Crescimento e infectividade de Leishmania infantum chagasi em diferentes meios de cultivo

Abstract

Visceral leishmaniasis is a disease of great importance to Public Health because it is a zoonosis and because of its wide distribution worldwide. The laboratory culture of Leishmania infantum chagasi is necessary to understand its complexity, leading to studies to develop vaccines and drugs that have an action against the protozoan. The present study aims to standardize the cultivation of L. infatum chagasi and to analyze the parameters of infectivity after successive passages. Promastigote forms of L. infantum chagasi isolated from a dog were cultured in different commercial media and one of them was added 2% human urine. The counting by hematometer was done during seven days, resulting in a growth curve. For infectivity analysis, BALB / c peritoneal macrophages were infected with promastigote forms of L. infantum chagasi grown with the highest growth media. The results demonstrated that Schneider's medium supplemented with 2% sterile human urine induced a greater growth of the promastigote forms of L. infantum chagasi when compared to other commercial media and to Schneider without supplementation with urine. In addition, it was observed that the Schneider medium supplemented with 2% urine presented parameters of infectivity superior to Schneider's medium without supplementation. After selection of the Schneider medium supplemented with urine, it was observed that from the third passage there was a decrease in the parameters of infectivity in BALB / c peritoneal macrophages. The added medium of human urine was the only one in which it was possible to define the logarithmic and stationary phases having a peak of growth on day 5. The decreases in the infectivity parameters may be related to the need to perform the complete cycle of Leishmania.