Amoebicidal effect of Fluconazole and Verapamil together against trophozoites and cysts of Acanthamoeba castellanii

Abstract

Acanthamoeba species are an important pathogen that causes Acanthamoeba keratitis, which causes a visual loss, and encephalitis, which lead to the central nervous system infection and death. The options available to successfully treat Acanthamoeba infections have limited success. New therapeutic approaches must thus be developed, and especially combination medication therapy may be a successful and an effective strategy. The aim of this study was to assess the combination efficacy of verapamil and fluconazole against Acanthamoeba trophozoites and cysts. The effects of drugs on growth inhibition against Acanthamoeba were tested using amoebicidal assays. The viability of Acanthamoeba was assessed using Trypan blue and hemocytometer counts. The effect of three different concentrations of fluconazole, verapamil and fluconazole + verapamil combination on growth inhibition against Acanthamoeba trophozoites and cysts was significant compared to the control (p<0.05). While Acanthamoeba reduced the viability of 250 µg/ml fluconazole and verapamil on trophozoites to 2.3 x 104 and 3 x 104 numbers, fluconazole + verapamil combination showed 100% growth inhibition on trophozoites. Moreover, the combination of 250 µg/ml fluconazole + verapamil showed up to 90% growth inhibition on cysts. As a result, it was revealed that the combination of fluconazole and verapamil was more effective against the trophozoites and cysts of Acanthamoeba.

Keywords

• Acanthamoeba castellanii
• Fluconazole
• Verapamil
• Combination
• Amoebicidal effect
• Growth inhibition

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