A Rabbit Model of Acanthamoeba Keratitis That Better Reflects the Natural Human Infection

Area of Science:

• Ophthalmology
• Infectious Diseases
• Parasitology

Background:

• Acanthamoeba keratitis (AK) is a severe corneal disease caused by ubiquitous protozoa.
• Current animal models for AK exhibit rapid disease progression, failing to accurately represent human AK.
• There is a need for improved animal models that better simulate human AK pathogenesis and immune responses.

Purpose of the Study:

• To develop and evaluate a novel method for establishing Acanthamoeba keratitis in rabbits.
• To compare the pathogenesis and immune response of the novel AK model with the conventional intrastromal injection model.
• To create an animal model that more closely mimics the clinical presentation and immune dynamics of human AK.

Main Methods:

• Two experimental groups of New Zealand white rabbits were established (n=14 each).
• Group A received conventional intrastromal injections of Acanthamoeba healyi trophozoites.
• Group B received microinjections of A. healyi trophozoites anterior to the corneal stroma, creating a novel AK model.
• Clinical, histopathological, and immunological evaluations were performed over 35 days.

Main Results:

• Both the conventional and novel models successfully established AK in rabbits.
• The novel model (Group B) demonstrated an efficient immune response with reduced pathology compared to the conventional model (Group A).
• The infection in the novel model was self-limiting and chronic, closely resembling human AK.

Conclusions:

• The novel microinjection method provides a more accurate and relevant animal model for studying Acanthamoeba keratitis.
• This improved model allows for better simulation of human AK pathogenesis and immune responses.
• The findings support the use of this novel model for future research into AK treatments and mechanisms.