1
|
Schoneberg C, Böttcher J, Janowetz B, Rostalski A, Kreienbrock L, Campe A. An intercomparison study of ELISAs for the detection of porcine reproductive and respiratory syndrome virus – evaluating six conditionally dependent tests. PLoS One 2022; 17:e0262944. [PMID: 35077518 PMCID: PMC8789123 DOI: 10.1371/journal.pone.0262944] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2021] [Accepted: 01/08/2022] [Indexed: 11/18/2022] Open
Abstract
Latent class analysis is a widely used statistical method for evaluating diagnostic tests without any gold standard. It requires the results of at least two tests applied to the same individuals. Based on the resulting response patterns, the method estimates the test accuracy and the unknown disease status for all individuals in the sample. An important assumption is the conditional independence of the tests. If tests with the same biological principle are used, the assumption is not fulfilled, which may lead to biased results. In a recent publication, we developed a method that considers the dependencies in the latent class model and estimates all parameters using frequentist methods. Here, we evaluate the practicability of the method by applying it to the results of six ELISA tests for antibodies against the porcine reproductive and respiratory syndrome (PRRS) virus in pigs that generally follow the same biological principle. First, we present different methods of identifying suitable starting values for the algorithm and apply these to the dataset and a vaccinated subgroup. We present the calculated values of the test accuracies, the estimated proportion of antibody-positive animals and the dependency structure for both datasets. Different starting values led to matching results for the entire dataset. For the vaccinated subgroup, the results were more dependent on the selected starting values. All six ELISA tests are well suited to detect antibodies against PRRS virus, whereas none of the tests had the best values for sensitivity and specificity simultaneously. The results thus show that the method used is able to determine the parameter values of conditionally dependent tests with suitable starting values. The choice of test should be based on the general fit-for-purpose concept and the population under study.
Collapse
Affiliation(s)
- Clara Schoneberg
- Department of Biometry, Epidemiology and Information Processing, WHO Collaborating Centre for Research and Training for Health in the Human-Animal-Environment Interface, University for Veterinary Medicine Hannover, Hannover, Germany
- * E-mail:
| | | | | | | | - Lothar Kreienbrock
- Department of Biometry, Epidemiology and Information Processing, WHO Collaborating Centre for Research and Training for Health in the Human-Animal-Environment Interface, University for Veterinary Medicine Hannover, Hannover, Germany
| | - Amely Campe
- Department of Biometry, Epidemiology and Information Processing, WHO Collaborating Centre for Research and Training for Health in the Human-Animal-Environment Interface, University for Veterinary Medicine Hannover, Hannover, Germany
| |
Collapse
|
2
|
Zhao J, Zhang R, Zhu L, Deng H, Li F, Xu L, Huan J, Sun X, Xu Z. Establishment of a peptide-based enzyme-linked immunosorbent assay for detecting antibodies against PRRSV M protein. BMC Vet Res 2021; 17:355. [PMID: 34798885 PMCID: PMC8602981 DOI: 10.1186/s12917-021-03060-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2021] [Accepted: 10/31/2021] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Porcine reproductive and respiratory syndrome (PRRS) is one of the most economically devastating diseases affecting the swine industry globally. Evaluation of antibody responses and neutralizing antibody titers is the most effective method for vaccine evaluation. In this study, the B cell line epitopes of PRRSV M protein were predicted, and two peptide ELISA assays were established (M-A110-129 ELISA, M-A148-174 ELISA) to detect antibodies against PRRSV M protein. Field serum samples collected from pig farms were used to validate the peptide ELISA and compare it with an indirect immunofluorescence assay. RESULTS The sensitivity and specificity of M-A110-129 ELISA and M-A148-174 ELISA were (111/125) 88.80%, (69/70) 98.57% and (122/125) 97.60%, (70/70) 100%, relative to indirect immunofluorescence assay. This peptide ELISA could detect antibodies against different genotypes of PRRSV including type 1 PRRSV, classical PRRSV, HP-PRRSV, and NADC30 like PRRSV, but not antibodies against other common swine viruses. The results of ROC analysis showed that the area under the curve (AUC) of the M-A110-129 ELISA and M-A148-174 ELISA were 0.967 and 0.996, respectively. Compared the concordance of results using two peptide ELISA assays, the IDEXX PRRSV X3 Ab ELISA and a virus neutralization test, were assessed using a series of 147 sera from pigs vaccinated with the NADC30-like PRRSV inactivated vaccine. The M-A148-174 ELISA had the best consistency, with a Cohen's kappa coefficient of 0.8772. The concordance rates of the Hipra PRRSV ELISA kit, M-A110-129 ELISA and M-A148-174 ELISA in the field seropositive detection results were 91.08, 86.32 and 95.35%, relative to indirect immunofluorescence assay. CONCLUSIONS In summary, compared with M-A110-129 ELISA, the PRRSV M-A148-174 ELISA is of value for detecting antibodies against PRRSV and the evaluation of the NADC30-like PRRSV inactivated vaccine, but the advantage is insufficient in serological early diagnosis.
Collapse
Affiliation(s)
- Jun Zhao
- College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, 611130, China
| | - Rubo Zhang
- College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, 611130, China
| | - Ling Zhu
- College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, 611130, China.,Key Laboratory of Animal Diseases and Human Health of Sichuan Province, Chengdu, 611130, China
| | - Huidan Deng
- College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, 611130, China.,Key Laboratory of Animal Diseases and Human Health of Sichuan Province, Chengdu, 611130, China
| | - Fengqing Li
- College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, 611130, China.,College of Animal Science, Xichang University, Xichang, 615000, Sichuan, China
| | - Lei Xu
- College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, 611130, China
| | - Jianbo Huan
- College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, 611130, China
| | - Xiangang Sun
- College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, 611130, China.,Key Laboratory of Animal Diseases and Human Health of Sichuan Province, Chengdu, 611130, China
| | - Zhiwen Xu
- College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, 611130, China. .,Key Laboratory of Animal Diseases and Human Health of Sichuan Province, Chengdu, 611130, China.
