Acanthamoeba keratitis in a mouse model using a novel approach

Context: Acanthamoeba is increasingly implicated in causing keratitis in patients wearing contact lens or ocular trauma and has a poor prognosis. Establishment of an animal model is critical to study the disease pathology, pathogenesis and to evaluate anti-amoebic drugs. Some studies have used contact lenses to establish Acanthamoeba keratitis (AK) in a mouse model, which is expensive and not very successful as lenses get dislodged.

Objective: To assess the feasibility of using parafilm (Bemis Company Inc., USA) as an alternative to contact lens for the establishment of AK in the mouse model.

Methods: Thirty-six Balb/c mice in three groups of six mice each for two strains of Acanthamoeba were used to induce AK. Three experimental approaches used were; i) Acanthamoeba impregnated contact lens, ii) Acanthamoeba impregnated parafilm and iii) scratching followed by inoculation of Acanthamoeba suspension. In all three models, tarsorrhaphy was performed. Infection was evaluated by clinical examination and also through microscopic examination of corneal scrapings and corneal sections.

Results: AK model was successfully established with parafilm whereas only one mouse developed AK with the use of contact lens and none with scratching and Acanthamoeba inoculation.

Conclusion: The use of parafilm is convenient, reliable and cheaper and can be considered an alternative to contact lenses to induce AK in a mouse model.