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Published on: July 17, 2013
Rapid diffusion of fluorescent tracers into Staphylococcus epidermidis biofilms visualized by time lapse microscopy
Suriani Abdul Rani1, Betsey Pitts, Philip S Stewart
1Center for Biofilm Engineering and Department of Chemical Engineering, Montana State University-Bozeman, Bozeman, MT 59717-3980, USA.
Antimicrobial Agents and Chemotherapy
|January 28, 2005
Summary
Fluorescent tracers rapidly diffused into Staphylococcus epidermidis biofilms, confirming that antibiotic and biocide molecules can penetrate these microbial communities effectively.
Area of Science:
- Microbiology
- Biophysics
Background:
- Bacterial biofilms, such as those formed by Staphylococcus epidermidis, present a significant challenge in healthcare due to their inherent resistance to antimicrobial agents.
- Understanding the transport of solutes into biofilms is crucial for developing effective treatment strategies.
Purpose of the Study:
- To visualize and quantify the diffusion of fluorescent tracers into Staphylococcus epidermidis biofilms.
- To determine the effective diffusion coefficients of different-sized molecules within the biofilm matrix.
Main Methods:
- Time-lapse confocal scanning laser microscopy was employed to observe tracer diffusion.
- Rhodamine B and fluorescein were used as fluorescent tracers of varying sizes.
- Diffusion coefficients were calculated based on the rate of tracer penetration into cell clusters.
Main Results:
- Rhodamine B (larger tracer) diffused into the center of 200-600 micrometer cell clusters within minutes, with an effective diffusion coefficient of 3.7 x 10(-7) cm(2)/s (11% of that in water).
- Fluorescein (smaller tracer) diffused more rapidly, exhibiting an effective diffusion coefficient of 1.6 x 10(-6) cm(2)/s (32% of that in water).
Conclusions:
- Solutes comparable in size to many antibiotics and biocides can diffuse rapidly into bacterial biofilms.
- These findings provide visual evidence supporting the potential for antimicrobial agents to reach target sites within biofilms.
