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Comparison of different rodent species as hosts of human pathogenic leishmania.
Vojtková, Barbora
6 ABSTRACT Leishmania parasites (Kinetoplastida: Trypanosomatidae) are causative agents of leishmaniases, a group of vector-borne diseases with various manifestations and complex epidemiology. Principal vectors are sand flies (Diptera: Psychodidae) and among mammalian hosts, rodents are predominantly represented. Rodents are also the most common laboratory models for the research of leishmaniases. However, reservoirs of most Leishmania species are still poorly recognized and the scope of standard model hosts is still insufficient to mimic well the wide spectrum of leishmaniases. This PhD thesis summarizes three different topics, all dealing with experimental infections of rodents with important human parasites - Leishmania major and L. donovani. The first topic was focused on the effect of sand fly saliva on the development of cutaneous leishmaniasis. BALB/c mice infected intradermally with L. major were repeatedly bitten by P. duboscqi females every two weeks. The multiple and repeated sand fly bites significantly enhanced the development of cutaneous lesions and increased parasite load. The second topic was aimed at enrichment of the spectrum of laboratory model animals for Leishmania research. Three Asian rodent species (Cricetulus griseus, Lagurus lagurus and Phodopus sungorus) were infected with L....
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Xenodiagnosis and its use in leishmaniases research
Vojtková, Barbora ; Volf, Petr (advisor) ; Svobodová, Milena (referee)
The aim of these theses was to summarize the knowledge about the use of xenodiagnostic methods in the past and their current potential for parasitological research. Xenodiagnosis it is a diagnostic method using bloodsucking arthropods (disease vectors) as a biologic medium suitable for detection of parasites in the blood of investigated individuals (vertebrates). It is expected that parasites grow within the midgut of the vector and then are easily detectable microscopically. The method was used for the first time in 1914 by French researcher Émile Bumpt for detection of Trypasoma cruzi, causative agent of Chargas' disease. During few decades and thanks to engagement of many scientific groups, it became one of the most efficient and effective diagnostic methods. For instance, the most suitable species of vectors, the experiment duration and the optimal numbers of vectors and/or experiments were assigned to get reliable results. Xenodiagnoses as a diagnostic method lost its importance after introduction of molecular methods, first of all after onset of polymerase chain reaction. At present, however, the xenodiagnosis is suitable for experiments studiing if the host is infectious for the vector. This method appears as a good tool for testing of new reservoir hosts and for the monitoring of the role...
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Comparison of different rodent species as hosts of human pathogenic leishmania.
Vojtková, Barbora ; Sádlová, Jovana (advisor) ; Kodym, Petr (referee) ; Shaw, Jeffrey Jon (referee)
6 ABSTRACT Leishmania parasites (Kinetoplastida: Trypanosomatidae) are causative agents of leishmaniases, a group of vector-borne diseases with various manifestations and complex epidemiology. Principal vectors are sand flies (Diptera: Psychodidae) and among mammalian hosts, rodents are predominantly represented. Rodents are also the most common laboratory models for the research of leishmaniases. However, reservoirs of most Leishmania species are still poorly recognized and the scope of standard model hosts is still insufficient to mimic well the wide spectrum of leishmaniases. This PhD thesis summarizes three different topics, all dealing with experimental infections of rodents with important human parasites - Leishmania major and L. donovani. The first topic was focused on the effect of sand fly saliva on the development of cutaneous leishmaniasis. BALB/c mice infected intradermally with L. major were repeatedly bitten by P. duboscqi females every two weeks. The multiple and repeated sand fly bites significantly enhanced the development of cutaneous lesions and increased parasite load. The second topic was aimed at enrichment of the spectrum of laboratory model animals for Leishmania research. Three Asian rodent species (Cricetulus griseus, Lagurus lagurus and Phodopus sungorus) were infected with L....
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Role of asymptomatic hosts in leishmaniasis transmission.
Sandner, Bruno ; Sádlová, Jovana (advisor) ; Kodym, Petr (referee)
Leishmania parasites have a digenetic-life cycle, circulating between vertebrate hosts and insect vectors, mainly phlebotomine sand flies (Diptera: Phlebotominae). Mammals serve as principal reservoirs of the disease and maintain the leishmania population even in the absence of the vector. Knowledge of the role of asymptomatic hosts in parasite transmission is one of the key prerequisites to understand epidemiology of leishmaniases. The aim of this work is to summarize the studies on asymptomatic hosts of visceral leishmaniasis caused by L. infantum and L. donovani. In L. infantum, asymptomatic hosts have been shown to be involved in transmission, namely dogs, humans, and other putative reservoir hosts. Asymptomatic dogs infect the same proportion of vectors as symptomatic dogs, and in humans, HIV coinfection significantly increased the infectiousness. VL caused by L. donovani is regarded as mostly anthroponotic, but the parasite has been often detected in animal hosts and zoonotic transmission has been suggested in East Africa. Transmission from asymptomatic individuals has not been established, but the studies on this topic are very scarce. Further intensive research is needed to confirm the role of potential reservoir hosts and asymptomatic individuals in the transmission of leishmaniases....
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Leishmania of the subgenus Mundinia: genetical analysis and experimental infections of rodents and vectors.
Bečvář, Tomáš ; Sádlová, Jovana (advisor) ; Modrý, David (referee)
Leishmaniasis is a human and animal disease caused by digenetic parasites of the genus Leishmania, which is now divided into 4 subgenera - L. (Leishmania), L. (Viannia), L. (Sauroleishmania) and L. (Mundinia). Subgenus Mundinia was established in 2016 and consists of 5 species - L. enriettii and L. macropodum are parasites of wild mammals and L. martiniquensis, L. orientalis and unnamed L. sp. from Ghana are infectious to humans. Mundinia are geographically widely dispersed, their distribution covers all continents, except of Antarctica. Despite phlebotomine sand flies (Diptera: Psychodidae) also biting midges (Diptera: Ceratopogonidae) are supposed to be involved in transmission of these species, which is a unique feature for this subgenus. But there is little to no current information on natural reservoir hosts and vector species for any Mundinia species. In this thesis we tested possible vectors and potential model organisms (Guinea-pigs) and reservoir hosts of Mundinia species by experimental infections. We used 3 sand fly species sharing geographical distribution with respective Mundinia species and available in our laboratory for experimental infections. Sand flies from Australia had never been colonised so we used the permissive vector Lu. migonei for testing development of L. macropodum....
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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,...
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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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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...
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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
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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...
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