Pathology of Experimental Toxoplasmosis in Eastern Barred Bandicoots in Tasmania

Abstract

Wild-caught eastern barred bandicoots (Perameles gunnii) initially seronegative to Toxoplasma gondii, were inoculated orally with approximately 100 T. gondii oocysts. The bandicoots were maintained in indoor pens under laboratory conditions and observed daily. Serial blood samples were tested for agglutinating antibodies to T. gondii. Inoculated bandicoots died 15 and 17 days post infection. A rise in Direct Agglutination Test (DAT) titres was detected at the time of death (1:256, 1:64 respectively). Clinical observations, serological changes, gross findings at necropsy, and histopathological changes were consistent with acute toxoplasmosis. The findings indicate that eastern barred bandicoots are likely to die from primary T. gondii infection, often even before detectable antibodies are produced, reinforcing the significance of toxoplasmosis as a potential contributor to the reduction in numbers of wild populations of eastern barred bandicoots.

Short Communication / Kısa Bilimsel Çalışma: Systemic toxoplasmosis in a kangaroo (Macropus sp.)

“…Concordant with literature, performed necropsy revealed congestion, edema and consolidation in lungs (1,2,3,7,9), lymph node enlargement (3,5,18) and sero-sanguineous fluid accumulation in the abdominal cavity (1,3,17,18). However, it was not noticed, many gross findings related with toxoplasmosis reported in literature such as, splenomegaly (3,5,7,18), sero-sanguinous fluid accumulation in the thoracic cavity and in pericardium (1,2,7,17), focal ulcers and haemorrhagia at the small intestines (1,2,5,17,18), multiple pale foci at myocardium (1,9,17,18), enlargement and nutmeg scene at liver (1,17), haemorrhage at heart, kidneys and lymph nodules (1), malasia at brain (5).…”

“…Their vulnerability to toxoplasmosis is explaining with increased stress factors and immunsupression due to zoo conditions and/or their possibly infrequent contact with feline species during evolution processes (5,6,18). Toxoplasmosis can cause sudden deaths with the absence of prominent clinical findings in captive and wild Australian marsupials, is not always fatal (1,3,4,7,9,18). Clinical findings can be associated with respiratoric, neurologic and gastrointestinal disorders (9,17,18).…”

“…Toxoplasmosis is common in many warm-blooded animals and human (4,6,13,15,17). It is not only a major cause of congenital disease and abortion in human and domestic animals, but also a lifethreatening opportunistic infection for immunologically vulnerable hosts (2,3). This is a widespread protozoon in Turkey, therefore, several experimental studies nearby studies representing pathologic and epidemiologic findings of naturally infected animals are present (10,11,12,14).…”

“…Disease generally progresses subclinically in mankind and animals (6,10,13,14,15), while it causes sudden deaths in kangaroos (3,4,9,18). Oocyte shedding subclinically infected stray cats are suspected to be the source of toxoplasmosis in kangaroos (1,4,6).…”

“…In the differential and definitive diagnosis of T. gondii infections, serologic (e.g. IFA, Sabin Feldman Dye test) (3,4,7,9), ultrastructural (2,8), immunohistochemical (7,8,9,11,12), molecular examinations (1) and bioassay studies in experimental animals (14,18) generally take place among the main diagnostic tools.…”