• Question: What parasites do you look at?

    Asked by lauracloud to Tim on 16 Nov 2012.
    • Photo: Tim Downing

      Tim Downing answered on 16 Nov 2012:


      Hi Laura,

      I examine single-cell parasites called Leishmania (pronounced “leash-mane-ee-aa”). These are much smaller than human cells and have little tails. They are spread from sandfly to humans. So when inside the sandfly, the parasites use their tails to move to the sandfly midgut. Positioning themselves there means that when the sandfly bites one of us, then the parsites will be pushed out into our bloodstream. Even though the sandfly wants to feed on our blood, the parasites force the sandfly to ingest and egest the human blood repeatedly so that they gain access to us.

      When inside our bodies, they loose their tails (flagella) once they have gotten inside white blood cells. Inside the cells, they divide until the cell dies. The parasites are released and they spread to other cells. Infected people can have the infection for a long time, and so when other sandflies bite the infected human host, it’s spread to other sandflies and eventually people. The parasite can also infect dogs, cows and other animals.

      As a result, this parasite infects millions of people globally each year. It also evolves resistance to drug treatment quickly. This is why many researchers scattered around the globe are trying to eliminate it. I try to assist this by examining mutations in the parasites’ DNA code.

      Tim

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