Amphotericin B mediates killing in Cryptococcus neoformans through the induction of a strong oxidative burst.
Microbes Infect
; 13(5): 457-67, 2011 May.
Article
en En
| MEDLINE
| ID: mdl-21310262
We studied the effects of Amphotericin B (AmB) on Cryptococcus neoformans using different viability methods (CFUs enumeration, XTT assay and propidium iodide permeability). After 1h of incubation, there were no viable colonies when the cells were exposed to AmB concentrations ≥ 1 mg/L. In the same conditions, the cells did not become permeable to propidium iodide, a phenomenon that was not observed until 3h of incubation. When viability was measured in parallel using XTT assay, a result consistent with the CFUs was obtained, although we also observed a paradoxical effect in which at high AmB concentrations, a higher XTT reduction was measured than at intermediate AmB concentrations. This paradoxical effect was not observed after 3h of incubation with AmB, and lack of XTT reduction was observed at AmB concentrations higher than 1mg/L. When stained with dihydrofluorescein, AmB induced a strong intracellular oxidative burst. Consistent with oxidative damage, AmB induced protein carbonylation. Our results indicate that in C. neoformans, Amphotericin B causes intracellular damage mediated through the production of free radicals before damage on the cell membrane, measured by propidium iodide uptake.
Texto completo:
1
Colección:
01-internacional
Base de datos:
MEDLINE
Asunto principal:
Anfotericina B
/
Estallido Respiratorio
/
Cryptococcus neoformans
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Antifúngicos
Idioma:
En
Revista:
Microbes Infect
Asunto de la revista:
ALERGIA E IMUNOLOGIA
/
MICROBIOLOGIA
Año:
2011
Tipo del documento:
Article
País de afiliación:
España
Pais de publicación:
Francia