| Popis: |
We investigated the ability of five commercially available contact lens disinfectants to kill Acanthamoeba cysts. Two methods were employed: a microtiter plate method (using Acanthamoeba polyphaga SHI and A. castellanii CLAP 150112 g), which determines the presence or absence of growth after a challenge and measures efficacy by total kill only, and a bacterial lawn plaque method (A. polyphaga only), which quantitates the number of cysts surviving different periods of exposure. With the microtiter method, there was no growth of excysted Acanthamoeba after exposure to LENS PLUS ® Oxysepto ® 1 Disinfecting Solution ∗ for 4 hours or to Allergan ® HYDROCARE ® Cleaning and Disinfecting Solution ∗ for 6 hours. Excysted Acanthamoeba were recovered in all trials after exposure to ReNu ®, † Opti-Soft ®, † or AOSept ®† for up to 24 hours. With the bacterial lawn plaque method, HYDROCARE and Oxysept 1 (with or without Ultrazyme TM Enzymatic Cleaner) reduced the challenge cysts to zero recovery by the 8- and 24-hour time points, respectively; ReNu, Opti-Soft, and AOSept disinfectants showed poor anti-Acanthamoebal activity, reducing the cyst challenge by only 66, 66, and 79%, respectively, at 24 hours. The difference in the efficacies of Oxysept 1 and AOSept (both nominally 3% hydrogen peroxide) is probably due to the initial rapid neutralization of hydrogen peroxide in the AOSept system during the disinfection soaking cycle. |
