Virtual Genetics Education Centre

Antibiotic resistance

For decades, we have used antibiotics to treat bacterial infections. Now, we are threatened by bacteria that are resistant to antibiotics. Antibiotic resistance has developed and spread through the improper use of the drugs, propagating 'resistance mutations'.

What are antibiotics?

Antibiotics are used to treat infections caused by bacteria. These include conditions like pneumonia, meningitis and food poisoning. The first antibiotic available commercially was penicillin. Now we have many different antibiotics used to treat infections caused by different bacteria. Antibiotics work by inhibiting crucial reactions in a bacterial cell that keep them growing.

What is resistance and how does it occur?

Bacteria can evolve to become resistant to antibiotics. In other words, the drugs we use to treat life threatening diseases, are no longer cures. Occasional antibiotic resistant infections are bad enough, the real problem is that antibiotic resistant bacteria are spreading, and fast.

Mutations in a bacteria's DNA result in antibiotic resistance, and some of these mutations can be spread from one cell to another, speeding up the process. In a population of bacteria then, lets assume 1 out of 1000 cells have mutated to become resistant. If we then treat these bacteria with an antibiotic, all of the sensitive cells will be killed, allowing the resistant cells to multiple and eventually spread.

Improper, non-clinical use of antibiotics also speeds up the spread of resistance. For example, the farming industry often use antimicrobials to increase the growth of their livestock. Use of antibiotics in this context increases the number of resistant bacteria in livestock, which eventually make their way onto our plates and into our food products.

What can we do?

To prevent the further spread of antibiotic resistance we need to change our behaviours. Some small things we can do to help include:

  • Only use antibiotics where prescribed by our doctors or a qualified professional
  • Never use antibiotics left over from a previous course
  • Always take the full course of a drug, even if you feel better after a couple of days
  • Don't share your antibiotics with other family members or friends. They aren't intended for anyone but the person to which they were prescribed
  • Prevent infections by keeping your vaccinations up to date and exercising good hygiene practises

A common misconception about antibiotic resistance is that it is us, humans that become resistant. This is not true - bacteria become resistant to antibiotics.

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