Immunomics analysis of Babesia microti protein markers by high-throughput screening assay.

Babesia microti is a protozoan considered to be a major etiological agent of emerging human babesiosis. It imposes an increasing public-health threat and can be overlooked because of low parasitemia or mixed infection with other pathogens. More sensitive and specific antigens are needed to improve the diagnosis of babesiosis. To screen the immune diagnostic antigens of B. microti, 204 sequences from homologue proteins between B. microti and B. bovis genome sequences in PiroplasmaDB were selected. The high throughput cloned and expressed B. microti proteins were screened with the sera from the BALB/c mice infected by B. microti using protein arrays. Ten (5.9%, 10/169) highly immunoreactive proteins were identified, and most (80%, 8/10) of these highly immunoreactive proteins had not been characterized before, making them potentially useful as candidate antigens for the development of diagnostic tools for babesiosis.