open reading frame 3 (ORF3) and replaced this region with a red fluorescent protein (RFP) gene to generate icPEDV-ΔORF3-RFP. icPEDV-ΔORF3-RFP replicated efficiently in vitro and in vivo, was efficiently transmitted among pigs, and produced lethal disease outcomes. However, the diarrheic scores in icPEDV-ΔORF3-RFP-infected pigs were lower than those in wild-type-virus- or icPEDV-infected pigs, and the virus formed smaller plaques than those of PC22A. Together, these data describe the development of a robust reverse-genetics platform for identifying genetic factors that regulate pathogenic outcomes and transmission efficiency in vivo, providing key infrastructural developments for developing and evaluating the efficacy of live attenuated vaccines and therapeutics in a clinical setting. IMPORTANCE Porcine epidemic diarrhea virus (PEDV) emerged in the United States in 2013 and has since killed 10% of U.S. farm pigs. Though the disease has been circulating internationally for decades, the lack of a rapid reverse-genetics platform for manipulating PEDV and identifying genetic factors that impact transmission and virulence has hindered the study of this important agricultural disease. Here, we present a DNA-based infectious-clone system that replicates the pathogenesis of circulating U.S. strain PC22A both in vitro and in piglets. This infectious clone can be used both to study the genetics, virulence, and transmission of PEDV coronavirus and to inform the creation of a live attenuated PEDV vaccine.
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Affiliation(s)
- Anne Beall
- University of North Carolina Chapel Hill, Chapel Hill, North Carolina, USA
| | - Boyd Yount
- University of North Carolina Chapel Hill, Chapel Hill, North Carolina, USA
| | - Chun-Ming Lin
- Food Animal Health Research Program, Ohio Agricultural Research and Development Center, The Ohio State University, Wooster, Ohio, USA
| | - Yixuan Hou
- Food Animal Health Research Program, Ohio Agricultural Research and Development Center, The Ohio State University, Wooster, Ohio, USA
| | - Qiuhong Wang
- Food Animal Health Research Program, Ohio Agricultural Research and Development Center, The Ohio State University, Wooster, Ohio, USA
| | - Linda Saif
- Food Animal Health Research Program, Ohio Agricultural Research and Development Center, The Ohio State University, Wooster, Ohio, USA
| | - Ralph Baric
- University of North Carolina Chapel Hill, Chapel Hill, North Carolina, USA
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Wang L. Immunohistochemical Staining for Detection of Porcine Epidemic Diarrhea Virus in Tissues. SPRINGER PROTOCOLS HANDBOOKS 2016. [PMCID: PMC7121281 DOI: 10.1007/978-1-4939-3414-0_2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
Porcine epidemic diarrhea virus (PEDV), a member of the genus Alphacoronavirus, has resulted in significant economic losses in the European, Asian, and North American swine industries in previous years. PEDV infection causes acute diarrhea/vomiting, dehydration, and high morbidity and mortality in seronegative neonatal piglets. In this chapter, materials and methods for performing immunohistochemistry (IHC) for the detection of PEDV antigens in frozen or formalin-fixed, paraffin-embedded (FFPE) tissues are provided. In IHC of frozen tissues where viral antigens are well preserved, the use of specific antibodies labeled with fluorescence dyes provides excellent advantages and convenience, resulting in high sensitivity and specificity of IHC and reduction of operation time. In IHC of FFPE tissues where tissue or cell morphology is well preserved, the use of specific antibodies labeled with enzymes, such as alkaline phosphatase, also gives rise to significant advantages in defining the correlation of viral antigens with histopathologic lesions. PEDV antigens in frozen tissues are visualized as green staining in the cytoplasm of infected cells by fluorescent dyes conjugated with antibodies when activated by exciting light of a specific wavelength under a fluorescence microscope. In FFPE tissues, PEDV antigens are visualized as red staining in the cytoplasm of infected cells by the deposition of the substrate chromogen, Fast Red.
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Affiliation(s)
- Leyi Wang
- Animal Disease Diagnostic Lab, Ohio Department of Agriculture, Reynoldsburg, Ohio USA
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132
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Wang L, Hayes J, Sarver C, Byrum B, Zhang Y. Porcine deltacoronavirus: histological lesions and genetic characterization. Arch Virol 2016; 161:171-5. [PMID: 26475155 PMCID: PMC7087246 DOI: 10.1007/s00705-015-2627-4] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2015] [Accepted: 09/24/2015] [Indexed: 02/07/2023]
Abstract
First identified in 2012 in a surveillance study in Hong Kong, porcine deltacoronavirus (PDCoV) is a proposed member of the genus Deltacoronavirus of the family Coronaviridae. In February of 2014, PDCoV was detected in pigs with clinical diarrheal symptoms for the first time in the USA. Since then, it has been detected in more than 20 states in the USA and in other countries, including Canada, South Korea, and mainland China. So far, histological lesions in the intestines of pigs naturally infected with PDCoV under field conditions have not been reported. In this report, we describe the characteristic histological lesions in the small intestine that were associated with PDCoV infection, as evidenced by detection of viral nucleic acid by RT-PCR. In addition, we performed genomic analysis to determine the genetic relationship of all PDCoV strains from the four countries. We found that PDCoV mainly caused histological lesions in the small intestines of naturally infected piglets. Sequence analysis demonstrated that the PDCoV strains of different countries are closely related and shared high nucleotide sequence similarity; however, deletion patterns in the spike and 3' untranslated regions are different among the strains from mainland China, Hong Kong, the USA, and South Korea. Our study highlights the fact that continual surveillance is needed to trace the evolution of this virus.
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Affiliation(s)
- Leyi Wang
- Animal Disease Diagnostic Laboratory, Ohio Department of Agriculture, 8995 East Main Street, Building #6, Reynoldsburg, OH, 43068, USA.
| | - Jeff Hayes
- Animal Disease Diagnostic Laboratory, Ohio Department of Agriculture, 8995 East Main Street, Building #6, Reynoldsburg, OH, 43068, USA
| | - Craig Sarver
- Animal Disease Diagnostic Laboratory, Ohio Department of Agriculture, 8995 East Main Street, Building #6, Reynoldsburg, OH, 43068, USA
| | - Beverly Byrum
- Animal Disease Diagnostic Laboratory, Ohio Department of Agriculture, 8995 East Main Street, Building #6, Reynoldsburg, OH, 43068, USA
| | - Yan Zhang
- Animal Disease Diagnostic Laboratory, Ohio Department of Agriculture, 8995 East Main Street, Building #6, Reynoldsburg, OH, 43068, USA.
