Abstract

Introduction: Piscirickettsia salmonis is the predominant bacterial pathogen affecting the Chilean salmonid industry. This bacterium is the etiological agent of piscirickettsiosis, a significant fish disease. The efforts have not been efficient to be able to characterize proteomically this bacterium. Methods: The P. salmonis LF-89 (equivalent to ATCC VR-1361) type strain was grown on AUSTRAL broth at 18 °C for exponential phase. Proteins were digest by trypsin and peptides were subjected to a two-dimensional chromatography coupled to a mass spectrometer LTQ Velos pro. And the bioinformatics analyzes were performed using the SEQUEST algorithm and the proteins were annotated against the GO database (gene ontology) Results: We have identified 1537 proteins using (multidimensional identification technology) MudPit, by LCMS/MS. Using gene ontology we have grouped the proteins by compartment, biological processes and molecular function. Where 60% of the proteins are involved in metabolic processes, followed by transport and regulation with 10%. Additionally we identified proteins corresponding to pathogenicity factors such as the type IV secretion system, flagellum, and antibiotic resistance proteins. The heat shock protein HSP60 or GroEL, a known chaperone, is the most abundant protein. This protein was found in outer membrane, periplasm, internal membrane and cytoplasm. Conclusion: This is the most complete study carried out in P. salmonis, from the proteomic point of view, and obtaining a total characterization of the behavior of this bacterium in an exponential growth phase. This type of proteomic studies are key for the search of new therapeutic and effective targets against P. salmonis.