Genetic and antigenetic variability of Mycoplasma hyopneumoniae field strains and its implication for improved diagnostics of Enzootic Pneumoniae (EP)

• Forschungsstelle: BLV
• Projektnummer: 1.05.04
• Projekttitel Englisch: Genetic and antigenetic variability of Mycoplasma hyopneumoniae field strains and its implication for improved diacnostics of Enzootics Pneumoniae (EP)

Schlüsselwörter (Englisch)

Enzootic pneumoniae, diagnosis, Mycoplasma hyopneumoniae, serology, genetic variability

Kurzbeschreibung (Englisch)

A precise and trustful diagnosis of Mycoplasma hyopneumoniae, the etiologic agent of porcine enzootic pneumonia, still poses a challenge, despite recent methodological improvements including PCR assays or commercial kits for serological testing. Various observations indicate a biological basis for these prob-lems. Genetic and antigenetic variability is known for M. hyopneumoniae, and we recently showed that different subtypes of M. hyopneumoniae can be distinguished by PCR. In this project we want to explore this variability, by isolation and characterization of M. hyopneumoniae strains and the analysis of sera concurrently taken from the same animals and farms that were affected by the disease. The genetic vari-ability will be investigated by several typing methods and sequence analysis. The immunological proper-ties of the strains will be compared using ELISA targeting different antigens. Epitopes common to all M. hyopneumoniae strains analyzed from several geographical regions will be further characterized and tested for their applicability to improve current serology. Moreover, the genetic characterization will allow to dissect possible subtypes and pathotypes of M. hyopneumoniae. This approach of a combined genetic and antigenetic characterization of M. hyopneumoniae strains will certainly elucidate the biological back-ground of the currently problematic diagnosis, thereby improving the situation and help in the effort of sanitation.

Projektziele (Englisch)

The main aim of this study is a molecular epidemiological investigation of the biodiversity of M. hyopneumoniae strains currently infecting pig herds in Switzerland. Special attention will be paid to analyze particular genotypic and phenotypic traits of M. hyopneumoniae in correlation with pathology and epidemiology of enzootic pneumoniae that was caused by these isolates. This study is expected to result in the characterization of antigens and specific genes common to all M. hyopneumoniae strains. These results will be basically necessary to improve and simplify diagnostic methods which are currently based on targets that seem not be present in all strains. Furthermore, the molecular analysis of the significant differences among the various M. hyopneumoniae strains and correlation with clinical, pathological and epidemiological characteristics should give new insights in the molecular mechanisms of pathogenicity of M. hyopneumoniae.

Umsetzung und Anwendungen (Deutsch)

UMS 2009:
Projekt erfreulich verlaufen, die relevanten Fragen des
BVET wurden beantwortet. Etablierung PCR wurde umgesetzt.
Status: KOmmt an UMS 2010 (mvo)

Publikationen / Ergebnisse (Deutsch)

29.10.2009: Umsetzungssitzung 2009: Projekt erfreulich verlaufen, die relevanten Fragen des BVET wurden beantwortet. Etablierung PCR wurde umgesetzt. (mvo).

Publikationen / Ergebnisse (Englisch)

Mayor, D.; Zeeh, F.; Frey, J. and Kuhnert, P. (2007). Diversity of Mycoplasma hyopneumoniae in pig farms revealed by direct molecular typing of clinical material. Vet. Res. 38:391-398.

Mayor, Desirée. Genetic variability and molecular typing methods of Mycoplasma hyopneumoniae field strains. Inauguraldissertation, Institut für Veterinär-Bakteriologie, Universität Bern.

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