Experimental dual infection of pigs with an H1N1 swine influenza virus (A/Sw/Hok/2/81) and Mycoplasma hyopneumoniae

Yazawa, Shigeto; Okada, Mizue; Ono, Masaaki; Fujii, Seiichi; Okuda, Yo; Shibata, Isao; Kida, Hiroshi

doi:10.1016/j.vetmic.2003.11.005

Cited by 39 publications

(33 citation statements)

References 18 publications

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“…Since it was reported that SIVs (H1N2) were isolated from the nasal swabs of pigs that never showed any symptoms in the abattoir in Saitama Prefecture [25], it is possible that many pigs were subclinically infected with SIV in the field, i.e., without any clinical signs. Moreover, in previous experimental infections of pigs with SIV (A/swine/Hokkaido/2/81, H1N1), pigs did not show clinical signs [30]. Thus, factors such as environmental stress and superinfection with bacteria are likely to contribute to severe respiratory symptoms.…”

Section: Discussionmentioning

confidence: 94%

Occurrence of a Pig Respiratory Disease Associated with Swine Influenza A (H1N2) Virus in Tochigi Prefecture, Japan

Yoneyama

Hayashi

Kojima

et al. 2010

The Journal of Veterinary Medical Science

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Section: Discussionmentioning

confidence: 94%

Occurrence of a Pig Respiratory Disease Associated with Swine Influenza A (H1N2) Virus in Tochigi Prefecture, Japan

Yoneyama

Hayashi

Kojima

et al. 2010

The Journal of Veterinary Medical Science

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“…Infection occurs through direct contact with respiratory secretions from carrier animals, but an airborne transmission is also strongly suspected [6,10,11]. Secondary infections, especially with porcine reproductive virus and influenza virus can intensify the clinical picture of EP [12,13,16].…”

Section: Introductionmentioning

confidence: 99%

Diversity ofMycoplasma hyopneumoniaein pig farms revealed by direct molecular typing of clinical material

et al. 2007

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-Mycoplasma hyopneumoniae is the etiological agent of enzootic pneumonia in swine.Various reports indicate that different strains are circulating in the swine population. We investigated the variety of M. hyopneumoniae strains by a newly developed genetic typing method based on the polyserine repeat motif of the LppS homolog P146. PCR amplification using M. hyopneumoniae specific, conserved primers flanking the region encoding the repeat motif, followed by sequencing and cluster analysis was carried out. The study included strains isolated from different geographic regions as well as lysates from lung swabs from a series of pig farms in Switzerland. High diversity of M. hyopneumoniae was observed but farms being in close geographic or operative contact generally seemed to be affected by the same strains. Moreover, analysis of multiple samples from single pig farms indicated that these harbored the same, farm-specific strain. The results indicate that multiple strains of M. hyopneumoniae are found in the swine population but that specific strains or clones are responsible for local outbreaks. The method presented is a highly reproducible epidemiologic tool allowing direct typing of M. hyopneumoniae from clinical material without prior isolation and cultivation of strains. enzootic pneumonia / epidemiology / LppS / P146

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“…Although the severity of SI may be enhanced by viral co--infections (Yazawa et al 2004, Olsen et al 2006, Grau-Roma & Segalés 2007), very few cases had a positive immunoreaction to PCV-2. Preventative methods used in most commercial Brazilian herds, such as vaccinations used in other countries (Grau-Roma et al 2011), may explain why there was a low frequency of this ϐinding.…”

Section: Resultsmentioning

confidence: 99%

Histopathological and immunohistochemical findings of swine with spontaneous influenza A infection in Brazil, 2009-2010

et al. 2012

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1148ença altamente contagiosa, de curso rápido e pronta recuperação, causada pelo vírus inϐluenza tipo A (SIV). Os principais sinais clínicos são tosse, febre, anorexia e baixo desenvolvimento. A doença está presente em outros países e, geralmente, está associada com outros agentes infecciosos. No Brasil, a primeira descrição ocorreu em 2011 e foi associada ao vírus H1N1 pandêmico (pH1N1). O principal objetivo deste estudo foi caracterizar as alterações histoló-gicas em casos de doença respiratória suína sugestiva de . It is a highly contagious disease with a rapid course and recovery. The major clinical signs and symptoms are cough, fever, anorexia and poor performance. The disease has been associated with other co-infections in many countries, but not in Brazil, where, however, the ϐirst outbreak has been reported in 2011. The main aim of this study was to characterize the histological features in association with the immunohistochemical (IHC) results for inϐluenza A (IA), porcine circovirus type 2 (PCV2) and porcine reproductive and respiratory syndrome virus (PRRSV) in lung samples from 60 pigs submitted to Setor de Patologia Veterinária at the Universidade Federal do Rio Grande do Sul (SPV-UFRGS), Brazil, during 2009-2010. All of these lung samples had changes characterized by interstitial pneumonia with necrotizing bronchiolitis, never observed previously in the evaluation of swine lungs in our laboratory routine. Pigs in this study had showed clinical signs of a respiratory infection. Swine samples originated from Rio Grande do Sul 31 (52%), Santa Catarina 14 (23%), Paraná 11 (18%), and Mato Grosso do Sul 4 (7%). Positive anti-IA IHC labelling was observed in 45% of the cases, which were associated with necrotizing bronchiolitis, atelectasis, purulent bronchopneumonia and hyperemia. Moreover, type II pneumocyte hyperplasia, alveolar and bronchiolar polyp-like structures, bronchus-associated lymphoid tissue (BALT) hyperplasia and pleuritis were the signiϐicant features in negative anti-IA IHC, which were also associated with chronic lesions. There were only two cases with positive anti-PCV2 IHC and none to PRRSV. Therefore, SIV was the predominant infectious agent in the lung samples studied. The viral antigen is often absent due to the rapid progress of SI, which may explain the negative IHC results for IA (55%); therefore, IHC should be performed at the beginning of the disease. This study has shown how important a careful histological evaluation is for the diagnosis. Since 2009, a new histological feature of swine pneumonia in animals with respiratory clinical signs has been observed in samples from pigs with clinical respiratory disease submitted to SPV-UFRGS. In addition, the results proved the importance of histological evaluation for swine herd health management. Brazil, 2009Brazil, -2010 IS e estudar a associação dessas alterações com os resultados de imuno-histoquímica (IHQ) anti-vírus da inϐluenza A (SIV), anti-circovírus suíno tipo 2 (PCV2) e anti-vírus da síndrome reprodutiva e respiratória (...

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Experimental dual infection of pigs with an H1N1 swine influenza virus (A/Sw/Hok/2/81) and Mycoplasma hyopneumoniae

Cited by 39 publications

References 18 publications

Occurrence of a Pig Respiratory Disease Associated with Swine Influenza A (H1N2) Virus in Tochigi Prefecture, Japan

Occurrence of a Pig Respiratory Disease Associated with Swine Influenza A (H1N2) Virus in Tochigi Prefecture, Japan

Diversity ofMycoplasma hyopneumoniaein pig farms revealed by direct molecular typing of clinical material

Histopathological and immunohistochemical findings of swine with spontaneous influenza A infection in Brazil, 2009-2010

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