• Question: Do you think that there could be "war" between the speed at which bacteria develop antibiotic resistance and the speed at which scientists develop new effective antibiotics and how is it likely to effect us in the future?

    Asked by MaximDis to ☣ Danna, Juan, Daniela ? on 16 Jun 2016.
    • Photo: Danna Gifford

      Danna Gifford answered on 16 Jun 2016:

      Hi MaximDis,

      It already is sort of a “war” between us and them. The first resistant bacteria are usually observed in some infections within 10-20 years of introducing a new antibiotic, and for some a lot sooner. We can make small chemical changes to the structure of antibiotics we already possess, but bacteria can usually evolve resistance to these very quickly.

      A good example of this is with a class of antibiotics called the beta-lactams, of which penicillin was the first discovered and the best known. Resistance to penicillin was first seen in 1947, only about 4 years after it started to be mass-produced for medicine. Some bacteria make a compound called a beta-lactamase, which is an enzyme that can break down beta-lactam antibiotics

      By making modifications of penicillin and other beta-lactams, modified “2nd-generation” antibiotics were then able to work again on beta-lactamase producing bacteria. But then mutations in their beta-lactamase genes allowed bacteria to again break down the antibiotic. So we made more changes to the antibiotic “3rd-generation”, and bacteria evolved again…

      The thing about this arms race is that bacteria can evolve much faster than our ability to make changes to the antibiotic, so it’s an unwinnable war, over the long term. A better solution is to find or create completely new compounds that bacteria have never seen before, which makes evolving resistance much harder (but not impossible!).

    • Photo: Daniela Lobo

      Daniela Lobo answered on 16 Jun 2016:

      As Danna said, the reason why we have 2nd, 3rd generation antibiotics, it’s because bacteria evolve (quite quickly) to become resistant, and right now there are very few completely new antibiotics that could be used. So, yeah, that could be seen as a “war” between man and microbe.
      Last year, a group of researchers reported the finding of a completely new antibiotic called “Teixobactin”. This antibiotic is produced by soil bacteria, and it kills bacteria by making the cell wall vulnerable – the bacteria lysis/”explodes”. In their study they say it destroys bacteria – that are now resistant to most of our available antibiotics -without them developing resistance to teixobactin. Teixobactin seems to belong to a new class of antibiotics.

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