Antimicrobial Resistance (AMR)

What is AMR: Antibiotics fight bacteria by killing them and/ or preventing them from spreading. Some bacteria, however, acquire genes that protect them from being attacked by antibiotics. This means that the antibiotic becomes less effective and eventually ineffective. The figure shows the antibiotic discovery and resistance timeline. The discovery of antibiotics is expensive and a lengthy process, and hence it is essential to ensure that existing antibiotics continue to be effective in fighting bacteria.

Acute respiratory illnesses (ARIs) can be classified as either bacterial or viral; unfortunately, both types present with very similar symptoms in patients, making the correct diagnosis difficult to determine. Ensuring patients can receive swift and appropriate treatment is key to successful healthcare, but antibiotics cannot cure viral infections and their unnecessary over-prescription and use is leading to a dangerous increase in antibiotic resistance, and the emergence of untreatable superbugs.

Impact of AMR: AMR could lead to an estimated 10 million deaths every year globally by 2050 at a cost of £66 trillion in lost productivity to the global economy.

Media coverage: The second most covered topic related to AMR is over prescription of antibiotics and below are a few useful links.
Antibiotic use falling but resistant infections rising“, BBC news, Oct. 2019
Cut in antibiotic prescriptions sees fall in superbug cases” BBC news, Aug. 2019
Antibiotic resistance plan to fight ‘urgent’ global threat“, BBC news – Jan. 2019
One in five’ GP antibiotic prescription is inappropriate, claims PHE” – ITV News, Feb. 2018
Stop prescribing ‘precious’ antibiotics for sore throats, GPs told” – BBC news, Jan. 2018

Role of point-of-use diagnostics: Procalcitonin (PCT) is a bacterial biomarker which can be monitored in the blood from 6-12 h of initial infection, and levels will increase in response to the severity of the bacterial infection. Meanwhile, PCT does not increase in concentration in response to viral infections, making it the ideal biomarker to distinguish between bacterial and viral infections. Point-of-use diagnostics can provide objective data that can guide healthcare professionals in deciding if the use of antibiotics is needed. Further, point-of-use diagnostics can assist healthcare professionals to communicate to patients that their prescribing decisions are backed by objective evidence.

The normal concentration of PCT in blood is between 10 pM and 150 pM. The current methods for measuring PCT levels include enzyme linked fluorescent assay (ELFA), time resolved amplified cryptate emission (TRACE) and chemiluminescent immunoassay; all of which are not suited for use in doctor’s offices, due to expensive, complicated, and bulky instrumentation, combined with extensive sample processing times.

Our approach: We aim to address this gap by developing a quantitative point-of-use biosensor based on optical waveguides. We are designing internally-referenced waveguide biosensor that will remove the effect of other components of blood, leaving only the optical signal from PCT. This will avoid the need for lengthy sample processing and expensive instrumentation, which is currently a major bottleneck for point-of-use applications.