2008 Annual Report 1a.Objectives (from AD-416) The objectives of this work are to identify important virulence (e.g. colonization/ adhesion factors) proteins of Mycoplasma gallisepticum via a proteomic approach and to subsequently apply the obtained knowledge towards a greater understanding of the mycoplasmosis disease process towards development of novel means of control. 1b.Approach (from AD-416) Initially, candidate proteins will be identified via proteomic comparisons of pathogenic Mycoplasma gallisepticum strains and their non-pathogenic derivatives. Differential protein expression will be determined and proteins of interest identified. Time and resource permitting, similar investigations may be performed to compare the proteomes of Mycoplasma gallisepticum vaccine strains and pathogenic field strains. Knowledge attained will be applied towards understanding the mycoplasmosis disease process and towards the development of novel means of control. 3.Progress Report Research related to this Project addresses Component 4C (Respiratory Diseases of Poultry) of the Animal Health National Program Action Plan which includes the expected output “to define determinants of virulence and characterize mechanisms of infections”. The initial proteomic comparison of virulent and avirulent Mycoplasma gallisepticum (MG) strains via differential gel electrophoresis revealed numerous protein candidates towards the identification of virulence-related proteins. Current proteomic comparisons are being performed utilizing liquid chromatography separation and the results will be used to confirm the initial findings. Progress thus far includes the isolation and culture of the specific MG strains and subsequent sample preparation/proteome isolation. However, the samples remain in queue and are currently awaiting protein separation and identification. Subsequently, we have applied for a one year extension to allow for the completion of the proteome analyses and candidate protein identification. Manuscripts and technology transfer associated with this project are delineated in the inhouse project, 6406-32000-010-00D, COUNTERMEASURES TO PREVENT AND CONTROL AVIAN MYCOPLASMOSIS. This project is monitored via phone calls, emails, and direct visits.