Immunohistochemical Detection of Encephalitozoon cuniculi in Ocular Structures of Immunocompetent Rabbits.

Edita Jeklová,Vladimír Jekl,Vladimír Kummer,Lenka Levá,Martin Faldyna

doi:10.3390/ani9110988

Edita Jeklová, Vladimír Jekl + Show 3 more

Open Access

https://doi.org/10.3390/ani9110988

Copy DOI

Abstract

Simple SummaryEncephalitozoonosis 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.Encephalitozoonosis is a common infectious disease widely spread among rabbits. Its causative agent, Encephalitozoon cuniculi, is considered as a zoonotic and emerging pathogen capable of infecting both immunocompetent and immunocompromised hosts, including humans. In rabbits, clinical signs include neurological, kidney and ocular disease. The aim of this study was to detect E. cuniculi in ocular structures in immunocompetent rabbits after experimental oral infection using immunohistochemistry. In infected animals, E. cuniculi spores were present in periocular connective tissue, sclera, cornea, choroidea, iris, retina and lens, as a round to ovoid organism reacting with a specific anti-E. cuniculi monoclonal antibody 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. In the present study, E. cuniculi was also detected in the lenses of adult rabbits, which indicates that ways of lens infection other than intrauterine and haematogenic are possible.

Highlights

Encephalitozoon cuniculi is an opportunistic, obligate intracellular, single-cell, spore-forming microsporidian parasite that infects a wide range of mammalian hosts and even birds
Encephalitozoonosis used to be a frequent problem in laboratory rabbits, affecting the health status of the animals and interfering with experiments [6], but current research colonies are routinely tested by serological methods for specific antibodies
In experimentally infected rabbits, E. cuniculi spores were present in many different ocular structures as round to ovoid organisms

Summary

Introduction

Encephalitozoon cuniculi is an opportunistic, obligate intracellular, single-cell, spore-forming microsporidian parasite that infects a wide range of mammalian hosts and even birds. The most commonly infected animals are domestic rabbits. Animals 2019, 9, 988 in laboratory rabbits with paralysis by Wright and Craighead [1] and named by Levaditi et al [2]. E. cuniculi is considered as a zoonotic and emerging pathogen capable of infecting both immunocompetent and immunocompromised hosts [3]. E. cuniculi has become an important opportunistic pathogen in immunosuppressed individuals, such as HIV/AIDS patients and patients receiving antitumor or immunosuppressive treatments [4,5]. Encephalitozoonosis used to be a frequent problem in laboratory rabbits, affecting the health status of the animals and interfering with experiments [6], but current research colonies are routinely tested by serological methods for specific antibodies. E. cuniculi remains a cause of morbidity and mortality in pet and conventionally raised rabbits, with the seroprevalence of IgG antibodies in asymptomatic pet rabbits ranging between 35% and 68% [7,8,9]

Objectives

Methods

Results

Conclusion