What is the problem?

Tuberculosis (TB) caused by the Mycobacterium tuberculosis (M. tb) bacterium is one the three major causes of infectious disease deaths worldwide. Approximately one quarter of the global population is infected, with annually 10 million new cases and 1.4 million deaths. While TB is treatable with suitable antibiotic combinations, disease symptoms are variable and easily confused with other conditions, meaning that individuals with active disease and capable of infecting others are not always quickly identified, allowing continued transmission. Fast, accurate identification of these patients is key to achieving the prompt antibiotic administration necessary to prevent infected individuals spreading disease. The World Health Organisation (WHO) has identified new diagnostic technologies to detect TB disease as one research focus for their End TB Strategy designed to reduce TB incidence by 80% by 2030.

A potential solution

A multidisciplinary research team aims to develop and evaluate tools to capture and detect M. tb in samples from patients with possible TB disease: specifically sputum coughed up by infected adults. Work undertaken by Prof Jim Spencer (School of Cellular and Molecular Medicine) and Dr Annela Seddon (School of Physics), alongside Dr Rob Hughes (Dept. Mechanical Engineering), and Dr Sara Carriera (School of Cellular and Molecular Medicine), and funded previously through the BristolBridge “Bridging the Gaps” EPSRC network grant, identified surface modified magnetic nanoparticles as a way to extract and concentrate bacteria and make steps towards employing this as a diagnostic. Alongside this, work in Prof Carmen Galan’s group (School of Chemistry) has identified that fluorescent carbon dots are able to bind to and label bacteria, and that these can be decorated with glycans to target them to specific species. By combining these approaches it is hoped that these materials can be specifically targeted towards TB, enabling capture and detection of bacteria from patient samples.

Next steps

The long term goal is to create a rapid diagnostic method capable of identifying TB disease and that is able to be used in resource-poor settings i.e. the low- and-middle-income countries (LMICs) where the TB disease burden is greatest and medical infrastructure is limited. With the expertise of colleagues at Kenya Medical Research Institute (KEMRI), access to clinical samples will allow the team to assess the success of this approach and move towards a working device prototype.