| |
Collapse
|
3
|
Henao-Diaz A, Zhang M, Giménez-Lirola L, Ramirez E, Gauger P, Baum DH, Clavijo MJ, Rotolo M, Main RG, Zimmerman J. Adapting a porcine reproductive and respiratory syndrome virus (PRRSV) oral fluid antibody ELISA to routine surveillance. Prev Vet Med 2021; 188:105250. [PMID: 33429134 DOI: 10.1016/j.prevetmed.2020.105250] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2020] [Revised: 12/20/2020] [Accepted: 12/21/2020] [Indexed: 10/22/2022]
Abstract
Distinct from tests used in diagnostics, tests used in surveillance must provide for detection while avoiding false alarms, i.e., acceptable diagnostic sensitivity but high diagnostic specificity. In the case of the reproductive and respiratory syndrome virus (PRRSV), RNA detection meets these requirements during the period of viremia, but antibody detection better meets these requirements in the post-viremic stage of the infection. Using the manufacturer's recommended cut-off (S/P ≥ 0.4), the diagnostic specificity of a PRRSV oral fluid antibody ELISA (IDEXX Laboratories, Inc., Westbrook, ME, USA) evaluated in this study was previously reported as ≥ 97 %. The aim of this study was to improve its use in surveillance by identifying a cut-off that would increase diagnostic specificity yet minimally impact its diagnostic sensitivity. Three sample sets were used to achieve this goal: oral fluids (n = 596) from pigs vaccinated with a modified live PRRSV vaccine under experimental conditions, field oral fluids (n = 1574) from 94 production sites of known negative status, and field oral fluids (n = 1380) from 211 sites of unknown PRRSV status. Based on the analysis of samples of known status (experimental samples and field samples from negative sites), a cut-off of S/P ≥ 1.0 resulted in a diagnostic specificity of 99.2 (95 % CI: 98.8, 99.7) and a diagnostic sensitivity of 96.5 (95 % CI: 85.2, 99.2). Among 211 sites of unknown status, 81 sites were classified as antibody positive using the manufacturer's cut-off; 20 of which were reclassified as negative using a cut-off of S/P ≥ 1.0. Further analysis showed that these 20 sites had a small proportion of samples (18.0 %) with S/P values just exceeding the manufacturer's cut-off (x̄ = 0.5). Whereas the remainder of positive sites (n = 61) had a high proportion of samples (76.3 %) with high S/P values (x̄ = 6.6). Thus, the manufacturer's cut-off (S/P ≥ 0.4) is appropriate for diagnostic applications, but a cut-off of S/P ≥ 1.0 provided the higher specificity required for surveillance. A previously unreported finding in this study was a statistically significant association between unexpected reactors and specific production sites and animal ages or stages. While beyond the scope of this study, these data suggested that certain animal husbandry or production practices may be associated with non-specific reactions.
Collapse
Affiliation(s)
- Alexandra Henao-Diaz
- Veterinary Diagnostic Laboratory, College of Veterinary Medicine, Iowa State University, Ames, IA, 50011, USA
| | - Min Zhang
- Department of Statistics, College of Liberal Arts and Sciences, Iowa State University, Ames, IA, 50011, USA
| | - Luis Giménez-Lirola
- Veterinary Diagnostic Laboratory, College of Veterinary Medicine, Iowa State University, Ames, IA, 50011, USA
| | - Esteban Ramirez
- Grupo Porcícola Mexicano Kekén. Mérida, Yucatán, 97100, Mexico
| | - Phil Gauger
- Veterinary Diagnostic Laboratory, College of Veterinary Medicine, Iowa State University, Ames, IA, 50011, USA
| | - David H Baum
- Veterinary Diagnostic Laboratory, College of Veterinary Medicine, Iowa State University, Ames, IA, 50011, USA
| | - Maria J Clavijo
- Veterinary Diagnostic Laboratory, College of Veterinary Medicine, Iowa State University, Ames, IA, 50011, USA; PIC North America, 100 Bluegrass Commons Blvd. Ste. 2200, Hendersonville, TN, 37075, USA
| | - Marisa Rotolo
- PIC North America, 100 Bluegrass Commons Blvd. Ste. 2200, Hendersonville, TN, 37075, USA
| | - Rodger G Main
- Veterinary Diagnostic Laboratory, College of Veterinary Medicine, Iowa State University, Ames, IA, 50011, USA
| | - Jeffrey Zimmerman
- Veterinary Diagnostic Laboratory, College of Veterinary Medicine, Iowa State University, Ames, IA, 50011, USA.
| |
Collapse
|
4
|
Biernacka K, Podgórska K, Tyszka A, Stadejek T. Comparison of six commercial ELISAs for the detection of antibodies against porcine reproductive and respiratory syndrome virus (PRRSV) in field serum samples. Res Vet Sci 2018; 121:40-45. [PMID: 30316015 DOI: 10.1016/j.rvsc.2018.10.005] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2018] [Revised: 10/03/2018] [Accepted: 10/05/2018] [Indexed: 11/29/2022]
Abstract
Porcine reproductive and respiratory syndrome (PRRS) is one of the most common infectious diseases of swine globally. Since the course of PRRS virus (PRRSV) infection is subclinical, laboratory diagnosis is necessary to detect the virus or specific antibodies. The aim of this study was to assess the sensitivity and specificity of IDEXX PRRS X3 Ab Test (IDEXX, USA), Civtest Suis E/S (Hipra, Spain), INgezim PRRS 2.0 (Ingenasa, Spain), VetExpert PRRS Ab ELISA 4.0 (BioNote, Korea), Pigtype PRRSV Ab (Qiagen, Germany) and PrioCHECK PRRSV Antibody ELISA (ThermoFisher, USA), using serum samples obtained from 5 conventional PRRSV-positive and 5 PRRSV-negative Polish pig farms. Specificity of ELISAs ranged from 94.2% (ThermoFisher) to 100% (IDEXX and Hipra). ThermoFisher ELISA had the highest detection rate and detected 67.2% samples from PRRSV-positive farms as positive but considering its low specificity some of the positive results may be incorrect. IDEXX ELISA considered as a reference detected 64.8% positive sera in PRRSV-positive farms. On the other hand Hipra Elisa identified only 51.8% of samples as positive. The diagnostic sensitivity of five ELISAs relative to IDEXX ranged from 80.3% (Hipra) to 96.3% (ThermoFisher). Our study showed significant differences in specificity and diagnostic sensitivity between the compared kits. The differences in the performance appeared to be practically negligible on farms where early infection with PRRSV occurred. However, on PRRSV-negative farms, or farms with PRRSV stable sow herds, some ELISAs can give results not reflecting the infection status in specific age groups.
