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Effect of abiotic and biotic factors on Leishmania development in sand fly vectors
Hlaváčová, Jana ; Volf, Petr (advisor) ; Alten, Bülent (referee) ; Traub-Cseko, Yara Maria (referee)
The thesis deals with Leishmania development in sand flies focusing on factors that could affect the vectorial part of their lifecycle. First, we examined an effect of temperature on Leishmania development in sand flies since the global warming was suggested to be one of the most important factors affecting dissemination of leishmaniasis. Development of three Leishmania species were studied at two different temperatures (20 and 26řC); L. infantum in natural vectors Lutzomyia longipalpis and Phlebotomus perniciosus, and two closely related Viannia species L. braziliensis and L. peruviana in Lu. longipalpis. Leishmania peruviana thrived well only at the lower temperature tested. At the higher temperature, most of infections were lost between days 2 and 8 post feeding, i.e. time of blood-meal remnants defecation. This suggests that this Andean species is adapted to slower metabolism of vectors living at lower temperatures. On the other hand, L. infantum and L. braziliensis successfully developed in sand flies at both temperatures tested, which might be substantial for their further spread to new areas. Next, an impact of gregarine Psychodiella sergenti on L. tropica in Phlebotomus sergenti was studied. Gregarines are commonly found in sand flies, and in mosquitoes, they can affect development of other...
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Effect of abiotic and biotic factors on Leishmania development in sand fly vectors
Hlaváčová, Jana ; Volf, Petr (advisor) ; Alten, Bülent (referee) ; Traub-Cseko, Yara Maria (referee)
The thesis deals with Leishmania development in sand flies focusing on factors that could affect the vectorial part of their lifecycle. First, we examined an effect of temperature on Leishmania development in sand flies since the global warming was suggested to be one of the most important factors affecting dissemination of leishmaniasis. Development of three Leishmania species were studied at two different temperatures (20 and 26řC); L. infantum in natural vectors Lutzomyia longipalpis and Phlebotomus perniciosus, and two closely related Viannia species L. braziliensis and L. peruviana in Lu. longipalpis. Leishmania peruviana thrived well only at the lower temperature tested. At the higher temperature, most of infections were lost between days 2 and 8 post feeding, i.e. time of blood-meal remnants defecation. This suggests that this Andean species is adapted to slower metabolism of vectors living at lower temperatures. On the other hand, L. infantum and L. braziliensis successfully developed in sand flies at both temperatures tested, which might be substantial for their further spread to new areas. Next, an impact of gregarine Psychodiella sergenti on L. tropica in Phlebotomus sergenti was studied. Gregarines are commonly found in sand flies, and in mosquitoes, they can affect development of other...
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Mosquitoes and biting midges as vectors in the Czech Republic
Rádrová, Jana ; Votýpka, Jan (advisor) ; Modrý, David (referee) ; Alten, Bülent (referee)
Insect is the largest and the most diverse class of animals and many species have significant impact to people and his activities, whether positive or negative. Since the late 19th century it is known, that bloodsucking insects can serve as vectors of pathogens, causative agents of many infection diseases. As climate change, the distribution and abundance of arthropods including bloodsucking insects can be affected. Emergence of new vector-borne diseases in Europe is likely to be among the most important effects of global changes. In recent years, several vector-borne diseases affecting humans and domestic animals have (re)emerged and spread in Europe with major health, ecological and socio-economical consequences. For example mosquito-borne West Nile virus affects human and animal health, as well. On the other hand, two newly emerged zoonosis, caused by Bluetongue and Schmallenberg viruses and transmitted by biting midges, affect mainly small domestic ruminants. In the frame of broader projects, two epidemiological and entomological surveys focused on mosquitoes and biting midges as possible vectors of West Nile virus, Bluetongue or Schmallenberg virus were carried out in the Czech Republic. New mosquito and biting midges species were recorded for the Czech Republic, the presence of West Nile...
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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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