Question: Why can't any of the drugs that we have been using for the past 80 years kill 'superbug' infections?

Jess Bean answered on 17 Jun 2013:

That’s a great question! In fact your question is actually answering itself.

So you probably know that bacteria are found pretty much everywhere, and most importantly that they can multiply very quickly. Bacteria multiply by a process called binary fission, where one bacterium can split itself in two, and so on and so on until there are millions of them. This splitting can happen every few minutes! Have a look…

Every time a bacterium splits in two, its genetic code copies itself so each bacterium has its own copy .Every time this happens, there is a chance that parts of the code are not copied properly, or even left out – this is called a mutation. Most of the time this is not a problem (it would be like having blue eyes instead of brown) but a problem occurs if the mutation means the bacterium is not killed by antibiotics. Antibiotics are any chemicals that are found in nature that kill bacteria.

That one bacterium that is not killed by that antibiotic can then go on to grow and pass down the antibiotic resistance to its descendants – we call this bacterium ‘resistant’ to that antibiotic.

“That’s fine” you say “we can just kill it with a different antibiotic that it hasn’t got resistance to!”. We could do this, but imagine if this exact thing has been happening for the past 80 years! With its super-fast replication, bacteria have had years and years to develop mutations to resist most antibiotics. This hasn’t been helped by the fact that companies are finding it very hard to find new antibiotics.

It must be said, the vast majority of bacteria are still killed by antibiotics, it’s just these resistant bacteria, the “superbugs” that are proving tricky.