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Elsohaby I, Arango-Sabogal JC, Selim A, Attia KA, Alsubki RA, Mohamed AM, Megahed A. Bayesian estimation of sensitivity and specificity of fecal culture, fecal PCR and serum ELISA for diagnosis of Mycobacterium avium subsp. paratuberculosis infections in sheep. Prev Vet Med 2022; 206:105712. [PMID: 35843026 DOI: 10.1016/j.prevetmed.2022.105712] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2021] [Revised: 06/12/2022] [Accepted: 07/06/2022] [Indexed: 11/19/2022]
Abstract
The objective of the present study was to evaluate the diagnostic accuracy of the individual fecal culture (IFC), fecal PCR (FPCR), and serum ELISA for the detection of Mycobacterium avium subsp. paratuberculosis (MAP) infections in sheep from four governorates in Egypt, using a latent class model (LCM) fitted within a Bayesian framework. Furthermore, the within-governorate prevalence of MAP infection in sheep was estimated as a secondary objective. Fecal and blood samples were collected from 370 sheep in four Egyptian governorates. Fecal samples were analyzed by IFC and RT-PCR based on ISMav2 gene, while ELISA was performed on serum samples. The sensitivity (Se) and specificity (Sp) of the three diagnostic tests were estimated using a three-tests-four-populations Bayesian LCM to obtain posterior estimates [medians and 95% Bayesian credible intervals (95% BCI)] for each parameter. The median Se estimates (95% BCI) for IFC, FPCR, and serum ELISA were 31.8% (22.8-41.4), 49.7% (31.8-79.9), and 61.2% (39.8-81.4), respectively. The median Sp estimates (95% BCI) for IFC, FPCR, and serum ELISA were 97.7% (96.1-98.9), 97.7% (95.6-99.5), and 98.4% (96.9-99.3), respectively. The median within-governorate paratuberculosis prevalence (95% BCI) was 5.2% (1.1-13.6), 8.4% (2.9-17.7), 9.4% (3.0-20.7), and 18.2% (10.5-29.5) for the Gharbia, Menoufia, Qalyubia, and Kafr El-Sheikh governorates, respectively. In conclusion, at a ratio of the optical density (OD) sample/OD positive control threshold of > 45%, ELISA showed the highest Se among the three tests and comparable Sp to IFC and FPCR. The test ELISA evaluated in this study is an interesting alternative for detecting MAP in sheep due to its higher Se, lower cost, and shorter turnaround laboratory time compared to IFC and FPCR.
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Affiliation(s)
- Ibrahim Elsohaby
- Department of Animal Medicine, Division of Infectious Diseases, Faculty of Veterinary Medicine, Zagazig University, Egypt; Department of Infectious Diseases and Public Health, Jockey Club of Veterinary Medicine and Life Sciences, City University of Hong Kong, Kowloon, Hong Kong.
| | - Juan Carlos Arango-Sabogal
- Département de pathologie et microbiologie, Faculté de médecine vétérinaire, Université de Montréal, Saint-Hyacinthe, Québec J2S 2M2, Canada.
| | - Abdelfattah Selim
- Department of Animal Medicine (Infectious Diseases), Faculty of Veterinary Medicine, Benha University, Egypt
| | - Kotb A Attia
- Department of Biochemistry, College of Science, King Saud University, P.O. Box 2455, Riyadh 11451, Saudi Arabia
| | - Roua A Alsubki
- Department of Clinical Laboratory Science, College of Applied Medical Sciences, King Saud University, P.O. Box 2455, Riyadh 11451, Saudi Arabia
| | - Arif M Mohamed
- Department of Biochemistry, College of Science, King Saud University, P.O. Box 2455, Riyadh 11451, Saudi Arabia
| | - Ameer Megahed
- Department of Animal Medicine (Internal Medicine), Faculty of Veterinary Medicine, Benha University, Egypt; Department of Large Animal Clinical Sciences, College of Veterinary Medicine, University of Florida, FL 32610, USA
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Paratuberculosis: The Hidden Killer of Small Ruminants. Animals (Basel) 2021; 12:ani12010012. [PMID: 35011118 PMCID: PMC8749836 DOI: 10.3390/ani12010012] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2021] [Revised: 12/02/2021] [Accepted: 12/15/2021] [Indexed: 12/15/2022] Open
Abstract
Simple Summary Paratuberculosis is a chronic disease of ruminants and many non-ruminant animals caused by the bacterium Mycobacterium avium subsp. paratuberculosis. Affected animals show diarrhoea, loss of weight, and decreased production performance with consequent economic losses. This bacterium has been detected in some humans suffering from a chronic intestinal disease known as Crohn’s disease (CD) and, therefore, some scientists believe that CD is the human form of paratuberculosis. The disease in small ruminants has been reported in all continents, with goats being more susceptible than sheep. The clinical signs of the disease in goats are not so obvious as often do not show signs of diarrhoea, and the animal may die before being finally diagnosed. In Africa and many developing countries, paratuberculosis is described as a “neglected disease” particularly in small ruminants, which play a vital role in the livelihood of poor communities. This overview attempts to highlight the current research and gaps on this disease in small ruminants to draw more attention for further studies on diagnosis, prevention and control. Abstract Paratuberculosis (PTB) is a contagious and chronic enteric disease of ruminants and many non-ruminants caused by Mycobacterium avium subsp. paratuberculosis (MAP), and is characterised by diarrhoea and progressive emaciation with consequent serious economic losses due to death, early culling, and reduced productivity. In addition, indirect economic losses may arise from trade restrictions. Besides being a production limiting disease, PTB is a potential zoonosis; MAP has been isolated from Crohn’s disease patients and was associated with other human diseases, such as rheumatoid arthritis, Hashimoto’s thyroiditis, Type 1 diabetes, and multiple sclerosis. Paratuberculosis in sheep and goats may be globally distributed though information on the prevalence and economic impact in many developing countries seem to be scanty. Goats are more susceptible to infection than sheep and both species are likely to develop the clinical disease. Ingestion of feed and water contaminated with faeces of MAP-positive animals is the common route of infection, which then spreads horizontally and vertically. In African countries, PTB has been described as a “neglected disease”, and in small ruminants, which support the livelihood of people in rural areas and poor communities, the disease was rarely reported. Prevention and control of small ruminants’ PTB is difficult because diagnostic assays demonstrate poor sensitivity early in the disease process, in addition to the difficulties in identifying subclinically infected animals. Further studies are needed to provide more insight on molecular epidemiology, transmission, and impact on other animals or humans, socio-economic aspects, prevention and control of small ruminant PTB.