Collapse
Affiliation(s)
- Kinga Biernacka
- Department of Pathology and Veterinary Diagnostics, Faculty of Veterinary Medicine, Warsaw University of Life Sciences-SGGW, Nowoursynowska 159c, 02-776 Warsaw, Poland
| | - Katarzyna Podgórska
- Department of Swine Diseases, National Veterinary Research Institute, Partyzantow 57, 24-100 Pulawy, Poland.
| | - Anna Tyszka
- Veterinary Diagnostic Laboratory, Vet Lab Group, Ostrodzka 46, 11-036 Gietrzwald, Poland.
| | - Tomasz Stadejek
- Department of Pathology and Veterinary Diagnostics, Faculty of Veterinary Medicine, Warsaw University of Life Sciences-SGGW, Nowoursynowska 159c, 02-776 Warsaw, Poland.
| |
Collapse
|
5
|
Sattler T, Pikalo J, Wodak E, Revilla-Fernández S, Steinrigl A, Bagó Z, Entenfellner F, Claude JB, Pez F, Francillette M, Schmoll F. Efficacy of live attenuated porcine reproductive and respiratory syndrome virus 2 strains to protect pigs from challenge with a heterologous Vietnamese PRRSV 2 field strain. BMC Vet Res 2018; 14:133. [PMID: 29673363 PMCID: PMC5907707 DOI: 10.1186/s12917-018-1451-y] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2017] [Accepted: 04/05/2018] [Indexed: 12/03/2022] Open
Abstract
Background Effective vaccines against porcine reproductive and respiratory syndrome virus (PRRSV), especially against highly pathogenic (HP) PRRSV are still missing. The objective of this study was to evaluate the protective efficacy of an experimental live attenuated PRRSV 2 vaccine, composed of two strains, against heterologous challenge with a Vietnamese HP PRRSV 2 field strain. For this reason, 20 PRRSV negative piglets were divided into two groups. The pigs of group 1 were vaccinated with the experimental vaccine, group 2 remained unvaccinated. All study piglets received an intranasal challenge of the HP PRRSV 2 on day 0 of the study (42 days after vaccination). Blood samples were taken on days 7 and 21 after vaccination and on several days after challenge. On day 28 after challenge, all piglets were euthanized and pathologically examined. Results On days 7 and 21 after vaccination, a PRRSV 2 viraemia was seen in all piglets of group 1 which remained detectable in seven piglets up to 42 days after vaccination. On day 3 after challenge, all piglets from both groups were positive in PRRSV 2 RT-qPCR. From day 7 onwards, viral load and number of PRRSV 2 positive pigs were lower in group 1 than in group 2. All pigs of group 1 seroconverted after PRRSV 2 vaccination. PRRSV antibodies were detected in serum of all study pigs from both groups from day 14 after challenge onwards. In group 2, moderate respiratory symptoms with occasional coughing were seen following the challenge with HP PRRSV 2. Pigs of group 1 remained clinically unaffected. Interstitial pneumonia was found in four piglets of group 1 and in all ten piglets of group 2. Histopathological findings were more severe in group 2. Conclusions It was thus concluded that the used PRRSV 2 live experimental vaccine provided protection from clinical disease and marked reduction of histopathological findings and viral load in pigs challenged with a Vietnamese HP PRRSV 2 field strain.
Collapse
Affiliation(s)
- Tatjana Sattler
- Institute for Veterinary Disease Control, AGES, Robert-Koch-Gasse 17, 2340, Mödling, Austria. .,Clinic for Ruminants and Swine, University of Leipzig, An den Tierkliniken 11, 04103, Leipzig, Germany.
| | - Jutta Pikalo
- Institute for Veterinary Disease Control, AGES, Robert-Koch-Gasse 17, 2340, Mödling, Austria
| | - Eveline Wodak
- Institute for Veterinary Disease Control, AGES, Robert-Koch-Gasse 17, 2340, Mödling, Austria
| | | | - Adi Steinrigl
- Institute for Veterinary Disease Control, AGES, Robert-Koch-Gasse 17, 2340, Mödling, Austria
| | - Zoltán Bagó
- Institute for Veterinary Disease Control, AGES, Robert-Koch-Gasse 17, 2340, Mödling, Austria
| | | | | | - Floriane Pez
- BioSellal, Bâtiment Accinov, 317 avenue Jean Jaurès, 69007, Lyon, France
| | - Maela Francillette
- BioSellal, Bâtiment Accinov, 317 avenue Jean Jaurès, 69007, Lyon, France
| | - Friedrich Schmoll
- Institute for Veterinary Disease Control, AGES, Robert-Koch-Gasse 17, 2340, Mödling, Austria
| |
Collapse
|
6
|
More S, Bøtner A, Butterworth A, Calistri P, Depner K, Edwards S, Garin-Bastuji B, Good M, Gortázar Schmidt C, Michel V, Miranda MA, Nielsen SS, Raj M, Sihvonen L, Spoolder H, Stegeman JA, Thulke HH, Velarde A, Willeberg P, Winckler C, Baldinelli F, Broglia A, Beltrán Beck B, Kohnle L, Morgado J, Bicout D. Assessment of listing and categorisation of animal diseases within the framework of the Animal Health Law (Regulation (EU) No 2016/429): porcine reproductive and respiratory syndrome (PRRS). EFSA J 2017; 15:e04949. [PMID: 32625601 PMCID: PMC7009866 DOI: 10.2903/j.efsa.2017.4949] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Porcine reproductive and respiratory syndrome (PRRS) has been assessed according to the criteria of the Animal Health Law (AHL), in particular criteria of Article 7 on disease profile and impacts, Article 5 on the eligibility of PRRS to be listed, Article 9 for the categorisation of PRRS according to disease prevention and control rules as in Annex IV and Article 8 on the list of animal species related to PRRS. The assessment has been performed following a methodology composed of information collection and compilation, expert judgement on each criterion at individual and, if no consensus was reached before, also at collective level. The output is composed of the categorical answer, and for the questions where no consensus was reached, the different supporting views are reported. Details on the methodology used for this assessment are explained in a separate opinion. According to the assessment performed, PRRS can be considered eligible to be listed for Union intervention as laid down in Article 5(3) of the AHL. The disease would comply with the criteria as in Sections 4 and 5 of Annex IV of the AHL, for the application of the disease prevention and control rules referred to in points (d) and (e) of Article 9(1). The animal species to be listed for PRRS according to Article 8(3) criteria are domestic pigs and wild boar.
