Respiratory disease presents as a major cause of morbidity and mortality in both developing and developed countries worldwide and is responsible for 1 in 5 deaths in the UK and accountable for 7% of all hospital admissions in Europe. The burden of respiratory disease is continually growing with respiratory related mortality claiming responsibility for 3.2 million deaths worldwide in 2015 and this is projected to increase to 3.5 million in 2030. Respiratory infection ranks as the third leading cause of death and the leading cause of disability-adjusted life-years (DALYS). Chronic obstructive pulmonary disease (COPD) is a major cause of morbidity and mortality in the UK costing £2.7billion every year. Patients suffer chronic ill-health with acute exacerbation, frequently associated with infection. Multiple antibiotic courses are given although viral infection is thought to be a common cause. In the context of COPD and bronchiectasis, the presence of bacteria in the bronchial tree can represent a range of significance from commensal colonisation to life-threatening exacerbations.
The Gillespie group has developed an innovative molecular assay (CBSMBLA, Chronic Bronchial Sepsis Molecular Bacterial Load Assay) that accurately identifies bacteria and quantifies the number of live organisms based bacterial ribosomal RNA detection (1).
During the PhD project, this innovative molecular assay will be transformed into a truly rapid point-of-care test based on a cutting-edge label- and amplification-free electrochemical biosensor platform developed in the Bachmann group (2).
This project will be jointly supervised by Dr Till Bachmann an expert in point-of-care
detection of infectious diseases and antimicrobial resistance at the Division of Infection and Pathway Medicine (University of Edinburgh) and Professor Stephen Gillespie an expert in clinical microbiology, tuberculosis drug development and antimicrobial resistance diagnostics at the School of Medicine of the University of St. Andrews.
The project will be truly interdisciplinary in nature with insights into infection medicine on the one side and electrochemical biosensor test development for point of care diagnostics on the other end. The project will combine aspects from various different disciplines: medicine (COPD, bacterial infection), biology (aspects of ribosomal RNA secondary and tertiary structure on probe hybridisation efficiency), chemistry (surface chemistry, probe immobilisation on gold electrodes, surface characterisation), electrochemistry (electrochemical impedance spectroscopy assay development), engineering (microfluidic cartridge development, sensor integration), and bioinformatics (bacteria specific probe design).
(1) Honeyborne I, McHugh TD, Phillips PP, Bannoo S, Bateson A, Carroll N, Perrin FM, Ronacher K, Wright L, van Helden PD, Walzl G, Gillespie SH. Molecular bacterial load assay, a culture-free biomarker for rapid and accurate quantification of sputum Mycobacterium tuberculosis bacillary load during treatment. J Clin Microbiol. 2011 Nov;49(11):3905-11.
(2) Henihan G*, Schulze H*, Corrigan D, Giraud G, Terry JG, Hardie A, Campbell CJ, Walton AJ, Crain J, Pethig R, Templeton KE, Mount AR, Bachmann TT (2016) Label- and amplification-free electrochemical detection of bacterial ribosomal RNA. Biosensors & Bioelectronics 81, 487–494.