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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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Sexual transmission of Toxoplasma gondii from males to females: experimental verification using laboratory animal model
Navrátil, Jiří ; Kodym, Petr (advisor) ; Votýpka, Jan (referee)
Toxoplasma gondii is cosmopolitly living parasite which prevalence in human extends to tens of percent. In its life cycle it uses any homoiothermic vertebrate as an intermediate host. The definitive host are felines from Felidae family. The acute phase of infection is medically important in immunocompromised pacients and by its risk of congenital toxoplasmosis in pregnant women who never suffered from this illness before. Infection could have serious and rarely even lethal consequences in both cases. This thesis focuses on experimental verification of theory of sexual transmission of toxoplasmosis from male to female on laboratory mice. Possible transmission was tested in acute phase and latent phase of infection. The result was negative in both cases. Moreover, we observed the parasite's affinity to tissue of organs in male mice by PCR technique. Particularly, our interest was in comparing genital organs with others. It was discovered that lungs and spleen are the most infected organs in acute phase of infection. Toxoplasma was also present in genital organs (especially in epididymis) but not more frequently than in others. We observed statistically significant difference between sexual and non-sexual organs in acute and latent toxoplasmosis - non-sexual organs were more infected in both phases....
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Options of the sexual transmission of toxoplasmosis
Forejtková, Zita ; Kaňková, Šárka (advisor) ; Kodym, Petr (referee)
Toxoplasmosis is a disease caused by coccidia Toxoplasma gondii. This disease occurs in humans and warm-blooded animals throughout the world and is matter of great economic and medical importance. This bachelor thesis contains a summary of current information on the possibility of sexual transmission of T. gondii. Sexual transmission was confirmed in warm- blooded animals. A higher prevalence of toxoplasmosis was found in people who are infected with some venereal diseases. There is another indirect evidence supporting the hypothesis of sexual transmission of T. gondii. This route of transmission could play an important role, especially during pregnancy and to people with impaired immune responses.
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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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Toxoplasma and Host's Reproductive Function
Hlaváčová, Jana ; Kaňková, Šárka (advisor) ; Kodym, Petr (referee)
Toxoplasma gondii (Apicomplexa) is probably one of the most common human parasite in developed countries. It has a wide range of hosts including a variety of warm-blooded animals as well as humans. In this bachelor thesis you can find review of literature focusing on an influence of T. gondii on host's reproductive functions. Toxoplasmosis is accompanied by hormonal changes which may be one reason for the negative effect on host's fertility. Throughout the thesis are mentioned immunosuppression and reduced quality control of embryos associated with T. gondii. Both of these phenomena probably affect pregnancy, prenatal and postnatal development of the offsprings of mothers with latent toxoplasmosis. And these also play a role in shifting of sex ratio in infected hosts.
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