Collapse
|
7
|
Zhang Z, Wen X, Dong J, Ge X, Zhou L, Yang H, Guo X. Epitope mapping and characterization of a novel Nsp10-specific monoclonal antibody that differentiates genotype 2 PRRSV from genotype 1 PRRSV. Virol J 2017. [PMID: 28629383 PMCID: PMC5477253 DOI: 10.1186/s12985-017-0782-9] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
Background Porcine reproductive and respiratory syndrome virus (PRRSV), the causative agent of PRRS, has two distinct and highly diverse genotypes (genotype 1 and genotype 2) in the field. Accurate diagnosis and differentiation of the two genotypes of PRRSV are critical to the effective prevention and control of PRRS. The non-structural protein 10 (Nsp10) plays a vital role in viral replication and is one of the most conserved proteins of PRRSV, thus constituting a good candidate for PRRSV diagnosis. Results In this study, we generated a monoclonal antibody (mAb) 4D9 against Nsp10 by immunizing BALB/c mice with purified recombinant Nsp10 expressed by an Escherichia coli system. Through fine epitope mapping of mAb 4D9 using a panel of eukaryotic expressed polypeptides with GFP-tags, we identified the motif 286AIQPDYRDKL295 as the minimal unit of the linear B-cell epitope recognized by mAb 4D9. Protein sequence alignment indicated that 286AIQPDYRDKL295 was highly conserved in genotype 2 PRRSV strains, whereas genotype 1 PRRSV strains had variable amino acids in this motif. Furthermore, a mutant of the motif carrying two constant amino acids of genotype 1 PRRSV, Cys290 and Glu293, failed to react with mAb 4D9. More importantly, the mAb 4D9 could differentiate genotype 2 PRRSV strains from genotype 1 PRRSV strains using Western blotting and immunofluorescence analysis. Conclusion Our findings suggest that Nsp10-specific mAb generated in this study could be a useful tool for basic research and may facilitate the establishment of diagnostic methods to discriminate between genotype 1 and genotype 2 PRRSV infection.
Collapse
Affiliation(s)
- Zhibang Zhang
- Key Laboratory of Animal Epidemiology and Zoonosis of the Ministry of Agriculture, College of Veterinary Medicine and State Key Laboratory of Agrobiotechnology, China Agricultural University, No. 2 Yuanmingyuan West Road, Haidian District, Beijing, 100193, People's Republic of China
| | - Xuexia Wen
- Key Laboratory of Animal Epidemiology and Zoonosis of the Ministry of Agriculture, College of Veterinary Medicine and State Key Laboratory of Agrobiotechnology, China Agricultural University, No. 2 Yuanmingyuan West Road, Haidian District, Beijing, 100193, People's Republic of China
| | - Jianguo Dong
- Key Laboratory of Animal Epidemiology and Zoonosis of the Ministry of Agriculture, College of Veterinary Medicine and State Key Laboratory of Agrobiotechnology, China Agricultural University, No. 2 Yuanmingyuan West Road, Haidian District, Beijing, 100193, People's Republic of China
| | - Xinna Ge
- Key Laboratory of Animal Epidemiology and Zoonosis of the Ministry of Agriculture, College of Veterinary Medicine and State Key Laboratory of Agrobiotechnology, China Agricultural University, No. 2 Yuanmingyuan West Road, Haidian District, Beijing, 100193, People's Republic of China
| | - Lei Zhou
- Key Laboratory of Animal Epidemiology and Zoonosis of the Ministry of Agriculture, College of Veterinary Medicine and State Key Laboratory of Agrobiotechnology, China Agricultural University, No. 2 Yuanmingyuan West Road, Haidian District, Beijing, 100193, People's Republic of China
| | - Hanchun Yang
- Key Laboratory of Animal Epidemiology and Zoonosis of the Ministry of Agriculture, College of Veterinary Medicine and State Key Laboratory of Agrobiotechnology, China Agricultural University, No. 2 Yuanmingyuan West Road, Haidian District, Beijing, 100193, People's Republic of China.
| | - Xin Guo
- Key Laboratory of Animal Epidemiology and Zoonosis of the Ministry of Agriculture, College of Veterinary Medicine and State Key Laboratory of Agrobiotechnology, China Agricultural University, No. 2 Yuanmingyuan West Road, Haidian District, Beijing, 100193, People's Republic of China.
| |
Collapse
|
8
|
Fablet C, Renson P, Pol F, Dorenlor V, Mahé S, Eono F, Eveno E, Le Dimna M, Liegard-Vanhecke D, Eudier S, Rose N, Bourry O. Oral fluid versus blood sampling in group-housed sows and finishing pigs: Feasibility and performance of antibody detection for porcine reproductive and respiratory syndrome virus (PRRSV). Vet Microbiol 2017; 204:25-34. [PMID: 28532802 DOI: 10.1016/j.vetmic.2017.04.001] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2017] [Accepted: 04/03/2017] [Indexed: 11/19/2022]
Abstract
The feasibility of using individual and pen-based oral fluid samples to detect PRRSV antibodies in growing-finishing pigs and group-housed sows was investigated. The diagnostic performances of a commercial oral fluid ELISA (OF-ELISA) and a serum ELISA (SER-ELISA) performed on individual or pooled samples from 5 or 10 pigs and sows was evaluated. The performance of the OF-ELISA was also assessed for pen-based oral fluids. Eight hundred and thirty-four pigs and 1598 sows from 42 PRRSV-infected and 3 PRRSV-negative herds were oral fluid sampled and bled. PRRSV antibodies were detected by an OF-ELISA performed at individual, pool (5 or 10 samples) and pen levels. Serum samples were tested by a SER-ELISA at individual and pool levels. The sensitivity and specificity of ELISAs for individual samples were assessed by Bayesian analysis. The relative diagnostic performance for the pools was calculated by taking individual samples as the gold standard. SER-ELISA and individual OF-ELISA results were used as references for estimating OF-ELISA performance for pen-based samples. Individual oral fluid collection was feasible in all kinds of pigs, whereas pen-based samples were unsuccessful in 40% of the group-housed sow pens. High levels of sensitivity comparable to those of the SER-ELISA were found for the OF-ELISA when performed on individual, 5-sample pool or pen-based samples from pigs or sows. The OF-ELISA lacked specificity for individual samples from sows. Pooling 5 individual oral fluid samples or using pen-based samples increased test specificity.
Collapse
Affiliation(s)
- C Fablet
- Agence Nationale de Sécurité Sanitaire (ANSES), Unité Epidémiologie et Bien-Etre du Porc, B.P. 53, 22440 Ploufragan, France; Université Bretagne-Loire, France.
| | - P Renson
- Agence Nationale de Sécurité Sanitaire (ANSES), Unité Virologie Immunologie Porcines, B.P. 53, 22440 Ploufragan, France; Union des Groupements de Producteurs de Viande de Bretagne (UGPVB), 104 rue Eugène Pottier, CS 26553, 35065 Rennes, France; Université Bretagne-Loire, France
| | - F Pol
- Agence Nationale de Sécurité Sanitaire (ANSES), Unité Epidémiologie et Bien-Etre du Porc, B.P. 53, 22440 Ploufragan, France; Université Bretagne-Loire, France
| | - V Dorenlor
- Agence Nationale de Sécurité Sanitaire (ANSES), Unité Epidémiologie et Bien-Etre du Porc, B.P. 53, 22440 Ploufragan, France; Université Bretagne-Loire, France
| | - S Mahé
- Agence Nationale de Sécurité Sanitaire (ANSES), Unité Virologie Immunologie Porcines, B.P. 53, 22440 Ploufragan, France; Université Bretagne-Loire, France
| | - F Eono
- Agence Nationale de Sécurité Sanitaire (ANSES), Unité Epidémiologie et Bien-Etre du Porc, B.P. 53, 22440 Ploufragan, France; Université Bretagne-Loire, France
| | - E Eveno
- Agence Nationale de Sécurité Sanitaire (ANSES), Unité Epidémiologie et Bien-Etre du Porc, B.P. 53, 22440 Ploufragan, France; Université Bretagne-Loire, France
| | - M Le Dimna
- Agence Nationale de Sécurité Sanitaire (ANSES), Unité Virologie Immunologie Porcines, B.P. 53, 22440 Ploufragan, France; Université Bretagne-Loire, France
| | - D Liegard-Vanhecke
- Agence Nationale de Sécurité Sanitaire (ANSES), Unité Epidémiologie et Bien-Etre du Porc, B.P. 53, 22440 Ploufragan, France; Université Bretagne-Loire, France
| | - S Eudier
- Agence Nationale de Sécurité Sanitaire (ANSES), Unité Epidémiologie et Bien-Etre du Porc, B.P. 53, 22440 Ploufragan, France; Université Bretagne-Loire, France
| | - N Rose
- Agence Nationale de Sécurité Sanitaire (ANSES), Unité Epidémiologie et Bien-Etre du Porc, B.P. 53, 22440 Ploufragan, France; Université Bretagne-Loire, France
| | - O Bourry
- Agence Nationale de Sécurité Sanitaire (ANSES), Unité Virologie Immunologie Porcines, B.P. 53, 22440 Ploufragan, France; Université Bretagne-Loire, France
| |
Collapse
|
9
|
Diseases Primarily Affecting the Reproductive System. Vet Med (Auckl) 2017. [PMCID: PMC7150237 DOI: 10.1016/b978-0-7020-5246-0.00018-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
|
10
|
Sattler T, Pikalo J, Wodak E, Schmoll F. Ability of ELISAs to detect antibodies against porcine respiratory and reproductive syndrome virus in serum of pigs after inactivated vaccination and subsequent challenge. BMC Vet Res 2016; 12:259. [PMID: 27871292 PMCID: PMC5117522 DOI: 10.1186/s12917-016-0888-0] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2015] [Accepted: 11/17/2016] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND In this study, six enzyme-linked immunosorbent assays (ELISA), intended for routine porcine reproductive and respiratory syndrome virus (PRRSV) herd monitoring, are tested for their ability to detect PRRSV specific antibodies in the serum of pigs after vaccination with an inactivated PRRSV type 1 vaccine and subsequent infection with a highly pathogenic (HP) PRRSV field strain. For this reason, ten piglets (group V) from a PRRSV negative herd were vaccinated twice at the age of 2 and 4 weeks with an inactivated PRRSV vaccine. Ten additional piglets (group N) from the same herd remained unvaccinated. Three weeks after second vaccination, each of the piglets received an intradermal application of an HP PRRSV field strain. Serum samples were taken before first vaccination as well as before and 3, 7, 10 and 14 days after HP PRRSV application. All serum samples were tested for PRRSV RNA by reverse transcriptase quantitative polymerase chain reaction (RT-qPCR) as well as for PRRSV antibodies with all six study ELISAs. RESULTS At the beginning of the study (before vaccination), all of the piglets were PRRSV antibody negative with all study ELISAs. They also tested negative for PRRSV RNA measured by RT-qPCR. From day 3 after HP PRRSV application until the end of the study, a viremia was detected by RT-qPCR in all of the piglets. On day 0 (day of HP PRRSV application), nine out of ten piglets of the pre-vaccinated group tested PRRSV antibody positive with one of the tested ELISAs, although with lower S/P values than after infection. On day 10 after HP PRRSV application, all study ELISAs except one had significantly higher S/P or OD values, respectively more positive samples, in group V than in group N. CONCLUSIONS Only one of the tested ELISAs was able to detect reliably PRRSV antibodies in pigs vaccinated with an inactivated PRRSV vaccine. With most of the tested ELISAs, higher S/P values respectively more positive samples after PRRSV infection were seen in the pre-vaccinated group than in the non-vaccinated.
