Immunohistochemical Detection of Encephalitozoon cuniculi in Ocular Structures of Immunocompetent Rabbits
Veterinary Research Institute, Hudcova 296/70, 621 00 Brno, Czech Republic
Jekl & Hauptman Veterinary Clinic, Mojmírovo nám. 3105/6a, 612 00 Brno, Czech Republic
Author to whom correspondence should be addressed.
Received: 11 October 2019 / Revised: 14 November 2019 / Accepted: 14 November 2019 / Published: 18 November 2019
Encephalitozoonosis is a common infectious disease widely spread among rabbits. Its causative agent, Encephalitozoon cuniculi, is considered to be transmissible to humans. In rabbits, clinical signs include discoordination, head tilt, excessive water intake, excessive urination and cataracts. This study investigates, for the first time, whether the E. cuniculi organism can be detected in ocular structures in healthy adult rabbits after experimental oral infection using immunohistochemistry—detection of the organism in the tissue using a specific staining method. In infected animals, E. cuniculi spores were detected in many ophthalmic structures (periocular connective tissue, sclera, cornea, choroidea, iris, retina and lens) as early as 2 weeks after infection. There were no signs of inflammatory lesions in any of the ocular tissues examined at 2, 4, 6 and 8 weeks after infection. E. cuniculi was also detected in the lens of adult rabbits, which indicates that ways of lens infection other than intrauterine and haematogenic are possible. This information can help to understand E. cuniculi dissemination to various ocular tissues structures after oral infection.