|
|
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.
|
|
|
Role of rodents of the genus Arvicanthis in Leishmania major maintenance: xenodiagnosis and experimental transmission of infections.
Hrnčířová, Kateřina ; Sádlová, Jovana (advisor) ; Kodym, Petr (referee)
A cutaneous leishmaniasis is the most common clinical form of human disease caused by parasite of the genus Leishmania. They are transmitted between the hosts by haematophagous females of dipteran sand flies of the genus Phlebotomus in the Old World and Lutzomyia in the New World. One of the major agents of cutaneous leishmaniasis in the Old World is Leishmania major. The disease caused by this species is a zoonosis where rodents act as reservoir host. The parasite long time circulates between reservoir rodents and sand flies, while humans are infected only accidentaly in the focus of infection. Rodents of the genus Arvicanthis belongs to the most abundant in the African continent. The genus has evolved in Ethiopia from where it expanded to a major part of Sub - Saharan Africa and the delta of the river Nile. These rodents are very abundant in endemic locations of cutaneous and visceral leishmanias and fulfil many reservoir host criterias including repeated field findings of individuals infected by L. major and another Leishmania species in nature. However, their role in the disease cycle remains to be confirmed. A. neumanni used in this study is an East African species spread from Ethiopia and Somalia to Kenya and Tanzania. Animals were experimentally infected with three different L. major...
|
|
|
Genes participating in response to Leishmania major revealed by targeted mutation.
Ezrová, Zuzana ; Lipoldová, Marie (advisor) ; Krulová, Magdaléna (referee)
Leishmania major is an intracellular parasite which often successfully multiplies and disseminates in a body of the host thanks to strategies that help it to escape the components of immune system of the host organism. Thus, the parasites evoke an impairment of regulatory pathways that in physiological conditions lead to an expression of genes involved in a response to L. major and its efficient elimination. Gene targeted deletion, also called gene knock-out, can result in phenotypic alteration and associated enhanced susceptibility or resistance of the host. Although such detected genes do not have to signify their variability in population and hence they may not be responsible for the worsened outcome of leishmaniasis of some people necessarily, studies in which they are analysed and general knowledge being also a subject of this thesis help us together with techniques of forward genetics to reveal the biochemical pathways during the infection and their elements that influence the outcome of the disease and might be useful for researches of new medicine drugs or gene therapy.
|
guest ::