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Steinrigl A, Fernández SR, Stoiber F, Pikalo J, Sattler T, Schmoll F. First detection, clinical presentation and phylogenetic characterization of Porcine epidemic diarrhea virus in Austria. BMC Vet Res 2015; 11:310. [PMID: 26714453 PMCID: PMC4696200 DOI: 10.1186/s12917-015-0624-1] [Citation(s) in RCA: 52] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2015] [Accepted: 12/22/2015] [Indexed: 11/23/2022] Open
Abstract
Background Porcine epidemic diarrhea (PED) is a syndrome that is characterized by rapidly spreading watery diarrhea affecting pigs of all ages, but with major effects on suckling piglets. The disease, as well as the causative Alphacoronavirus, the Porcine epidemic diarrhea virus (PEDV), was first described in Europe in the 1970s and since then has spread over many Asian and American countries, where it recently led to devastating effects on swine health and pork industry. While the disease was seldom reported in Europe within the last few decades, a few recent reports re-emergence of PED in German pig farms. The hitherto isolated German strain seems to be closely related to a low pathogenic PEDV variant from the USA. This case report describes the first detection of PEDV in Austria. Case presentation Reduced feed uptake and occasional diarrhea were observed in December 2014 in a group of fattening pigs, kept on an Austrian swine farm. The concerned pigs had been recently purchased from Germany. Within a few weeks, diarrhea became apparent also in pigs of Austrian origin, which were kept in a different stable on the same farm. Gastrointestinal symptoms among fattening pigs were generally mild, quickly resolving and did not lead to death. PEDV RNA was identified by RT-qPCR in pooled feces and serum and PEDV antibodies were detectable in serum in both groups of pigs. Phylogenetic analysis of the nearly complete PEDV spike gene shows that the Austrian PEDV strain is highly similar to other strains involved in recent outbreaks in Western and Central Europe. Conclusion This is the first report demonstrating the presence of PEDV in Austria. The virus was probably introduced by purchasing piglets from a German source, which underlines the significance of trans-boundary animal trade for the distribution of highly contagious diseases, such as PED. Electronic supplementary material The online version of this article (doi:10.1186/s12917-015-0624-1) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Adolf Steinrigl
- Austrian Agency for Health and Food Safety, Institute for Veterinary Disease Control, Robert Koch Gasse 17, 2340, Mödling, Austria.
| | - Sandra Revilla Fernández
- Austrian Agency for Health and Food Safety, Institute for Veterinary Disease Control, Robert Koch Gasse 17, 2340, Mödling, Austria.
| | | | - Jutta Pikalo
- Austrian Agency for Health and Food Safety, Institute for Veterinary Disease Control, Robert Koch Gasse 17, 2340, Mödling, Austria.
| | - Tatjana Sattler
- Austrian Agency for Health and Food Safety, Institute for Veterinary Disease Control, Robert Koch Gasse 17, 2340, Mödling, Austria. .,University of Leipzig, Large Animal Clinic for Internal Medicine, An den Tierkliniken 11, 04103, Leipzig, Germany.
| | - Friedrich Schmoll
- Austrian Agency for Health and Food Safety, Institute for Veterinary Disease Control, Robert Koch Gasse 17, 2340, Mödling, Austria.
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Lee C. Porcine epidemic diarrhea virus: An emerging and re-emerging epizootic swine virus. Virol J 2015; 12:193. [PMID: 26689811 PMCID: PMC4687282 DOI: 10.1186/s12985-015-0421-2] [Citation(s) in RCA: 360] [Impact Index Per Article: 40.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2015] [Accepted: 11/10/2015] [Indexed: 12/22/2022] Open
Abstract
The enteric disease of swine recognized in the early 1970s in Europe was initially described as “epidemic viral diarrhea” and is now termed “porcine epidemic diarrhea (PED)”. The coronavirus referred to as PED virus (PEDV) was determined to be the etiologic agent of this disease in the late 1970s. Since then the disease has been reported in Europe and Asia, but the most severe outbreaks have occurred predominantly in Asian swine-producing countries. Most recently, PED first emerged in early 2013 in the United States that caused high morbidity and mortality associated with PED, remarkably affecting US pig production, and spread further to Canada and Mexico. Soon thereafter, large-scale PED epidemics recurred through the pork industry in South Korea, Japan, and Taiwan. These recent outbreaks and global re-emergence of PED require urgent attention and deeper understanding of PEDV biology and pathogenic mechanisms. This paper highlights the current knowledge of molecular epidemiology, diagnosis, and pathogenesis of PEDV, as well as prevention and control measures against PEDV infection. More information about the virus and the disease is still necessary for the development of effective vaccines and control strategies. It is hoped that this review will stimulate further basic and applied studies and encourage collaboration among producers, researchers, and swine veterinarians to provide answers that improve our understanding of PEDV and PED in an effort to eliminate this economically significant viral disease, which emerged or re-emerged worldwide.
