Résumé
By employing 4-methylumbelliferyl-beta-D-NN',N"-triacetylchitotriose substrate in a semi quantitative assay, chitinolytic activity in viable spores of Encephalitozoon cuniculi and E. intestinalis was detected and dependence on reaction time, spore concentration, concentration of substrate and temperature were demonstrated. It was possible to block the chitinolytic activity by chitin hydrolysate. By incubation at 80§C for 10 min or at 55§C for 20 min the spores were loosing the chitinolytic activity. Incubation of the spores in trypsin reduced the chitinolytic activity. Cellulase activity could not be detected.
Sujets)
Animaux , Chitinase/métabolisme , Encéphalitozoon/enzymologie , Cellulase/métabolisme , Chitinase/antagonistes et inhibiteurs , Spores/enzymologie , Trypsine/pharmacologieRésumé
Microsporidia is a common term that has been used to refer to a group of eukaryotic, obligate intracellular protozoan parasites belonging to the phylum Microspora. They are important agricultural parasites, contaminating commercial insects; they are also important by infecting laboratory rodents, rabbits and primates. Ever since the early cases found by Magarino Torres, who reported the presence of Encephalitozoon in a patient suffering of a meningoencephalomyelitis, some human pathology caused by microsporidia has been described. However, only after the acquired immunodeficiency syndrome outbreak have these organisms appeared as significant etiological agents in different pathologies. Even so, they remain underestimated. In the present article, the importance of microsporidia for the human pathology in immunocompromised host has been stressed
Sujets)
Humains , Animaux , Syndrome d'immunodéficience acquise/parasitologie , Microsporida/classification , Microsporidiose/parasitologie , Sujet immunodépriméRésumé
An enzyme-linked lectin assay (ELLA) based on the ELISA assay, using intact formalin-fixed promastigotes to coat poly-L-lysine-treated microtiter plates is described. The assay was used to study the lectin receptors of Leishmania donovani chagasi, L. donovani donovani and L. mexicana amazonensis. ConA, RCA, WGA, and PNA receptors were found in the three parasites. SBA receptors were found to be as frequent as the other receptors in L. donovani chagasi but not in the other two parasites which showed little SBA binding. Trypsin treatment of the two L. donovani subspecies did not remove any of the lectin receptors studied