Experimental oral and ocularEncephalitozoon cuniculiinfection in rabbits

Abstract

Encephalitozoon cuniculi is an obligate intracellular pathogen that has a wide host distribution, but primarily affects rabbits. The aim of this study was to characterize both the cell-mediated and the antibody response in rabbits after experimental infection using 2 different infection routes: oral and ocular. SPF rabbits were infected with low (10³ spores) and high (10⁷ spores) infection doses. Monitored parameters included clinical signs, detection of spores in urine, antibody response detected with ELISA, and cell-mediated immunity detected by antigen-driven lymphocyte proliferation. At week 13 post-infection, half of the rabbits in each group were suppressed by intramuscular administration of dexamethasone. At week 18 post-infection, animals were euthanized. Clinical signs were mild with exacerbation after immunosuppression. Spores in urine and antigen-specific cell-mediated immunity were detected from weeks 5 and 4 post-infection, respectively. Specific IgM was detected 1 week after infection, and IgG antibodies followed 1 week later in rabbits infected with the high dose. Immunological responses were dose dependent. The authors can conclude that both oral and ocular experimental infection with E. cuniculi resulted in an immune response of the infected animals. Rabbits could be used as an experimental model for the study of ocular microsporidiosis.

Prevalence of antibodies to Encephalitozoon cuniculi in European hares (Lepus europaeus)

“…The most frequently infected animals are domestic rabbits [2]; however, spontaneous infections have been documented in other mammalian species [1]. Encephalitozoonosis is a chronic and latent disease leading to renal failure, encephalitis, disorders of brain and urinary tract and may lead to death [3].…”

Bilateral lenticular Encephalitozoon cuniculi infection in a snow leopard (Panthera uncia)

“…In the veterinary literature, E. cuniculi infection has been most extensively described in rabbits. Typical manifestations include nonsuppurative granulomatous meningoencephalitis, chronic interstitial nephritis, cataract, and phacoclastic uveitis . Reports of ocular lesions associated with Encephalitozoon spp.…”

Encephalitozoon cuniculi in pet rabbits: diagnosis and optimal management

“…A single seropositive test result can be seen in animals that are exposed, exposed and have recovered from infection, or are infected with or without signs of clinical disease. Several studies 3,4,34,35 have subsequently evaluated the usefulness of ELISA titers (IgG, IgM) and protein electrophoresis as diagnostic aids for E. cuniculi infection in rabbits. All of these studies recommend that more than one titer be obtained to ascertain exposure and acute infection status, although IgM is the only antibody that truly indicates acute infection.…”