An Investigation of the Pathology and Pathogens Associated with Porcine Respiratory Disease Complex in Denmark

Hansen, Mette Sif; Pors, Susanne Elisabeth; Jensen, Henrik Elvang; Bille‐Hansen, Vivi; Bisgaard, Magne; Flachs, Esben Meulengracht; Nielsen, Ole Lerberg

doi:10.1016/j.jcpa.2010.01.012

Cited by 179 publications

(248 citation statements)

References 19 publications

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“…PRRS virus is exotic in Brazil. Pasteurella multocida (P. multocida) appears as the most common bacterial agent in PRDC related to pleuropneumonia cases (Morés 2006, Hansen et al 2010, Fablet et al 2011.…”

Section: Introductionmentioning

confidence: 99%

Anatomopathological pneumonic aspects associated with highly pathogenic Pasteurella multocida in finishing pigs

et al. 2017

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The bacterium Pasteurella multocida is a frequent cause of porcine respiratory disease complex in finishing pigs. Historically, the bacterium is recognized as an opportunistic agent, causing secondary bacterial pneumonia in pigs. Several Brazilian reports have suggested the ability of P. multocida to cause primary pulmonary infection that leads to the death of finishing pigs prior to slaughter. The aim of this study was to evaluate anatomopathological pulmonary findings associated with P. multocida infection that were obtained from animals with clinical respiratory disease and from animals at slaughter. Twenty-five lung samples from 14 herds of finishing pigs with acute clinical respiratory disease and 19 lungs collected at slaughter from a different set of 14 herds were studied. In all lung samples, bacterial isolation was performed, and only samples with pure P. multocida growth were included in the study. Gross and histopathological lesions were evaluated, as well as Influenza A, porcine circovirus type 2 (PCV2) and Mycoplasma hyopneumoniae co-infections. Pleuritis and pericarditis were more often observed in clinical samples (P<0.05). Moreover, there was a numerical trend indicating that pericarditis, lymphadenomegaly and cavity exudates were more often present in clinical samples. Thirteen lung samples were negative to M. hyopneumoniae, Influenza A and PCV2 by immunohistochemistry (IHC), with only P. multocida identified. In these cases, gross lesions such as pleuritis, pericarditis and lymphadenomegaly were always present, and no histologic lesions indicative of other agents such as Actinobacillus pleuropneumoniae, Actinobacillus suis or Haemophilus parasuis were observed. These findings suggest the ability of some P. multocida isolates to cause primary respiratory and systemic infection. However, in this study, it was not possible to determine specific virulence markers to explain these findings.

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Section: Introductionmentioning

confidence: 99%

Anatomopathological pneumonic aspects associated with highly pathogenic Pasteurella multocida in finishing pigs

et al. 2017

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“…Epithelial hyperplasia in the bronchus and in the bronchioles was observed in 4 cases with BALT hyperplasia. This characteristic feature results from the adherence of M. hyopneumoniae to the cilia (Hansen et al 2010). Observation of epithelial hyperplasia can be impaired in samples that have some degree of autolysis, which was the case with sample #7.…”

Section: Discussionmentioning

confidence: 98%

“…Among the histological ϐindings in the swine lungs, BALT hyperplasia is one of the most indicative of M. hyopneumoniae infection (Sarradel et al 2003, Redondo et al 2009, Hansen et al 2010. The presence of macrophages, neutrophils and alveolar edema is commonly associated with secondary bacterial infection (Redondo et al 2009, Hansen et al 2010.…”

Section: Discussionmentioning

confidence: 99%

“…Despite its low mortality rate, M. hyopneumoniae infections are associated with high morbidity rates. The agents adherence to the cilia of the epithelial cells in the lower airways affects the mucociliary defense mechanism and assists in the entrance of other bacteria, resulting in delayed growth in the affected animals and carcass condemnation at slaughter (Desrosiers 2001, Srinivasan et al 2002, Martínez et al 2007, Hansen et al 2010.…”

Section: Introductionmentioning

confidence: 99%

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Nested-PCR for the detection of Mycoplasma hyopneumoniae in bronchial alveolar swabs, frozen tissues and formalin-fixed paraffin-embedded swine lung samples: comparative evaluation with immunohistochemical findings and histological features

et al. 2012

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Pesq. Vet. Bras. 32(8) The diagnosis of Mycoplasma hyopneumoniae infection is often performed through histopathology, immunohistochemistry (IHC) and polymerase chain reaction (PCR) or a combination of these techniques. PCR can be performed on samples using several conservation methods, including swabs, frozen tissue or formalin-ϐixed and parafϐin-embedded (FFPE) tissue. However, the formalin ϐixation process often inhibits DNA ampliϐication. To evaluate whether M. hyopneumoniae DNA could be recovered from FFPE tissues, 15 lungs with cranioventral consolidation lesions were collected in a slaughterhouse from swine bred in herds with respiratory disease. Bronchial swabs and fresh lung tissue were collected, and a fragment of the corresponding lung section was placed in neutral buffered formalin for 48 hours. A PCR assay was performed to compare FFPE tissue samples with samples that were only refrigerated (bronchial swabs) or frozen (tissue pieces). M. hyopneumoniae was detected by PCR in all 15 samples of the swab and frozen tissue, while it was detected in only 11 of the 15 FFPE samples. Histological features of M. hyopneumoniae infection were presented in 11 cases and 7 of these samples stained positive in IHC. Concordance between the histological features and detection results was observed in 13 of the FFPE tissue samples. PCR was the most sensitive technique. Comparison of different sample conservation methods indicated that it is possible to detect M. hyopneumoniae from FFPE tissue. It is important to conduct further research using archived material because the efϐiciency of PCR could be compromised under these conditions.