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Affiliation(s)
- 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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135
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Annamalai T, Saif LJ, Lu Z, Jung K. Age-dependent variation in innate immune responses to porcine epidemic diarrhea virus infection in suckling versus weaned pigs. Vet Immunol Immunopathol 2015; 168:193-202. [PMID: 26433606 PMCID: PMC7112776 DOI: 10.1016/j.vetimm.2015.09.006] [Citation(s) in RCA: 76] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2015] [Revised: 08/17/2015] [Accepted: 09/12/2015] [Indexed: 01/02/2023]
Abstract
Porcine epidemic diarrhea (PED) is an enteric coronaviral infection that causes severe morbidity and mortality in suckling pigs, but less severe disease in older pigs. Consequently, it causes significant economic losses to the pork industry. There are limited studies on the innate immune responses to PED virus (PEDV) in pigs. The aims of our study were to investigate differences in innate immune responses to PEDV infection in suckling and weaned pigs and to examine if disease severity coincides with reduced innate immune responses. Weaned 26-day-old pigs (n=20) and 9-day-old nursing pigs (n=20) were assigned to PEDV inoculated or uninoculated control groups. The pigs were observed daily for clinical signs, virus shedding and were euthanized at post-inoculation days (PIDs) 1 and 5 to assay immune responses. Blood samples were collected at PIDs 1, 3 and 5. The natural killer (NK) cell frequencies, NK cell activities (lysis of target K562 tumor cells in vitro), CD3+CD4+ T cell and CD3+CD8+ T cell frequencies were measured in blood and ileum at PIDs 1 and 5. The PEDV infected suckling pigs showed severe diarrhea and vomiting at PID 1, whereas the PEDV infected weaned pigs showed milder clinical signs starting at PID 3. PEDV infected suckling pigs had significantly higher diarrhea scores, earlier fecal PEDV RNA shedding and significantly higher viremia (viral RNA in serum) compared to weaned pigs. There was no mortality in either infected suckling or infected weaned pigs. The control pigs not inoculated with PEDV did not show any clinical signs and no detectable fecal or serum PEDV RNA. Strikingly, PEDV infected suckling pigs had significantly lower NK cell frequencies, undetectable NK cell activity and lower IFNγ producing NK cells in blood and ileum compared to PEDV infected weaned pigs. Pro-inflammatory cytokine profiles of PEDV infected suckling pigs differed from those of PEDV infected weaned pigs and coincided with onset of fecal PEDV RNA shedding and serum PEDV RNA titers. The infected suckling pigs have higher and earlier increases in serum IFNα, but lower serum IL-8 and TNFα levels compared to infected weaned pigs. CD3+CD4+ T cell frequencies were significantly higher in ileum of suckling pigs than in weaned pigs, whereas there was no difference in CD3+CD8+ T cell frequencies. In conclusion, the observations of impaired lytic activity and IFN-γ production by NK cells in suckling pigs coincided with the increased severity of PEDV infection in the suckling pigs compared with the weaned pigs.
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Affiliation(s)
- Thavamathi Annamalai
- Food Animal Health Research Program, Ohio Agricultural Research and Development Center, Department of Veterinary Preventive Medicine, The Ohio State University, Wooster, OH, USA
| | - Linda J Saif
- Food Animal Health Research Program, Ohio Agricultural Research and Development Center, Department of Veterinary Preventive Medicine, The Ohio State University, Wooster, OH, USA.
| | - Zhongyan Lu
- Food Animal Health Research Program, Ohio Agricultural Research and Development Center, Department of Veterinary Preventive Medicine, The Ohio State University, Wooster, OH, USA
| | - Kwonil Jung
- Food Animal Health Research Program, Ohio Agricultural Research and Development Center, Department of Veterinary Preventive Medicine, The Ohio State University, Wooster, OH, USA.
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136
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Foddai A, Nielsen LH, Møgelmose V, Alban L. Probability of introducing porcine epidemic diarrhea virus into Danish pig herds by imported spray-dried porcine plasma. Porcine Health Manag 2015; 1:18. [PMID: 28405424 PMCID: PMC5382482 DOI: 10.1186/s40813-015-0010-1] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2015] [Accepted: 10/23/2015] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Porcine epidemic diarrhea virus (PEDV) has never been reported in Denmark, but it has been found in Europe, Asia and North America. Ultimately, PEDV has been associated with devastating outbreaks in pig farms. We developed a stochastic simulation model to carry out a quantitative risk assessment and to estimate the annual probability (PPlasma) of introducing PEDV into the Danish pig population, by imported spray-dried porcine plasma (SDPP). The model was based on information from literature and Danish feed companies. Moreover testing the batch of raw blood (before the spray-drying) was considered as potential risk mitigation measure in the future. RESULTS The median PPlasma was 0.2 % (90 % P.I.: 0.003 %; 2.6 %). Hence, the annual probability of introducing PEDV into the Danish pig population by imported SDPP appeared very low, and on average at least one introduction each 500 years - corresponding to 1/0.002 - could be expected. However, if PEDV survived the spray-drying process and storage was insufficient to completely remove the remaining viable virus (e.g. due to storage at low environmental temperatures during a short time period) the PPlasma was 4.7 % (0.06 %; 57.4 %). In that case, on average, at least one PEDV introduction each 21 years could be expected. This probability could be reduced to 0.3 % (0.004 %; 6.0 %) if the raw batch of blood could be tested before drying (corresponding to at least one introduction each 333 years on average). CONCLUSIONS This study provides preliminary and important information on the probability of introducing PEDV into the Danish pig population by use of SDPP. Currently PED is not a notifiable disease in the EU and uncertainty was present in our estimates due to possible underreporting in EU Member States, from which SDPP is imported into Denmark. In the future, PED might become a notifiable disease, and in such a case, new knowledge could become available on its epidemiology. Moreover, SDPP could be imported more safely if: producers find a way to substantiate freedom from disease (at least) in herds delivering blood for SDPP, the batch of blood tests negative for PEDV and conditions for processing/storage required by the international laws are respected.
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Affiliation(s)
- Alessandro Foddai
- Risk Analysis Group, Department of Food Safety and Veterinary Issues, Danish Agriculture & Food Council, Axeltorv 3, DK-1609 Copenhagen V, Denmark
- Section of Epidemiology, Technical University of Denmark, National Veterinary Institute, Bülowsvej 27, DK-1870 Frederiksberg C, Denmark
| | - Lisbeth Harm Nielsen
- Risk Analysis Group, Department of Food Safety and Veterinary Issues, Danish Agriculture & Food Council, Axeltorv 3, DK-1609 Copenhagen V, Denmark
| | - Vibeke Møgelmose
- Risk Analysis Group, Department of Food Safety and Veterinary Issues, Danish Agriculture & Food Council, Axeltorv 3, DK-1609 Copenhagen V, Denmark
| | - Lis Alban
- Risk Analysis Group, Department of Food Safety and Veterinary Issues, Danish Agriculture & Food Council, Axeltorv 3, DK-1609 Copenhagen V, Denmark
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137
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Jung K, Hu H, Eyerly B, Lu Z, Chepngeno J, Saif LJ. Pathogenicity of 2 porcine deltacoronavirus strains in gnotobiotic pigs. Emerg Infect Dis 2015; 21:650-4. [PMID: 25811229 PMCID: PMC4378491 DOI: 10.3201/eid2104.141859] [Citation(s) in RCA: 139] [Impact Index Per Article: 15.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
To verify whether porcine deltacoronavirus infection induces disease, we inoculated gnotobiotic pigs with 2 virus strains (OH-FD22 and OH-FD100) identified by 2 specific reverse transcription PCRs. At 21–120 h postinoculation, pigs exhibited severe diarrhea, vomiting, fecal shedding of virus, and severe atrophic enteritis. These findings confirm that these 2 strains are enteropathogenic in pigs.
