What is antibiotic resistance?
Antibiotics can cure infections caused by harmful bacteria, but their essential role in medicine is being jeopardised by a phenomenon known as “antibiotic resistance”. This means that bacteria are evolving, and becoming more difficult to kill with antibiotics – they are ‘antibiotic-resistant bacteria’.
Our research aims to use cutting-edge technologies like DNA sequencing, and large database analysis, to understand how and why these bacteria are evolving, how we can prevent this drug-resistance from spreading, and how to improve the treatment of patients with drug-resistant infections.
How are bacteria evolving antibiotic resistance ?
Just like humans, bacteria have DNA too. Over time, the DNA sequence of a bacteria can change (‘mutate’), due to damage, or random errors when the DNA is being replicated. Most of the time mutations are bad and the bacteria can die. But very rarely, a mutation can lead to beneficial changes for the bacteria. For instance, the mutation might make a protein able to target and destroy antibiotics. In this case, if antibiotics are given, the bacteria with the mutation will survive and multiply. The more antibiotics we use, the more we are encouraging the ‘antibiotic-resistant bacteria’ to survive. You can read more about antibiotic resistance here.
Video on antibiotic resistance for GCSE students:
Watch antibiotic-resistant bacteria grow:
How antibiotic resistance arises:
(note: this explains a little about another way that bacteria can mutate – by sharing DNA, also called ‘horizontal gene transfer’. If you’re doing GCSE, you don’t need to know about it yet, but it’s very important for the real world of superbugs!)
How does this relate to our activities?
If you play the ‘Dance Dance Evolution’ game, you can have a go at replicating a DNA sequence – when you make an error, you’re introducing a new mutation to this DNA sequence. You can read more about the game here.
If you play the ‘Antibiotic Resistance Coconut Shy’, you can try your hand at killing ‘coconut’ bacteria by throwing antibiotics at them. But some are harder to kill than others – they are resistant! You will see how using antibiotics removes the easy-to-kill bacteria, leaving only the resistant ones left! You can read more about the game here.
What does our research involve?
In our lab we read the DNA sequences of ‘antibiotic-resistant bacteria’, using cutting-edge technology.
Then, we work as DNA detectives, deciphering the sequences to discover the mutations that cause this ‘antibiotic resistance’. We can also use the DNA to see whether bacteria are related to each other (just like CSI can do with humans!). This can help us diagnose patients with resistant infections rapidly, and also track down where infections are spreading.
Why is this important?
Traditionally, to diagnose an infection, we take samples of blood, urine or sputum, and try and grow bacteria from the sample in a laboratory. Then extensive laboratory tests are done to find out what type of bacteria is causing the infection, where it has come from, and whether it is an ‘antibiotic-resistant bacteria’.
This is fine for fast-growing bacteria, where the tests may take a few days, but for bacteria like tuberculosis, which grows very slowly, this can take months. Our research group shown you can extract the DNA from the tuberculosis bacteria, and analyse it to find out all of this information without having to do all the tests – this can be done in a few weeks, rather than months! This means that patients with tuberculosis can be given the right treatment, faster. We can also use it to try and track down outbreaks, and stop tuberculosis spreading. In March 2018, Public Health England started using this technique, meaning that the UK is the first country in the world to adopt routine, large-scale DNA sequencing of bacteria into health care.
Our research group has also been developing methods to sequence the DNA of bacteria directly from the patient samples, to identify what type of bacteria is causing infection, and whether it has any of these ‘antibiotic resistance’ mutations. This could allow us to get results in hours, rather than days, and patients to get the right treatment for their infection faster.
Find our more about how genome sequencing can be used in medicine. The same techniques can be used to analyse the genetic sequences of humans, bacteria causing infections (bacterial pathogens), and viruses like the Ebola Virus – see examples described in this video.
Find out more about how genome sequencing can be used to stop superbug outbreaks, like MRSA, in work done by the Sanger Centre in Cambridge: