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- Endocytobiosis and ...
- Volume 17
- Isolation of free-l...
- Nebentitel
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On the Occasion of the "International Conference on the Molecular Biology and Biotechnology of Ciliates and Anaerobic Protozoa in connection with the 22nd Annual meeting of the German Society for Protozoology" (March 4-8, 2003, Nijmegen, The Netherlands)
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127-136
- Zusammenfsg.
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In the course of the investigation of free-living amoebae (FLA) from various aquatic sources with respect to their potential pathogenicity we repeatedly met amoebae obviously harbouring pro- and eukaryotic endocytobionts. In the present overview the most important examples are presented. Rod-shaped bacteria replicating within vacuoles of acanthamoebae were observed such as Ralstonia pickettii and Pseudomonas aeruginosa Legionella-like amoebal pathogens (Llap's) multiplying within the cytoplasm of acanthamoebae were identified as Leginella lytica and as Flavobacterium succinicans. Three different species of free-living amoebae exhibited intracellularly replicating coccoid bacteria. Two of them had a Chlamydia-like dimorphic development cycle. Two strains of the novel species Parachlamydia acanthamobae were observed within acanthamoebae isolated from human nasal mucosa and served as the founding species for the newly established Parachlamydiaceae (Everett et. al. 1999).This species is considered meanwhile as emerging pathogen causing pneumonia under special circumstances. Another member belonging to this family, Neochlamydia hartmannellae, was found replicating within the cytoplasm of Hartmannella vermiformis isolated from the water conduit system of a dental treatment unit. An Ehrlichia-like endoparasite was observed within Saccamoeba sp.. At two occasions Naegleria sp. was isolated hosting also coccoid Gram negative bacteria which could not yet be identified. They inhibited cyst formation but on the other side they did not interfere with the transformation to the flagellate stage of the amoeboflagellate. Three examples of eukaryotic endoparasites are presented. Microsporidia-like endocytobionts with intranuclear development had been discovered twice within vannellae. Yeast-like endoparasites with saprophytic traits were seen within Thecamoeba similis. The large fungus-like endoparasite Cochlonema euryblastum (Drechsler 1942) was rediscovered within Thecamoeba quadrilineata. These findings provide promising models for further studies of the interaction between FLA and their intracellular pro- and eukaryotic parasites.
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