1
|
Garcia-Morante B, Maes D, Sibila M, Betlach AM, Sponheim A, Canturri A, Pieters M. Improving Mycoplasma hyopneumoniae diagnostic capabilities by harnessing the infection dynamics. Vet J 2022; 288:105877. [PMID: 35901923 DOI: 10.1016/j.tvjl.2022.105877] [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: 04/08/2021] [Revised: 07/15/2022] [Accepted: 07/23/2022] [Indexed: 11/17/2022]
Abstract
Mycoplasma hyopneumoniae remains one of the most problematic bacterial pathogens for pig production. Despite an abundance of observational and laboratory testing capabilities for this organism, diagnostic interpretation of test results can be challenging and ambiguous. This is partly explained by the chronic nature of M. hyopneumoniae infection and its tropism for lower respiratory tract epithelium, which affects diagnostic sensitivities associated with sampling location and stage of infection. A thorough knowledge of the available tools for routine M. hyopneumoniae diagnostic testing, together with a detailed understanding of infection dynamics, are essential for optimizing sampling strategies and providing confidence in the diagnostic process. This study reviewed known information on sampling and diagnostic tools for M. hyopneumoniae and summarized literature reports of the dynamics of key infection outcomes, including clinical signs, lung lesions, pathogen detection, and humoral immune responses. Such knowledge could facilitate better understanding of the performance of different diagnostic approaches at various stages of infection.
Collapse
Affiliation(s)
- Beatriz Garcia-Morante
- Department of Veterinary Population Medicine, College of Veterinary Medicine, University of Minnesota, 1365 Gortner Ave, St. Paul, MN 55108, USA; IRTA, Centre de Recerca en Sanitat Animal (CReSA, IRTA-UAB), Campus de la Universitat Autònoma de Barcelona, 08193 Bellaterra, Spain
| | - Dominiek Maes
- Department of Reproduction, Obstetrics and Herd Health, Faculty of Veterinary Medicine, Unit Porcine Health Management, Ghent University, Salisburylaan, 133 B-9820 Merelbeke, Belgium
| | - Marina Sibila
- IRTA, Centre de Recerca en Sanitat Animal (CReSA, IRTA-UAB), Campus de la Universitat Autònoma de Barcelona, 08193 Bellaterra, Spain
| | - Alyssa M Betlach
- Department of Veterinary Population Medicine, College of Veterinary Medicine, University of Minnesota, 1365 Gortner Ave, St. Paul, MN 55108, USA; Swine Vet Center, 1608 S Minnesota Ave, St. Peter, MN 56082, USA
| | - Amanda Sponheim
- Department of Veterinary Population Medicine, College of Veterinary Medicine, University of Minnesota, 1365 Gortner Ave, St. Paul, MN 55108, USA; Boehringer Ingelheim Animal Health USA Inc., 3239 Satellite Blvd NW, Duluth, GA 30096, USA
| | - Albert Canturri
- Department of Veterinary Population Medicine, College of Veterinary Medicine, University of Minnesota, 1365 Gortner Ave, St. Paul, MN 55108, USA
| | - Maria Pieters
- Department of Veterinary Population Medicine, College of Veterinary Medicine, University of Minnesota, 1365 Gortner Ave, St. Paul, MN 55108, USA; Veterinary Diagnostic Laboratory, College of Veterinary Medicine, University of Minnesota, 1333 Gortner Ave, St Paul, 55108 MN, USA; Swine Disease Eradication Center, College of Veterinary Medicine, University of Minnesota, 1988 Fitch Ave, St. Paul, MN 55108, USA.