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Using Omics Approaches in the Discovery of Biomarkers for Early Diagnosis of Johne's Disease in Sheep and Goats. Animals (Basel) 2021; 11:ani11071912. [PMID: 34199073 PMCID: PMC8300312 DOI: 10.3390/ani11071912] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2021] [Revised: 06/18/2021] [Accepted: 06/23/2021] [Indexed: 12/16/2022] Open
Abstract
Simple Summary Johne’s disease (JD) is caused by Mycobacterium avium subsp. paratuberculosis (MAP) and is an important and emerging problem in livestock. Most JD research has been carried out on cattle, but interest in the pathogenesis and diagnosis of this disease in sheep and goats is greatest in developing countries. Sheep and goats are also a relevant part of livestock production in Europe and Australia, and these species provide an excellent resource to study and better understand the mechanism of survival of MAP and gain insights into possible approaches to control this disease. This review gives an overview of the literature on paratuberculosis in sheep and goats, highlighting the immunological aspects and the potential for “omics” approaches to identify effective biomarkers for the early detection of infection. Abstract Johne’s disease (JD) is caused by Mycobacterium avium subsp. paratuberculosis (MAP) and is an important and emerging problem in livestock; therefore, its control and prevention is a priority to reduce economic losses and health risks. Most JD research has been carried out on cattle, but interest in the pathogenesis and diagnosis of this disease in sheep and goats is greatest in developing countries. Sheep and goats are also a relevant part of livestock production in Europe and Australia, and these species provide an excellent resource to study and better understand the mechanism of survival of MAP and gain insights into possible approaches to control this disease. This review gives an overview of the literature on paratuberculosis in sheep and goats, highlighting the immunological aspects and the potential for “omics” approaches to identify effective biomarkers for the early detection of infection. As JD has a long incubation period before the disease becomes evident, early diagnosis is important to control the spread of the disease.
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Pisanu S, Cubeddu T, Cacciotto C, Pilicchi Y, Pagnozzi D, Uzzau S, Rocca S, Addis MF. Characterization of paucibacillary ileal lesions in sheep with subclinical active infection by Mycobacterium avium subsp. paratuberculosis. Vet Res 2018; 49:117. [PMID: 30514405 PMCID: PMC6278003 DOI: 10.1186/s13567-018-0612-0] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2018] [Accepted: 11/13/2018] [Indexed: 01/10/2023] Open
Abstract
Paratuberculosis (PTB) or Johne's disease is a contagious enteritis of ruminants caused by Mycobacterium avium subsp. paratuberculosis (MAP). Ovine PTB is less understood than bovine PTB, especially concerning paucibacillary infection and its evolution into clinical disease. We combined shotgun proteomics, histopathology and immunohistochemistry for the characterization of ileal tissues collected from seven asymptomatic sheep negative to serum ELISA, positive to feces and tissue MAP IS900 and F57 PCR, histologically classified as paucibacillary, actively infected, together with 3 MAP-free controls (K). Following shotgun proteomics with label-free quantitation and differential analysis, 96 proteins were significantly changed in PTB vs K, and were mostly involved in immune defense processes and in the macrophage-MAP interaction. Principal component analysis (PCA) of protein abundances highlighted two PTB sample clusters, PTB1 and PTB2, indicating a dichotomy in their proteomic profiles. This was in line with the PCA of histopathology data and was related to features of type 2 (PTB1) and type 3a (PTB2) lesions, respectively. PTB2 proteomes differed more than PTB1 proteomes from K: 43 proteins changed significantly only in PTB2 and 11 only in PTB1. The differential proteins cathelicidin, haptoglobin, S100A8 and S100A9 were evaluated by immunohistochemistry. K tissues were negative to cathelicidin and haptoglobin and sparsely positive to S100A8 and S100A9. PTB tissues were positive to all four proteins, with significantly more cells in PTB2 than in PTB1. In conclusion, we described several pathways altered in paucibacillary PTB, highlighted some proteomic differences among paucibacillary PTB cases, and identified potential markers for disease understanding, staging, and detection.
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Affiliation(s)
- Salvatore Pisanu
- Porto Conte Ricerche, SP 55 Porto Conte/Capo Caccia, Km 8.400, Loc. Tramariglio, 07041, Alghero, Italy
| | - Tiziana Cubeddu
- Dipartimento di Medicina Veterinaria, Università degli Studi di Sassari, Via Vienna 2, 07100, Sassari, Italy
| | - Carla Cacciotto
- Porto Conte Ricerche, SP 55 Porto Conte/Capo Caccia, Km 8.400, Loc. Tramariglio, 07041, Alghero, Italy
| | - Ylenia Pilicchi
- Dipartimento di Medicina Veterinaria, Università degli Studi di Sassari, Via Vienna 2, 07100, Sassari, Italy
| | - Daniela Pagnozzi
- Porto Conte Ricerche, SP 55 Porto Conte/Capo Caccia, Km 8.400, Loc. Tramariglio, 07041, Alghero, Italy
| | - Sergio Uzzau
- Porto Conte Ricerche, SP 55 Porto Conte/Capo Caccia, Km 8.400, Loc. Tramariglio, 07041, Alghero, Italy.,Dipartimento di Scienze Biomediche, Università degli Studi di Sassari, Viale S. Pietro 43/B, 07100, Sassari, Italy
| | - Stefano Rocca
- Dipartimento di Medicina Veterinaria, Università degli Studi di Sassari, Via Vienna 2, 07100, Sassari, Italy
| | - Maria Filippa Addis
- Porto Conte Ricerche, SP 55 Porto Conte/Capo Caccia, Km 8.400, Loc. Tramariglio, 07041, Alghero, Italy. .,Dipartimento di Medicina Veterinaria, Università degli Studi di Milano, Via Celoria 10, 20133, Milan, Italy.
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Economic Cost of Ovine Johne's Disease in Clinically Affected New Zealand Flocks and Benefit-Cost of Vaccination. Vet Sci 2018; 5:vetsci5010016. [PMID: 29382184 PMCID: PMC5876568 DOI: 10.3390/vetsci5010016] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/25/2017] [Revised: 01/24/2018] [Accepted: 01/25/2018] [Indexed: 11/17/2022] Open
Abstract
The aims of this study were to estimate the on-fam economic cost of ovine Johne’s disease (OJD) based on collected incidence and mortality data, and the benefit-cost of OJD vaccination in typical OJD affected flocks in New Zealand after having vaccinated for a number of years. Owners of 20 sheep breeding and finishing farms known to be clinically affected by ovine Johne’s disease in New Zealand participated in the study and were monitored for up to two years. Farms were categorized as fine-wool (Merino, Half-Bred, Corriedale, n = 15), and other breeds (Romney, composite breeds, n = 5). Ovine JD was confirmed by gross- and histo-pathology in 358 ewes culled due to chronic progressive wasting. An additional 228 ewes with low body condition score (BCS), but not targeted for culling, were tested with ELISA to estimate the proportion of OJD in ewes in the lower 5% BCS of the flock. Calculations were done separately for fine-wool and other breeds. Based on the data, mortality due to OJD, its associated cost and the benefit-cost of vaccination were evaluated for a hypothetical farm with 2000 ewes by stochastic simulation. Total ewe mortality was similar in fine-wool and other breeds, but the estimated mortality due to OJD was 2.7 times as high in fine-wool (median 1.8%, interquartile range IQR 1.2–2.7%) than other breeds (median 0.69%, IQR 0.3–1.2%), but with large variation between farms. ELISA results demonstrated fine-wool sheep had a higher seroprevalence than other breeds (39%, 95% CI 18–61% vs. 9%, 95% CI 0–22%). Stochastic modelling indicated that the average annual cost of mortality due to OJD in a flock of 2000 ewes was NZD 13,100 (IQR 8900–18,600) in fine-wool and NZD 4300 (IQR 2200–7600) in other breeds. Vaccinating replacement lambs against OJD may be cost-effective in most flocks when the pre-vaccination annual ewe mortality due to OJD is >1%. To make the best-informed decision about vaccination it is therefore essential for farmers to accurately diagnose OJD to establish incidence.
