Fact Checked Fact Checked
This article has been fact checked by a licensed expert before publication to ensure all information provided is correct and safe. What is antibiotic resistance?
Since the discovery of penicillin in the 1920s, antibiotics have revolutionised the treatment of infectious diseases and helped save millions of lives around the world.
They’re a type of antimicrobial medicine that destroys bacteria and prevents them from spreading. Despite being ineffective against viruses and day-to-day illnesses like the common cold, antibiotics are often mistakenly prescribed for them. Misusing them in this way has played a major part in a growing crisis in healthcare – antibiotic resistance.
The World Health Organisation (WHO) has called antibiotic resistance one of the top global public health threats, and in 2019 was responsible for 1.27 million deaths around the world.
Medically reviewed by
Craig Marsh, Independent Prescriber
Antibiotic resistance occurs when bacteria change and develop so that medications which should work against them, and effectively fight bacterial infections, no longer do.
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What causes antibiotic resistance?
A number of factors can contribute to antibiotic resistance. The WHO lists several reasons for it occurring, which include:
- the overprescribing of antibiotics;
- patients not finishing the full course they’re prescribed;
- overuse of antibiotics for fish farming and livestock;
- poor infection control in hospital settings;
- poor sanitation and hygiene;
- a lack of new antibiotics being developed.
Overprescribing refers to antibiotics being used for conditions or illnesses that don’t require them. The more they’re used when they’re not necessary, the more chance bacteria have of adapting and becoming resistant to the effects of the antibiotics.
For example, if you’re given a course of antibiotics for a non-bacterial infection like a cold, you increase your chances of those same antibiotics being less effective when you do have a bacterial infection, like a UTI.
Antibiotics aren’t essential for every bacterial infection; the human body’s natural immune system can manage most minor infections. For more serious infections antibiotics are very useful, but using them when you don’t need them, can mean they may not work in the future. This can reduce your own treatment options when you have a bacterial infection, but it also contributes to the wider problem of drug resistant ‘superbugs’, and antibiotics working less and less on a wider scale.
How can antibiotic resistance be prevented?
The WHO has stated that antimicrobial resistance doesn’t just affect poor and developing countries, but is present throughout the world. While no one can tackle the widespread issue of antibiotic resistance single handedly, there are things you can do to avoid using them when you don’t need to.
Sometimes antibiotics are used as a precaution, when a prescriber suspects you have a bacterial infection. Without a proper examination of your symptoms, there’s no way of telling whether you need antibiotics. It’s also difficult to tell which ones will work most effectively to clear your infection. Before agreeing to treatment, it’s worth discussing your symptoms with a clinician to make sure antibiotics are the safest, most suitable treatment for you.
Some conditions, such as urinary tract infections (UTIs) will sometimes get better on their own. If your symptoms aren’t improving, it might be worth doing a urine test to confirm whether the infection is bacterial. Respiratory infections, including bronchitis, tonsillitis, and sinusitis, are often treated with antibiotics when they can improve without them. Up to 40% of antibiotic prescriptions for these conditions are thought to be unnecessary.
Why are antibiotics overprescribed?
There are lots of reasons antibiotics are overprescribed. A significant driving force behind antibiotic resistance is the misuse of antibiotics in primary care settings, such as hospitals and GP surgeries.
Attitudes towards prescribing them can vary, and guidelines on how to use antibiotics aren’t always consistent. GPs can sometimes feel pressured to ‘do something’ if their patients ask for antibiotics, or might prescribe them despite not being absolutely certain they’re the right choice of medication.
In hospitals, antibiotics are sometimes used as a precaution if doctors think patients are at risk of developing a bacterial infection while receiving treatment, and so the medication can be used to get ahead of it. They’re also used to protect patients ahead of surgeries that could lead to infections.
Who is affected by antibiotic resistance?
It can affect anyone, at any stage of their life. People with weakened immune systems are especially at risk of experiencing health complications as a result of antibiotic resistance.
Patients undergoing chemotherapy, dialysis and joint replacements could all face complications if first-line classes of antibiotics are no longer effective for them. If you have a chronic condition like asthma, rheumatoid arthritis or diabetes, antibiotic resistance can limit your treatment options if you develop a bacterial infection.
Antibiotic sensitivity tests
Antibiotic sensitivity tests are a way of determining which medication will work best for a bacterial infection. They can be arranged through your GP, or might be performed during a hospital stay.
The tests require a sample, such as a blood, urine or sputum culture, from the site of the infection. These are then sent to a lab and studied to see which medication works most effectively.
The results for each antibiotic usually shown as follows:
- Susceptible – the infection responds well to the medication, which means it should work effectively.
- Intermediate – the medication could work in high doses.
- Resistant – the medication isn’t a good choice as it doesn’t destroy the bacteria or fungus causing your infection.
If you have an infection that isn’t responding well to standard treatments, then antibiotics might be the most effective way of managing it. By completing a sensitivity test, clinicians can decide which antibiotic to use.
Superbugs
The term ‘superbugs’ refers to strains of bacteria that are currently resistant to some antibiotics. They include MRSA (methicillin-resistant Staphylococcus aureus), Clostridium difficile (C. diff) and the bacteria that cause multi-drug-resistant tuberculosis, as well as others.
As bacteria change and develop and antibiotic resistance increases, more and more conditions that were previously treatable could become life-threatening. With current antibiotics unable to treat them, pressure is mounting for researchers to develop new kinds that will work effectively.
Taking antibiotics the right way
When you’re prescribed antibiotics, it’s important to take them the right way.
This means taking the entire course, and making sure you don’t skip any doses.
If your symptoms improve after only a few days, it might be tempting to end your treatment abruptly. In recent years, the concept of seeing out a course of antibiotics has been challenged, with some health professionals claiming it has no relation to how effective they are, or that doing so prevents antibiotic resistance.
However, this guidance is in place to make sure patients take antibiotics consistently. Medications have varying lengths of treatment, but taking the full course you’ve been prescribed is the best way of clearing an infection and avoiding any risks regarding antibiotic resistance.
It’s also worth reading the patient information leaflet (PIL) that comes with any antibiotics you’re prescribed. It can outline any contraindications (reasons you should avoid them), and things that can interfere with how well they work, like other medications and alcohol use.
How we source info.
When we present you with stats, data, opinion or a consensus, we’ll tell you where this came from. And we’ll only present data as clinically reliable if it’s come from a reputable source, such as a state or government-funded health body, a peer-reviewed medical journal, or a recognised analytics or data body. Read more in our editorial policy.
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Antibiotics, explained. NPS MedicineWise.
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Antimicrobial Resistance. [online] World Health
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Antibiotic overprescribing: Still a major concern.
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A qualitative literature review exploring the drivers influencing antibiotic over-prescribing by GPs in primary care and recommendations to reduce unnecessary prescribing. Perspectives in Public Health, 141(1), p.175791391987918.
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Antibiotic Sensitivity Test: MedlinePlus Medical Test. medlineplus.gov.
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Langford, B.J. and Morris, A.M. (2017).
Is it time to stop counselling patients to ‘finish the course of antibiotics’?. Canadian Pharmacists Journal / Revue des Pharmaciens du Canada, [online] 150(6), pp.349–350.
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World Health Organization.
Causes of Antibiotic Resistance. Www.who.int, 31 Jan. 2017.
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