• Question: Antibiotic resistance is blamed on people not taking the whole course of treatment. But how does that select for resistance? Wouldn't completing an antibiotic course of treatment be an even stronger selection for the rare, resistant bacteria?

    Asked by rockpeacepunk to Alexander, Josh, Serena, Simone, Stuart on 21 Jun 2013.
    • Photo: Simone Sturniolo

      Simone Sturniolo answered on 21 Jun 2013:


      I guess their point is that if you had taken the whole course, resistant or not, you could have wiped out the entire bacteria colony (resistant means not immortal, after all). But on the other hand, suspending the treatment will only kill off the weaker bacteria without actually harming the strong, resistant ones, and this will help them proliferate. It’s just like with poisons: a lot will kill you, small quantities can make you immune or resistant. If we give antibiotics to bacteria little by little, we’re just helping them getting used to them.

      Another factor is probably that sometimes people takes antibiotics for not really valid reasons. That’s why they have to be prescribed by doctors, after all. We should use them only in cases when they are truly needed. If we can overcome something with our own immune system, we’d probably better just do so.

    • Photo: Stuart Archer

      Stuart Archer answered on 21 Jun 2013:


      Simone hit the nail on the head there!

      As he hinted in his second paragraph, antibiotics are often taken when they don’t need to be. The problem is that a lot of doctors, when they’re not entirely sure what’s wrong with you, will just prescribe a course of antibiotics to make you feel better, even if it doesn’t have any medical value. Therefore, any small amounts of bacteria that you have in your body will start to develop resistances in the way that Simone described.

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