Abstract

Monitoring Infections using Electrochemical Sensors that Detect Bacterial Metabolites

Edgar Goluch, Assistant Professor, Northeastern University

While there is a significant emphasis on the need for new antimicrobial compounds to treat bacterial infections, the best way to improve patient outcomes continues to be early detection followed by fast identification and treatment. As the concentration of bacteria increases at the infection site, the bacterial cells begin to change their activities to improve the bacterial community’s survival. The bacteria coordinate these changes, such as formation of biofilm and dormancy, using chemical signaling. The bacterial cells continuously excrete into their local environment peptides and small molecules for this purpose. Various cellular activities are then up-or-down regulated based on the concentration of these signaling molecules. Our sensors selectively detect and measure the concentration of these signaling molecules in order to determine the presence and level of infection. This talk will focus on our work with Pseudomonas aeruginosa, an opportunistic pathogen. We detect pyocyanin, a quorum-sensing molecule that is unique to this species and linked to biofilm formation. As pyocyanin is redox-active, it can be detected electrochemically using standard techniques such as square wave voltammetry (SWV). I will present the recent results of my group’s work showing that the effectiveness of antiobiotics to kill Pseudomonas cells in a biofilm can be evaluated by monitoring the concentration of pyocyanin in the sample. I will also discuss preliminary data that demonstrates our ability to identify Pseudomonas in human wound exudate using this single marker. This work was supported by the U.S. National Science Foundation under Grants #1125535 and # 1542812.