Babesia bigemina Apical Membrane Antigen-1: features of the gene and predictive information of the protein from Italian strains

Babesia bigemina is a tick-borne haemoparasite affecting cattle in different parts of the world. One of the few antigens characterized in this species codifies for the Apical Membrane Antigen 1 (AMA-1), a transmembrane protein recently identified. In this work, we characterized the ama-1 gene from four Italian B.bigemina strains, two obtained from Ragusa, Sicily (ITA1 and ITA3), one obtained from Benevento, Campania (ITA2) and one coming from Perugia, Umbria (ITA4). Italian sequences were compared to the Australian strain, whose sequence is available in the Sanger Institute web site, and to some strains coming from different parts of the world. This study provides useful information on the features of B.bigemina AMA-1 gene from Italian strains of the parasite and some predictive information of the protein obtained by bioinformatics. A comparison among Italian strains of B.bigemina showed a very high degree of both nucleotide and aminoacidic identity. The gene resulted highly conserved among Italian and foreign strains and the protein was included in the AMA-1 family. By the means of bioinformatics it was possible to compare some features of B.bigemina AMA-1 protein with the already characterized Plasmodium falciparum orthologue. Predictive results show that a structural and thus functional homology between B.bigemina and P.falciparum AMA-1 can be supposed. Moreover several putative antigenic peptides were detected and they could be used for investigations about the recognition by specific antibodies. These data put the basis for a further study on B.bigemina AMA-1 antigen.