Acanthamoeba culbertsoni: Electron-Dense Granules in a Highly Virulent Clinical Isolate
| Autor: | Adolfo Martínez-Palomo, Bibiana Chávez-Munguía, Martha Espinosa-Cantellano, Maritza Omaña-Molina, Lizbeth Salazar-Villatoro, Jacob Lorenzo-Morales, Elizabeth Ramírez-Flores |
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| Rok vydání: | 2015 |
| Předmět: |
0301 basic medicine
Male 030106 microbiology Virulence Acanthamoeba Biology Microbiology 03 medical and health sciences Mice Microscopy Electron Transmission Cytotoxic T cell Animals Humans Viability assay Trophozoites Incubation Keratitis Mice Inbred BALB C Tight junction Amebiasis biology.organism_classification 030104 developmental biology Cytoplasm ACANTHAMOEBA CULBERTSONI |
| Zdroj: | The Journal of eukaryotic microbiology. 63(6) |
| ISSN: | 1550-7408 |
| Popis: | The virulence of various amoebic parasites has been correlated with the presence of electron-dense granules (EDGs) in the cytoplasm of trophozoites. Here, we report the finding by transmission electron microscopy of a large number of EDGs in a recent culture of Acanthamoeba culbertsoni, isolated from a severe case of human keratitis. When this isolate was maintained in culture for 6 mo, the granules almost disappeared. However, after induction of mice brain lesions with the long-term cultured isolate, recovered amoebas had abundant EDGs. Trophozoites of the original isolate, or those recovered from experimental lesions, secreted EDGs into the medium when incubated with MDCK cells. To analyze a possible cytotoxic effect the conditioned medium was incubated with MDCK monolayers. After 5 h, the media containing EDGs produced opening of the tight junctions; at 24 h, cell viability was compromised, and at 48 h most of the cells were detached from the monolayer. In contrast, trophozoites in long-term cultures did not release EDGs to the medium during incubation with MDCK cells, and the corresponding conditioned medium did not have any effect on MDCK monolayers. Our observations further support the hypothesis that EDGs play a role in the cytopathogenic mechanisms of A. culbertsoni. |
| Databáze: | OpenAIRE |
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