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138
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Lin CM, Annamalai T, Liu X, Gao X, Lu Z, El-Tholoth M, Hu H, Saif LJ, Wang Q. Experimental infection of a US spike-insertion deletion porcine epidemic diarrhea virus in conventional nursing piglets and cross-protection to the original US PEDV infection. Vet Res 2015; 46:134. [PMID: 26589292 PMCID: PMC4654902 DOI: 10.1186/s13567-015-0278-9] [Citation(s) in RCA: 69] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2015] [Accepted: 10/21/2015] [Indexed: 02/08/2023] Open
Abstract
Although the original US porcine epidemic diarrhea virus (PEDV) was confirmed as highly virulent by multiple studies, the virulence of spike-insertion deletion (S-INDEL) PEDV strains is undefined. In this study, 3-4 day-old conventional suckling piglets were inoculated with S-INDEL PEDV Iowa106 (4 pig litters) to study its virulence. Two litters of age-matched piglets were inoculated with either the original US PEDV PC21A or mock as positive and negative controls, respectively. Subsequently, all pigs were challenged with the original US PEDV PC21A on 21-29 days post-inoculation (dpi) to assess cross-protection. All S-INDEL Iowa106- and the original US PC21A-inoculated piglets developed diarrhea. However, the severity of clinical signs, mortality (0-75%) and fecal PEDV RNA shedding titers varied among the four S-INDEL Iowa106-inoculated litters. Compared with the original PC21A, piglets euthanized/died acutely from S-INDEL Iowa106 infection had relatively milder villous atrophy, lower antigen scores and more limited intestinal infection. Two of four S-INDEL Iowa106-infected sows and the original PC21A-infected sow showed anorexia and watery diarrhea for 1-4 days. After the original PC21A challenge, a subset (13/16) of S-INDEL Iowa106-inoculated piglets developed diarrhea, whereas all (5/5) and no (0/4) pigs in the mock and original PC21A-inoculated pigs had diarrhea, respectively. Our results suggest that the virulence of S-INDEL PEDV Iowa106 was less than the original US PEDV PC21A in suckling pigs, with 100% morbidity and 18% (6/33) overall (0-75%) mortality in suckling pigs depending on factors such as the sow's health and lactation and the piglets' birth weight. Prior infection by S-INDEL Iowa106 provided partial cross-protection to piglets against the original PC21A challenge at 21-29 dpi.
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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.
| | - Thavamathi Annamalai
- 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.
| | - 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.
| | - Zhongyan Lu
- 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.
| | - Mohamed El-Tholoth
- 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. .,Department of Virology, Faculty of Veterinary Medicine, Mansoura University, Mansoura, Egypt.
| | - Hui Hu
- 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.
| | - 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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139
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Carvajal A, Argüello H, Martínez-Lobo FJ, Costillas S, Miranda R, G de Nova PJ, Rubio P. Porcine epidemic diarrhoea: new insights into an old disease. Porcine Health Manag 2015; 1:12. [PMID: 28405418 PMCID: PMC5382377 DOI: 10.1186/s40813-015-0007-9] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2015] [Accepted: 09/23/2015] [Indexed: 11/10/2022] Open
Abstract
Porcine epidemic diarrhea (PED) is an enteric disease in swine caused by an alphacoronavirus. It affects swine of all ages causing acute diarrhoea and can lead to severe dehydration and death in suckling piglets. Being recognized for the first time in Europe and Asia during the seventies and the eighties, respectively, it has remained a relevant cause of diarrhea outbreaks in Asia for years and to the present. It has become a major concern in swine production since 2013 when the virus was detected for first time in the USA and in other American countries causing a high number of pig deaths and significant economic losses. The present review aims at approaching the reader to the state of the art of PED giving answer to some of the most recent questions which have arisen related to this disease.
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Affiliation(s)
- Ana Carvajal
- Department of Animal Health, University of León, Campus de Vegazana. 24071, León, Spain
| | - Héctor Argüello
- Food Safety Department, Teagasc Food Research Centre, Dublin, Ireland
| | | | - Sara Costillas
- Department of Animal Health, University of León, Campus de Vegazana. 24071, León, Spain
| | - Rubén Miranda
- Department of Animal Health, University of León, Campus de Vegazana. 24071, León, Spain
| | - Pedro J G de Nova
- Department of Animal Health, University of León, Campus de Vegazana. 24071, León, Spain
| | - Pedro Rubio
- Department of Animal Health, University of León, Campus de Vegazana. 24071, León, Spain
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140
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Liu X, Lin CM, Annamalai T, Gao X, Lu Z, Esseili MA, Jung K, El-Tholoth M, Saif LJ, Wang Q. Determination of the infectious titer and virulence of an original US porcine epidemic diarrhea virus PC22A strain. Vet Res 2015; 46:109. [PMID: 26408019 PMCID: PMC4582625 DOI: 10.1186/s13567-015-0249-1] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2015] [Accepted: 08/19/2015] [Indexed: 11/28/2022] Open
Abstract
The infectious dose of a virus pool of original US PEDV strain PC22A was determined in 4-day-old, cesarean-derived, colostrum-deprived (CDCD) piglets. The median pig diarrhea dose (PDD50) of the virus pool was determined as 7.35 log10 PDD50/mL, similar to the cell culture infectious titer, 7.75 log10 plaque-forming units (PFU)/mL. 100 PDD50 caused watery diarrhea in all conventional suckling piglets (n = 12) derived from a PEDV-naive sow, whereas 1000 and 10 000 PDD50 did not cause diarrhea in piglets derived from two PEDV-field exposed-recovered sows. This information is important for future PEDV challenge studies and validation of PEDV vaccines.
