Developing microdialysis sampling as an in situ analysis tool for quorum sensing from biofilms.

by Stenken, Julie A.

Microdialysis sampling has been widely used for in vivo extracellular chem. sampling for 40 years. The porous nature of the membrane and the long established in vivo use of this technique suggest that it may be a useful model for studies involving the chem. communication in bacterial biofilms and their surrounding environment particularly the immune system. Microdialysis probes, CMA 20, 10 mm membrane, with 100 kDa MWCO polyethersulfone (PES) membranes were used for these studies. Biofilms from Pseudomonas aeruginonsa, Pseudomonas fluorescens, Staphylococcus aureus, Staphylococcus epidermidis and Vibrio harveyi were grown onto the microdialysis probes. Assessment of film presence was achieved using appropriate stains and SEM. Acyl lactones from the gram-neg. species were collected in dialyzates and quantified using LCMS. Anal. methods to measure the peptides from the gram-pos. bacteria are being developed and validated. Ongoing work is focused on integrating measurements of signaling occurring between biofilms and activated macrophages.