In Vitro Comparison of the Acanthamoeba Cysticidal Activity of Povidone Iodine, Natamycin, and Chlorhexidine
Travis K. Redd, Maya Talbott, Vicky Cevallos, Prajna Lalitha, Gerami D. Seitzman, Thomas M. Lietman, Jeremy D. Keenan
Abstract
Purpose: cysts. In this study, we directly compared the cysticidal activity and potency of several candidate medical therapies in vitro. Design: Experimental study. Participants: specimens obtained from 9 patients with keratitis seen at the Francis I. Proctor Foundation from 2008 through 2012. Methods: The minimum cysticidal concentration (MCC) of povidone iodine, natamycin, and chlorhexidine was investigated using an established assay technique. The relative potency of each agent was estimated starting with concentrations commonly used in clinical practice and determining the number of two-fold dilutions required to reach the MCC. Statistical comparisons of relative potency were performed using bootstrap simulations and permutation tests. Main Outcome Measures: Minimum cysticidal concentration and the number of two-fold dilutions required to reach the MCC. Results: < 0.001) to reach the MCC. Conclusions: keratitis.