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Affiliation(s)
- 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, Ohio, 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.
| | - 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, Ohio, USA.
| | - Thavamathi Annamalai
- 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, Ohio, USA.
| | - 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, Ohio, USA.
| | - Zhongyan Lu
- 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, Ohio, USA.
| | - Malak A Esseili
- 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, Ohio, USA.
| | - Kwonil Jung
- 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, Ohio, USA.
| | - Mohamed El-Tholoth
- 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, Ohio, USA.
- Department of Virology, Faculty of Veterinary Medicine, Mansoura University, Mansoura, Egypt.
| | - 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, Ohio, 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, Ohio, USA.
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141
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Development of an indirect ELISA, blocking ELISA, fluorescent microsphere immunoassay and fluorescent focus neutralization assay for serologic evaluation of exposure to North American strains of Porcine Epidemic Diarrhea Virus. BMC Vet Res 2015; 11:180. [PMID: 26232106 PMCID: PMC4522128 DOI: 10.1186/s12917-015-0500-z] [Citation(s) in RCA: 61] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2015] [Accepted: 07/20/2015] [Indexed: 11/10/2022] Open
Abstract
Background Recent, severe outbreaks of porcine epidemic diarrhea virus (PEDV) in Asia and North America highlight the need for well-validated diagnostic tests for the identification of PEDV infected animals and evaluation of their immune status to this virus. PEDV was first detected in the U.S. in May 2013 and spread rapidly across the country. Some serological assays for PEDV have been previously described, but few were readily available in the U.S. Several U.S. laboratories quickly developed indirect fluorescent antibody (IFA) assays for the detection of antibodies to PEDV in swine serum, indicating prior exposure. However, the IFA has several disadvantages, including low throughput and relatively subjective interpretation. Different serologic test formats have advantages and disadvantages, depending on the questions being asked, so a full repertoire of tests is useful. Therefore, the objective of this study was to develop and validate multiple improved serological assays for PEDV, including an indirect ELISA (iELISA); a highly specific monoclonal antibody-based blocking ELISA (bELISA); fluorescent microsphere immunoassays (FMIA) that can be multiplexed to monitor exposure to multiple antigens and pathogens simultaneously; and a fluorescent focus neutralization assay (FFN) to measure functional virus neutralizing antibodies. Results A recombinant North American nucleoprotein (NP) based iELISA was developed and validated along with a bELISA using newly developed PEDV-NP specific biotinylated monoclonal antibodies (mAbs) and an FMIA using magnetic beads coupled with expressed NA PEDV-NP. Receiver operating characteristic (ROC) analysis was performed using swine serum samples (iELISA n = 1486, bELISA n = 1186, FMIA n = 1420). The ROC analysis for the FMIA showed estimated sensitivity and specificity of 98.2 and 99.2 %, respectively. The iELISA and bELISA showed a sensitivity and specificity of 97.9 and 97.6 %; and 98.2 and 98.9 %, respectively. Inter-rater (kappa) agreement was calculated to be 0.941 between iELISA and IFA, 0.945 between bELISA and IFA and 0.932 between FMIA and IFA. Similar comparative kappa values were observed between the iELISA, bELISA and FMIA, which demonstrated a significant level of testing agreement among the three assays. No cross-reactivity with the closely related coronaviruses, transmissible gastroenteritis virus (TGEV) or porcine respiratory coronavirus (PRCV) was noted with these assays. All three assays detected seroconversion of naïve animals within 6–9 days post exposure. The FFN assay allows relative quantitation of functional neutralizing antibodies in serum, milk or colostrum samples. Conclusion Well-validated iELISA, bELISA and FMIA assays for the detection of PEDV antibodies were developed and showed good correlation with IFA and each other. Each assay format has advantages that dictate how they will be used in the field. Newly developed mAbs to the PEDV-NP were used in the bELISA and for expediting FFN testing in the detection and quantitation of neutralizing antibodies. In addition, these PEDV mAbs are useful for immunohistochemistry, fluorescent antibody staining and other antigen-based tests. Measurement of neutralizing antibody responses using the FFN assay may provide a valuable tool for assessment of vaccine candidates or protective immunity.
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142
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Marthaler D, Bruner L, Collins J, Rossow K. Third strain of porcine epidemic diarrhea virus, United States. Emerg Infect Dis 2015; 20:2162-3. [PMID: 25417647 PMCID: PMC4257813 DOI: 10.3201/eid2014.140908] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
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143
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Abstract
Severe outbreaks of porcine epidemic diarrhea virus (PEDV) have re-emerged in Korea and rapidly swept across the country, causing tremendous economic losses to producers and customers. Despite the availability of PEDV vaccines in the domestic market, the disease continues to plague the Korean pork industry, raising issues regarding their protective efficacy and new vaccine development. Therefore, PEDV isolation in cell culture is urgently needed to develop efficacious vaccines and diagnostic assays and to conduct further studies on the virus biology. In the present study, one Korean PEDV strain, KOR/KNU-141112/2014, was successfully isolated and serially propagated in Vero cells for over 30 passages. The in vitro and in vivo characteristics of the Korean PEDV isolate were investigated. Virus production in cell culture was confirmed by cytopathology, immunofluorescence, and real-time RT-PCR. The infectious virus titers of the viruses during the first 30 passages ranged from 10(5.1) to 10(8.2) TCID50 per ml. The inactivated KNU-141112 virus was found to mediate potent neutralizing antibody responses in immunized guinea pigs. Animal studies showed that KNU-141112 virus causes severe diarrhea and vomiting, fecal shedding, and acute atrophic enteritis, indicating that strain KNU-141112 is highly enteropathogenic in the natural host. In addition, the entire genomes or complete S genes of KNU-141112 viruses at selected cell culture passages were sequenced to assess the genetic stability and relatedness. Our genomic analyses indicated that the Korean isolate KNU-141112 is genetically stable during the first 30 passages in cell culture and is grouped within subgroup G2b together with the recent re-emergent Korean strains.
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Affiliation(s)
- Sunhee Lee
- Animal Virology Laboratory, School of Life Sciences, BK21 Plus KNU Creative BioResearch Group, Kyungpook National University, Daegu 702-701, Republic of Korea
| | - Youngnam Kim
- Animal Virology Laboratory, School of Life Sciences, BK21 Plus KNU Creative BioResearch Group, Kyungpook National University, Daegu 702-701, Republic of Korea
| | - Changhee Lee
- Animal Virology Laboratory, School of Life Sciences, BK21 Plus KNU Creative BioResearch Group, Kyungpook National University, Daegu 702-701, Republic of Korea.
