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Antibiotic Resistance

In this series of articles, medical students from across the country will share their knowledge of medical physiology, anatomy and biochemistry to give you a taster of medical school. This will be a fantastic opportunity to build upon your A-Level Knowledge.

Remember it's more important to understand the principles than to mindlessly memorise facts.


One of the greatest medical discoveries of the 1900s that changed the face of today’s healthcare was penicillin. Penicillin – the first ‘natural antibiotic’ – was discovered in 1928 by Alexander Fleming. But what are antibiotics and why should we worry about them?

What are antibiotics?

Antibiotics are chemical substances used to fight bacterial infections by either destroying the bacteria itself (bactericidal), or preventing it from reproducing (bacteriostatic). While our immune system can normally fight off most pathogens, antibiotics are required in severe bacterial infections to aid the body’s natural fighters. Just between 1944 and 1972, human life expectancy jumped by eight years – an increase largely credited to the introduction of antibiotics.

What is antibiotic resistance and how has it spread?

Antibiotic resistance is the phenomenon by which bacteria are immune or resistant to antibiotics. If antibiotics can’t treat bacterial diseases and infections we’ll soon go back to a world where surgeries were fatal (owing to bacterial infections). Before the discovery of antibiotics, a bacterium called Streptococcus pyogenes caused half of all post-birth deaths and was a major cause of death from burns. Staphylococcus aureus was fatal in almost 80% of infected wounds.

Interestingly, Fleming predicted the rise of antibiotic resistance back in 1945 while giving his Nobel Prize acceptance speech. He said: “Then there is the danger that the ignorant man may easily underdose himself and by exposing his microbes to non-lethal quantities of the drug, make them resistant.”

Antibiotic resistance is caused by a widely known phenomenon – evolution. Back when antibiotics were discovered, a small population of bacteria were already resistant to the effects of antibiotics due to genetic mutations. Since these bacteria were more likely to live longer, they were able to pass on the mutation to their offspring. In due time, the percentage of resistant bacteria rapidly rose resulting in widespread antibiotic resistance. This was the case in Staphylococcus aureus which evolved to become resistant to methicillin (antibiotic), known as Methicillin-Resistant Staphylococcus aureus (MRSA). Thus, doctors now prescribe different antibiotics to fight off S.aureus diseases. This however poses its own problems with some bacteria being resistant to multiple drugs such as Multiple-Drug-Resistant Gram-Negative Bacilli (MDRGNB).

What can you do to reduce antibiotic resistance?

  • Get vaccinated against common diseases. If you are already protected from the disease, you won’t have to use antibiotics.

  • Always complete your dose of antibiotics – even if you start feeling better earlier.

  • Don’t ask your doctor for an antibiotic for colds. The common cold is actually caused by a virus and antibiotics are ineffective in treating viral diseases.

  • Encourage local policymakers to allocate more money to research and development in medicine. The last completely new antibiotic was discovered in 1984! All antibiotics brought to the market in the past 30 years have only been slight variations on older drugs.

Further Reading:


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