Development of Leishmania from L.donovani complex in various vectors

This thesis focuses on the development of protozoan parasites from Leishmania donovani complex in their insect vectors and summarizes results of five parts of the project I participated in during my Ph.D. studies. Sand flies of genera Phlebotomus and Lutzomyia are the only proven vectors of leishmaniasis, however, the role of alternative vectors, like ticks, fleas and biting midges is frequently discussed in the literature. In this work, we showed that Eurasian species of biting midge Culicoides nubeculosus does not support late stage infections of L. major and L. infantum. We also demonstrated that microscopical observation of Leishmania promastigotes in the digestive tract of bloodfeeding arthropods remains a crucial method for any conclusion about the vector competence of the suspected insect. In the second part of our study were compared the life-cycle parameters and vector competence of two Ethiopian P. orientalis colonies for L. donovani. Marked differences between colonies were found in life-cycle parametes, however, molecular analyses did not reveal any genetic differences. Experimental infections showed that both P. orientalis colonies are very susceptible to L. donovani infection and even the lowest infective dose tested (2 × 103 promastigotes/ml; corresponding to 1-2 promastigotes) was..