• Question: In your profile you have put that you look for mutations when bacteria divide, but why is it important to find these mutations?

    Asked by kimberley10 to Bethany on 25 Jun 2014.
    • Photo: Bethany Dearlove

      Bethany Dearlove answered on 25 Jun 2014:

      Great question! There are a number of reasons why we might want to look at mutations. For tracking how a disease is spreading, I look for an accumulation of mutations as the disease spread from person to person. For example, if we had:
      Patient1: ATGGGAC
      Patient2: ATGAGAC
      Patient3: ATGAGAT
      Patient4: GTCCATT
      we’d say that Patient2 most likely got it from Patient1 (G mutated to A), and Patient3 got it from Patient2 (G to A like Patient2, and then an additional C to T). However, Patient4 is completely different, so probably not in the transmission chain at all, and was infected by a completely different source. If we understand how a disease spreads better, then we can think of better ways to treat it – for example, targeting treatments for people most at risk of the disease.

      It might be the case that the disease isn’t spreading between patients at all – a recent study using a similar method to that above showed that 75% of C. difficile cases in a hospital were not related (the equivalent of Patient4). This means we need to think about where else patients could be getting it from.