“Multilocus Sequence Typing: a useful typing method for differentiation of Trypanosoma cruzi isolates”

LAUTHIER JJ, ALBERTI D´AMATO AM, MONJE RUMI MM, RAGONE PG, UNCOS A, DIOSQUE P

Armaca Dos Búzios, Rio de Janeiro

Congreso; XIII International Congress of Protistology-XXV Meeting of the Brazilian Society of Protozoology-XXXVI Annual Meeting on Basic Research in Chagas Disease; 2009

The currently characterization of different isolates of Trypanosoma cruzi has problems due difficulties of data comparison among laboratories. Besides standard characterization techniques have a small resolution power so far. The Multilocus Sequence Typing (MLST) technique allows us the comparison of different isolates through the analysis of 400-500 bp form sequences of housekeeping genes. In this work, we proposed an MLST algorithm which allows the discrimination of the circulating genotypes of our study area (Chaco Province, Argentina) with only two sequence steps. This scheme is based on the analysis of Rho-Like GTP binding protein (RL-Gtp), Small GTP-binding protein Rab7 (Gtp) and Glucose-6-phosphate isomerase (Gpi), which together allow the identification of the 4 lineages described in our study area (T. cruzi I, IIc, IId and IIe). Moreover, seven genotypes were identify for T. cruzi I with this scheme. We work with different typing techniques (MLEE, RAPD, HVR probes, microsatellites) to identify the current variability of T. cruzi in our study area. So far MLEE was used as a gold standard typing method. We proppouse the used of the present scheme of MLST as suitable method of T. cruzi typing based on the accurate and confident features of this technique. Finally, MLST has the advantage of detect a small quantity of DNA (100 fg/ul), which is relevant when this is applied to biological samples without previous isolation as showed our results