| |
Collapse
|
2
|
Fablet C, Rose N, Grasland B, Robert N, Lewandowski E, Gosselin M. Factors associated with the growing-finishing performances of swine herds: an exploratory study on serological and herd level indicators. Porcine Health Manag 2018; 4:6. [PMID: 29588859 PMCID: PMC5863451 DOI: 10.1186/s40813-018-0082-9] [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: 10/23/2017] [Accepted: 01/22/2018] [Indexed: 12/20/2022] Open
Abstract
Background Growing and finishing performances of pigs strongly influence farm efficiency and profitability. The performances of the pigs rely on the herd health status and also on several non-infectious factors. Many recommendations for the improvement of the technical performances of a herd are based on the results of studies assessing the effect of one or a limited number of infections or environmental factors. Few studies investigated jointly the influence of both type of factors on swine herd performances. This work aimed at identifying infectious and non-infectious factors associated with the growing and finishing performances of 41 French swine herds. Results Two groups of herds were identified using a clustering analysis: a cluster of 24 herds with the highest technical performance values (mean average daily gain = 781.1 g/day +/− 26.3; mean feed conversion ratio = 2.5 kg/kg +/− 0.1; mean mortality rate = 4.1% +/− 0.9; and mean carcass slaughter weight = 121.2 kg +/− 5.2) and a cluster of 17 herds with the lowest performance values (mean average daily gain =715.8 g/day +/− 26.5; mean feed conversion ratio = 2.6 kg/kg +/− 0.1; mean mortality rate = 6.8% +/− 2.0; and mean carcass slaughter weight = 117.7 kg +/− 3.6). Multiple correspondence analysis was used to identify factors associated with the level of technical performance. Infection with the porcine reproductive and respiratory syndrome virus and the porcine circovirus type 2 were infectious factors associated with the cluster having the lowest performance values. This cluster also featured farrow-to-finish type herds, a short interval between successive batches of pigs (≤3 weeks) and mixing of pigs from different batches in the growing or/and finishing steps. Inconsistency between nursery and fattening building management was another factor associated with the low-performance cluster. The odds of a herd showing low growing-finishing performance was significantly increased when infected by PRRS virus in the growing-finishing steps (OR = 8.8, 95% confidence interval [95% CI]: 1.8–41.7) and belonging to a farrow-to-finish type herd (OR = 5.1, 95% CI = 1.1–23.8). Conclusions Herd management and viral infections significantly influenced the performance levels of the swine herds included in this study. Electronic supplementary material The online version of this article (10.1186/s40813-018-0082-9) contains supplementary material, which is available to authorized users.
Collapse
Affiliation(s)
- C Fablet
- 1Agence Nationale de Sécurité Sanitaire de l'alimentation, de l'environnement et du travail (Anses), Laboratoire de Ploufragan/Plouzané, Unité Epidémiologie et Bien-Etre du Porc, B.P. 53, 22440 Ploufragan, France.,Université Bretagne-Loire, Cité internationale 1 place Paul Ricoeur CS 54417, 35044 Rennes, France
| | - N Rose
- 1Agence Nationale de Sécurité Sanitaire de l'alimentation, de l'environnement et du travail (Anses), Laboratoire de Ploufragan/Plouzané, Unité Epidémiologie et Bien-Etre du Porc, B.P. 53, 22440 Ploufragan, France.,Université Bretagne-Loire, Cité internationale 1 place Paul Ricoeur CS 54417, 35044 Rennes, France
| | - B Grasland
- 2Agence Nationale de Sécurité Sanitaire de l'alimentation, de l'environnement et du travail (Anses), Laboratoire de Ploufragan/Plouzané, Unité Génétique Virale et Biosécurité, B.P. 53, 22440 Ploufragan, France.,Université Bretagne-Loire, Cité internationale 1 place Paul Ricoeur CS 54417, 35044 Rennes, France
| | - N Robert
- 3Boehringer Ingelheim France - Santé Animale, Les Jardins de la Teillais, 3 allée de la grande Egalonne, 35740 Pacé, France
| | - E Lewandowski
- 3Boehringer Ingelheim France - Santé Animale, Les Jardins de la Teillais, 3 allée de la grande Egalonne, 35740 Pacé, France
| | - M Gosselin
- Univet Santé Elevage, rue Monge, 22600 Loudéac, France
| |
Collapse
|
3
|
Ameri M, Zhou EM, Hsu WH. Western Blot Immunoassay as a Confirmatory Test for the Presence of Anti-Mycoplasma Hyopneumoniae Antibodies in Swine Serum. J Vet Diagn Invest 2016; 18:198-201. [PMID: 16617702 DOI: 10.1177/104063870601800210] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022] Open
Abstract
A Western blot immunoassay (WBI) was developed as a confirmatory test for 2 commercial Mycoplasma hyopneumoniae (Mhyo) ELISAs. The WBI detected at least 5 antigen bands (150, 130, 74, 70, and 30 kDa) from Mhyo whole membrane proteins that were not present in the antigens prepared from M. hyorhinis and M. hyosynoviae. Among discrepant sera from vaccinated pigs ( n = 17) and field samples ( n = 91) assayed by WBI: 1) 2 of the ELISA-positive samples reacted with all 5 antigens bands; 2) all blocking ELISA-positive samples ( n = 53) bound 150-, 130-, 74-, and 70-kD antigen bands; and 3) all indirect ELISA-positive samples ( n = 55) bound 150-, 130-, and 30-kD antigens. We conclude that the WBI targeting the top 4 antigen bands is a useful confirmatory test for samples initially screened using the commercial Mhyo ELISAs.
