National Repository of Grey Literature 2 records found  Search took 0.00 seconds. 
Role of catalase and chitinase in the life cycle of Leishmania parasites
Glanzová, Kristýna ; Sádlová, Jovana (advisor) ; Kodym, Petr (referee)
Leishmaniasis is an infectious disease caused by protozoa of the genus Leishmania (Kinetoplastida: Trypanosomatidae) which are transmitted by phlebotomine sand flies (Diptera: Phlebotominae). For the dixenous life cycle, leishmania parasites are equipped with enzymes that facilitate survival in both insect vectors and mammalian hosts. Gene for the enzyme catalase which protects cells from reactive oxygen species by the elimination of H2O2 and is present in related monoxenous trypanosomatids is, however, missing in Leishmania genome. Chitinase can be involved in the interaction of leishmania parasites with chitin-containing structures in sand flies (peritrophic matrix, stomodeal valve). The expression of the enzyme in amastigotes suggests its significant function also in the mammalian host. I tested the role of these enzymes in the life cycle of leishmania by direct comparison of L. mexicana mutants (i) with inserted catalase gene and (ii) with deleted chitinase gene with control groups. I conducted experimental infections of Lu. longipalpis including transmission of leishmania to the hosts by bite, tested the survival of leishmania in macrophages and performed experimental infections of BALB/c mice followed by xenodiagnoses. The experiments confirmed that the presence of catalase in leishmania does...
African rodents as reservoirs of Leishmania parasites.
Glanzová, Kristýna ; Sádlová, Jovana (advisor) ; Votýpka, Jan (referee)
Leishmania spp. (Kinetoplastida: Trypanosomatidae) are protozoa related to the Trypanosoma genus that are causative agents of leishmaniasis. Their life cycle alternates between mammalian hosts and insect vectors. The principal vectors are phlebotomine sand flies (Diptera: Phlebotominae) that occur mostly in the tropics, however, several species range to the temperate regions. Various species of rodents serve as reservoir hosts of leishmania. In endemic localities, they represent most abundant mammals and their burrows are used as breeding sites of larval stages of sand flies. In this bachelor thesis I summarize available literature about rodents that serve as reservoir hosts of six human pathogenic leishmania species present in Africa. Several species of African rodents are regarded as reservoir host of L. major and one species (Ctenodactylus gundi) as a suspected reservoir host L. tropica. On the other hand, rodent infections caused by L. aethiopica, L. infantum and L. donovani should be still considered as accidental. In the case of Leishmania sp. from Ghana, reservoir hosts are still entirely unknown. All species of proven African rodent reservoir hosts share clustered distribution in colonies where animals live in high population densities.

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