Achievement amastigotes of Leishmania infantum and investigation of pathological changes in the tissues of infected golden hamsters.

Leishmania infantum is an agent of visceral leishmaniasis (VL). Amastigote form is a more appropriate target for investigations on vaccines, treatment, and diagnosis. This study aimed to achieve the amastigotes of L. infantum in the golden hamster and J774 macrophages and report the pathological changes that occur in the liver and spleen of the hamsters with VL. 4 male golden hamsters were infected with L. infantum promastigotes. After 5 months, the hamsters were euthanized and touch and pathology smears were prepared from the livers and spleens. Then, these tissues were homogenized and centrifuged at 100×g. Supernatants were collected and centrifuged at 2000×g and the pellets were collected. In the next part of our study, J774 macrophages were infected with L. infantum promastigotes. Then, the infected macrophages were ruptured. Centrifuge stages were done same the previous part. The amastigotes were observed in touch and pathology smears. A load of amastigotes in the livers was more than the spleens in both types of smears. Although the livers' structure had undergone pathological changes, the spleens were unchanged. Also, the macrophage infectivity ratio was up to 95%. Our results present a simple and accessible way of achieving a lot of pure and real amastigotes for different fields in Leishmania. Also, it seems that the pathological changes occurring in the spleen and the liver of animals with VL are different and probably can be attributed to the genetic and immune process of the infected animals.