Collapse
Affiliation(s)
- Mehrdad Ameri
- Department of Veterinary Diagnostic and Production Animal Medicine, College of Veterinary Medicine, Iowa State University, Ames 50011, USA
| | | | | |
Collapse
|
4
|
Pujols J, Segalés J, Polo J, Rodríguez C, Campbell J, Crenshaw J. Influence of spray dried porcine plasma in starter diets associated with a conventional vaccination program on wean to finish performance. Porcine Health Manag 2016; 2:4. [PMID: 28405430 PMCID: PMC5382401 DOI: 10.1186/s40813-016-0021-6] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2015] [Accepted: 01/20/2016] [Indexed: 12/03/2022] Open
Abstract
Background Conventional vaccination programs using a single injection of a combined vaccine against porcine circovirus type 2 (PCV2) and Mycoplasma hyopneumoniae (MHYO) can promote a strong immune response that reduces feed intake for 24 to 48 h post injection. Often such vaccines are given around the time of weaning during a critical stress period in which feed intake is already compromised. Spray dried porcine plasma (SDPP) is a protein source used in starter diets that increases post-weaning feed intake of pigs. The objectives of this study were to determine the effects of a conventional vaccination program along with feeding SDPP in a starter diet on antibody development and wean to finish performance of pigs. Results Pigs fed the starter diet with SDPP had improved body weight, average daily weight gain and average daily feed intake during the initial 14 d after weaning along with improved feed efficiency during the initial 7 d after weaning and these responses were independent of vaccination. Vaccination at 3 d after weaning had no significant effect on performance during the initial 14 d after weaning. Cumulative mortality was reduced for pigs fed the starter diet with SDPP, while vaccinated pigs had reduced mortality from d 48 to 145. Both vaccinated pigs and those fed the starter diet with SDPP had heavier carcass weight. One pig per pen was challenged with PCV2 at d 63. A higher percentage of vaccinated pigs were sero-positive for antibodies against PCV2 and MHYO at d 35, 63 and 78. Antibody values against PCV2 were higher for vaccinated pigs at d 35 and 63, but lower at d 146. Percentage of positive samples for PCV2 genome in serum was reduced for vaccinated pigs at d 117 and 146. Antibody values against MHYO were increased for vaccinated pigs at d 35, 63 and 78. Conclusions Vaccination supported a long term antibody response against PCV2 and a moderate but weaker antibody response against MHYO for early finishing pigs challenged with PCV2. Using SDPP in the starter diet along with vaccination supported the best long-term beneficial effects on survival to market and carcass weight.