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“…One section not fixed on a silanized slide was hematoxylin and eosin (HE) stained for routine histologic evaluation. Microscopic lesions typical of mycoplasmal pneumonia were graded as follows: zero (0), absence of lesions; one (1), discrete peribronchial, peribronchiolar and perivascular diffuse lymphocytic infiltrate, and discrete hyperplasia of type II pneumocytes; two (2), moderate peribronchial, peribronchiolar and perivascular diffuse lymphocytic infiltrate, moderate hyperplasia of type II pneumocytes and discrete BALT hyperplasia; three (3), intense peribronchial, peribronchiolar and perivascular diffuse lymphocytic infiltrate, intense hyperplasia of type II pneumocytes and moderate BALT hyperplasia; and four (4) intense and diffuse BALT hyperplasia (Hansen et al, 2010). As previously mentioned, only PCR positive samples for at least one of the agents (M. hyopneumoniae and/or M. hyorhinis) associated with histological lesions (grade 1 to 4) were included in this study.…”

Section: Methodsmentioning

confidence: 99%

Mycoplasma hyorhinis infection in early cases of mycoplasmal pneumonia in swine and evaluation of diagnostic assays

Pereira

Vannucci²,

Gabardo

et al. 2017

Pesq. Vet. Bras.

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RESUMO.-[Infecção por Mycoplasma hyorhinis em casos precoces de pneumonia micoplásmica em suínos e comparação entre técnicas diagnósticas.] A pneumonia micoplásmica causada por bactérias do gênero Mycoplasma é uma enfermidade de grande importância para indústria suinícola, sendo ainda controverso o papel desempenhado por Mycoplasma hyorhinis nessa doença. A confirmação da presença dessas bactérias bem como a identificação de seus papéis em doenças respiratórias continua sendo um grande desafio. Os objetivos desse estudo foram comparar diferentes técnicas, em especial a de hibridização fluorescente in situ (FISH), para diagnóstico de micoplasmoses respiratória em suínos naturalmente infectados e avaliar a presença do M. hyorhinis em casos precoces de pneumonia micoplásmica. Mycoplasmal pneumonia is an important disease in the pig industry. Due to the controversial role of Mycoplasma hyorhinis in this disease, confirmation of the presence of this bacterium and the identification of its roles in respiratory disease remain major challenges. The objectives of this study were to evaluate the presence of M. hyorhinis in early cases of mycoplasmal pneumonia and to determine the usefulness of fluorescent in situ hybridization (FISH) for the diagnosis of respiratory mycoplasmosis in naturally infected pigs. Ninety M. hyopneumoniae and/or M. hyorhinis-infected lung tissue samples based on diagnostic mosaic (DM) were used. The average age of the animals was 116 and 57 days (P<0.01) for groups 1 (positive-M. hyopneumoniae only) and 2 (positive-M. hyorhinis only), respectively. These findings suggest that development of lesions caused by M. hyorhinis occurs earlier than for M. hyopneumoniae. Using the DM as the gold standard, the sensitivity and specificity of FISH for M. hyopneumoniae were 75 and 100%, respectively, and were 40 and 73.3% for the immunohistochemistry (IHC). The sensitivity and specificity of FISH for M. hyorhinis were 76.7 and 100%, respectively. These findings demonstrate that FISH can be a useful tool for diagnosing mycoplasmosis. Viral antigens (PCV2 or influenza A) were detected in 53.3% (16/30) of the samples in group 2 (M. hyorhinis-PCR positive) and 13.3% (4/30) of the samples in group 1 (M. hyopneumoniae-PCR positive). This finding indicates that the association of M. hyorhinis and viral infection in nursery pigs likely starts due to a viral immunosuppressive condition.

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An Investigation of the Pathology and Pathogens Associated with Porcine Respiratory Disease Complex in Denmark

Cited by 179 publications

References 19 publications

Anatomopathological pneumonic aspects associated with highly pathogenic Pasteurella multocida in finishing pigs

Anatomopathological pneumonic aspects associated with highly pathogenic Pasteurella multocida in finishing pigs

Nested-PCR for the detection of Mycoplasma hyopneumoniae in bronchial alveolar swabs, frozen tissues and formalin-fixed paraffin-embedded swine lung samples: comparative evaluation with immunohistochemical findings and histological features

Mycoplasma hyorhinis infection in early cases of mycoplasmal pneumonia in swine and evaluation of diagnostic assays

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