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Mathevon Y, Foucras G, Falguières R, Corbiere F. Estimation of the sensitivity and specificity of two serum ELISAs and one fecal qPCR for diagnosis of paratuberculosis in sub-clinically infected young-adult French sheep using latent class Bayesian modeling. BMC Vet Res 2017; 13:230. [PMID: 28774299 PMCID: PMC5543559 DOI: 10.1186/s12917-017-1145-x] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2017] [Accepted: 07/19/2017] [Indexed: 11/10/2022] Open
Abstract
Background The objective was to evaluate the diagnostic accuracy of two serum ELISAs and one quantitative PCR on feces for the diagnosis of paratuberculosis in sub-clinically infected young-adult sheep. A cross-sectional study was performed to collect 1197 individual blood and fecal samples from 2- to 3-year-old sub-clinically infected ewes in 14 closed meat sheep flocks in France. Fecal excretion was determined using qPCR based on IS900 sequence detection, and serology was performed on serum samples using two commercial ELISAs. Data were analyzed in a 3-test multiple-population Bayesian latent class model accounting for potential dependence between the three tests fitted in OpenBUGS. Separate analyses were performed according to whether doubtful ELISA results were handled as positive or negative and based on two thresholds for fecal qPCR (Ct ≤ 42 or Ct ≤ 40). Results The best fit to the data was provided by accounting for a pairwise dependence between the two ELISAs on sensitivity and pairwise dependence between the three tests on specificity. Under this model, the estimated ELISA sensitivities were 17.4% (95% PCI: 10.6 – 25.9) and 17.9% (95% PCI 11.4 – 25.6), with estimated specificities of 94.8% (95% PCI: 93.1 – 96.3) and 94.0% (95% PCI: 92.2 – 95.7). Fecal qPCR demonstrated significantly higher sensitivity (47.5%; 95% PCI: 29.3 – 69.9) and specificity (99.0%; 95% PCI: 97.9 – 99.9) than the ELISAs. Assumptions regarding doubtful ELISA results and qPCR thresholds had only a slight impact on test accuracy estimates. Models not accounting for pairwise dependence between ELISA and fecal qPCR results yielded higher sensitivity and specificity estimates but always provided a worse fit to the data. Conclusions Although the overall sensitivity of serum ELISAs and fecal qPCR remains low, the higher diagnostic performances of fecal qPCR make it more suitable for paratuberculosis diagnosis in sub-clinically infected sheep. Our results also illustrate that all dependence structures should be investigated when evaluating diagnostic test accuracy and selection based on a rigorous statistical approach. Electronic supplementary material The online version of this article (doi:10.1186/s12917-017-1145-x) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Yoann Mathevon
- IHAP, Ecole Nationale Vétérinaire de Toulouse, 23 chemin des Capelles, F-31076, Toulouse Cedex 3, France
| | - Gilles Foucras
- IHAP, Ecole Nationale Vétérinaire de Toulouse, 23 chemin des Capelles, F-31076, Toulouse Cedex 3, France
| | - Rémy Falguières
- CAPEL Ovilot, 237 avenue Pierre Semard, 46000, Cahors, France
| | - Fabien Corbiere
- IHAP, Ecole Nationale Vétérinaire de Toulouse, 23 chemin des Capelles, F-31076, Toulouse Cedex 3, France.
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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, Zancanaro G, 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): paratuberculosis. EFSA J 2017; 15:e04960. [PMID: 32625604 PMCID: PMC7010113 DOI: 10.2903/j.efsa.2017.4960] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
Paratuberculosis 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 paratuberculosis to be listed, Article 9 for the categorisation of paratuberculosis according to disease prevention and control rules as in Annex IV and Article 8 on the list of animal species related to paratuberculosis. 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, paratuberculosis 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 in Sections 3, 4 and 5 of Annex IV of the AHL, for the application of the disease prevention and control rules referred to in points (c), (d) and (e) of Article 9(1). The animal species to be listed for paratuberculosis according to Article 8(3) criteria are several species of mammals and birds as susceptible species and some species of the families Bovidae, Cervidae and Leporidae as reservoirs.
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Ponce Barraza E, Cárdenas Reyna T, Angulo C, Herrera Ramírez JC, López GV, Medina-Basulto GE, Eda S, Hori-Oshima S. Evaluation of two in-house immunoenzymatic tests to serodiagnose subclinical paratuberculisis in a sheep flock in Mexicali valley, Mexico. J Immunoassay Immunochem 2017; 38:420-429. [PMID: 28422564 DOI: 10.1080/15321819.2017.1319862] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
Paratuberculosis (PTB) or Johne's disease is a common ruminant infectious disease caused by Mycobacterium avium subsp. paratuberculosis (MAP). In this study, two MAP antigens were compared for their diagnostic utility to detect subclinical PTB in a sheep flock in Mexicali, Mexico. Sheep (n = 31) without clinical signs but positive on a direct fecal-polymerase chain reaction were tested with two preabsorbed in-house enzyme linked immunosorbent assays (ELISAs) using: (1) an ethanol-extracted surface lipid antigen (EVELISA) and (2) a protoplasmic antigen (ELISA-PPA). Sensitivities of the EVELISA and ELISA-PPA were 84% (95% CI; 66-95%) and 29% (95% CI; 14-48%), respectively. The EVELISA test could be a fast and effective way to identify subclinical ovine PTB for severely affected flocks.
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Affiliation(s)
- Elizama Ponce Barraza
- a Instituto de Investigaciones en Ciencias Veterinarias , Universidad Autónoma de Baja California , Mexicali Baja California , Mexico
| | - Tomás Cárdenas Reyna
- a Instituto de Investigaciones en Ciencias Veterinarias , Universidad Autónoma de Baja California , Mexicali Baja California , Mexico
| | - Carlos Angulo
- b Immunology & Vaccinology Group , Centro de Investigaciones Biológicas en Noroeste , La Paz , México
| | - José Carlomán Herrera Ramírez
- a Instituto de Investigaciones en Ciencias Veterinarias , Universidad Autónoma de Baja California , Mexicali Baja California , Mexico
| | - Gilberto V López
- a Instituto de Investigaciones en Ciencias Veterinarias , Universidad Autónoma de Baja California , Mexicali Baja California , Mexico
| | - Gerardo Enrique Medina-Basulto
- a Instituto de Investigaciones en Ciencias Veterinarias , Universidad Autónoma de Baja California , Mexicali Baja California , Mexico
| | - Shigetoshi Eda
- c Department of Forestry, Wildlife and Fisheries, Center for Wildlife Health , The University of Tennessee , Knoxville , Tennessee
| | - Sawako Hori-Oshima
- a Instituto de Investigaciones en Ciencias Veterinarias , Universidad Autónoma de Baja California , Mexicali Baja California , Mexico
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Chaubey KK, Gupta RD, Gupta S, Singh SV, Bhatia AK, Jayaraman S, Kumar N, Goel A, Rathore AS, Sahzad, Sohal JS, Stephen BJ, Singh M, Goyal M, Dhama K, Derakhshandeh A. Trends and advances in the diagnosis and control of paratuberculosis in domestic livestock. Vet Q 2016; 36:203-227. [PMID: 27356470 DOI: 10.1080/01652176.2016.1196508] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023] Open
Abstract
Paratuberculosis (pTB) is a chronic granulomatous enteritis caused by Mycobacterium avium subsp. paratuberculosis (MAP) in a wide variety of domestic and wild animals. Control of pTB is difficult due to the lack of sensitive, efficacious and cost-effective diagnostics and marker vaccines. Microscopy, culture, and PCR have been used for the screening of MAP infection in animals for quite a long time. Besides, giving variable sensitivity and specificity, these tests have not been considered ideal for large-scale screening of domestic livestock. Serological tests like ELISA easily detects anti-MAP antibodies. However, it cannot differentiate between the vaccinated and infected animals. Nanotechnology-based diagnostic tests are underway to improve the sensitivity and specificity. Newer generation diagnostic tests based on recombinant MAP secretory proteins would open new paradigm for the differentiation between infected and vaccinated animals and for early detection of the infection. Due to higher seroreactivity of secretory proteins vis-à-vis cellular proteins, the secretory proteins may be used as marker vaccine, which may aid in the control of pTB infection in animals. Secretory proteins can be potentially used to develop future diagnostics, surveillance and monitoring of the disease progression in animals and the marker vaccine for the control and eradication of pTB.
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Affiliation(s)
- Kundan Kumar Chaubey
- a Microbiology Laboratory, Animal Health Division , Central Institute for Research on Goats , Mathura , India.,b Department of Microbiology and Immunology , GLA University , Mathura , India
| | - Rinkoo Devi Gupta
- c Department of Life sciences and Biotechnology , South Asian University , New Delhi , India
| | - Saurabh Gupta
- a Microbiology Laboratory, Animal Health Division , Central Institute for Research on Goats , Mathura , India.,b Department of Microbiology and Immunology , GLA University , Mathura , India
| | - Shoor Vir Singh
- a Microbiology Laboratory, Animal Health Division , Central Institute for Research on Goats , Mathura , India
| | - Ashok Kumar Bhatia
- b Department of Microbiology and Immunology , GLA University , Mathura , India
| | - Sujata Jayaraman
- d Amity Institutes of Microbial Technology , Amity University , Jaipur , India
| | - Naveen Kumar
- a Microbiology Laboratory, Animal Health Division , Central Institute for Research on Goats , Mathura , India
| | - Anjana Goel
- b Department of Microbiology and Immunology , GLA University , Mathura , India
| | - Abhishek Singh Rathore
- c Department of Life sciences and Biotechnology , South Asian University , New Delhi , India
| | - Sahzad
- a Microbiology Laboratory, Animal Health Division , Central Institute for Research on Goats , Mathura , India
| | - Jagdip Singh Sohal
- d Amity Institutes of Microbial Technology , Amity University , Jaipur , India
| | - Bjorn John Stephen
- a Microbiology Laboratory, Animal Health Division , Central Institute for Research on Goats , Mathura , India
| | - Manju Singh
- a Microbiology Laboratory, Animal Health Division , Central Institute for Research on Goats , Mathura , India
| | - Manish Goyal
- e Division of Parasitology , Central Drug Research Institute , Lucknow , India
| | - Kuldeep Dhama
- f Pathology Division , Indian Veterinary Research Institute (IVRI) , Bareilly , India
| | - Abdollah Derakhshandeh
- g Department of Pathobiology, School of Veterinary Medicine , Shiraz University , Shiraz , Iran
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Windsor PA, Eppleston J, Dhand NK, Whittington RJ. Effectiveness of Gudair™ vaccine for the control of ovine Johne's disease in flocks vaccinating for at least 5 years. Aust Vet J 2015; 92:263-8. [PMID: 24964836 DOI: 10.1111/avj.12194] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 12/09/2013] [Indexed: 11/29/2022]
Abstract
OBJECTIVE Examine the prevalence of shedding of Mycobacterium avium subsp. paratuberculosis (Mptb) at least 5 years after starting vaccination with Gudair™ in flocks of varying initial prevalence of ovine Johne's disease (OJD) and identify risk factors for variation in vaccine efficacy. METHODS Pooled faecal culture (PFC) was conducted for 41 flocks from southern NSW and Victoria to determine estimates of current OJD prevalence. The data were compared to estimates of prevalence at or prior to commencement of vaccination at least 5 years earlier, based on available serological or PFC tests when vaccination commenced. A cross-sectional study was conducted to identify risk factors for differing prevalence levels in 36 of the flocks. RESULTS Historical data enabled classification of 37 flocks as high (13; 35.1%), medium (10; 27.0%) or low (14; 37.8%) estimated initial OJD prevalence. Results of PFC in 2008-09 identified that 81.1% (30/37) of flocks had detectable shedders, with 48.6% (18/37) flocks still classified as medium or high OJD prevalence, including 50% (7/14) of flocks initially classified as low prevalence. Shedding was not detected in 18.9% (7/37) flocks. Flocks with OJD prevalence exceeding 1% at 5 years or more following the commencement of vaccination were associated with reports of sheep straying and introduction of new sheep. CONCLUSION Despite significant declines in estimated OJD prevalence following vaccination for ≥5 years, 81.1% of flocks were shedding Mptb and considered at risk of spreading the disease or suffering recrudescence of losses if vaccination were to cease. Flock managers are advised to persist with vaccination.
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Affiliation(s)
- P A Windsor
- Faculty of Veterinary Science, University of Sydney, PMB 3, Camden, New South Wales, 2570, Australia.
