National Repository of Grey Literature 18 records found  1 - 10next  jump to record: Search took 0.00 seconds. 
Leishmaniases of northern Africa and their vectors
Hanušniaková, Ida ; Dvořák, Vít (advisor) ; Sádlová, Jovana (referee)
Leishmaniasis belongs to the most important world human as well as animal diseases. It occurs in almost all continents. Its nearest area of occurrence from our point of view is the Mediterranean, including the states of North Africa. A significant portion of all registered cases occurs here and the prevalence has been increasing in last decades. Algeria is the second in the world in number of cases of cutaneous leishmaniasis and in the other countries the situation is quite similar. Two major forms of the disease occur in the region: visceral and cutaneous leishmaniasis. Leishmania major is the most abundant species in the are, followed by L. infantum and L. tropica. In the Old World, leishmanises are transmitted by sand flies of the genus Phlebotomus. The most important proven vectors are Phlebotomus papatasi, P. sergenti, P. perfiliewi or P. perniciosus. Rodents are considered to be main reservoir organisms (Psammomys obesus, Meriones shawi), together with dogs in which canine leishmaniasis may occur with clinical symptoms; at the same time they serve as reservoirs of the disease. This bachelor thesis summarizes occurrence of individual Leishmania species, clinical symptoms they cause in the hosts and their vectors in North Africa. Key words: leishmaniasis, phlebotomus, North Africa, Leishmania,...
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...
Biology of Leishmania enriettii species complex.
Bečvář, Tomáš ; Sádlová, Jovana (advisor) ; Spitzová, Tatiana (referee)
vytvořený v roce 2016, ve kterém je zařazeno 5 druhů leishmanií - pouze divokých druhů savců, zatímco druhy "L. siamensis" . izolovaná v Ghaně mají potenciál infikovat i člověka. Areál rozšíření těchto druhů je velmi široký a zasahuje do všech kontinentů světa kromě Antarktidy, čemuž odpovídá i neobvyklá hostitelů a přenašečů onemocnění. Mezi vektory patří nejen flebotomové dvoukřídlý krevsající hmyz čele i tiplíci (Diptera: což je v rámci rodu zcela unikátní Škála zvířat, ze kterých byli zástupci podrodu izolováni je široká, od ů í či dobytka po hlodavce, ale skutečné doklady o jejich rezervoárové roli chybí. Mnohé otázky, zejména přesná identita rezervoárových zvířat a přenašečů, musí být zodpovězeny, než pochopíme unikátního Klíčová slova: leishmanióza, "Leishmania siamensis" , leishmanióza koní, fylogeneze, agbamekanu
Alternative vectors of Leishmania (Kinetoplastida: Trypanosomatidae)
Jursová, Klára ; Sádlová, Jovana (advisor) ; Dvořák, Vít (referee)
The life cycle of Leishmania (Kinetoplastida: Tripanosomatidae) alternates between vertebrate hosts and insect vectors. Phlebotomine sand flies (Diptera: Psychodidae) were supposed to be the only arthropod vectors supporting morphological and functional development of the parasite including production of infective metacyclic forms capable to infect the vertebrate host. Recently also other bloodsucking arthropods have been suggested for possible transmission of some Leishmania species. The bachelor thesis summarizes the recent knowledge about these alternative vectors of Leishmania.
A comparison of the peritrophic matrix in four sand fly species (Diptera: Psychodidae) and its role in the Leishmania development (Kinetoplastida: Trypanosomatidae).
Homola, Miroslav ; Sádlová, Jovana (advisor) ; Hypša, Václav (referee)
anglický Phlebotomine sand flies (Diptera: Psychodidae) are the only proven vectors of Leishmania parasites (Kinetoplastida: Trypanosomatidae). In Nematoceran Diptera, including sand flies, adults produce a type 1 peritrophic matrix (PM) which is secreted in response to the distension of the midgut caused by blood meal. The PM is an acellular envelope composed of chitin fibres and proteins, which protects the midgut epithelium against abrasion and pathogens and improves digestion. In hematophagous insects, the PM also plays a central role in heme detoxification. Female sand flies acquire Leishmania with a bloodmeal and the parasites undergo complicated development in their gut finished by the colonization of the stomodeal valve. The PM is one of the most important barriers in Leishmania development and its role in the vector competence of the S. schwetzi is the main topic of this master thesis. The PM's kinetic and morfology in the S. schwetzi is compared with other three sand fly species which differ in susceptibility to L. donovani. The key role of the PM in S. schwetzi vector competence is finally proved by disrupting the PM using the exogenous chitinase from Beauveria bassiana. Under these artificial conditions, the Leishmania parasites (L. donovani and L. major) are able to exit the PM,...
