Sofia Johansson

Project 1: Microfluidic antibiotic susceptibility testing using electrical read-out

Antimicrobial resistance is one of our greatest global challenges, predicted to cause 10 million deaths annually by 2050. One challenge in the fight against antibiotic resistance is fast and reliable diagnostic tools so that antibiotics are used only when necessary and useful. The goal of the project is to develop an on-site diagnostic tool that can be used in dairy farms to determine antibiotic susceptibility (AST) and to identify the bacterial species. The technology is based on microfluidics with electrical read-out to enable a truly portable device that can be used by a non-expert directly on milk samples. By capturing and monitoring the growth rate of bacteria in microfluidic channels, the detection time for antibiotic resistance can be significantly reduced compared to current practices. We hypothesize that simultaneous AST and species identification would be made possible through careful analysis of the curve shape in the impedance spectra and could be used to distinguish cell properties such as size and cell wall composition (e.g. Gram positive/negative), which is important both for the selection of antibiotics and the prevention of disease.

Project 2: Trans-epithelial electrical resistance (TEER) in Organs-on-Chip

Organs-on-chip are developed to improve current in vitro models to better recapitulate human physiology. With improved models comes the possibility to reduce animal testing according to the 3R (replacement, refinement, reduction) principle. In addition to improving the cell culture conditions, microfabricated organs-on-chip devices lend themselves well to integrated sensing with the potential to acquire detailed and time-resolved information on important biological processes. We work, in particular, with trans-epithelial electrical resistance (TEER) to monitor the integrity of biological barriers, such as the intestine epithelium. Our systems deliver information rich TEER data where impedance spectra are measured every 15 min over 10+ days’ time periods at multiple locations along the microfluidic culture chamber, as well as in combination with optical in situ monitoring.