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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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Sauroleishmania: development in the vectors and hosts
Tichá, Lucie ; Volf, Petr (advisor) ; Kodym, Petr (referee)
Leishmania of subgenus Sauroleishmania are parasites of reptiles, most often lizards, and are not pathogenic for humans. Therefore, they are neglected group of pathogens and their life cycle is not well-known. They are transmitted probably by ingestion of infected vector which is usually considered as sand flies of genus Sergentomyia (Diptera: Psychodidae). Sauroleishmania are traditionally denominated in Hypopylaria and it is expected that their development is limited to sand fly hindgut. The main aim of this work is to summarize the present knowledge about Sauroleishmania life cycle and to elucidate some aspects of their development in the vector and host. In the first part of thesis we studied development of four Sauroleishmania species in various sand flies of genera Sergentomyia and Phlebotomus. Late-stage infections of Leishmania (S.) adleri and L. (S.) hoogstraali were found in six and two sand fly species, respectively. Hypopylarian infections of Leishmania (S.) adleri were found in Se. schwetzi, P. papatasi and P. sergenti, while in P. argentipes, P. orientalis and P. duboscqi this Sauroleishmania migrated anteriorly in the midgut (peripylarian development). Similar type of development was observed also in P. argentipes and P. orientalis infected by Leishmania (S.) hoogstraali. Both L....
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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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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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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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