Comparing lethal dose of povidone-iodine and virkon® to the acanthamoeba cyst: In vitro study.

ABSTRACT

Objective: To compare the least concentration of Povidone-iodine and Virkon®, phenolic-based compound with accelerated hydrogen peroxide and potassium peroxymonosulfate, which can cause a lethal effect to the cyst form of the Acanthamoeba spp. Methods: Acanthamoeba spp. was isolated from the keratitis patient and was cultured using amonoxenic medium supplement with heat killed Escherichia coli and incubated for up to seven days for the production of mature cysts. Acanthamoeba cysts on the culture plates were mixed with several dilutions of Povidone-iodine to compare to several dilutions of Virkon®. After incubation for 1 hour, they were washed and centrifuged to remove the chemical supernatant. The pellets of the mature cyst were viewed by a light microscope for seven days, and further recultured on the monoxenic medium to confirm that the cysts were all died (cysticidal) for seven days. Results: Povidone-iodine 0.04% and Virkon® 0.25% solutions were the least concentrations which could cause a lethal effect to the Acanthamoeba cyst. Conclusion: Our results demonstrated that both the Povidone-iodine and Virkon® showed antiamoebic activity. The further study should be done to determine whether Povidone-iodine and Virkon® can be used as a disinfecting solution for contact len cases.