Establishment of an Acanthamoeba keratitis mouse model

<p><em>Acanthamoeba castellanii</em> results in <em>Acanthamoeba</em> keratitis (AK), which occurs mainly in contact lens user with poor eye hygiene. The findings of many <em>in vitro</em> studies of AK, especially the development of therapeutic drugs, need to be confirmed by <em>in vivo</em> experiments. For the establishment of an AK mouse model, in this study, <em>A. castellanii</em> cell suspensions (equal mixtures of trophozoites and cysts) were loaded onto 2-mm contact lens pieces to be inserted into mouse eyes that were scratched using an ophthalmic surgical blade under anesthesia; the eyelids of the mice were sutured. Keratitis symptoms were grossly observed, and PCR was performed using P-FLA primers for amplification of the <em>Acanthamoeba</em> 18S-rRNA gene from the mouse ocular tissue. The experimental AK mouse model, characterized by typical hazy blurring and melting of the mouse cornea, was established on day 1 post-inoculation. AK was induced with at least 0.3&times;10⁵ <em>A.</em> <em>castellanii</em> cells (optimal number, 5&times;10⁴), and the infection persisted for 2 months. In addition, PCR products amplified from the extracted mouse eye DNA confirmed the development of <em>Acanthamoeba</em>-induced keratitis during the infection periods. In conclusion, it is suggested that the present AK mouse model may serve as an important <em>in vivo</em> model for various future studies.</p>