Antigen heterogeneity and epitope variable expression in Mycoplasma meleagridis isolates

Immunoblotting was used to check the antigenic profiling of 27 Mycoplasma m eleagridis strains isolated in different countries. Hyperimmune polyclonal rabbit antiserum as well as monoclonal antibodies (MAbs) raised against M, meleagridis (MM) showed antigen heterogeneity among strains. Five anti-MM M Abs were selected for lack of reaction against heterologous avian mycoplasm a. Three of these five Mabs did not cross-react with 63 mycoplasma strains from six species affecting turkeys other than M. meleagridis. The five Mabs used to analyse the epitopes of 30 M. meleagridis strains indicated that s ome epitopes were not expressed in all strains. Moreover, other epitopes we re located on proteins which differed according to number or molecular mass from strain to strain. The five Mabs therefore. recognised variable surfac e proteins, among which two were amphiphilic membrane proteins. Three of the selected Mabs recognised 29 or 30 of the 30 tasted strains. Th e in vitro expression of surface epitopes in M. meleagridis ATCC 25284 was investigated by colony immunobinding and allowed demonstration of a variabl e antigenic system, (C) 2001 Elsevier Science B.V. All rights reserved.