Isolation and identification of Trypanosoma species in Gilbert's potoroo (Potorous gilbertii)

Little is known of the prevalence and life cycle of trypanosomes in Australia. The first record of Australian trypanosomes in mammals was made by T.L. Bancroft in 1888 with the discovery of T. lewisi in rats. Since then T. pteropi from the flying fox, T. hipposideri from the dusky horseshoe-bat (Hipposideros bicolor albanensis), T. binneyi from the platypus (Ornithorhynchus anatinus), T. thylacis from the northern brown bandicoot (Thylacis obesulus) and more recently novel Trypanosoma sp. from the Kangaroo (Macropus giganteus) and a common wombat (Vombatus ursinus), have been detected (Mackerras1959; Noyes et al., 1998). Recently, trypanosomes were identified in blood smears from the critically endangered Gilbert’s potoroo (Potorous gilbertii). This is the first record of trypanosomes in Western Australia and within the family Potoroidae. This novel trypanosome was characterised using conventional light microscopy and molecular tools to determine morphological and molecular characteristics. From stained blood smears various stages of the trypanosome life cycle were observed and the trypanosomes were also successfully established in vitro culture systems. Phylogenetic analyses of partial Trypanosoma sequences of the 18S rRNA gene indicated that Gilbert’s potoroo trypanosome was closely related to an isolate from the wombat discovered in Victoria. Morphological characterisation confirmed that the isolate belongs to the Stercorarian group of trypanosomes in the subgenus Herpetosoma, an observation consistent with the phylogenetic tree analyses