Collapse
Affiliation(s)
- Joan Pujols
- IRTA, Centre de Recerca en Sanitat Animal (CReSA, IRTA-UAB), Campus de la Universitat Autònoma de Barcelona, 08193 Bellaterra, Barcelona, Spain
| | - Joaquim Segalés
- UAB, Centre de Recerca en Sanitat Animal (CReSA, IRTA-UAB), Campus de la Universitat Autònoma de Barcelona, 08193 Bellaterra, Barcelona, Spain.,Departament de Sanitat i Anatomia Animals, Universitat Autònoma de Barcelona (UAB), 08193 Bellaterra, Barcelona, Spain
| | - Javier Polo
- APC EUROPE, S.A. Avda, Sant Julià 246-258, Pol. Ind. El Congost, E-08403 Granollers, Spain
| | - Carmen Rodríguez
- APC EUROPE, S.A. Avda, Sant Julià 246-258, Pol. Ind. El Congost, E-08403 Granollers, Spain
| | - Joy Campbell
- APC Inc., 2425 SE Oak Tree Court, Ankeny, IA 50021 USA
| | - Joe Crenshaw
- APC Inc., 2425 SE Oak Tree Court, Ankeny, IA 50021 USA
| |
Collapse
|
5
|
Fano E, Pijoan C, Dee S, Deen J. Longitudinal assessment of two Mycoplasma hyopneumoniae enzyme-linked immunosorbent assays in challenged and contact-exposed pigs. J Vet Diagn Invest 2012; 24:383-7. [PMID: 22379055 DOI: 10.1177/1040638711434942] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
The objective of the current study was to compare the sensitivity of 2 Mycoplasma hyopneumoniae enzyme-linked immunosorbent assays (ELISAs) in experimentally challenged and contact-exposed pigs in a long-term longitudinal assessment. On day 0 of the assessment, twelve 2-month-old M. hyopneumoniae-negative pigs were inoculated with M. hyopneumoniae strain 232 (group A). Twelve negative pigs were placed alongside the inoculated pigs, allowing direct contact exposure (group B). A third group of 12 pigs was allocated into 2 independent pens; no direct contact was allowed (group C). A longitudinal serologic profile was performed; samples were collected on days 0, 28, 35, 42, 49, 63, 91, 119, 154, and 170 of the study. Serum samples were tested using a blocking ELISA and an indirect ELISA. Results of the study demonstrated higher sensitivity of the blocking ELISA during early infection (clinical signs). Both ELISAs were 100% sensitive in challenged and naturally infected groups at several testing points during late infection (63, 91, 119, 154, and 170 days of the study) and showed a long antibody detection period. Both tests worked equally well during the chronic phase of infection but the blocking ELISA was more sensitive during acute stages of infection.
Collapse
|
6
|
Characterization of a highly immunogenic Mycoplasma hyopneumoniae lipoprotein Mhp366 identified by peptide-spot array. Vet Microbiol 2009; 142:293-302. [PMID: 19913364 DOI: 10.1016/j.vetmic.2009.10.007] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2009] [Revised: 10/05/2009] [Accepted: 10/07/2009] [Indexed: 01/10/2023]
Abstract
Enzootic pneumonia (EP) in pigs caused by Mycoplasma hyopneumoniae is a highly prevalent, chronic respiratory disease, which causes considerable economic losses in the swine industry. Most herds are vaccinated, but classical bacterin vaccines do not prevent colonization and it is not possible to detect flourishing M. hyopneumoniae infections in vaccinated herds since commonly used commercial ELISAs cannot differentiate infected from vaccinated animals. To solve this problem, new immunogenic proteins, up-regulated or solely expressed during infection, need to be identified. For this purpose a peptide-spot array was constructed which presents 105 potential linear B-cell epitopes identified by in silico analysis in 35 putative lipoproteins encoded on the genome of M. hyopneumoniae type strain 232. Subjecting this array to immunoblotting using porcine convalescent serum revealed a single strongly immunoreactive epitope on the Mhp366 protein which did not react with serum from bacterin-immunized pigs. In addition, it was not possible to detect Mhp366 in total cell lysates of in vitro grown M. hyopneumoniae strains, using a polyclonal rabbit serum raised against a recombinant GST-Mhp366 fusion protein. To investigate the possibility of using an Mhp366-based ELISA in the field for differentiating vaccinated herds with and without a flourishing infection it was shown that (i) homologues of the corresponding mhp366 gene were present in all 17 M. hyopneumoniae strains and porcine lung samples tested from different geographic origins and (ii) an ELISA based on epitope-specific synthetic peptides as solid phase antigen allowed a classification of field samples. Therefore, Mhp366 might be the first antigen identified which facilitates the detection of flourishing M. hyopneumoniae infections even in vaccinated herds.
