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Published on: July 1, 2011
Characterization of membrane surface proteins of Mycoplasma agalactiae during natural infection
1Istituto Zooprofilattico Sperbnentale della Sardegna G Pegreffi, Sassari, Italy.
Abstract:
We have analyzed antigenic variation of seven M. agalactiae wild strains using different sera from naturally infected sheep. Only 30 day sera recognized all surface proteins and inhibited the growth of mycoplasmas. Furthermore, we have observed that two strongly immunogenic proteins: 55 and 35 kDa were digested using 500 micrograms/ml of trypsin. These two bands are immunoprecipitated together with four other proteins but only the 35 kDa protein is recognized by eluted antibodies.
Insights
Mycoplasma agalactiae antigenic variation was studied. Thirty-day sheep sera recognized all surface proteins, inhibiting mycoplasma growth, with only the 35 kDa protein recognized by eluted antibodies after trypsin digestion.
Area of Science:
- Veterinary Microbiology
- Immunology
- Molecular Biology
Background:
- Mycoplasma agalactiae causes contagious agalactia, a significant disease in small ruminants.
- Antigenic variation in M. agalactiae complicates vaccine development and disease control.
- Understanding surface protein immunogenicity is crucial for targeted interventions.
Purpose of the Study:
- To analyze the antigenic variation of seven Mycoplasma agalactiae wild strains.
- To identify specific sera capable of recognizing and inhibiting mycoplasma growth.
- To investigate the immunogenicity and antibody recognition of M. agalactiae surface proteins.
Main Methods:
- Analysis of antigenic variation using sera from naturally infected sheep.
- Growth inhibition assays with different sera.
- Trypsin digestion of surface proteins (55 kDa and 35 kDa) at 500 µg/ml.
- Immunoprecipitation and antibody elution studies.
Main Results:
- Sera collected 30 days post-infection recognized all analyzed surface proteins.
- These 30-day sera demonstrated mycoplasmacidal activity, inhibiting bacterial growth.
- Two highly immunogenic proteins (55 kDa and 35 kDa) were identified and susceptible to trypsin digestion.
- While both proteins were immunoprecipitated, only the 35 kDa protein was recognized by eluted antibodies.
Conclusions:
- Specific antibody responses in sheep sera evolve over time, with 30-day sera showing broad recognition of M. agalactiae surface antigens.
- The 35 kDa surface protein is a key target for specific antibody recognition following infection.
- Findings provide insights into M. agalactiae antigenic variation and potential targets for diagnostic or vaccine strategies.