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Detection of Mycobacterium avium subsp. paratuberculosis in a sheep flock in Tuscany. Trop Anim Health Prod 2015; 47:1567-71. [PMID: 26245917 DOI: 10.1007/s11250-015-0899-z] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2015] [Accepted: 07/28/2015] [Indexed: 12/17/2022]
Abstract
Paratuberculosis is an infectious disease which affects ruminants. In this work, a sheep flock in Garfagnana district (Tuscany, Italy) was examined by agar gel immune-diffusion (AGID) tests, culture, and PCR from feces, milk, tissue samples, and cheeses. At the first AGID test, 7/280 (2.5 %) animals were positive. From these animals, feces and milk samples were collected: 4/7 feces (57.14 %) and 2/7 milk samples (28.57 %) were positive to culture and 7/7 (100 %) feces samples and 1/7 milk samples (14.28 %) were positive to PCR; 2/4 (50 %) cheeses ripened for 14 days and 1/3 (33.33 %) cheese ripened for 20 days were positive to PCR, from which no viable microorganisms were isolated. Then, the AGID-positive animals were slaughtered and tissue samples were taken from one sheep with PCR-positive feces and milk: the liver, intestine, mesenteric lymph nodes, but not the spleen and mammary lymph nodes were positive to culture; all these samples were instead PCR-positive. After 1 year, a second AGID survey was performed on the remaining animals: 6/244 (2.45 %) subjects were positive to this test. Data obtained revealed the presence of paratuberculosis in a sheep population in Garfagnana.
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12
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Estimation of flock/herd-level true Mycobacterium avium subspecies paratuberculosis prevalence on sheep, beef cattle and deer farms in New Zealand using a novel Bayesian model. Prev Vet Med 2014; 117:447-55. [DOI: 10.1016/j.prevetmed.2014.10.004] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2013] [Revised: 10/03/2014] [Accepted: 10/04/2014] [Indexed: 11/20/2022]
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Prieto JM, Balseiro A, Casais R, Abendaño N, Fitzgerald LE, Garrido JM, Juste RA, Alonso-Hearn M. Sensitive and specific enzyme-linked immunosorbent assay for detecting serum antibodies against Mycobacterium avium subsp. paratuberculosis in fallow deer. CLINICAL AND VACCINE IMMUNOLOGY : CVI 2014; 21:1077-85. [PMID: 24872517 PMCID: PMC4135915 DOI: 10.1128/cvi.00159-14] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/31/2014] [Accepted: 05/22/2014] [Indexed: 11/20/2022]
Abstract
The enzyme-linked immunosorbent assay (ELISA) is the diagnostic test most commonly used in efforts to control paratuberculosis in domestic ruminants. However, commercial ELISAs have not been validated for detecting antibodies against Mycobacterium avium subsp. paratuberculosis in wild animals. In this study, we compared the sensitivities and specificities of five ELISAs using individual serum samples collected from 41 fallow deer with or without histopathological lesions consistent with paratuberculosis. Two target antigenic preparations were selected, an ethanol-treated protoplasmic preparation obtained from a fallow deer M. avium subsp. paratuberculosis isolate (ELISAs A and B) and a paratuberculosis protoplasmic antigen (PPA3) (ELISAs C and D). Fallow deer antibodies bound to the immobilized antigens were detected by using a horseradish peroxidase (HRP)-conjugated anti-fallow deer IgG antibody (ELISAs A and C) or HRP-conjugated protein G (ELISAs B and D). A commercially available assay, ELISA-E, which was designed to detect M. avium subsp. paratuberculosis antibodies in cattle, sheep, and goats, was also tested. Although ELISAs A, C, and E had the same sensitivity (72%), ELISAs A and C were more specific (100%) for detecting fallow deer with lesions consistent with paratuberculosis at necropsy than was the ELISA-E (87.5%). In addition, the ELISA-A was particularly sensitive for detecting fallow deer in the latent stages of infection (62.5%). The antibody responses detected with the ELISA-A correlated with both the severity of enteric lesions and the presence of acid-fast bacteria in gut tissue samples. In summary, our study shows that the ELISA-A can be a cost-effective diagnostic tool for preventing the spread of paratuberculosis among fallow deer populations.
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Affiliation(s)
- José M Prieto
- Department of Animal Health, Department of Agriculture of the Regional Government of the Principality of Asturias, SERIDA, Deva, Asturias, Spain
| | - Ana Balseiro
- Department of Animal Health, Department of Agriculture of the Regional Government of the Principality of Asturias, SERIDA, Deva, Asturias, Spain
| | - Rosa Casais
- Department of Animal Health, Department of Agriculture of the Regional Government of the Principality of Asturias, SERIDA, Deva, Asturias, Spain
| | - Naiara Abendaño
- Department of Animal Health, Basque Institute for Agricultural Research and Development, NEIKER-Tecnalia, Technological Park of Bizkaia, Derio, Bizkaia, Spain
| | - Liam E Fitzgerald
- Department of Animal Health, Basque Institute for Agricultural Research and Development, NEIKER-Tecnalia, Technological Park of Bizkaia, Derio, Bizkaia, Spain
| | - Joseba M Garrido
- Department of Animal Health, Basque Institute for Agricultural Research and Development, NEIKER-Tecnalia, Technological Park of Bizkaia, Derio, Bizkaia, Spain
| | - Ramon A Juste
- Department of Animal Health, Basque Institute for Agricultural Research and Development, NEIKER-Tecnalia, Technological Park of Bizkaia, Derio, Bizkaia, Spain
| | - Marta Alonso-Hearn
- Department of Animal Health, Basque Institute for Agricultural Research and Development, NEIKER-Tecnalia, Technological Park of Bizkaia, Derio, Bizkaia, Spain
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Begum J, Das P, Lingaraju MC, Ranjanna S, Irungbam K, Mohan A, Syam R. Evaluation of efficacy of saponin and freund's incomplete adjuvanted paratuberculosis vaccine in murine model. Vet World 2014. [DOI: 10.14202/vetworld.2014.528-535] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
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15
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Gurung RB, Begg DJ, Purdie AC, Bach H, Whittington RJ. Immunoreactivity of protein tyrosine phosphatase A (PtpA) in sera from sheep infected with Mycobacterium avium subspecies paratuberculosis. Vet Immunol Immunopathol 2014; 160:129-32. [PMID: 24788024 DOI: 10.1016/j.vetimm.2014.03.013] [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: 07/25/2013] [Revised: 03/25/2014] [Accepted: 03/26/2014] [Indexed: 01/29/2023]
Abstract
Evasion of host defense mechanisms and survival inside infected host macrophages are features of pathogenic mycobacteria including Mycobacterium avium subspecies paratuberculosis, the causative agent of Johne's disease in ruminants. Protein tyrosine phosphatase A (PtpA) has been identified as a secreted protein critical for survival of mycobacteria within infected macrophages. The host may mount an immune response to such secreted proteins. In this study, the humoral immune response to purified recombinant M. avium subsp. paratuberculosis PtpA was investigated using sera from a cohort of sheep infected with M. avium subsp. paratuberculosis and compared with uninfected healthy controls. A significantly higher level of reactivity to PtpA was observed in sera collected from M. avium subspecies paratuberculosis infected sheep when compared to those from uninfected healthy controls. PtpA could be a potential candidate antigen for detection of humoral immune responses in sheep infected with M. avium subspecies paratuberculosis.