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144
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Tian PF, Jin YL, Xing G, Qv LL, Huang YW, Zhou JY. Evidence of recombinant strains of porcine epidemic diarrhea virus, United States, 2013. Emerg Infect Dis 2015; 20:1735-8. [PMID: 25272273 PMCID: PMC4193173 DOI: 10.3201/eid2010.140338] [Citation(s) in RCA: 72] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
To investigate the evolutionary process by which porcine epidemic diarrhea virus (PEDV) in the United States hypothetically descended from strains in China, we analyzed PEDV-positive samples collected in China during January 2012–July 2013. Recombination in 2 strain sublineages was likely associated with identification of PEDV in the United States in 2013.
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145
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Madson DM, Arruda PHE, Magstadt DR, Burrough ER, Hoang H, Sun D, Bower LP, Bhandari M, Gauger PC, Stevenson GW, Wilberts BL, Wang C, Zhang J, Yoon KJ. Characterization of Porcine Epidemic Diarrhea Virus Isolate US/Iowa/18984/2013 Infection in 1-Day-Old Cesarean-Derived Colostrum-Deprived Piglets. Vet Pathol 2015; 53:44-52. [PMID: 26113613 DOI: 10.1177/0300985815591080] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Porcine epidemic diarrhea virus (PEDV) was first recognized in North America in April 2013 and has since caused devastating disease. The objective of this study was to characterize disease and viral detection associated with an original North American PEDV isolate inoculated in neonatal piglets. Thirty-six 1-day-old cesarean-derived and colostrum-deprived piglets were randomly assigned to the control (n = 16) or challenged group (n = 20); the latter were orogastrically inoculated with 1 ml of US/Iowa/18984/2013 PEDV isolate titered at 1 × 10(3) plaque-forming units per milliliter. Rectal swabs were collected from all piglets prior to inoculation and every 12 hours postinoculation (hpi) thereafter, with 4 control and 5 challenged piglets euthanized at 12, 24, 48, and 72 hpi. One piglet had a positive real-time quantitative polymerase chain reaction test on rectal swab at 12 hpi, and all remaining piglets were positive thereafter, with highest viral quantities detected at 24 and 36 hpi. Diarrhea was evident in 30% and 100% of challenged piglets at 18 and 24 hpi, respectively. Viral antigen was detected in enterocytes by immunohistochemistry in the duodenum and ileum of piglets euthanized at 12 hpi and was apparent throughout the small intestine of all piglets thereafter, with villus height:crypt depth ratios consistently below 4:1. Viremia was confirmed in 18 of 20 pigs at euthanasia. Clinical disease was severe and developed rapidly following infection with an original North American PEDV isolate, with lesions, viremia, and antigen detection possible by 12 hpi.
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Affiliation(s)
- D M Madson
- Department of Veterinary Diagnostic and Production Animal Medicine, Iowa State University, Ames, IA, USA
| | - P H E Arruda
- Department of Veterinary Diagnostic and Production Animal Medicine, Iowa State University, Ames, IA, USA
| | - D R Magstadt
- Department of Veterinary Diagnostic and Production Animal Medicine, Iowa State University, Ames, IA, USA
| | - E R Burrough
- Department of Veterinary Diagnostic and Production Animal Medicine, Iowa State University, Ames, IA, USA
| | - H Hoang
- Department of Veterinary Microbiology and Preventive Medicine, Iowa State University, Ames, IA, USA
| | - D Sun
- Department of Veterinary Microbiology and Preventive Medicine, Iowa State University, Ames, IA, USA
| | - L P Bower
- Department of Veterinary Diagnostic and Production Animal Medicine, Iowa State University, Ames, IA, USA
| | - M Bhandari
- Department of Veterinary Microbiology and Preventive Medicine, Iowa State University, Ames, IA, USA
| | - P C Gauger
- Department of Veterinary Diagnostic and Production Animal Medicine, Iowa State University, Ames, IA, USA
| | - G W Stevenson
- Department of Veterinary Diagnostic and Production Animal Medicine, Iowa State University, Ames, IA, USA
| | - B L Wilberts
- Department of Veterinary Pathology, Iowa State University, Ames, IA, USA
| | - C Wang
- Department of Veterinary Diagnostic and Production Animal Medicine, Iowa State University, Ames, IA, USA Department of Statistics, Iowa State University, Ames, IA, USA
| | - J Zhang
- Department of Veterinary Diagnostic and Production Animal Medicine, Iowa State University, Ames, IA, USA
| | - K J Yoon
- Department of Veterinary Diagnostic and Production Animal Medicine, Iowa State University, Ames, IA, USA Department of Veterinary Microbiology and Preventive Medicine, Iowa State University, Ames, IA, USA
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146
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Bowman AS, Nolting JM, Nelson SW, Bliss N, Stull JW, Wang Q, Premanandan C. Effects of disinfection on the molecular detection of porcine epidemic diarrhea virus. Vet Microbiol 2015; 179:213-8. [PMID: 26072369 PMCID: PMC7127254 DOI: 10.1016/j.vetmic.2015.05.027] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2015] [Revised: 05/28/2015] [Accepted: 05/30/2015] [Indexed: 11/29/2022]
Abstract
Routine detection of porcine epidemic diarrhea virus (PEDV) is currently limited to RT-PCR but this test cannot distinguish between viable and inactivated virus. We evaluated the capability of disinfectants to both inactivate PEDV and sufficiently damage viral RNA beyond RT-PCR detection. Five classes of disinfectants (phenol, quaternary ammonium compound, sodium hypochlorite, oxidizing agent, and quaternary ammonium/glutaraldehyde combination) were evaluated in vitro at varying concentrations, both in the presence and absence of swine feces, and at three different temperatures. No infectious PEDV was recovered after treatment with evaluated disinfectants. Additionally, all tested disinfectants except for 0.17% sodium hypochlorite dramatically reduced qRT-PCR values. However, no disinfectants eliminated RT-PCR detection of PEDV across all replicates; although, 0.52%, 1.03% and 2.06% solutions of sodium hypochlorite and 0.5% oxidizing agent did intermittently produce RT-PCR negatives. To simulate field conditions in a second aim, PEDV was applied to pitted aluminum coupons, which were then treated with either 2.06% sodium hypochlorite or 0.5% oxidizing agent. Post-treatment surface swabs of the coupons tested RT-PCR positive but were not infectious to cultured cells or naïve pigs. Ultimately, viable PEDV was not detected following application of each of the tested disinfectants, however in most cases RT-PCR detection of viral RNA remained. RT-PCR detection of PEDV is likely even after disinfection with many commercially available disinfectants.