Collapse
Affiliation(s)
- Tatjana Sattler
- Large Animal Clinic for Internal Medicine, University of Leipzig, An den Tierkliniken 11, 04103, Leipzig, Germany. .,Institute for Veterinary Disease Control, AGES, Robert-Koch-Gasse 17, 2340, Mödling, Austria.
| | - Jutta Pikalo
- Institute for Veterinary Disease Control, AGES, Robert-Koch-Gasse 17, 2340, Mödling, Austria
| | - Eveline Wodak
- Institute for Veterinary Disease Control, AGES, Robert-Koch-Gasse 17, 2340, Mödling, Austria
| | - Friedrich Schmoll
- Institute for Veterinary Disease Control, AGES, Robert-Koch-Gasse 17, 2340, Mödling, Austria
| |
Collapse
|
11
|
Sattler T, Pikalo J, Wodak E, Schmoll F. Performance of ELISAs for detection of antibodies against porcine respiratory and reproductive syndrome virus in serum of pigs after PRRSV type 2 live vaccination and challenge. Porcine Health Manag 2015; 1:19. [PMID: 28405425 PMCID: PMC5382508 DOI: 10.1186/s40813-015-0015-9] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2015] [Accepted: 12/05/2015] [Indexed: 11/10/2022] Open
Abstract
Background The aim of the study was to evaluate the performance of different newly developed and/or commercially available ELISAs for detection of PRRSV specific antibodies. Consequently, ten PRRSV negative piglets (group V) were vaccinated with a PRRSV type 2 vaccine. Blood samples were taken before as well as seven, 21 and 42 days after vaccination. At day 42 after vaccination (day 0 of the study) all of the piglets from group V and 10 non-prevaccinated PRRSV negative piglets (group N) were challenged with an HP PRRSV type 2 field strain. Blood samples were taken before and at days 3, 7, 10, 14, 21 and 28 after challenge. The success of vaccination and challenge was measured with RT qPCR. All serum samples were tested with six ELISAs for detection of PRRSV antibodies. Three of them are nucleocapsid-based, two use a glycoprotein extract and one uses inactivated whole virus as antigen. The specificity of the ELISAs was evaluated using 301 serum samples of piglets from PRRSV negative herds. Results The piglets from group V tested positive by RT qPCR at day 7 after vaccination and all piglets tested positive at day 3 after challenge. PRRSV specific antibodies were seen with all nucleocapsid-based ELISAs from day 21 after vaccination onwards in group V and from day 10 after challenge in group N. The glycoprotein-based ELISAs detected antibodies from day 42 after vaccination (group V) and day 21 after challenge (group N). The agreement according to kappa-coefficient was almost perfect. The glycoprotein-based ELISAs were able to distinguish PRRSV type 2, although with some cross reactions. Regarding specificity, the ELISAs performed differently (specificity between 97.4 % and 100 %), whereas most of the ELISAs with higher sensitivity had a slightly lower specificity. Conclusions All tested ELISA were able to detect PRRSV antibodies in the serum of pigs vaccinated with a PRRSV type 2 vaccine and after challenge with an HP PRRSV type 2 field strain. The onset on antibody detection differed, depending on the type of antigen used in the ELISAs. Most of the ELISAs with a higher sensitivity had a lower specificity.
Collapse
Affiliation(s)
- Tatjana Sattler
- Large Animal Clinic for Internal Medicine, University of Leipzig, An den Tierkliniken 11, 04103 Leipzig, Germany.,Institute for Veterinary Disease Control, AGES, Robert-Koch-Gasse 17, 2340 Mödling, Austria
| | - Jutta Pikalo
- Institute for Veterinary Disease Control, AGES, Robert-Koch-Gasse 17, 2340 Mödling, Austria
| | - Eveline Wodak
- Institute for Veterinary Disease Control, AGES, Robert-Koch-Gasse 17, 2340 Mödling, Austria
| | - Friedrich Schmoll
- Institute for Veterinary Disease Control, AGES, Robert-Koch-Gasse 17, 2340 Mödling, Austria
| |
Collapse
|
12
|
Gerber PF, Opriessnig T. Detection of immunoglobulin (Ig) A antibodies against porcine epidemic diarrhea virus (PEDV) in fecal and serum samples. MethodsX 2015; 2:368-73. [PMID: 26587386 PMCID: PMC4625113 DOI: 10.1016/j.mex.2015.10.001] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2015] [Accepted: 10/07/2015] [Indexed: 11/20/2022] Open
Abstract
Many assays for detection of antibodies against porcine epidemic diarrhea virus (PEDV) are based on detection of neutralizing antibodies or immunoglobulin (Ig) G in serum samples. However, due to the particular features of the mucosal immune system, presence of serum antibodies against enteric pathogens, such as PEDV, not always correlates with protection. In contrast, anti-PEDV IgA antibodies correlate with protection against subsequent challenges. An indirect PEDV IgA ELISA was previously developed to monitor IgA levels in colostrum and milk samples. In the present paper we describe an adaptation of the protocol for detection of IgA antibodies in serum and fecal samples.The adapted protocol will aid in future assessment of protective levels of humoral response against PEDV infection by measuring IgA levels in serum and fecal samples. Fecal samples are non-invasive and easy to collect at any time by animal caretakers and therefore offering advantages over the serum sample collection procedure. A strong positive correlation between the anti-PEDV levels in fecal and serum samples was identified; however, detection of IgA antibodies was often more successful in serum than in paired fecal samples due to overall lower sample-to-positive (S/P) ratios for the latter sample type.