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Affiliation(s)
- Ratna B Gurung
- Faculty of Veterinary Science, University of Sydney, Camden, NSW, Australia
| | - Douglas J Begg
- Faculty of Veterinary Science, University of Sydney, Camden, NSW, Australia
| | - Auriol C Purdie
- Faculty of Veterinary Science, University of Sydney, Camden, NSW, Australia
| | - Horacio Bach
- Department of Medicine, Division of Infectious Diseases, University of British Columbia, Vancouver, BC, Canada
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16
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Antigenicity in sheep of synthetic peptides derived from stress-regulated Mycobacterium avium subsp. paratuberculosis proteins and comparison with recombinant protein and complex native antigens. Vet Immunol Immunopathol 2014; 158:46-52. [DOI: 10.1016/j.vetimm.2013.05.016] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2012] [Revised: 05/23/2013] [Accepted: 05/29/2013] [Indexed: 11/22/2022]
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Dhand NK, Johnson WO, Eppleston J, Whittington RJ, Windsor PA. Comparison of pre- and post-vaccination ovine Johne's disease prevalence using a Bayesian approach. Prev Vet Med 2013; 111:81-91. [DOI: 10.1016/j.prevetmed.2013.03.003] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2012] [Revised: 03/06/2013] [Accepted: 03/09/2013] [Indexed: 10/27/2022]
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O'Brien R, Hughes A, Liggett S, Griffin F. Composite testing for ante-mortem diagnosis of Johne's disease in farmed New Zealand deer: correlations between bacteriological culture, histopathology, serological reactivity and faecal shedding as determined by quantitative PCR. BMC Vet Res 2013; 9:72. [PMID: 23574863 PMCID: PMC3639118 DOI: 10.1186/1746-6148-9-72] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2013] [Accepted: 04/01/2013] [Indexed: 11/16/2022] Open
Abstract
Background In the absence of overt clinical signs of Johne’s Disease (JD), laboratory based tests have largely been limited to organism detection via faecal culture or PCR and serological tests for antibody reactivity. In this study we describe the application of quantitative faecal PCR for the detection of Mycobacterium avium subsp. paratuberculosis (MAP) in New Zealand farmed deer to quantify the bacterial load in cervine faecal samples as an adjunct to an existing serodiagnostic test (Paralisa™) tailored for JD diagnosis in deer. As ELISA has potential as a cheap, high throughput screening test for JD, an attempt was made to assess the sensitivity, specificity and positive/negative predictive (PPV/NPV) values of Paralisa™ for estimating levels of faecal shedding of MAP as a basis for JD management in deer. Results Correlations were made between diagnostic tests (ELISA, qPCR, culture and histopathology) to establish the precision and predictive values of individual tests. The findings from this study suggest there is strong correlation between bacterial shedding, as determined by faecal qPCR, with both culture (r = 0.9325) and histopathological lesion severity scoring (r = 0.7345). Correlation between faecal shedding and ELISA reactivity in deer was weaker with values of r = 0.4325 and r = 0.4006 for Johnin and Protoplasmic antigens, respectively. At an ELISA Unit (EU) cutoff of >50 (Johnin antigen) the PPV of Paralisa™ for significant faecal shedding in deer (>104 organisms/g) was moderate (0.55) while the NPV was higher (0.89). At an EU cutoff of ≥150, the PPV for shedding >105 organisms/g rose to 0.88, with a corresponding NPV of 0.85. Conclusions The evidence available from this study suggests that Paralisa™ used at a cutoff of 50EU could be used to screen deer herds for MAP infection with sequential qPCR testing used to cull all Paralisa™ positive animals that exhibit significant MAP faecal shedding.
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Affiliation(s)
- Rory O'Brien
- Disease Research Laboratory, Department of Microbiology & Immunology, University of Otago, Dunedin, New Zealand.
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19
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Gardner IA, Nielsen SS, Whittington RJ, Collins MT, Bakker D, Harris B, Sreevatsan S, Lombard JE, Sweeney R, Smith DR, Gavalchin J, Eda S. Consensus-based reporting standards for diagnostic test accuracy studies for paratuberculosis in ruminants. Prev Vet Med 2011; 101:18-34. [PMID: 21601933 DOI: 10.1016/j.prevetmed.2011.04.002] [Citation(s) in RCA: 65] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2010] [Revised: 04/03/2011] [Accepted: 04/05/2011] [Indexed: 11/17/2022]
Abstract
The Standards for Reporting of Diagnostic Accuracy (STARD) statement (www.stard-statement.org) was developed to encourage complete and transparent reporting of key elements of test accuracy studies in human medicine. The statement was motivated by widespread evidence of bias in test accuracy studies and the finding that incomplete or absent reporting of items in the STARD checklist was associated with overly optimistic estimates of test performance characteristics. Although STARD principles apply broadly, specific guidelines do not exist to account for unique considerations in livestock studies such as herd tests, potential use of experimental challenge studies, a more diverse group of testing purposes and sampling designs, and the widespread lack of an ante-mortem reference standard with high sensitivity and specificity. The objective of the present study was to develop a modified version of STARD relevant to paratuberculosis (Johne's disease) in ruminants. Examples and elaborations for each of the 25 items were developed by a panel of experts using a consensus-based approach to explain the items and underlying concepts. The new guidelines, termed STRADAS-paraTB (Standards for Reporting of Animal Diagnostic Accuracy Studies for paratuberculosis), should facilitate improved quality of reporting of the design, conduct and results of paratuberculosis test accuracy studies which were identified as "poor" in a review published in 2008 in Veterinary Microbiology.
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Affiliation(s)
- Ian A Gardner
- Department of Medicine and Epidemiology, School of Veterinary Medicine, University of California, Davis, CA 95616, USA.
