About Resistance Guided Therapy
How do antibiotics work?
Antibiotics are prescribed medications that can kill bacteria or slow their growth.
There are many types of antibiotics and they work in different ways to fight bacteria. In general, antibiotics interfere with the bacteria’s ability to grow and survive, such as disrupting an important part of the bacteria called the ‘cell wall’. Examples of some commonly prescribed antibiotics include penicillins, tetracyclines and macrolides.
Antibiotics target bacteria in our body. Our digestive tracts contain trillions of ‘good’ bacteria that help us digest food and prevent unhealthy levels of ‘bad’ bacteria building up. Unfortunately, misuse of antibiotics can wipe out our good bacteria and cause an imbalance, leading to negative health effects.
It is important to only take antibiotics when necessary and ensure the right antibiotic is used. Some common side effects of antibiotic use can include nausea, vomiting, and diarrhoea.
What is ‘antibiotic resistance’?
Accordingly to the World Health Organisation (WHO), antibiotic resistance is one of the biggest threats to global health, food security and development. Due to natural biological processes, bacteria can overcome the effects of antibiotics if exposed to them at a high or frequent amount. This ability of bacteria to survive in the presence of antibiotics is referred to as ‘resistance’.
How do bacteria gain resistance? This comes down to the fact that bacteria reproduce at a very high rate, and every time they divide there’s a chance they might gain a genetic mutation that gives them a new function. This new function could stop an antibiotic from working.
Even just one single resistant bacterium can survive antibiotic treatment and then multiply, leading to a large resistant population. This resistant strain can then spread to other people.
This is a problem because it reduces treatment options for people that contract antibiotic resistant infections. It’s a very slow process for new antibiotics to be developed, so using existing ones smarter is crucial for us to overcome the global threat of antibiotic resistance.
Resistance Guided Therapy
New STI testing technology is helping to overcome antibiotic resistance. Ordinary tests work by detecting the unique DNA of bacteria, such as chlamydia or gonorrhoea. New tests now enable the additional detection of DNA sequences that indicate a ‘resistance gene’, meaning certain antibiotics may not work if prescribed. This information is extremely valuable to your doctor, allowing them to use Resistance Guided Therapy to prescribe antibiotics that are most likely to treat your strain of infection. This can improve cure rate, treatment time and cost, as well as helping to overcome the global threat of antibiotic resistance.
An example of Resistance Guided Therapy is a new approach to gonorrhoea management. The current treatment for gonorrhoea involves a painful injection of the antibiotic ceftriaxone – one of the last effective antibiotics for gonorrhoea. Using Resistance Guided Therapy, scientists can detect gonorrhoea as well as whether it has genes making it vulnerable to a simple oral antibiotic known as ciprofloxacin. This is beneficial as the patient won’t even require an injection anymore, and the cure rate can increase^. Doctors can also save the injection as a last-line antibiotic for those who really need it.
This technology can be applied to other STIs as well – identifying if the contracted STI is resistant or susceptible to available antibiotics, and allowing doctors to prescribe the best antibiotic for their patients.
^Harris SR et al. Lancet Infect Dis. 2018