Some sexually transmitted infections (STIs) such as N. gonorrhoeae and M. genitalium are difficult to treat immediately as they’ve become resistant to commonly used antibiotics. Delays or incorrect treatment have the potential to cause serious complications for an individual, as well as contribute to antibiotic resistance.
The time in which it takes to grow N. gonorrhoeae in the laboratory, and the challenges associated with growing M. genitalium at all, are both barriers to testing which antibiotics work in the treatment of these infections.
DNA holds the key
Antibiotic resistance can be checked by testing the DNA code of bacteria. Researchers from St George’s University together with Atlas Genetics are developing simple 30 min DNA tests to recognise the presence of the most common sexually transmitted bacteria such as N. gonorrhoeae and M. genitalium. Vitally, the test also recognises particular mutations in the DNA which determine whether a patient will respond to commonly prescribed antibiotics.
Through the development of this test the team have identified those strains of N. gonorrhoeae which are resistant to ciprofloxacin - an antibiotic to which nearly 30% are resistant. They have also developed a DNA test to detect the resistance of M. genitalium to azithromycin, a drug to which 40% of M. genitalium are resistant.
Finding the perfect match
If the tests could be completed quickly, whilst patients were still in clinic, they could significantly increase the likelihood of giving the correct treatment through the early identification of resistance to particular antibiotics. With this in mind the research team are using Invention for Innovation (i4i) funding from the NIHR to develop and confirm the accuracy of these new tests. The aim is to be able to check for both the presence of N. gonorrhoeae or M. genitalium and ciprofloxacin or azithromycin resistance respectively, all within 30 minutes of getting the sample.
Throughout this study, due to finish at the end of 2017, there has been extensive consultation with patients, public and healthcare workers to get the test design right. The equipment they have been using is a diagnostic platform from industrial collaborator Atlas Genetics, comprised of disposable cartridges and a small desk-top instrument. These attributes make it a quick to use system ideal for a clinical or community setting.
If successful, implementation of the test could radically change the ways we treat patients in sexual health clinics and the community. Alongside this, the immediate and accurate use of antibiotics is vitally important to limit antibiotic resistance and deliver effective treatment.