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20
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Liapi M, Leontides L, Kostoulas P, Botsaris G, Iacovou Y, Rees C, Georgiou K, Smith G, Naseby D. Bayesian estimation of the true prevalence of Mycobacterium avium subsp. paratuberculosis infection in Cypriot dairy sheep and goat flocks. Small Rumin Res 2011. [DOI: 10.1016/j.smallrumres.2010.09.010] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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21
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Florou M, Leontides L, Kostoulas P, Billinis C, Sofia M. Strain-Specific Sensitivity Estimates ofMycobacterium aviumsubsp.paratuberculosisCulture in Greek Sheep and Goats. Zoonoses Public Health 2009; 56:49-52. [DOI: 10.1111/j.1863-2378.2008.01179.x] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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22
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Nielsen S, Toft N. Ante mortem diagnosis of paratuberculosis: A review of accuracies of ELISA, interferon-γ assay and faecal culture techniques. Vet Microbiol 2008; 129:217-35. [DOI: 10.1016/j.vetmic.2007.12.011] [Citation(s) in RCA: 250] [Impact Index Per Article: 15.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2007] [Revised: 12/11/2007] [Accepted: 12/13/2007] [Indexed: 10/22/2022]
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23
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24
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Berger S, Hinz D, Bannantine JP, Griffin JFT. Isolation of high-affinity single-chain antibodies against Mycobacterium avium subsp. paratuberculosis surface proteins from sheep with Johne's disease. CLINICAL AND VACCINE IMMUNOLOGY : CVI 2006; 13:1022-9. [PMID: 16960114 PMCID: PMC1563570 DOI: 10.1128/cvi.00163-06] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Johne's disease, caused by infection with Mycobacterium avium subsp. paratuberculosis, causes significant economic losses to the livestock farming industry. Improved investigative and diagnostic tools-necessary to understand disease processes and to identify subclinical infection-are much sought after. Here, we describe the production of single-chain antibodies with defined specificity for M. avium subsp. paratuberculosis surface proteins. Single-chain antibodies (scFv) were generated from sheep with Johne's disease by cloning heavy-chain and lambda light-chain variable regions and expressing these in fusion with gene III of filamentous phages. Two scFv clones (designated SurfS1.2 and SurfS2.2) were shown to be immunoreactive against M. avium subsp. paratuberculosis surface targets by flow cytometry, and immunoblotting identified specificity for a 34-kDa proteinase-susceptible determinant. Both antibodies were cross-reactive against Mycobacterium avium subsp. avium but nonreactive against Mycobacterium bovis or Mycobacterium phlei cells and were shown to be capable of enriching M. avium subsp. paratuberculosis cells by a factor of approximately 10(6)-fold when employed in magnetic bead separation of mixed Mycobacterium sp. cultures. Further, magnetic bead separation using SurfS1.2 and SurfS2.2 was capable of isolating as few as 10(3) M. avium subsp. paratuberculosis cells from ovine fecal samples, indicating the diagnostic potential of these reagents. Finally, inclusion of SurfS1.2 or SurfS2.2 in in vitro broth culture with M. avium subsp. paratuberculosis indicated that surface binding activity did not impede bacterial growth, although colony clumping was prevented. These results are discussed in terms of the potential use of single-chain phage display monoclonal antibodies as novel diagnostic reagents.
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Affiliation(s)
- Sven Berger
- Disease Research Laboratory, Department of Microbiology and Immunology, University of Otago, Dunedin, New Zealand
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25
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Kostoulas P, Leontides L, Billinis C, Florou M. Application of a semi-dependent latent model in the Bayesian estimation of the sensitivity and specificity of two faecal culture methods for diagnosis of paratuberculosis in sub-clinically infected Greek dairy sheep and goats. Prev Vet Med 2006; 76:121-34. [PMID: 16797753 DOI: 10.1016/j.prevetmed.2006.04.008] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2005] [Revised: 03/22/2006] [Accepted: 04/25/2006] [Indexed: 11/21/2022]
Abstract
In this study, we compared the frequency of isolation of Mycobacterium avium subsp. paratuberculosis (MAP) from faecal samples grown on Herrold's egg-yolk medium (HEYM) or on Lowenstein-Jensen (LJ) medium and estimated the sensitivity (Se) and specificity (Sp) of the methods separately in sub-clinically infected Greek dairy sheep and goats, using latent-class models and Bayesian estimation procedures. Faecal and blood samples were collected from 400 animals > or =1 year old in April-May 2002. The HEYM supported growth of MAP better than the LJ method and their agreement was very poor (weighted kappa=0.062 (95% CI: -0.098, 0.222)). There was no evidence of dependence between the Ses whereas the Sps were positively correlated. Thus, a semi-dependent model that assumed independence of Ses and accounted for the dependence of Sps was adopted. Under this model, the parallel interpretation of the results of the two methods gave median estimates and 95% credible intervals (CrIs) for Se(par), Sp(par) of 15% (CrIs: 3, 45%), 96% (92, 98%) in sheep and 16% (6, 36%) and 97% (94, 99%) in goats.
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Affiliation(s)
- P Kostoulas
- Laboratory of Epidemiology, Biostatistics and Animal Health Economics, University of Thessaly, Trikalon 224, GR-43100 Karditsa, Greece.
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26
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Kostoulas P, Leontides L, Enøe C, Billinis C, Florou M, Sofia M. Bayesian estimation of sensitivity and specificity of serum ELISA and faecal culture for diagnosis of paratuberculosis in Greek dairy sheep and goats. Prev Vet Med 2006; 76:56-73. [PMID: 16806541 DOI: 10.1016/j.prevetmed.2006.04.006] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2005] [Revised: 03/03/2006] [Accepted: 04/18/2006] [Indexed: 11/16/2022]
Abstract
Latent class models were used to estimate the sensitivity (Se) and the specificity (Sp) of a serum ELISA and a faecal culture (FC) method for the diagnosis of paratuberculosis separately, in sheep and goats. The estimates were obtained by a Bayesian method. Possible dependence of diagnostic errors was investigated by comparing models where independence was assumed to models allowing for conditional dependence given the true disease status. ROC analysis for the serum ELISA was also performed and optimized cut-off values based on the misclassification cost term were determined. No evidence of conditional dependence was found. Assuming independence, posterior medians and 95% credible intervals for the Se(ELISA), Sp(ELISA), Se(FC) and Sp(FC), were 63% (42, 93%), 95% (90, 98%), 8% (2, 17%) and 98% (95, 100%) in goats and 37% (10, 80%), 97% (93, 99%), 16% (2, 48%) and 97% (95, 99%) in sheep. AUC was calculated 0.702 for sheep and 0.847 for goats. For the serum ELISA, there is need of species- and purpose-specific cut-off selection. For instance, with 20% prevalence situation and assuming equal and five-fold cost of a false negative to a false positive test result, the optimal cut-off is 0.3 and 0.05 in sheep, respectively, while it is 0.6 and 0.1 in goats, respectively. Serum ELISA performed better in goats than in sheep. Lowering the cut-off, in relation to the one recommended by the manufacturer, improved Se(ELISA) without seriously compromising Sp(ELISA), in either species.
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Affiliation(s)
- P Kostoulas
- Laboratory of Epidemiology, Biostatistics and Animal Health Economics, University of Thessaly, Trikalon 224, GR-43100 Karditsa, Greece.
