Description succincte
(Allemand)
|
Enzootische Pneumonie (EP) des Schweines, durch Mycoplasma hyopneumoniae (Mhyo) hervorgerufen, wurde seit 1996 erfolgreich in der Schweiz bekämpft. EP wurde aus den Schweizer Hausschweinbeständen weitgehend eliminiert und wird nur noch vereinzelt diagnostiziert. Wildschweine sind Träger von Mhyo, wobei diese auch atypische Mhyo Stämme tragen. Die epidemiologische Rolle der atypischen Stämme bei EP ist unklar. Deshalb sollen spezifisch Pathogen-freie Schweine mit einem Mhyo Ausbruchstamm und einem atypischen Mhyo Wildschweinstamm per Aerosol infiziert und vergleichend untersucht werden, um die Pathogenität der atypischen Mhyo abzuschätzen. Anfallende diagnostische Proben werden für das Nationale EP-Referenzlabor gesammelt. Zudem sollen mindestens 5000 Seren von Schweizer Hausschweinen von 2018 serologisch untersucht werden, um die Seronegativität des Bestandes zu bestätigen. Es sollen auch zwei Genome von atypischen Schweizer Mhyo bioinformatisch mit anderen Mhyo verglichen werden, um Aussagen auf einen möglichen Wirtssprung vom Wild- zum Hausschwein zu treffen.
|
Description succincte
(Anglais)
|
Porcine Enzootic Pneumonia (EP) caused by Mycoplasma hyopneumoniae (Mhyo) was progressively controlled in Switzerland since 1996, and the number of EP cases dropped significantly. Hence, Mhyo was eliminated from Swiss pigs with only occasional Mhyo detections in domestic pigs per year. Wild boars harbour typical and atypical Mhyo, but in vivo data are missing to clarify the role of the atypical strains. Therefore, we will investigate whether wild boar-derived Mhyo strains are a reservoir for EP. To this end, we will infect specific pathogen-free pigs via aerosols with an atypical Swiss wild boar isolate and a typical Mhyo-outbreak strain to assess the virulence of the atypical strain. This will also generate well-defined diagnostic specimens for the National EP Reference Laboratory. At least 5,000 recent sera from Swiss domestic pigs will be analysed serologically to confirm seronegativity of the pig population. Two atypical Mhyo genomes will be compared bioinformatically to Mhyo outbreak strains to investigate a past host jump from wild boars to domestic pigs.
|
Objectifs du projet
(Anglais)
|
Mhyo has been progressively controlled in Switzerland since 2004. Consequently, nearly all pig farms in Switzerland are declared free of EP. Despite the successful control programme, Switzerland is experiencing sporadic outbreaks that cannot always be traced to imported pigs. This project aims to close the knowledge gaps mentioned above. The main objectives of this project therefore are to (i) Evaluate the relevance of atypical Mhyo strains isolated from Swiss wild boars with respect to their epizootic potential for Swiss pig farming (ii) Generate and characterize urgently-needed diagnostic reference specimens for the National Reference Laboratory at ZOBA, (iii) Implement an aerosol-based infection model at IVI using an infection chamber, which better mimics the natural route of infection and fosters animal welfare, (iv) Investigate the serological status of domestic pigs in Switzerland comprehensively, and finally, (v) Get insight into the phylogenetic position of atypical Mhyo strains.
|
Publications / Résultats
(Allemand)
|
Publications, posters and presentations
• Nadia Scalisi, Gudrun Overesch, Nicolas Ruggli, Peter Kuhnert, Joerg Jores, Title: Presence of Mycoplasma hyopneumoniae-specific antibodies in Swiss domestic pigs, Annual Congress of the Swiss Society of Microbiology 2021, Full virtual event, September 2-3, 2021, poster presentation
• Nadia Scalisi, Peter Kuhnert, Maria Elena Vargas Amado, Gudrun Overesch, Katharina D.C. Stärk, Nicolas Ruggli and Joerg Jores (2022) Seroprevalence of Mycoplasma hyopneumoniae in sows fifteen years after implementation of a control programme for enzootic pneumonia in Switzerland, Veterinary Microbiology, 270: 109455
• Nadia Scalisi (2022) Seroprevalence of Mycoplasma hyopneumoniae in sows fifteen years after implementation of a control programme for enzootic pneumonia in Switzerland, Doctoral Dissertation, Vetsuisse faculty, University of Bern
• Jörg Jores, Nicolas Ruggli, Nadia Scalisi, Jaeyoun Jang, Sergi Torres-Puig, A stress-free and easy-to-use system to expose pigs to aerosols, submitted and in review in the journal Vaccine: X (Elsevier)
|
