title: Efficacy of commercial soft contact lens disinfectant solutions against Acanthamoeba.
abstract: OBJECTIVE
  To investigate the relative efficacy of Japanese commercial soft contact lens disinfectant solutions against Acanthamoeba trophozoites and cysts.
  
  
  METHODS
  Eight types of multipurpose solution (MPS), two types of hydrogen peroxide solution, and one povidone-iodine solution were evaluated to determine their effect against Acanthamoeba trophozoites and cysts (ATCC 50514). Acanthamoeba cysts were cultured in encystment medium for either 1 or 2 weeks (1 and 2-week-old cysts). The trophozoites and cysts were treated with each disinfectant solution for 0, 2, 4, 8, or 24 h. After performing four tenfold serial dilutions of each test solution, dilutions were cultured for 10 days. The number of surviving organisms was calculated using the trimmed Spearman-Karber method.
  
  
  RESULTS
  Among the MPS tested, only four were effective against trophozoites after treatment for 4 h, and none was effective against 2-week-old cysts. Hydrogen peroxide had a significant effect on trophozoites and 1-week-old cysts, but not on 2-week-old cysts. In contrast, povidone-iodine caused a 2.6 log reduction in 2-week-old cysts.
  
  
  CONCLUSIONS
  MPS were found to have limited efficacy against trophozoites and no efficacy against 2-week-old cysts. Only povidone-iodine had any efficacy against 2-week-old cysts.
authors: Department of Ophthalmology and Regenerative Medicine, Ehime University Graduate School of Medicine, Shitsukawa, Toon, Ehime, 791-0295, Japan.
authors: Takeshi
authors: T
authors: Kobayashi
authors: Department of Ophthalmology, Ehime University Graduate School of Medicine, Toon, Japan.
authors: Lindsay
authors: L
authors: Gibbon
authors: Department of Ophthalmology, Ehime University Graduate School of Medicine, Toon, Japan.
authors: Tsuyoshi
authors: T
authors: Mito
authors: Department of Ophthalmology and Regenerative Medicine, Ehime University Graduate School of Medicine, Shitsukawa, Toon, Ehime, 791-0295, Japan. shiraia@m.ehime-u.ac.jp.|Department of Cell Growth and Tumor Regulation, Ehime University Graduate School of Medicine, Toon, Japan. shiraia@m.ehime-u.ac.jp.
authors: Atsushi
authors: A
authors: Shiraishi
authors: Department of Ophthalmology, Ehime University Graduate School of Medicine, Toon, Japan.
authors: Toshihiko
authors: T
authors: Uno
authors: Department of Ophthalmology, Ehime University Graduate School of Medicine, Toon, Japan.|Department of Infectious Diseases, Ehime University Graduate School of Medicine, Shitsukawa, Toon, Ehime, 791-0295, Japan.
authors: Yuichi
authors: Y
authors: Ohashi
mesh_terms: D000048:Acanthamoeba / Q000187:drug effects* / Q000254:growth & development; D000818:Animals; D018639:Contact Lens Solutions / Q000494:pharmacology*; D003263:Contact Lenses, Hydrophilic / Q000469:parasitology*; D006861:Hydrogen Peroxide / Q000494:pharmacology*; D006902:Hydroxymercuribenzoates / Q000494:pharmacology*; D021261:Parasitic Sensitivity Tests; D011206:Povidone-Iodine / Q000494:pharmacology*
chemical_list: D018639:Contact Lens Solutions; D006902:Hydroxymercuribenzoates; C030601:4-hydroxymercuribenzoate; D011206:Povidone-Iodine; D006861:Hydrogen Peroxide