Collapse
|
7
|
Prabakaran M, Ho HT, Prabhu N, Velumani S, Szyporta M, He F, Chan KP, Chen LM, Matsuoka Y, Donis RO, Kwang J. Development of epitope-blocking ELISA for universal detection of antibodies to human H5N1 influenza viruses. PLoS One 2009; 4:e4566. [PMID: 19238211 PMCID: PMC2642733 DOI: 10.1371/journal.pone.0004566] [Citation(s) in RCA: 55] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2008] [Accepted: 01/06/2009] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND Human infections with highly pathogenic H5N1 avian influenza viruses have generally been confirmed by molecular amplification or culture-based methods. Serologic surveillance has potential advantages which have not been realized because rapid and specific serologic tests to detect H5N1 infection are not widely available. METHODOLOGY/PRINCIPAL FINDINGS Here we describe an epitope-blocking ELISA to detect specific antibodies to H5N1 viruses in human or animal sera. The assay relies on a novel monoclonal antibody (5F8) that binds to an epitope comprising amino acid residues 274-281 (CNTKCQTP) in the HA1 region of H5 hemagglutinin. Database search analysis of publicly available sequences revealed that this epitope is conserved in 100% of the 163 H5N1 viruses isolated from humans. The sensitivity and specificity of the epitope-blocking ELISA for H5N1 were evaluated using chicken antisera to multiple virus clades and other influenza subtypes as well as serum samples from individuals naturally infected with H5N1 or seasonal influenza viruses. The epitope-blocking ELISA results were compared to those of hemagglutinin inhibition (HI) and microneutralization assays. Antibodies to H5N1 were readily detected in immunized animals or convalescent human sera by the epitope-blocking ELISA whereas specimens with antibodies to other influenza subtypes yielded negative results. The assay showed higher sensitivity and specificity as compared to HI and microneutralization. CONCLUSIONS/SIGNIFICANCE The epitope-blocking ELISA based on a unique 5F8 mAb provided highly sensitive and 100% specific detection of antibodies to H5N1 influenza viruses in human sera.
Collapse
Affiliation(s)
- Mookkan Prabakaran
- Animal Health Biotechnology, Temasek Life Sciences Laboratory, National University of Singapore, Singapore, Singapore
| | - Hui-Ting Ho
- Animal Health Biotechnology, Temasek Life Sciences Laboratory, National University of Singapore, Singapore, Singapore
| | - Nayana Prabhu
- Animal Health Biotechnology, Temasek Life Sciences Laboratory, National University of Singapore, Singapore, Singapore
| | - Sumathy Velumani
- Animal Health Biotechnology, Temasek Life Sciences Laboratory, National University of Singapore, Singapore, Singapore
| | - Milene Szyporta
- Animal Health Biotechnology, Temasek Life Sciences Laboratory, National University of Singapore, Singapore, Singapore
| | - Fang He
- Animal Health Biotechnology, Temasek Life Sciences Laboratory, National University of Singapore, Singapore, Singapore
| | - Kwai-Peng Chan
- Department of Pathology, Singapore General Hospital, Singapore, Singapore
| | - Li-Mei Chen
- Influenza Division, Centers for Disease Control and Prevention, Atlanta, Georgia, United States of America
| | - Yumiko Matsuoka
- Influenza Division, Centers for Disease Control and Prevention, Atlanta, Georgia, United States of America
| | - Ruben O. Donis
- Influenza Division, Centers for Disease Control and Prevention, Atlanta, Georgia, United States of America
| | - Jimmy Kwang
- Animal Health Biotechnology, Temasek Life Sciences Laboratory, National University of Singapore, Singapore, Singapore
- Department of Microbiology, Faculty of Medicine, National University of Singapore, Singapore, Singapore
| |
Collapse
|
8
|
Seroprevalence and risk factors associated with seropositivity in sows from 67 herds in north-west Germany infected with Mycoplasma hyopneumoniae. Prev Vet Med 2008; 88:255-63. [PMID: 19101052 DOI: 10.1016/j.prevetmed.2008.10.005] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2008] [Revised: 10/14/2008] [Accepted: 10/16/2008] [Indexed: 11/21/2022]
Abstract