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Affiliation(s)
- Andrew S Bowman
- Department of Veterinary Preventive Medicine, The Ohio State University, 1920 Coffey Road, Columbus, OH 43210, USA.
| | - Jacqueline M Nolting
- Department of Veterinary Preventive Medicine, The Ohio State University, 1920 Coffey Road, Columbus, OH 43210, USA
| | - Sarah W Nelson
- Department of Veterinary Preventive Medicine, The Ohio State University, 1920 Coffey Road, Columbus, OH 43210, USA
| | - Nola Bliss
- Department of Veterinary Preventive Medicine, The Ohio State University, 1920 Coffey Road, Columbus, OH 43210, USA
| | - Jason W Stull
- Department of Veterinary Preventive Medicine, The Ohio State University, 1920 Coffey Road, Columbus, OH 43210, USA
| | - Qiuhong Wang
- Department of Veterinary Preventive Medicine, The Ohio State University, 1920 Coffey Road, Columbus, OH 43210, USA; Food Animal Health Research Program, Ohio Agricultural Research and Development Center, College of Food, Agricultural, and Environmental Sciences, The Ohio State University, 1680 Madison Ave, Wooster, OH 44691, USA
| | - Christopher Premanandan
- Department of Veterinary Biosciences, The Ohio State University, 1925 Coffey Road, Columbus, OH, USA
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147
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Complete genome sequence of a porcine epidemic diarrhea virus from a novel outbreak in belgium, january 2015. GENOME ANNOUNCEMENTS 2015; 3:3/3/e00506-15. [PMID: 25999551 PMCID: PMC4440965 DOI: 10.1128/genomea.00506-15] [Citation(s) in RCA: 62] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Porcine epidemic diarrhea virus (PEDV) is a member of the family Coronaviridae and can cause severe outbreaks of diarrhea in piglets from different age groups. Here, we report the complete genome sequence (28,028 nt) of a PEDV strain isolated during a novel outbreak in Belgium.
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148
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Jung K, Annamalai T, Lu Z, Saif LJ. Comparative pathogenesis of US porcine epidemic diarrhea virus (PEDV) strain PC21A in conventional 9-day-old nursing piglets vs. 26-day-old weaned pigs. Vet Microbiol 2015; 178:31-40. [PMID: 25939885 PMCID: PMC7117181 DOI: 10.1016/j.vetmic.2015.04.022] [Citation(s) in RCA: 92] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2015] [Revised: 04/21/2015] [Accepted: 04/27/2015] [Indexed: 11/24/2022]
Abstract
US PEDV was highly enteropathogenic in seronegative 9-day-old nursing piglets. Infected weaned pigs were mostly sub-clinical and required a longer incubation period prior to PEDV infection, compared to nursing pigs. There was a lack of LGR5+ crypt stem cells and low proliferation of crypts in uninfected nursing piglets. The numbers of Ki67+ (marker for crypt proliferation) or LGR5+ crypt cells increased remarkably in nursing piglets after PEDV infection. Biologic mediators that promote crypt stem cell regeneration would be therapeutic targets.
Our study demonstrated potential mechanisms by which porcine epidemic diarrhea virus (PEDV) infection induces greater disease severity of nursing vs. weaned conventional pigs. Twenty-six-day-old weaned [PEDV-inoculated (n = 11); mock (n = 9)] and 9-day-old nursing pigs [PEDV-inoculated (n = 9); mock (n = 11)] were inoculated orally [8.9 log10 genomic equivalents (GE)/pig] with PC21A strain or mock (MEM). Pigs were monitored for clinical signs and PEDV RNA titers in feces and serum. For pathology and immunofluorescence staining for Ki67 (marker for crypt proliferation) and LGR5 (marker for crypt stem cell), 3–4 pigs were euthanized at postinoculation days (PIDs) 1, 3 and 5. Severe watery diarrhea and atrophic enteritis with moderate to high PEDV RNA titers in feces (7.5–12.2 log10 GE/ml) and low viral RNA titers in serum (5.6–8.6 log10 GE/ml) were observed in all inoculated nursing piglets at PIDs 1–5. In contrast, weaned pigs did not show evidence of PEDV infection at PID 1. Pigs exhibited high fecal shedding titers at PIDs 2–5 and mild to severe atrophic enteritis at PIDs 3–5, indicating a longer incubation for PEDV infection. While uninoculated or inoculated 27–31-day-old pigs showed large numbers of Ki67- or LGR5-positive cells in the intestinal crypts, there was a lack of LGR5-positive cells and low proliferation of crypts in jejunum of uninoculated 10–14-day-old piglets, possibly causing a slower turnover of enterocytes; however, the number of LGR5-positive cells and proliferation of intestinal crypts increased remarkably at 3–5 days after inoculation. Biologic mediators that promote crypt stem cell regeneration would be targets to improve the intestinal epithelium renewal during PEDV infection.
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Affiliation(s)
- Kwonil Jung
- Food Animal Health Research Program, Ohio Agricultural Research and Development Center, Department of Veterinary Preventive Medicine, The Ohio State University, 1680 Madison Ave., Wooster, OH 44691, USA.
| | - Thavamathi Annamalai
- Food Animal Health Research Program, Ohio Agricultural Research and Development Center, Department of Veterinary Preventive Medicine, The Ohio State University, 1680 Madison Ave., Wooster, OH 44691, USA
| | - Zhongyan Lu
- Food Animal Health Research Program, Ohio Agricultural Research and Development Center, Department of Veterinary Preventive Medicine, The Ohio State University, 1680 Madison Ave., Wooster, OH 44691, USA
| | - Linda J Saif
- Food Animal Health Research Program, Ohio Agricultural Research and Development Center, Department of Veterinary Preventive Medicine, The Ohio State University, 1680 Madison Ave., Wooster, OH 44691, USA.
