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Host immune response in cutaneous versus visceral form of leishmaniasis
Matějková, Barbora ; Leštinová, Tereza (advisor) ; Jelínková, Kristýna (referee)
Parasitic protozoans of the genus Leishmania circulate between vectors and hosts during their life cycle, in which they come into contact with the immune system. In the host body, infection can lead to the development of a disease called leishmaniasis. This can manifest itself in a number of ways, with the best known forms being referred to as visceral, mucocutaneous and cutaneous leishmaniasis. This thesis focuses on the host immune response during the cutaneous and visceral forms of leishmaniasis. In addition, attention has been given to host, vector and parasite factors that differ between cutaneous and visceral leishmaniasis forms and that may influence the different clinical manifestations. Attention is paid not only to factors related to immunity, but also to factors such as parasite inoculum dose sizes, temperature differences between skin and internal organs, parasite genetics, and others. Keywords - Leishmania, visceral leishmaniasis, cutaneous leishmaniasis, immune response, parasite, immunity
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Development of Leishmania from L.donovani complex in various vectors
Hrobáriková, Veronika
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...
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Visceral leishmaniasis in Ethiopia: transmission and variability
Gelaglie, Aysheshm Kassahun ; Votýpka, Jan (advisor) ; Gradoni, Luigi (referee) ; ÖZBEL, Yusuf (referee)
Leishmaniasis, a protozoan infection caused by Leishmania parasites is a neglected disease affecting millions across the world. It is exhibited by diverse clinical presentations that broadly classified as visceral (VL) and cutaneous (CL) leishmaniasis. Both CL and VL are endemic to Ethiopia, which the later is generally considered as fatal, if left untreated. Leishmania donovani is the sole agent of Ethiopian human VL. In Africa, the worst VL affected regions are found in Sudan and Ethiopia. VL is considered as an endemic and at the same time emerging disease in north, northwest, south and southwest with sporadic cases in Eastern Ethiopia. The epidemiology is more or less associated with seasonal migration to endemic areas and HIV/AIDS. The transmission of CL in Ethiopia is known to involve zoonotic cycle while VL transmission isn't clearly understood despite traditional generalization of anthroponosis in East African platform. The aim of this dissertation is to determine VL transmission cycle and study variability L. donovani and P. orientalis in Ethiopia. Studies on human and non-human hosts were conducted to determine the transmission dynamics. To assess the role of symptomatic and asymptomatic L. donovani infected persons in the epidemiology of VL, a community based cohort was conducted. As the...
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Development of Leishmania from L.donovani complex in various vectors
Hrobáriková, Veronika ; Volf, Petr (advisor) ; Alten, Bülent (referee) ; Gradoni, Luigi (referee)
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...
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Development of Leishmania from L.donovani complex in various vectors
Hrobáriková, Veronika
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...
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