By the development of monoclonal antibodies against the two immunodominant proteins α-1 giardin and β-giardin, we were able to observe the intracellular localization of these structural proteins in assemblages A and B. Taking into consideration some genetic studies as well as the biological differences observed between both strain, it had been proposed that both assemblages might correspond to different species [14]. Although some conclusions may be drawn from genotypic analysis, these need to be supported by phenotypic

studies. This is particularly clear for β-giardin, a protein that is 100% homologous at the deduced amino acid level, but with a very different pattern of localization between both assemblages. To date, not enough data is available to define them as separate species. Further genome and transcriptome sequencing, phenotypic studies MI-503 and correlation with clinical symptoms of different strains within an Assemblage may well be the next steps toward determining species in Giardia. These findings could contribute to understanding the variations in pathogenesis associated with infections caused by assemblage A and B isolates of this important parasite. Acknowledgements Financial support for this research project was provided by National Council for Science and Technology (CONICET), the National Agency for Advancement see more of Science and Technology (ANPCYT), and the Secretary of Science and Technology of

the National University of Córdoba (SECYT). Electronic supplementary material Additional file 1: Alignment of the putative amino acid sequences deduced from the nucleotide sequences of the β-giardin gene of Giardia lamblia WB isolate [GDB: GL4812] and those of the β-giardin

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