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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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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)
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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...
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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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Sugar solution sucking by females of blood-sucking Nematocera insect
Davídková, Tereza ; Votýpka, Jan (advisor) ; Sádlová, Jovana (referee)
The research of blood-sucking insect is important mainly because of the health aspect. In many cases, they are the carriers of a various disease. A lot of species of the Nematocera suborder feed only of sugary solutions. This food affects their behavior and their way of life. Blood-sucking insect is able to search for food with beneficial sugar content. The composition of this food affects the amount of body reserve, longevity, oviposition of eggs. These effects manifest differently with various organisms. The goal of this thesis is to summarize the knowledge of preferentially picked plants of blood-sucking females of the Nematocera suborder and to describe the affect of food sugar content on the examined insect and the pathogen transmission. Key words: blood-sucking insect, sugar feeding, Phlebotomus papatasi, Anopheles gambiae, fecundity, preferences, influence Powered by TCPDF (www.tcpdf.org)
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Host specificity, diversity and distribution of avian malaria parasites in a contact zone of two nightingale species
Šíma, Michal ; Munclinger, Pavel (advisor) ; Sádlová, Jovana (referee)
Avian contact zones were suggested to act as barriers to parasite expansions. I studied haemosporidian parasites (genera Plasmodium, Haemoproteus, and Leucocytozoon) of two Nightingale species which meet in a contact zone in Europe. In total 20 lineages of parasites were detected. Surprisingly, all common lineages were shared by the two host species. The parasite prevalence vary between species (Trush Nightingales were more often parasitized than Common Nightingales.) but did not vary to a large extent within zones inside species Parasitemia of the most frequent Haemoproteus LULU1 lineage assessed by Real-Time PCR method did not differ significantly between the two host species. Six out of nine hybrids of the nightingale species were parasitized. Haemosporidian lineages found in hybrids were also frequent in the parental species. In conclusion, the nightingale contact zone seems to have only little (if any) effect on the distribution of haemosporidian parasites.
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Vývoj leishmanií v přenašečích rodu Phlebotomus
Sádlová, Jovana
DISSERTATION ABSTRACT Development of Leishmania parasites in vector sandflies (Diptera: Phlebotominae) Jovana Sádlová Introduction. The work is dealing with two topics: (1) factors affecting development of Leishmania parasites in sandfly vectors and (2) mechanism of Leishmania transmission to the vertebrate host. It includes a review on Leishmania - sandfly - host interactions, four papers published in scientific journals and one manuscript submitted for publication. (1) Within the sandfly gut, Leishmania promastigotes encounter a number of factors which affect their development. They are usually well-adapted to the habitat inside the gut of their natural vectors, but characters of the parasites crucial for the development in the vector have not been elucidated. The main cell-surface molecules of promastigotes, lipophosphoglycan (LPG) and metalloprotease gp63, are known as the most important virulence factors influencing Leishmania interactions with the vertebrate host. However, their role in the vector part of Leishmania life-cycle remains to be clarified. The idea of the work is based on the fact that there are differences in the courses of sandfly infections with various strains and lines of L. major. Therefore, a detailed characterization of individual strains/lines may lead to the recognition of a...
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Genus Sergentomyia and its role in the transmission of Leishmania
Hlavačková, Kristýna ; Dvořák, Vít (advisor) ; Sádlová, Jovana (referee)
Sand flies, members of the subfamily Phlebotominae do not occur in the CzechRepublic, but as near as in the Mediterraneantheir fauna is quite abundant. Sand flies can be found approximately between 50řN and 40řS. Species of genus Phlebotomus, Sergentomyia and Lutzomyia include medically and veterinary important vectors of viral and bacterial diseases as well as leishmaniasis, one of the most important human protozoal diseases. 321 years have passed since the first sand fly was described, but only 110 years ago intensive taxonomic work began. Over the years many classification systems have been proposed, mainly based on division of morphological characters. The classification is not clearly settled even after several taxonomic revisions and many questions remain, especially about genus Sergentomyia, which is repeatedly mentioned in connection with transmission of mammals' leishmaniasis. This bachelor thesis gives contemporary summary of taxonomic knowledge of sand flies; special attention is given to genus Sergentomyia.
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Leishmania tropica in Mediterranean
Peštová, Jitka ; Votýpka, Jan (advisor) ; Sádlová, Jovana (referee)
In recent years new foci of Leishmania tropica appeared in the Mediterranean states of Northern Africa. While L. tropica was isolated from humans, dogs and sand fly species Phlebotomus sergenti in Morocco and from humans and gerbils (Gerbilus pyramidum floweri) in Egypt; in Tunisia, Algeria and Lybia the parasite was isolated from humans only. In the last three mentioned states, only L. tropica referred as Leishmania killicki is present. In most of the L. tropica foci in the Mediterranean countries of Northern Africa transmission mode was not determined. It is unknown whether the cycle of L. tropica is anthroponotic or zoonotic and what is reservoir and vector. In Morocco and Egypt, the most probable vector is P. sergenti only, while in Tunisia, Algeria and Lybia the vectors could be also P. (Paraphlebotomus) riouxi, P. (Paraphlebotomus) chabaudi, P. (Paraphlebotomus) alexandri or P. (Larroussius) perniciosus. Considering the rural distribution and sporadic occurence of L. killicki cases, the parasite is presumed to have a zoonotic cycle and its reservoir host could possibly be Ctenodactylus gundi, which is relatively abundant in L. kilicki foci.
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Autogeny by phlebotomine sandflies
Pavlasová, Michaela ; Votýpka, Jan (advisor) ; Sádlová, Jovana (referee)
1 Abstract In haematophagous insect autogeny means an eggs development and ability to set first egg batch without previous blood-feeding on a host. Autogeny developed in several groups of invertebrates mainly order Diptera and more rarely orders Heteroptera and Acari. It occurs mostly as an alternative possibility of development in case of unsuitable conditions or absence of hosts. This thesis includes present findings about autogeny among subfamily Phlebotominae and families Culicidae, Simuliidae, Ceratopogonidae and Tabanidae. The thesis focuses on factors influencing autogeny such as nutrition during larval development, geographic and genetic factors, temperature and photoperiodic aspects. The thesis is targeted mostly on sandflies, important vectors of many pathogens, and on influence of autogeny on its vectorial potential. Key words: autogeny, ovarian development, Phlebotomus, Culicidae, Simuliidae, Ceratopogonidae, Tabanidae
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