Xenodiagnosis of Leishmania major infections in symptomatic and asymptomatic rodents.
Vojtková, Barbora ; Sádlová, Jovana (advisor) ; Kodym, Petr (referee)
Leishmaniasis is a disease circulating in endemic areas between sand flies (Diptera: Phlebotominae) and reservoir hosts, which - in the case of Leishmania major - are principally rodents (Rodentia). Unlike in human patients, leishmaniasis is often asymptomatic in animal hosts. For transmission and maintenance of the parasite in nature, infectiousness of hosts for sand flies is essential; and the only method to directly test the infectiousness is xenodiagnosis. The main objective of this thesis is to establish a laboratory model for studying xenodiagnosis with L. major on inbred BALB/c mice and then to apply this model to potential reservoir ro- dents from the genus Mastomys. BALB/c mice were infected by intradermal inoculation of infective stages of L. major (iso- lated from sand fly guts) together with salivary gland homogenates from Phlebotomus duboscqi; infected mice were then exposed to P. duboscqi females for a period of ten weeks. Two inbred lines of BALB/c mice differed significantly in both the manifestation of the disease and infectiousness for sandflies. In BALB/c OlaHsdmice, great lesions were formed (up to 10 mm), mice were able to infect sand flies from the 2nd week after infection and their infec- tiousness reached up to 20.1% during the experiment. In BALB/c AnNCrl mice, only small...
Peritrophic matrix of bloodsucking Dipteran insects.
Homola, Miroslav ; Sádlová, Jovana (advisor) ; Votýpka, Jan (referee)
The peritrophic matrix is an acellular envelope which surrounds the food bolus in the midgut of many animal species (especially in insects). It fulfils many functions in the midgut e. g.: protects the gut against an abrasion and against toxic substances, improves the digestion of food and protects the gut epithelium against pathogens. The last function might be the main reason of the occurrence of the peritrophic matrix in large amount of insect species. The peritrophic matrix is composed of chitin fibres and proteins. Chitin provides the peritrophic matrix strength and flexibility. Chitin fibres can be organised into three elementary structures: random, hexagonal and squared. The size of pores in peritrophic matrix depends on incorporated proteins - especially peritrophins. These pores determine the permeability of the peritrophic matrix for various penetrating molecules including digestive enzymes. This bachelor thesis is focused on Insecta sensu stricto (Hexapoda) and mainly on the order Diptera, especially bloodsucking species. Following chapters review recent information about the peritrophic matrix and its nomenclature, occurrence, assembling, composition and functions. Powered by TCPDF (www.tcpdf.org)
Leishmania tropica: immunopathology and genetic control
Sohrabi, Yahya ; Lipoldová, Marie (advisor) ; Pravenec, Michal (referee) ; Sádlová, Jovana (referee)
Leishmaniasis is a neglected tropical disease caused by protozoan parasites of the genus Leishmania and transmitted by female sand flies. The outcome of Leishmania infection depends both on host and pathogen factors. Similarly as L. major, L. tropica very often causes cutaneous leishmaniasis in humans, but in rare occasions can also visceralize and cause systemic disease. Leishmaniasis cause by L. tropica has become a major public health problem in different endemic foci due to recent outbreaks in several urban areas and spread to new regions. The complications of the disease and lack of safe and effective drug and vaccine against the L. tropica infection require considerable attention to studies of the host-L. tropica interaction. Until recently, the research of leishmaniasis caused by L. tropica was limited due to lack of suitable inbred model and difficulties in inducing infection in animals. The aims of the present project were development of a suitable mouse model of the infection caused by L. tropica, and the study of mechanisms of the disease, and also mapping controlling genes/loci. We analysed susceptibility to L. tropica infection using recombinant congenic (RC) CcS/Dem mouse strains. These strains differ greatly in susceptibility to L. major due to random distribution of 12.5% of STS...
Types of Leishmania development in phlebotomine species
Nováková, Julie ; Votýpka, Jan (advisor) ; Sádlová, Jovana (referee)
The aim of this thesis is to depict the means of Leishmania development in sand flies (Phlebotominae). Three main Leishmania evolutionary branches (subgenera Leishmania, Viannia and Sauroleishmania) have a slightly different development in the vector, the Sauroleishmania development being the least known. The vector-bound development of the subgenus Leishmania is localized in the midgut and foregut of the sand fly solely, whereas species of the Viannia subgenus occur in the hindgut (although the necessity of this phase for a successful development and infection of the vertebrate host is a matter of doubt) and the subgenus Sauroleishmania development is according to literature confined to the hindgut. Quite little is known about the genus Endotrypanum, according to phylogenetic data set inside the Leishmania group. In my bachelor thesis, I review up-to-date literature on the topic of different types of Leishmania development inside the sand flies and their probable reasons.

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