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Albany, Australia

Austen J.M.,Murdoch University | Ryan U.M.,Murdoch University | Friend J.A.,20 Albany Highway | Ditcham W.G.F.,Murdoch University | Reid S.A.,Murdoch University
Parasitology | Year: 2011

A total of 41 ticks were collected from 15 quokkas on Bald Island and 2 ticks from a Gilbert's potoroo from Two Peoples Bay. Three species of Ixodid ticks Ixodes australiensis, Ixodes hirsti and Ixodes myrmecobii were identified on the quokkas known to have a high prevalence of Trypanosoma copemani. Tick faeces from ticks isolated from 8 individual quokkas and a Gilbert's potoroo were examined with one identified as positive for trypanosomes. Faecal examination revealed trypanosomes similar to in vitro life-cycle stages of T. copemani. In total 12 ticks were dissected and trypanosomes found in sections of their midgut and haemolymph, 49 and 117 days after collection. Tick faeces, salivary glands and midguts from I. australiensis were screened using an 18S rRNA PCR with amplification seen only from the midguts. Sequencing showed 100% homology to T. copemani (genotype A) and 99·9% homology to the wombat (AII) isolate of T. copemani. Trypanosomes were only detected in I. australiensis as neither I. hirsti nor I. myrmecobii survived the initial 30-day storage conditions. We therefore identify a vector for T. copemani as I. australiensis and, given the detection of trypanosomes in the faeces, suggest that transmission is via the faecal-oral route. © Cambridge University Press 2011.

Vaughan-Higgins R.J.,0 Labouchere Road | Bradfield K.,0 Labouchere Road | Friend J.A.,20 Albany Highway | Riley T.V.,University of Western Australia | Vitali S.D.,0 Labouchere Road
Journal of Zoo and Wildlife Medicine | Year: 2013

An adult, female numbat (Myrmecobius fasciatus) was submitted to the Perth Zoo Veterinary Department for postmortem examination in November 2011. This radio-collared wild numbat had been found dead in the Dryandra Woodland, 191 km southeast of Perth, Western Australia. On external examination, the body condition was good. Three ticks (Ixodes spp.) were found on the thoracic region. The external pouch was contaminated with dirt and palpably flocculent, and the nipples oozed a purulent material. Histopathology showed widespread fibrin thrombi containing bacterial microcolonies within interstitial vessels of the mammary gland with surrounding necrotic tissue. Bacterial microcolonies were present throughout the kidney, intestine, lung, and mammary tissue, and culture produced a moderate growth of Erysipelothrix rhusiopathiae. Although erysipelas has been reported as a cause of morbidity and mortality in marsupials, this is the first report of erysipelas in the order Dasyuromorphia (marsupial carnivores) and highlights the need for ongoing surveillance for causes of disease in wild numbats and species recovery programs. Copyright 2013 by American Association of Zoo Veterinarians.

Austen J.M.,Murdoch University | Ryan U.,Murdoch University | Ditcham W.G.F.,Murdoch University | Friend J.A.,20 Albany Highway | Reid S.A.,University of Queensland
Experimental Parasitology | Year: 2015

Trypanosoma copemani is known to be infective to a variety of Australian marsupials. Characterisation of this parasite revealed the presence of stercorarian-like life-cycle stages in culture, which are similar to T. rangeli and T. cruzi. The blood incubation infectivity test (BIIT) was adapted and used to determine if T. copemani, like T. cruzi and T. rangeli, has the potential to grow in the presence of human serum. To eliminate any effects of anticoagulants on the complement system and on human high density lipoprotein (HDL), only fresh whole human blood was used. Trypanosoma copemani was observed by microscopy in all human blood cultures from day 5 to day 19 post inoculation (PI). The mechanism for normal human serum (NHS) resistance in T. copemani is not known. The results of this study show that at least one native Australian trypanosome species may have the potential to be infective for humans. © 2015 Elsevier Inc.

Austen J.M.,Murdoch University | Reid S.A.,University of Queensland | Robinson D.R.,University of Bordeaux 1 | Friend J.A.,20 Albany Highway | And 3 more authors.
Parasitology | Year: 2015

Trypanosomes 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 copemani is 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 vivo and in vitro examination of blood and cultures from Australian marsupials was conducted using light microscopy, immunofluorescence, scanning electron microscopy and fluorescence in situ hybridization. Promastigote, sphaeromastigote and amastigote life-cycle stages were detected in vivo and in vitro. Novel trypanosome-like stages were also detected both in vivo and in vitro representing 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. © 2015 Cambridge University Press.

Moir M.L.,University of Western Australia | Moir M.L.,University of Melbourne | Coates D.J.,Locked Bag 104 | Kensington W.J.,University of Western Australia | And 2 more authors.
Biological Conservation | Year: 2016

Threatened organisms may act as host to a suite of dependent organisms, which are potentially cothreatened, yet management is rarely coordinated between host and dependent species. Here, we test the congruency of patterns of genetic structure between two critically endangered interacting taxa; the feather-leaf banksia (Banksia brownii R.Br.), and its host-specific herbivorous plant-louse Trioza barrettae Taylor & Moir, to establish whether conservation actions should be implemented jointly for both species. We also examine the role of host population size and fire history on the density of psyllids on host plants. We show that the patterns of mtDNA variation in T. barrettae and microsatellite variation in both species support the presence of at least two conservation units across each species, with the microsatellites also showing a high evolutionary congruency between plant and insect populations. The extinction of divergent B. brownii populations, therefore, is likely to have resulted in the extinction of divergent plant-louse populations. Larger populations of host plant (>. 150) and more recent fire history (<. 20 years since fire) are important factors in maintaining T. barrettae densities. High molecular congruency indicates the importance of considering patterns of genetic diversity of source material from both host and dependent organisms for ex situ conservation, in situ supplementations and reintroductions. As dependents such as T. barrettae are often lost to extinction before their host, considering the conservation of dependent biota in the early stages of species management is paramount. © 2016 Elsevier Ltd.

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