(130e) Combining Forward Osmosis with Electrochemistry to Detect Ultra-Low Concentrations of Bacterial Virulence Factors and Quorum Sensing Molecules in Bodily Fluids

Current diagnostic methods for bacterial infection require the use of culture plates, a process that takes 1 to 5 days before clinicians can confirm a bacterial infection and provide the required antibiotic to the patient. This delay in acquiring results can hinder patient care and contribute to the growing impact of antibiotic resistant bacteria. Therefore, rapid detection of bacterial infections at point-of-care would play a key role in improving patient care and potentially prevent bacterial antibiotic resistance. In this work, we present how electrochemistry can be coupled with low cost forward osmosis to detect ultra-low concentrations of unique bacterial quorum sensing molecules in bodily fluids to serve as an early stage indicator of the identity of the potential bacterial infection. In this case, the clinician can provide targeted antibiotics instead of waiting for a culture plate to determine the type of bacterial infection.

Disposable carbon-based electrochemical sensors were used to run square-wave voltammetry on liquid samples of bacteria. Pseudomonas aeruginosa was used as the model bacterial species due to its production of a unique redox active molecule, pyocyanin that can be detected electrochemically. Differing bodily fluids were spiked with known concentrations of pyocyanin that were initially undetectable with the bare carbon sensors. The sample was then concentrated using a low-cost forward osmosis setup and then electrochemically rescanned to determine the final detectable pyocyanin concentrations. The advantage of this setup is its low cost, reproducibility, and accuracy as compared to current sample concentration methods that involve centrifuges and/or evaporators. A calibration curve was performed to determine the time-dependent concentration of sample in the forward osmosis setup and was used to calculate the initial starting concentrations of pyocyanin in the sample prior to using forward osmosis. The results indicate the feasibility of utilizing forward osmosis alongside electrochemistry towards detecting low levels of bacterial virulence factors in bodily fluids.