Description: Das Projekt "Entamoeba histolytica: Parasit- und Wirtsdeterminanten der Gewebeinvasion" wird vom Umweltbundesamt gefördert und von Universität Tübingen, Institut für Tropenmedizin durchgeführt. Objective: - To better understand the pathophysiology of invasive amebiasis through analysing the host-parasite interrelation in human infections of the intestinal parasite Entamoeba histolytica at the molecular, clinical and epidemiological level. General Information: - Monoclonal antibodies selectively recognizing only cysts of pathogenic Entamoeba histolytica or non-pathogenic Entamoeba dispar are developed; - Antigens recognized by monoclonal antibodies are examined in order to assess their location and functional significance; - Entamoeba histolytica and Entamoeba dispar are detected and differentiated using an improved colorimetric polymerase chain reaction method directly from faecal samples; - Cell surface molecules of pathogenic E. histolytica and nonpathogenic E. dispar and their relation to virulence are examined; - Epidemiologic studies are under way in Diyarbakir/Turkey and in Cairo/Egypt in order to assess the prevalence of E. histolytica infections. Achievements: - Monoclonal antibodies were produced that specifically recognise native and fixed cysts of E. histolytica as well as against native and fixed cysts of E. dispar. Serological studies have shown that E. dispar itself can elicit a specific serum antibody response. An improved method based on the PCR-SHELA technique has been developed to identify E. histolytica and E. dispar in human faeces. This method is suitable for use with large numbers of specimens. - The prevalences of E. histolytica and E. dispar were determined separately in Eastern Turkey using stool microscopy, PCR and serological methods. According to PCR classification the prevalence of E. dispar was 13 per cent whereas not a single case of E. histolytica was detected. Anti-E. histolytica serum antibodies were found in 0.6 per cent of the population using an ELISA with a recombinant antigen. It is concluded that the prevalence of E. dispar in the Diyarbakir area is high but that the prevalence of E. histolytica is very low. - The presence of gene of cysteine proteinase 1 (ACP1) in non pathogenic E. dispar strains was demonstrated. - Episomal transfection and continuous expression of heterologous genes in E. dispar were achieved. This is the first report of stable expression of a foreign gene in E. dispar using upstream and downstream regulatory sequences of E. histolytica ribosomal protein L21 gene. Using solvent extraction as well as hydrophobic and anion exchange chromatography, two distinct lipid-anchored glycolipids whose composition was indicative of an LPG and a lipophosphopeptidoglyan (LPPG) were characterised. A direct correlation was observed between the relative abundance of these molecules in different amebic isolates and their virulence. A novel monoclonal antibody that reacts with the LPG of virulent strains has been cloned.
Types:
SupportProgram
Origin: /Bund/UBA/UFORDAT
Tags: Tübingen ? Gen ? Tierhaltungsanlage ? Amöben ? Arzneimittel ? Fäkalien ? Lipid ? Lösungsmittel ? Zytologie ? Wirtsorganismus ? Klonen ? Türkei ? Epidemiologische Studie ? Anionen ? Antikörper ? Extraktion ? Gentechnik ? Kettenreaktion ? Korrelationsanalyse ? Tropenkrankheit ? Parasitose ? Chromatografie ? Epidemiologie ? Infektionskrankheit ? Medizin ? Mensch ? Parasit ? Protein ? Studie ? Tropengebiet ? Pathogenität ? Zusammenarbeit ? Krankheitserreger ? Züchtung ? Gesundheit ? Infektion ? Umweltschutz ? Klassifikation ? Population ? Krankheit ? Klon ? Antigen ? PCR-Technik ? Serologie ? coordination ? Molekülstruktur ?
Region: Baden-Württemberg
Bounding box: 9° .. 9° x 48.5° .. 48.5°
License: cc-by-nc-nd/4.0
Language: Deutsch
Time ranges: 1994-05-01 - 1998-04-30
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