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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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How Intracellular Pathogens Manipulate Cellular Trafficking.
Petrů, Markéta ; Doležal, Pavel (advisor) ; Pyrih, Jan (referee)
Many intracellular single-celled organisms belong to medically important human pathogens. The selected parasites are subject of this thesis - Chlamydia spp., Legionella pneumophila, Trypanosoma cruzi and Toxoplasma gondii - as well as their interactions with the vesicular transport of the host cell. Basic pathways of vesicular transport are delineated and important participating molecules described. Furthermore, the effector proteins of pathogens that interact with these molecules are included. The special chapter is devoted to phenomenon of mimetics of SNARE proteins by bacteria. The manuscript concludes with a chapter on LpSNARE of Legionella pneumophila, which was found in our laboratory and which is a topic of my experimental work herein.
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The role of Toxoplasma gondii on the expression of Major Urinary Proteins in the house mouse
Hladovcová, Denisa ; Stopka, Pavel (advisor) ; Hrdý, Ivan (referee)
Major Urinary Proteins (MUP) are pheromonal transmitters involved in chemical communication in rodents. Complexes of MUPs and ligands mediate information about genetical background of an individual and co-create individual scent profile. They play a significant role in kinship determination, the crucial factor in the choice of a mating partner. It is assumed that the MUP production is energetically demanding due to the pressure of sexual selection, and the transmitted signal is thus supposed to be honest. This theory hasn't yet been experimentally tested, neither was proven the effect of another intense selection pressure- a parasitic infection. In my thesis, I describe the effect of an infection of a parasite Toxoplasma gondii on MUP production. The results suggest that the production is altered in both sexes, the production decreasing in males to the level of male castrates (or the female level). Considering the results of more detailed analysis of the infection we assume that the energetical demands of the MUP production doesn't allow the production of ordinary amounts if MUPs during the first phase of the infection as the energy is primarily devoted to the infection control. The increased production in latter phase can be attributed to the importance of scent communication. Decreased levels of...
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The effect of Toxoplasma gondii on the intermediate host
Vosátka, Martin ; Chaloupková, Helena (advisor) ; Hradec, Michal (referee)
Toxoplasma gondii is a protozoan parasite, which has a wide spectrum of warm-blooded hosts, human included. It has worldwide occurrence. The most important role for it has a feline, which serves like a definitive host and allows it to proliferate. The aim of this bachelor thesis was to sum up all identified information so far about the possibilities of relationship between protozoan parasite and its intermediate hosts mainly in area of behavior. Laboratory mouse, the most examined animal associated with behavioral changes, was chosen as an intermediate host. This thesis was also aimed on affecting of human behavior by Toxoplasma gondii in general and about problems connected with it, for example connection with mental diseases and higher risk of traffic accidents. Manipulation of mice by Toxoplasma leads to change in basic instincts necessary for survival. It is especially about attraction to feline odour, when the degree of attraction depends on the dose of stimulus. Area of learning and memory was examined at mice model as well. Worsen ability of learning and memory was demonstrated in most cases (Flegr et al., 2014). Also relationship between number of cysts in the brain and worse results were observed (Vyas et al., 2007). Another important area was human reaction time. Infected individuals had slower reactions, which indicates worsen long-term concentration (Havlíček et al., 2001). Worsen concentration plays an important role and it is connected with a chance of susceptibility to accidents and riskiness for drivers. The individuals with latent Toxoplasma had 2,65 times higher chance for traffic accident (Flegr et al., 2002). T. gondii plays an important role in mental diseases, especially in link with schizophrenia. Effective medication of schizophrenia can inhibit T. gondii (Yolken et al., 2009). Schizophrenia often results in suicide attempt. That is why possible link between suicide attempts and presence of the parasite was researched. The study shows connection between antibody levels of T. gondii and suicide attempts, but just in a subgroup of patients younger than 38 years. It is probably because of risk of suicide attempts in schizophrenia appears in earlier phase of the disease (Okusaga et al., 2011).
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One more drop for decreasing reproduction
Dvořáková-Hortová, K. ; Šídlová, A. ; Děd, Lukáš ; Hladovcová, D. ; Vieweg, M. ; Weidner, W. ; Steger, K. ; Stopka, P. ; Paradowska-Dogan, A.