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149
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Jung K, Eyerly B, Annamalai T, Lu Z, Saif LJ. Structural alteration of tight and adherens junctions in villous and crypt epithelium of the small and large intestine of conventional nursing piglets infected with porcine epidemic diarrhea virus. Vet Microbiol 2015; 177:373-8. [PMID: 25843943 PMCID: PMC7117115 DOI: 10.1016/j.vetmic.2015.03.022] [Citation(s) in RCA: 50] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2015] [Revised: 03/18/2015] [Accepted: 03/19/2015] [Indexed: 02/07/2023]
Abstract
Expression of zonula occludin-1 was reduced in the small intestine of PEDV-infected pigs. Expression of E-Cadherin was altered in the small intestine of PEDV-infected pigs. The structural alterations of tight and adherens junctions were extensive during PEDV infection. The structurally impaired tight and adherens junctions are involved in the pathogenesis of PEDV.
Integrity of the intestinal epithelium is critical for proper functioning of the barrier that regulates absorption of water and restricts uptake of luminal bacteria. It is maintained mainly by tight junctions (TJs) and adherens junctions (AJs). We conducted immunofluorescence (IF) staining for in situ identification of zonula occludin (ZO)-1 proteins for TJ and E-Cadherin proteins for AJ in the small and large intestinal villous and crypt epithelium of nursing pigs infected with porcine epidemic diarrhea virus (PEDV). Twenty 9-day-old piglets [PEDV-infected (n = 9) and Mock (n = 11)] from PEDV seronegative sows, were orally inoculated [8.9 log10 genomic equivalents/pig] with PEDV PC21A strain or mock. At post-inoculation days (PIDs) 1–5, infected pigs showed severe watery diarrhea and/or vomiting and severe atrophic enteritis. By immunohistochemistry, PEDV antigens were evident in enterocytes lining the villous epithelium. At PIDs 1–5, PEDV-infected pigs exhibited mildly to extensively disorganized, irregular distribution and reduced expression of ZO-1 or E-Cadherin in villous, but not crypt epithelial cells of the jejunum and ileum, but not in the large intestine, when compared to the negative controls. The structural destruction and disorganization of TJ and AJ were extensive in PEDV-infected pigs at PIDs 1–3, but then appeared to reversibly recover at PID 5, as evident by increased numbers of ZO-1-positive epithelial cells and markedly improved appearance of E-Cadherin-positive villous epithelium. Our results suggest a possible involvement of structurally impaired TJ and AJ in the pathogenesis of PEDV, potentially leading to secondary bacterial infections.
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Affiliation(s)
- Kwonil Jung
- 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.
| | - Bryan Eyerly
- 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
| | - Thavamathi Annamalai
- 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
| | - Zhongyan Lu
- 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
| | - 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.
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150
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Chen Q, Gauger P, Stafne M, Thomas J, Arruda P, Burrough E, Madson D, Brodie J, Magstadt D, Derscheid R, Welch M, Zhang J. Pathogenicity and pathogenesis of a United States porcine deltacoronavirus cell culture isolate in 5-day-old neonatal piglets. Virology 2015; 482:51-9. [PMID: 25817405 PMCID: PMC7111688 DOI: 10.1016/j.virol.2015.03.024] [Citation(s) in RCA: 124] [Impact Index Per Article: 13.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2015] [Revised: 02/25/2015] [Accepted: 03/05/2015] [Indexed: 11/02/2022]
Abstract
Porcine deltacoronavirus (PDCoV) was first identified in Hong Kong in 2009-2010 and reported in United States swine for the first time in February 2014. However, diagnostic tools other than polymerase chain reaction for PDCoV detection were lacking and Koch's postulates had not been fulfilled to confirm the pathogenic potential of PDCoV. In the present study, PDCoV peptide-specific rabbit antisera were developed and used in immunofluorescence and immunohistochemistry assays to assist PDCoV diagnostics. The pathogenicity and pathogenesis of PDCoV was investigated following orogastric inoculation of 5-day-old piglets with a plaque-purified PDCoV cell culture isolate (3 × 10(4) TCID50 per pig). The PDCoV-inoculated piglets developed mild to moderate diarrhea, shed increasing amount of virus in rectal swabs from 2 to 7 days post inoculation, and developed macroscopic and microscopic lesions in small intestines with viral antigen confirmed by immunohistochemistry staining. This study experimentally confirmed PDCoV pathogenicity and characterized PDCoV pathogenesis in neonatal piglets.
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Affiliation(s)
- Qi Chen
- Department of Veterinary Diagnostic and Production Animal Medicine, Iowa State University, Ames, IA, USA
| | - Phillip Gauger
- Department of Veterinary Diagnostic and Production Animal Medicine, Iowa State University, Ames, IA, USA
| | - Molly Stafne
- Department of Veterinary Diagnostic and Production Animal Medicine, Iowa State University, Ames, IA, USA
| | - Joseph Thomas
- Department of Veterinary Diagnostic and Production Animal Medicine, Iowa State University, Ames, IA, USA
| | - Paulo Arruda
- Department of Veterinary Diagnostic and Production Animal Medicine, Iowa State University, Ames, IA, USA
| | - Eric Burrough
- Department of Veterinary Diagnostic and Production Animal Medicine, Iowa State University, Ames, IA, USA
| | - Darin Madson
- Department of Veterinary Diagnostic and Production Animal Medicine, Iowa State University, Ames, IA, USA
| | - Joseph Brodie
- Department of Veterinary Diagnostic and Production Animal Medicine, Iowa State University, Ames, IA, USA
| | - Drew Magstadt
- Department of Veterinary Diagnostic and Production Animal Medicine, Iowa State University, Ames, IA, USA
| | - Rachel Derscheid
- Department of Veterinary Diagnostic and Production Animal Medicine, Iowa State University, Ames, IA, USA
| | - Michael Welch
- Department of Veterinary Diagnostic and Production Animal Medicine, Iowa State University, Ames, IA, USA
| | - Jianqiang Zhang
- Department of Veterinary Diagnostic and Production Animal Medicine, Iowa State University, Ames, IA, USA.
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