Risk factors for the spread of Mycoplasma hyopneumoniae in sows have not been studied although vertical transmission from sows to their offspring is considered a significant risk factor in the development of enzootic pneumonia in growers and finishers. Seropositivity for M. hyopneumoniae in sows, as assessed by commercial ELISA, is a possible indicator of infection pressure among sows. The objective of this study was to estimate seroprevalence and associated risk factors of a sow being seropositive for M. hyopneumoniae. A cross-sectional study was carried out in 2578 sows from 67 herds in north-west Germany. Data concerning general herd characteristics, acclimatisation practices, indoor and outside contacts, as well as data describing the immediate local environment were collected during a herd visit via questionnaire. Blood samples were seropositive in 65% of the 2578 sows, and all herds had >/=14% seropositive sows. Data analysis was performed in two steps. First, univariate analysis of predictor variables for the risk of a sow being seropositive for M. hyopneumoniae was performed using chi-square test. Secondly, all variables associated with the risk of a sow being seropositive (P</=0.25) were included in a multivariate model using a generalised linear model. The risk of a sow being seropositive for M. hyopneumoniae was increased in herds with two- or three-site production (OR 1.50), when piglets were not vaccinated against M. hyopneumoniae (OR 1.81), in herds with a 2-week farrowing intervals (OR 1.84) and in herds without all-in/all-out management of the farrowing units (OR 1.37). The lack of an acclimatisation period for replacement boars was also associated with the risk of a sow being seropositive (OR 2.10). The results indicate that M. hyopneumoniae seropositivity is common in sows in north-west Germany and is influenced by various management factors. It is recommended that evaluation of sow herd management should be included in any strategic health plan to control M. hyopneumoniae infection.
Collapse
|
9
|
Sibila M, Pieters M, Molitor T, Maes D, Haesebrouck F, Segalés J. Current perspectives on the diagnosis and epidemiology of Mycoplasma hyopneumoniae infection. Vet J 2008; 181:221-31. [PMID: 18396428 PMCID: PMC7110805 DOI: 10.1016/j.tvjl.2008.02.020] [Citation(s) in RCA: 121] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2007] [Revised: 02/13/2008] [Accepted: 02/22/2008] [Indexed: 11/28/2022]
Abstract
Mycoplasma hyopneumoniae is the principal aetiological agent of enzootic pneumonia (EP), a chronic respiratory disease that affects mainly finishing pigs. Although major efforts to control M. hyopneumoniae infection and its detrimental effects have been made, significant economic losses in pig production worldwide due to EP continue. M. hyopneumoniae is typically introduced into pig herds by the purchase of subclinically infected animals or, less frequently, through airborne transmission over short distances. Once in the herd, M. hyopneumoniae may be transmitted by direct contact from infected sows to their offspring or between pen mates. The ‘gold standard’ technique used to diagnose M. hyopneumoniae infection, bacteriological culture, is laborious and is seldom used routinely. Enzyme-linked immunosorbent assay and polymerase chain reaction detection methods, in addition to post-mortem inspection in the form of abattoir surveillance or field necropsy, are the techniques most frequently used to investigate the potential involvement of M. hyopneumoniae in porcine respiratory disease. Such techniques have been used to monitor the incidence of M. hyopneumoniae infection in herds both clinically and subclinically affected by EP, in vaccinated and non-vaccinated herds and under different production and management conditions. Differences in the clinical course of EP at farm level and in the efficacy of M. hyopneumoniae vaccination suggest that the transmission and virulence characteristics of different field isolates of M. hyopneumoniae may vary. This paper reviews the current state of knowledge of the epidemiology of M. hyopneumoniae infection including its transmission, infection and seroconversion dynamics and also compares the various epidemiological tools used to monitor EP.
Collapse
Affiliation(s)
- Marina Sibila
- Centre de Recerca en Sanitat Animal (CReSA), UAB-IRTA, Campus de la Universitat Autònoma de Barcelona, 08193 Bellaterra, Barcelona, Spain.
| | | | | | | | | | | |
Collapse
|