Toxoplasma gondii is a common protozoan parasite that infects warm-blooded animals throughout the world, including mice and humans. During infection, both, the parasite and the host, utilize various mechanisms to maximize their own reproductive success. Mice and humans are both the intermediate hosts for Toxoplasma gondii, which forms specialized vacuoles containing reproductive cysts in the formers’ tissue. As half of the human population is infected, developing a disease called toxoplasmosis, along with an ever-growing number of couples suffering with idiopathic infertility, it is therefore surprising that there is a lack of research on how T.gondii can alter reproductive parameters. In this study, a detailed histometric screening of the testicular function along with the levels of the pituitary luteinizing hormone (LH) were analysed in infected mice. Data on relative testis and epididymis weight, and sperm count were also collected. Based on the results obtained, the level of LH in the urine of Toxoplasma gondii infected mice was lower compared to the control. In direct correlation with the hormone level, testicular function and sperm production was also significantly lower in T. gondii positive group using sperm count and histometric analysis as a marker. Not only were the number of leptotene primary spermatocytes and spermatids lowered, but the number of Sertoli cells and the tubule diameter were elevated. In parallel, a pilot epigenetic study on global testicular methylation, and specific methylation of Crem, Creb1 and Hspa1genes essential for successfully ongoing spermatogenesis was performed. Global methylation was elevated in Toxoplasma infected mice, and differences in the DNA methylation of selected genes were detected between the Toxoplasma positive and control group. These findings demonstrate a direct relation between T. gondii infection and the decrease of male reproductive fitness in mice, which may contribute to an increase of infertility in humans.
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Serological diagnosis of toxoplasmosis
KAASOVÁ, Eliška
Toxoplasmosis caused by the protozoan Toxoplasma Gondii is one of the most widespread parasitic infection in the world, occurring in organism of both warm-blooded animals and humans. The majority of healthy individuals have no symptoms, in some cases there are slight clinical signs. However, serious heath complications or even death may be caused either by infection or reactivation of the latent form of infection among people with immunodeficiencies. Toxoplasmosis can inflict a severe fetal damage when a female is infected for the very first time in the first trimester of pregnancy. This can be prevented by the risk group screening and an early detection of the protozoan. Laboratory diagnostics use two basic methods in order to prove toxoplasmosis, a direct one and an indirect one. The direct methods such as a microscopic evidence of the protozoan or the isolation of Toxoplasma Gondii on laboratory animals are not usually used in practice. In recent years methods of molecular biology focused on the proof of the protozoan?s nuclear acid in the biological material come to the fore. The methods of indirect evidence are based on the detection of specific traces left by the infectious agent in human organism. Among them, serological methods are the most commonly used ones in the routine operation in the majority of laboratories in the Czech Republic. A basic principle is reaction between antigen and antibody. It is possible to determine whether the infection is in acute or chronic phase and what type of infection it is. This test was utilized for serological evidence of toxoplasmosis for the first time. Then other tests were made. That includes intradermal and imunofluorecent tests, complement fixation test, indirect hemaglutination, microprecipitation or imunoenzymatic methods. The mere evidence of the presence of antibodies is not usually sufficient for diagnosis. Determination of the phase of infection is essential, therefore it is needed to prove if the value of each class of immunoglobulins (or titers of all antibodies) increases, decreases or if they have a stable value. In some cases the avidity IgG may be crucial. The aim of this bachelor thesis is to detect antibodies against Toxoplasma Gondii and to evaluate their prevalence by using serological methods. And finally, these methods will be compared. The patient samples originate from the department of parasitology and serology of Fakultní nemocnice Plzeň, therefore there is an evaluation of the incidence of infection in Pilsen region. The complement fixation test is the most commonly used in routine operation for determination of the total level of antibodies or this test is supplemented by determination of levels of individual immunoglobulin classes by using the Enzyme linked immunosorbent assay. If there is the evidence of infection of toxoplasma by using KFR and the antibody titer is 1:8, it is necessary to supplement the determination by ELSA method to ascertain the level of immunoglobulin classes. This diagnosis has gradually developed from demanding and complex procedures towards fast and fully automated diagnosis. In total, 68 samples of patients with suspicion of toxoplasmosis were determined. The monitored group includes men, women and children. After consideration of the factors which may influence the reaction and on the basis of KFR, the infection of 26 persons was eliminated (negative results). The remaining 43 patients had a positive reaction for the presence of antibodies. After comparing the positive results and low titers with the clinical state of the patient or with the values measured in the past, the determination by the method of ELISA was indicated among 41 persons. The final result for August 2012 was the detection of acute toxoplasma infection of 4 people.
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