Antibiotic resistance — what is it and why is it a problem?

What is antibiotic resistance?

Antibiotic resistance happens when bacteria change to protect themselves from an antibiotic. They are then no longer sensitive to that antibiotic. When this happens, antibiotics that previously would have killed the bacteria, or stopped them from multiplying, no longer work.

What are 'superbugs'?

'Superbugs' are bacteria that are resistant to several different antibiotics. The methicillin resistant Staphylococcus aureus (MRSA) bacteria commonly found in hospitals, and the bacteria that cause tuberculosis (Mycobacterium tuberculosis), are now very hard to treat because of antibiotic resistance. Strains of Escherichia coli (E. coli) — the bacteria that causes many urinary tract infections — have also developed resistance to a number of antibiotics.

How does antibiotic resistance affect me?

Using antibiotics when you don't need them may mean that they won't work for you when you do need them in the future.

If you have an antibiotic-resistant bacterial infection:

  • you will have the infection for longer
  • you may be more likely to have complications of the infection
  • you could remain infectious for longer, and pass your infection to other people, which increases the problem.

You can help prevent antibiotic resistance

Many people think that antibiotics can cure a cold or flu and will help to shorten their illness. This is not true, because most respiratory tract infections are caused by viruses, so antibiotics won't have any effect.

You can prevent antibiotic resistance by:

What causes antibiotic resistance?

The more antibiotics are used, the more chances bacteria have to become resistant to them. Major causes of antibiotic resistance include:

  • using antibiotics when they are not needed
  • not taking antibiotics at the doses and times that a doctor prescribes — this allows time for the bacteria in your system to become resistant.

Antibiotics are also often overused in animals (in veterinary medicine and in agriculture).

How do bacteria develop antibiotic resistance?

Bacteria can become resistant to antibiotics by mutating (changing) their genes after being in contact with an antibiotic. These changes allow the bacteria to survive or 'resist' the antibiotic.

Unfortunately, bacteria can also develop antibiotic resistance through contact with other bacteria. Resistant bacteria can pass their genes to other bacteria, forming a new antibiotic resistant 'strain' of the bacteria.

Resistant strains of bacteria can spread to other people.

Development of antibiotic resistance

The development of antibiotics was one of the most important advances of medicine. Many bacterial infections (e.g. tuberculosis and infected wounds) that had previously had no effective treatment and often killed people, became treatable with antibiotics, saving millions of lives.

Now, because of the overuse and misuse of antibiotics, bacterial infections that were once easily cured with antibiotics are becoming harder to treat. This is due to antibiotic resistance.

The World Health Organization has called this one of the biggest threats to human health today.

  • World Health Organization. Antimicrobial resistance. Geneva: WHO. (accessed 16 March 2012).
  • Therapeutic guidelines: antibiotic version 14, 2010. Melbourne: Therapeutic Guidelines Ltd, 2010.