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27
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Griffin JFT, Spittle E, Rodgers CR, Liggett S, Cooper M, Bakker D, Bannantine JP. Immunoglobulin G1 enzyme-linked immunosorbent assay for diagnosis of Johne's Disease in red deer (Cervus elaphus). CLINICAL AND DIAGNOSTIC LABORATORY IMMUNOLOGY 2006; 12:1401-9. [PMID: 16339063 PMCID: PMC1317074 DOI: 10.1128/cdli.12.12.1401-1409.2005] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
This study was designed to develop a customized enzyme-linked immunosorbent assay (ELISA) for the serodiagnosis of Johne's disease (JD) in farmed deer. Two antigens were selected on the basis of their superior diagnostic readouts: denatured purified protein derivative (PPDj) and undenatured protoplasmic antigen (PpAg). ELISA development was based on the antigen reactivity of the immunoglobulin G1 (IgG1) isotype, which is a highly specific marker for mycobacterial disease seroreactivity in deer. Sensitivity estimates and test parameters were established using 102 Mycobacterium paratuberculosis-infected animals from more than 10 deer herds, and specificity estimates were determined using 508 uninfected animals from 5 known disease-free herds. A receiver-operated characteristic analysis determined that at a cut point of 50 ELISA units, there was a specificity of 99.5% and sensitivities of 84.0% with PPDj antigen, 88.0% with PpAg, and 91.0% when the antigens were used serially in a composite test. Estimated sensitivity was further improved using recombinant protein antigens unique for M. paratuberculosis, which identified infected animals that were unreactive to PPDj or PpAg. While 80% of animals that were seropositive in the IgG1 ELISA had detectable histopathology, the assay could also detect animals with subclinical disease. The test was significantly less sensitive (75%) for animals that were culture positive for M. paratuberculosis but with no detectable pathology than for those with pathological evidence of JD (>90%). When the IgG1 ELISA was used annually over a 4-year period in a deer herd with high levels of clinical JD, it eliminated clinical disease, increased production levels, and reduced JD-related mortality.
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Affiliation(s)
- J Frank T Griffin
- Disease Research Laboratory, Department of Microbiology and Immunology, University of Otago, PO Box 56, Dunedin, New Zealand.
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28
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Robbe-Austerman S, Gardner IA, Thomsen BV, Morrical DG, Martin BM, Palmer MV, Thoen CO, Ewing C. Sensitivity and specificity of the agar-gel-immunodiffusion test, ELISA and the skin test for detection of paratuberculosis in United States Midwest sheep populations. Vet Res 2006; 37:553-64. [PMID: 16641016 DOI: 10.1051/vetres:2006018] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2005] [Accepted: 01/13/2006] [Indexed: 11/14/2022] Open
Abstract
Our objective was to estimate the sensitivity and specificity of the agar-gel-immunodiffusion test (AGID), the ELISA, and the skin test for the detection of Mycobacterium avium subspecies paratuberculosis (MAP) in sheep using Bayesian methods without a gold standard. Fourteen flocks (2 465 sheep) were used. Five flocks (450 sheep) were considered MAP non-infected and 9 flocks (2 015 sheep) had sheep infected with MAP. Sheep were skin tested and blood was collected for AGID and ELISA testing. Results were analyzed using a Bayesian 3-test in 1-population model fitted in WinBUGS. The model allowed for dependence (correlation) between the two serologic tests, but these two tests were assumed to be conditionally independent of the skin test. The estimated specificity was 99.5% (95% PI of 98.9-99.9%) for the AGID; 99.3% (98.4-99.8%) for the ELISA using an optical density measured cutoff of 0.20; 99.2% (98.1-99.8%) using a cutoff of 0.15; 97.5% (95.8-98.7%) using a cutoff of 0.10; and 98.7% (97.3-99.5%) for the skin test. The estimated sensitivities were 8.3% (6.2-10.7%) for the AGID; 8.0% (6.0-10.4%), 10.6% (8.3-13.1%), and 16.3% (13.5-19.4%) for the ELISA using the cutoffs 0.20, 0.15, and 0.10 respectively; and 73.3% (62.3-85.8%) for the skin test. The skin test was specific in non-infected populations and sensitive in infected populations, although in some cases a positive skin test might represent MAP exposure rather than infection. The AGID and ELISA were specific but lacked sensitivity. The AGID and ELISA consistently identified two different populations of infected sheep with only moderate overlap between positive test results.
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Affiliation(s)
- Suelee Robbe-Austerman
- National Animal Disease Center, Agricultural Research Service, USDA, 2300 Dayton, Ames, Iowa 50010, USA.
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29
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Kostoulas P, Leontides L, Billinis C, Amiridis GS, Florou M. The association of sub-clinical paratuberculosis with the fertility of Greek dairy ewes and goats varies with parity. Prev Vet Med 2006; 74:226-38. [PMID: 16406563 DOI: 10.1016/j.prevetmed.2005.12.001] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2005] [Revised: 11/07/2005] [Accepted: 12/02/2005] [Indexed: 11/25/2022]
Abstract
Our cross-sectional study investigated the association of sub-clinical Mycobacterium avium subsp. paratuberculosis (MAP) infection with failing to produce a live offspring the season of lambing/kidding (November 2001 to January 2002) before testing (in April-May 2002), in four dairy-sheep and/or goat flocks in Greece (369 animals >or=1.5-year-old). From each selected animal 10 ml of blood and 10 g of feces from the rectum were obtained. The harvested sera were tested for antibodies to MAP with a commercial ELISA test kit; the feces were cultured on Herrold's egg-yolk medium supplemented with mycobactin J and antibiotics. An animal was considered sub-clinically infected when found either seropositive or culture positive. The true prevalence of sub-clinically infected animals, adjusted for the sensitivity and specificity of the parallel testing, was 14% (0.1-28%) and 35.9% (9.2-62.7%) in sheep and goats, respectively. The association of fertility of sheep and goats with sub-clinical paratuberculosis was investigated in random-effects logistic models. Sub-clinically infected animals (compared to uninfected) had OR for live offspring the previous year of 5.4 for parity <4, OR=0.05 for parity >6, and a non-significant OR for the middle parity category.
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Affiliation(s)
- P Kostoulas
- Laboratory of Epidemiology, Biostatistics and Animal Health Economics, School of Veterinary Medicine, University of Thessaly, 224 Trikalon st., 43100 Karditsa, Greece.
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McKenna S, Keefe G, Barkema H, McClure J, VanLeeuwen J, Hanna P, Sockett D. Cow-Level Prevalence of Paratuberculosis in Culled Dairy Cows in Atlantic Canada and Maine. J Dairy Sci 2004; 87:3770-7. [DOI: 10.3168/jds.s0022-0302(04)73515-8] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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Munjal SK, Boehmer J, Beyerbach M, Strutzberg-Minder K, Homuth M. Evaluation of a LAM ELISA for diagnosis of paratuberculosis in sheep and goats. Vet Microbiol 2004; 103:107-14. [PMID: 15381273 DOI: 10.1016/j.vetmic.2004.07.019] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2004] [Revised: 07/12/2004] [Accepted: 07/29/2004] [Indexed: 10/26/2022]
Abstract
A milk and serum ELISA containing lipoarabinomanan (LAM) antigen was evaluated in sheep and goats versus agar gel immunodiffusion (AGID) test and polymerase chain reaction (PCR) using milk and lymph nodes. Milk and serum samples were obtained from six, two, and four flocks with unknown, negative and positive status of infection, respectively. By comparison of serum ELISA activity and PCR results, the positive and negative predictive values were calculated. Receiver operation characteristic (ROC) analysis was used for calculating the specificity and sensitivity at different cut-offs.
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Affiliation(s)
- S K Munjal
- Division of Pathology, Indian Veterinary Research Institute, Izatnagar 243122, UP, India
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