|Photo by Caroline Wohlfeil|
This was followed with a talk by Luz Botero Gomez, a student at Murdoch University, on trypanosome infections in little marsupial call the Brushed-Tail Bettong or Woylie. We have previously covered trypanosomes in another marsupials on this blog, namely the koala, but as it turns out, there is a great diversity of Trypanosoma in native marsupials - most of it still unknown. Woylie are known to be infected with 3 species - T. cruzi (the species which causes Chagas disease), T. copemani, and an as yet unnamed clade of Trypanosoma. Some of those Trypanosoma species are also found in other Australian marsupials but only the woylie is known to carry all three. Much like the koala-infecting trypanosome, T. copemani seems to only cause problem when it occurs in mixed infection with other Trypanosoma species - such co-infections can leads to inflammations and lesions in the tissue. In addition, these different trypanosomes also seem to have varying degrees of tissue specificity, with some species occurring in the blood, while other in muscle tissues, but overall mixed infections are more likely to occur in organs and muscles. Given the Woylie is currently critically endangered, it is very important to know what kind of diseases are induced by these trypanosomes and how it is affected by whether they are single or mixed infections.
|Photo from Wikipedia by Helenabella|
This has enormous implications for conservation measures such as captive breeding programs - animals which have not been exposed to a wide range of parasites and pathogens can grow up to become immunologically naive so that when they are release into the wild, they may not be able to cope with the wide range of parasites they encounter. In addition, it is unknown what other physiological side-effects may result from lack of exposure to parasites. According to the hygiene hypothesis, the numerous types of allergies and auto-immune diseases which afflict some of us living in western societies have result from the lack of exposure to parasitic worms which are masters at manipulating and modulating our immune system. By limiting both the prevalence and variety of parasitic infections in those captive African Painted Dogs, are we consigning them to the same fate?
During the poster presentation, we saw some students who have come up with creative ways of presenting a 2 min talk - a student from James Cook University read a poem about whether wild dingoes pose a threat to the health of Indigenous communities in Queensland, while a student from University of Western Australia was literally singing the praises of using volatile chemicals for malaria parasite detection. Some of the most fascinating poster talks may present nightmarish scenarios to some people, but for different reasons.
|Photo by Kate Hutson|
Dinh Hoai Truong, a student from the Hutson lab at James Cook University presented a horror of a different kind - less visceral than having a parasite in your mouth, but more of a biosecurity nightmare to aquaculturists. He presented a poster on Neobenedenia - a hermaphroditic monogenean which infects the skin of Barramundi. His experiment showed that a single Neobenedenia is able produce eggs through self-fertilisation for consecutive generations without suffering any deleterious effects of inbreeding - each consecutive generation of inbred Neobenedenia are just as infective as the last. This means that even a single worm can start an entire sustained infestation at a fish farm. Unlike the widespread monogenean Gyrodactylus - a notorious aquacuture pest which has the viviparous "Russian Doll"-style "worm-within-a-worm" reproductive set-up (which allows them to swarm a fish like aphids on a rose bush) - Neobenedenia does what most monogeneans do and simply produce eggs. However because they are able to self-fertilise and have very short generation time, they can still become a serious pest to aquaculture.
In the next and final post on #ASP2012 (Australia), we will talk about how environmental factors can affect the generation time of Neobenedenia, and meet many other weird and wonderful marine parasites.
Next post: Swimming with the Parasites