Amphotericin B mediates killing in Cryptococcus neoformans through the induction of a strong oxidative burst

Sangalli-Leite, Fernanda; Scorzoni, Liliana; Mesa-Arango, Ana Cecilia; Casas Herranz, Celia; Herrero Perpiñán, Enrique; Mendes Gianinni, Maria José Soares; Rodríguez-Tudela, Juan Luis; Cuenca-Estrella, Manuel; Zaragoza, Oscar

doi:https://doi.org/10.1016/j.micinf.2011.01.015

View/Open

016556.pdf (1015.Kb)
Sol·licita una còpia

Issue date

2011

Author

Sangalli-Leite, Fernanda

Scorzoni, Liliana

Mesa-Arango, Ana Cecilia

Casas Herranz, Celia

Herrero Perpiñán, Enrique

Mendes Gianinni, Maria José Soares

Rodríguez-Tudela, Juan Luis

Cuenca-Estrella, Manuel

Zaragoza, Oscar

Suggested citation

Sangalli-Leite, Fernanda; Scorzoni, Liliana; Mesa-Arango, Ana Cecilia; Casas Herranz, Celia; Herrero Perpiñán, Enrique; Mendes Gianinni, Maria José Soares; ... Zaragoza, Oscar. (2011) . Amphotericin B mediates killing in Cryptococcus neoformans through the induction of a strong oxidative burst. Microbes and Infection, 2011, vol. 13, núm. 5 , p. 457-467. https://doi.org/10.1016/j.micinf.2011.01.015.

Abstract

We studied the effects of Amphotericin B (AmB) on Cryptococcus neoformans using different viability methods (CFUs enumeration, XTT assay and propidium iodide permeability). After 1 h 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 3 h 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 3 h of incubation with AmB, and lack of XTT reduction was observed at AmB concentrations higher than 1 mg/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.

URI

http://hdl.handle.net/10459.1/48424

DOI

https://doi.org/10.1016/j.micinf.2011.01.015

Is part of

Microbes and Infection, 2011, vol. 13, núm. 5 , p. 457-467