Purpose: The attachment of Acanthamoeba to soft contact lenses (SCL) is closely related to the onset of Acanthamoeba keratitis. We evaluated the attachment of Acanthamoeba on various SCL and the suppressive effects induced by poly-L-lysin, a basic protein, on the attachment of SCL to clarify the mechanism of attachment of Acanthamoeba to SCL.
Materials and methods: We used 8 types of hydrogel SCL and 10 types of silicone hydrogel SCL. Further, SCL were soaked in medium containing 10⁵/mL of Acanthamoeba polyphaga and poly-L-lysine (0, 5, 50, and 500 mg/L), and the number of Acanthamoeba on SCL were counted.
Results: The density of Acanthamoeba was less than 1/mm² on hydrogel SCL and more than 100/mm² on some of the silicone hydrogel SCL. Poly-L-lysine damaged Acanthamoeba and induced cell aggregation, thus inhibiting the attachment of Acanthamoeba on SCL in a dose-dependent manner.
Conclusions: Negative charge of sugar chains on the surface of Acanthamoeba appears to be involved in the attachment of SCL because poly-L-lysine inhibited the attachment of Acanthamoeba on SCL. Acanthamoeba tended to attach to some silicone hydrogel SCL.
Nippon Ganka Gakkai Zasshi (J Jpn Ophthalmol Soc) 124: 317-323, 2020.