Investigation of the morphological diversity of the potentially zoonoticTrypanosoma copemaniin quokkas and Gilbert's potoroos

Abstract

SUMMARYTrypanosomes are blood-borne parasites that can cause severe disease in both humans and animals, yet little is known of the pathogenicity and life-cycles of trypanosomes in native Australian mammals.Trypanosoma copemaniis known to be infective to a variety of Australian marsupials and has recently been shown to be potentially zoonotic as it is resistant to normal human serum. In the present study,in vivoandin vitroexamination of blood and cultures from Australian marsupials was conducted using light microscopy, immunofluorescence, scanning electron microscopy and fluorescencein situhybridization. Promastigote, sphaeromastigote and amastigote life-cycle stages were detectedin vivoandin vitro. Novel trypanosome-like stages were also detected bothin vivoandin vitrorepresenting an oval stage, an extremely thin stage, an adherent stage and a tiny round stage. The tiny round and adherent stages appeared to adhere to erythrocytes causing potential haematological damage with clinical effects similar to haemolytic anaemia. The present study shows for the first time that trypomastigotes are not the only life-cycle stages circulating within the blood stream of trypanosome infected Australian native marsupials and provides insights into possible pathogenic mechanisms of this potentially zoonotic trypanosome species.