Guided mode resonance imaging: A novel sensing technique to study bacterial biofilm antibiotic resistance (Conference Presentation)

Antimicrobial resistance (AMR) has been recognized as an increasingly serious threat to the effective prevention and treatment of a wide range of infections caused by bacteria, parasites, viruses and fungi. Biofilms are of particular interest because up to 65% of microbial infections are associated with such microorganism growth. Unfortunately, biofilms are considered to be far more resistant to antimicrobial agents than planktonic cells due to the nature of a biofilm, which consists of a structured colony of bacteria embedded in a self-produced polymer matrix. However, the mechanisms of biofilm antibiotic resistance are not fully understood due to the complexity observed within a biofilm community and the lack of non-invasive biofilm examination techniques. Here, we present a novel approach, which will not only monitor the early stage of bacterial biofilm formation in real time in order to provide early warning against biofilm formation, but also provide a research and clinical toolbox for investigating biofilm antibiotic resistance. Our system employs guided mode resonance (GMR) imaging to monitor the earliest stage of biofilm formation on a silicon nitride substrate. GMR imaging works by tracking the resonant wavelength of a nano-structured substrate, which is extremely sensitive to local refractive index changes at the sensor surface to the extent that we can see the initial attachment of bacterial cells and formation of micro-colonies. We have also observed the formation of E. coli biofilms in clinically relevant concentrations as they occur, i.e. on a timescale of a few hours [1]. [1] Optica 4,2 229-234 (2017)