Main content area

The hamster (Mesocricetus auratus) as an experimental model of toxocariasis: histopathological, immunohistochemical, and immunoelectron microscopic findings

da Silva, Ana Maria Gonçalves, Chieffi, Pedro Paulo, da Silva, Wellington Luiz Ferreira, Kanashiro, Edite Hatsumi Yamashiro, Rubinsky-Elefant, Guita, Cunha-Neto, Edécio, Mairena, Eliane Conti, De Brito, Thales
Parasitology research 2015 v.114 no.3 pp. 809-821
Toxocara canis, animal experimentation, animal models, antibodies, antigen-antibody complex, cats, circulating antigens, complement, dogs, eggs, fomites, golden hamsters, hands, histopathology, humans, immune response, immunoglobulins, immunohistochemistry, inflammation, kidney diseases, kidneys, laboratory animals, larvae, liver, lungs, microscopy, parasites, parasitology, paratenic hosts, soil, toxocariasis
Toxocariasis is a globally distributed parasitic infection caused by the larval stage of Toxocara spp. The typical natural hosts of the parasite are dogs and cats, but humans can be infected by the larval stage of the parasite after ingesting embryonated eggs in soil or from contaminated hands or fomites. The migrating larvae are not adapted to complete their life cycle within accidental or paratenic hosts like humans and laboratory animals, respectively, but they are capable of invading viscera or other tissues where they may survive and induce disease. In order to characterize hamsters (Mesocricetus auratus) as a model for Toxocara canis infection, histopathological and immunohistochemistry procedures were used to detect pathological lesions and the distribution of toxocaral antigens in the liver, lungs, and kidneys of experimentally infected animals. We also attempted to characterize the immunological parameters of the inflammatory response and correlate them with the histopathological findings. In the kidney, a correlation between glomerular changes and antigen deposits was evaluated using immunoelectron microscopy. The hamster is an adequate model of experimental toxocariasis for short-term investigations and has a good immunological and pathological response to the infection. Lung and liver manifestations of toxocariasis in hamsters approximated those in humans and other experimental animal models. A mixed Th2 immunological response to T. canis infection was predominant. The hamster model displayed a progressive rise of anti-toxocaral antibodies with the formation of immune complexes. Circulating antigens, immunoglobulin, and complement deposits were detected in the kidney without the development of a definite immune complex nephropathy.