Understanding the role of microbial extracellular electron uptake in human pathogens using multi-modal microfluidics
Abstract
Topic Address: Topic 11, Biotronics Program Officer: Dr. Albena Ivanisevic, Army Title: Understanding the role of microbial extracellular electron uptake in human pathogens using multi-modal microfluidics Applicant Name: John Mark Meacham; Collaborator Name: Arpita Bose IHE: Washington University in St. Louis, St. Louis, MO Several microbes are known to use natural conductive substances/surfaces as electron donors in a biological process called extracellular electron uptake (EEU). This fascinating capability enables these microbes to generate energy in the absence of soluble electron donors. However, EEU has yet to be explored in pathogens, and we hypothesize that they may use human cells as electron donors to support microbial survival and growth. To test this hypothesis, we propose to develop and establish a multi-modal microfluidic platform and experimental methods to expand our understanding of EEU in human pathogens. Conventional electrochemical techniques use electrodes as proxies for conductive substances/surfaces to measure the aggregate behavior of a bacterial population, but these methods do not account for differences in EEU due to the spatial separation of various microbial sub-populations (e.g., surface attached cells and free-floating planktonic cells). As spatial separation is critically important to the EEU process, these methods yield an incomplete understanding of the cellular response and mechanisms that underpin EEU. Here, we will integrate ultrasonic waves into our existing microfluidic bioelectrochemical cells to control the position of bacteria relative to electrodes as we measure the cellular response during surface-microbe interactions. Ultrasound offers precise, yet gentle noncontact force application to drive cells toward or away from a surface, or to concentrate cells at a fixed distance from the surface, replicating conditions found in nature. We will use this new tool to rigorously study EEU, determining the cellular response to EEU in human pathogens, the metabolic outputs of EEU, and whether electron mediators influence EEU in human pathogens. The project outcomes will advance knowledge in fundamental science and engineering, and will expand the understanding of microbial resilience in the body. Combined with future work using human cell lines and animal models, our studies will lead to identification of new antimicrobial targets.
Document Details
- Document Type
- DoD Grant Award
- Publication Date
- Jan 21, 2022
- Source ID
- FA95502110211XX0
Entities
People
- John Meacham
Organizations
- Air Force Office of Scientific Research
- United States Air Force
- Washington University in St. Louis