Collapse
Affiliation(s)
- Priscilla F. Gerber
- The Roslin Institute and The Royal (Dick) School of Veterinary Studies, University of Edinburgh, Midlothian, UK
| | - Tanja Opriessnig
- The Roslin Institute and The Royal (Dick) School of Veterinary Studies, University of Edinburgh, Midlothian, UK
- Department of Veterinary Diagnostic and Production Animal Medicine, Iowa State University, Ames, IA, USA
- Corresponding author at: The Roslin Institute and The Royal (Dick) School of Veterinary Studies, University of Edinburgh, Midlothian, UK.The Roslin Institute and The Royal (Dick) School of Veterinary Studies, University of EdinburghMidlothianUK
| |
Collapse
|
13
|
Seo BJ, Kim H, Cho HS, Park BY, Kim WI. Evaluation of two commercial PRRSV antibody ELISA kits with samples of known status and singleton reactors. J Vet Med Sci 2015; 78:133-8. [PMID: 26290128 PMCID: PMC4751132 DOI: 10.1292/jvms.15-0126] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
Two commercial PRRSV ELISA kits (IDEXX and Bionote) were evaluated for their sensitivity
and specificity using 476 PRRS-positive serum samples collected from 7 animal challenge
experiments and 1,000 PRRS-negative sera. Both ELISA kits exhibited 100% sensitivity with
sera collected 14 to 42 days post-infection, and the results from the kits were highly
correlated (R2=0.9207). The specificity of IDEXX or Bionote kit was 99.9% or
99.7%, respectively. In addition, the Bionote ELISA kit was used to examine 100 sera that
were determined to be falsely positive either by IDEXX 2XR or 3XR ELISA, and only 7 of
these samples were found to be positive. These results indicate that both ELISA kits
exhibited similar levels of sensitivity and specificity and would complement one another
for the verification of false-positive samples.
Collapse
Affiliation(s)
- Byoung-Joo Seo
- College of Veterinary Medicine and Bio-Safety Research Institute, Chonbuk National University, Iksan, Korea
| | | | | | | | | |
Collapse
|
14
|
Sattler T, Wodak E, Schmoll F. Evaluation of the specificity of a commercial ELISA for detection of antibodies against porcine respiratory and reproductive syndrome virus in individual oral fluid of pigs collected in two different ways. BMC Vet Res 2015; 11:70. [PMID: 25890153 PMCID: PMC4367893 DOI: 10.1186/s12917-015-0388-7] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2015] [Accepted: 03/06/2015] [Indexed: 01/16/2023] Open
Abstract
Background The monitoring of infectious diseases like the porcine reproductive and respiratory syndrome (PRRS) using pen-wise oral fluid samples becomes more and more established. The collection of individual oral fluid, which would be useful in the monitoring of PRRSV negative boar studs, is rather difficult. The aim of the study was to test two methods for individual oral fluid collection from pigs and to evaluate the specificity of a commercial ELISA for detection of PRRSV antibodies in these sample matrices. For this reason, 334 serum samples from PRRSV negative pigs (group 1) and 71 serum samples from PRRSV positive pigs (group 2) were tested for PRRSV antibodies with a commercial ELISA. Individual oral fluid was collected with a cotton gauze swab from 311 pigs from group 1 and 39 pigs from group 2. Furthermore, 312 oral fluid samples from group 1 and 67 oral fluid samples from group 2 were taken with a self-drying foam swab (GenoTube). The recollected oral fluid was then analysed twice with a commercial ELISA for detection of PRRSV antibodies in oral fluid. Results All serum samples from group 1 tested negative for PRRSV antibodies. The collection of oral fluid was sufficient in all samples. Sampling with GenoTubes was less time consuming than sampling with cotton gauze swabs. False positive results were obtained in 7 (measure 1) respectively 9 (measure 2) oral fluid samples recollected from cotton gauze swabs and in 9 and 8 samples from GenoTubes. The specificity of the oral fluid ELISA was 97.4% for cotton gauze swabs and 97.3% for GenoTubes. 70 out of 71 serum samples and all oral fluid samples from group 2 tested positive for PRRSV antibodies. The sensitivity of the oral fluid ELISA was 100%. According to the kappa coefficient, the results showed an almost perfect agreement between serum and oral fluid collected in both ways (kappa > 0.8). Conclusions Both methods used for individual oral fluid collection proved to be practical and efficient and can be used for PRRSV antibody detection. It has to be considered, however, that false positive results may occur more often than in serum samples.
Collapse
Affiliation(s)
- Tatjana Sattler
- Large Animal Clinic for Internal Medicine, University of Leipzig, An den Tierkliniken 11, 04103, Leipzig, Germany. .,Institute for Veterinary Disease Control, AGES, Robert-Koch-Gasse 17, 2340, Mödling, Austria.
| | - Eveline Wodak
- Institute for Veterinary Disease Control, AGES, Robert-Koch-Gasse 17, 2340, Mödling, Austria.
| | - Friedrich Schmoll
- Institute for Veterinary Disease Control, AGES, Robert-Koch-Gasse 17, 2340, Mödling, Austria.
