Abstract
Proteomics of Babesia microti has lagged behind other apicomplexans despite recent genome and transcriptome studies. Here, we used a combination of nanotechnology and mass spectrometry to provide a proteomic profile of B. microti acute infection. We identified ∼500 parasite proteins in blood with functions such as transport, carbohydrate and energy metabolism, proteolysis, DNA and RNA metabolism, signaling, translation, lipid biosynthesis, and motility and invasion. We also identified surface antigens with roles in the immune response to the parasite. This first evaluation of the B. microti proteome in erythrocytes provides information for the study of intracellular survival and development of diagnostic tools using mass spectrometry.