Biological, biochemical and molecular characterization of isolated of Leishmania spp of different endemic areas of Paraguay.

by González Caballero, Norath Natalia

Visceral leishmaniasis (LV) in Paraguay is a Public Health problem in continuous expansion, since its first autochthon case detected in 1945. Cases of VL in human and canines are being detected for the first time in regions considerednon-endemic until recently. Consequently and considering the lack of studies related to the etiological agent of VL or the circulating genetic population in Paraguay, a characterization of biological, biochemical and molecular patterns hasbeen carried out using isolates from different endemic areas of this country. In the present study, nineteen samples were isolated and studied by their development pattern in culture medium, isoenzyme electrophoresis and multilocus microsatelliteanalysis. The results obtained show that all studied Leishmania populations had identical phenotypic characteristics by in vitro growth pattern. Isoenzymatic characterization showed an electrophoretic pattern typical of L. infantum (sin L.chagasi) zimodeme -1 for all the isolated samples. In concordance to current literature that attributes a wide distribution of this parasite as aethiological agent ofLV in many endemic areas in Americas; it seems to be widespread in Paraguay also. Genetic variability has been analyzed, using multilocus microsatellite technique (MLMT). Comparison of molecular patterns of paraguayan isolates ofcanine and human origin with samples isolated in brazilian regions was carried out. The most differentiated genotype was detected in one unique isolate from a cutaneous lesion of an HIV coinfected patient, located in Brazil. This interestingresult sets the base ground for a more thorough analysis of this scenario. The results show that the MLMT is a sensitive technique to detect polymorphism within the studied L. infantum population. Though, a certain level of polymorphism hasbeen detected, the short number of analysed samples allows no ecological or epidemiological correlations to be made.