| |
Collapse
|
15
|
Sattler T, Wodak E, Revilla-Fernández S, Schmoll F. Comparison of different commercial ELISAs for detection of antibodies against porcine respiratory and reproductive syndrome virus in serum. BMC Vet Res 2014; 10:300. [PMID: 25518885 PMCID: PMC4276257 DOI: 10.1186/s12917-014-0300-x] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2014] [Accepted: 12/11/2014] [Indexed: 11/22/2022] Open
Abstract
BACKGROUND In recent years, several new ELISAs for the detection of antibodies against the porcine reproductive and respiratory disease virus (PRRSV) in pig serum have been developed. To interpret the results, specificity and sensitivity data as well as agreement to a reference ELISA must be available. In this study, three commercial ELISAs (INgezim PRRS 2.0 - ELISA II, Priocheck® PRRSV Ab porcine - ELISA III and CIVTEST suis PRRS E/S PLUS - ELISA IV, detecting PRRSV type 1 antibodies) were compared to a standard ELISA (IDEXX PRRS X3 Ab Test - ELISA I). The serum of three pigs vaccinated with an attenuated PRRSV live vaccine (genotype 2) was tested prior to and several times after the vaccination. Furthermore, serum samples of 245 pigs of PRRSV positive herds, 309 pigs of monitored PRRSV negative herds, 256 fatteners of assumed PRRSV negative herds with unknown herd history and 92 wild boars were tested with all four ELISAs. RESULTS ELISAs II and III were able to detect seroconversion of vaccinated pigs with a similar reliability. According to kappa coefficient, the results showed an almost perfect agreement between ELISA I as reference and ELISA II and III (kappa > 0.8), and substantial agreement between ELISA I and ELISA IV (kappa = 0.71). Sensitivity of ELISA II, III and IV was 96.0%, 100% and 91.5%, respectively. The specificity of the ELISAs determined in samples of monitored PRRSV negative herds was 99.0%, 95.1% and 96.4%, respectively. In assumed negative farms that were not continually monitored, more positive samples were found with ELISA II to IV. The reference ELISA I had a specificity of 100% in this study. CONCLUSIONS All tested ELISAs were able to detect a PRRSV positive herd. The specificity and sensitivity of the tested commercial ELISAs, however, differed. ELISA II had the highest specificity and ELISA III had the highest sensitivity in comparison to the reference ELISA. ELISA IV had a lower sensitivity and specificity than the other ELISAs.
Collapse
Affiliation(s)
- Tatjana Sattler
- Large Animal Clinic for Internal Medicine, University of Leipzig, An den Tierkliniken 11, 04103, Leipzig, Germany.
| | - Eveline Wodak
- Institute for Veterinary Disease Control, AGES, Robert-Koch-Gasse 17, 2340, Mödling, Austria.
| | | | - Friedrich Schmoll
- Institute for Veterinary Disease Control, AGES, Robert-Koch-Gasse 17, 2340, Mödling, Austria.
| |
Collapse
|
16
|
Giménez-Lirola LG, Gerber PF, Rowland RR, Halbur PG, Huang YW, Meng XJ, Opriessnig T. Development and validation of a 4-plex antibody assay for simultaneous detection of IgG antibodies against Torque teno sus virus 1 (TTSuV1), TTSuV2, and porcine reproductive and respiratory syndrome virus types 1 and 2. Res Vet Sci 2014; 96:543-50. [PMID: 24650623 DOI: 10.1016/j.rvsc.2014.02.014] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2013] [Revised: 01/27/2014] [Accepted: 02/17/2014] [Indexed: 10/25/2022]
Abstract
A fluorescent microbead-based immunoassay (FMIA) for simultaneous detection of IgG antibodies against Torque teno sus virus 1 (TTSuV1), TTSuV2, porcine reproductive and respiratory syndrome virus type 1 (PRRSV-1) and PRRSV-2 was developed. Serum samples were obtained over time from 20 pigs. Twelve of 20 were exposed to TTSuV2 on day 0, 20/20 were vaccinated with a PRRSV-2 vaccine on day 35, and 20/20 were exposed to PRRSV-2 on day 63. Anti-TTSuV antibodies were detected in 30% of the pigs on day 0, and 90% by day 35. All PRRSV-2 vaccinated pigs had detectable anti-PRRSV-2 IgG 21 days after vaccination. Field samples from 17 farms were also tested. The seroprevalence of both PRRSV and TTSuV increased with age. Comparison of the PRRSV-2 FMIA to an ELISA revealed good correlation in young pigs but a high rate of false positives in older pigs. Cross-reaction between PRRSV types was a problem.
Collapse
Affiliation(s)
- Luis G Giménez-Lirola
- Department of Veterinary Diagnostic and Production Animal Medicine, College of Veterinary Medicine, Iowa State University, 1600 S. 16th Street, Ames, IA 50011, USA
| | - Priscilla F Gerber
- Department of Veterinary Diagnostic and Production Animal Medicine, College of Veterinary Medicine, Iowa State University, 1600 S. 16th Street, Ames, IA 50011, USA; Laboratório de Pesquisa em Virologia Animal, Departamento de Medicina Veterinária Preventiva, Universidade Federal de Minas Gerais, Belo Horizonte, MG 31270-901, Brazil
| | - Raymond R Rowland
- Department of Diagnostic Medicine and Pathobiology, Kansas State University, Manhattan, KS 66506, USA
| | - Patrick G Halbur
- Department of Veterinary Diagnostic and Production Animal Medicine, College of Veterinary Medicine, Iowa State University, 1600 S. 16th Street, Ames, IA 50011, USA
| | - Yao-Wei Huang
- Department of Biomedical Sciences and Pathobiology, Center for Molecular Medicine and Infectious Diseases, College of Veterinary Medicine, Virginia Polytechnic Institute and State University, Blacksburg, VA 24061, USA; Institute of Preventive Veterinary Medicine & Key Laboratory of Animal Virology of Ministry of Agriculture, College of Animal Sciences, Zhejiang University, Hangzhou, 310058, China
| | - Xiang-Jin Meng
- Department of Biomedical Sciences and Pathobiology, Center for Molecular Medicine and Infectious Diseases, College of Veterinary Medicine, Virginia Polytechnic Institute and State University, Blacksburg, VA 24061, USA
| | - Tanja Opriessnig
- Department of Veterinary Diagnostic and Production Animal Medicine, College of Veterinary Medicine, Iowa State University, 1600 S. 16th Street, Ames, IA 50011, USA; The Roslin Institute and The Royal (Dick) School of Veterinary Studies, University of Edinburgh, Midlothian EH25 9RG, UK.
| |
Collapse
|