Comparative proteome analyses of Mycobacterium avium subspecies paratuberculosis Type I, Type II and Type III

摘要

Strains of Mycobacterium avium subspecies paratuberculosis have been subdivided into three groups, Type I, II and III, by pulsed-field gel electrophoresis (PFGE). Type I strains comprise pigmented, slow growing strains that appear to have a host preference for sheep; Type II strains comprise non-pigmented strains with a very broad host range; Type III strains comprise non-pigmented strains that have PFGE profiles intermediate between Type I and II and exhibit biological characteristics from both groups. It is proposed that Type I strains are an evolutionary intermediate between Mycobacterium avium subsp. avium and Type III strains. We have used 2-D gel electrophoresis to characterize the proteomes of the three strain types to investigate the molecular basis for the biological differences observed. Type I and II strains were found to express Type-specific proteins. No Type-specific strains were identified for Type III strains. Type-specific proteins were identified by Matrix Assisted Laser Desorption lonisation Mass Spectometry (MALDI MS). The relevance of these proteins to phenotype and evolutionary perspectives will be discussed.