In VitroEfficacy of Corifungin against Acanthamoeba castellanii Trophozoites and Cysts

Abstract

ABSTRACTPainful blinding keratitis and fatal granulomatous amebic encephalitis are caused by the free-living amebaeAcanthamoebaspp. Several prescription eye medications are used to treatAcanthamoebakeratitis, but the infection can be difficult to control because of recurrence of infection. For the treatment of encephalitis, no single drug was found useful, and in spite of the use of a combination of multiple drugs, the mortality rate remains high. Therefore, efficient, novel drugs are urgently needed for the treatment of amebic keratitis and granulomatous amebic encephalitis. In this study, we identified corifungin, a water-soluble polyene macrolide, as amebicidal.In vitro, it was effective against both the trophozoites and the cysts. Transmission electron microscopy ofAcanthamoeba castellaniiincubated with corifungin showed the presence of swollen mitochondria, electron-dense granules, degeneration of cytoplasm architecture, and loss of nuclear chromatin structure. These changes were followed by lysis of amebae. Corifungin also induced the encystment process ofA. castellanii. There were alterations in the cyst cell wall followed by lysis of the cysts. Corifungin is a promising therapeutic option for keratitis and granulomatous amebic encephalitis.