BACKGROUND: Acanthamoeba-associated keratitis occurs most often in contact lens wearers. The contact lens material may affect its ability to act as a mechanical vector, permitting transfer of viable amoebae from the storage case to the corneal surface. The purpose of this study was to investigate the effects of ionicity and water content on the comparative quantitative adherence of Acanthamoeba trophozoites and cysts to new, unworn hydrogel contact lenses and rigid gas-permeable contact lens materials. METHODS: Sixteen quarter segments of each of 8 types of unworn hydrogel lenses representative of FDA groups 1 to 4 were exposed to freshly prepared cultures of either trophozoites or cysts of A. castellanii or A. polyphaga for 1.5 h, and then washed. Three types of rigid lens button were similarly exposed to A. castellanii trophozoites or cysts. Adherent trophozoites and cysts were then enumerated. RESULTS: All hydrogel lenses showed binding of both trophozoites and cysts, with the former predominating in every case. It was primarily the ionic nature of a lens surface and secondly its water content that was associated with increased quantitative adherence of Acanthamoeba. Neither form of the amoebae bound to any of the hard lens buttons. CONCLUSIONS: Greater relative potential exists for contamination of ionic and high-water content hydrogels by Acanthamoeba. This combination may influence mechanical transmission of the protozoon to the corneal surface. Adherence to hard lenses (as buttons) did not occur if a postincubation wash step was performed.
BACKGROUND:Acanthamoeba-associated keratitis occurs most often in contact lens wearers. The contact lens material may affect its ability to act as a mechanical vector, permitting transfer of viable amoebae from the storage case to the corneal surface. The purpose of this study was to investigate the effects of ionicity and water content on the comparative quantitative adherence of Acanthamoeba trophozoites and cysts to new, unworn hydrogel contact lenses and rigid gas-permeable contact lens materials. METHODS: Sixteen quarter segments of each of 8 types of unworn hydrogel lenses representative of FDA groups 1 to 4 were exposed to freshly prepared cultures of either trophozoites or cysts of A. castellanii or A. polyphaga for 1.5 h, and then washed. Three types of rigid lens button were similarly exposed to A. castellanii trophozoites or cysts. Adherent trophozoites and cysts were then enumerated. RESULTS: All hydrogel lenses showed binding of both trophozoites and cysts, with the former predominating in every case. It was primarily the ionic nature of a lens surface and secondly its water content that was associated with increased quantitative adherence of Acanthamoeba. Neither form of the amoebae bound to any of the hard lens buttons. CONCLUSIONS: Greater relative potential exists for contamination of ionic and high-water content hydrogels by Acanthamoeba. This combination may influence mechanical transmission of the protozoon to the corneal surface. Adherence to hard lenses (as buttons) did not occur if a postincubation wash step was performed.
Authors: Charlotte E Joslin; Elmer Y Tu; Megan E Shoff; Gregory C Booton; Paul A Fuerst; Timothy T McMahon; Robert J Anderson; Mark S Dworkin; Joel Sugar; Faith G Davis; Leslie T Stayner Journal: Am J Ophthalmol Date: 2007-06-22 Impact factor: 5.258
Authors: Edyta B Hendiger; Marcin Padzik; Ines Sifaoui; María Reyes-Batlle; Atteneri López-Arencibia; Aitor Rizo-Liendo; Carlos J Bethencourt-Estrella; Desirée San Nicolás-Hernández; Olfa Chiboub; Rubén L Rodríguez-Expósito; Marta Grodzik; Anna Pietruczuk-Padzik; Karolina Stępień; Gabriela Olędzka; Lidia Chomicz; José E Piñero; Jacob Lorenzo-Morales Journal: Pathogens Date: 2020-05-05
Authors: Jennifer R Verani; Suchita A Lorick; Jonathan S Yoder; Michael J Beach; Christopher R Braden; Jacquelin M Roberts; Craig S Conover; Sue Chen; Kateesha A McConnell; Douglas C Chang; Benjamin J Park; Dan B Jones; Govinda S Visvesvara; Sharon L Roy Journal: Emerg Infect Dis Date: 2009-08 Impact factor: 6.883