(567az) Staphylococcus Epidermidis Biofilm Microstructure Characterized by Confocal Laser Scanning Microscopy

Biofilms are colonies of microorganisms encapsulated in the
protective layer of a polysaccharide matrix. Bacterial biofilms commonly form
on the surface of intravenous medical devices and are hypothesized to fracture
or erode from the device surface and proliferate throughout the blood stream,
thereby potentially causing systemic infection.  Every year ~1% of Americans have blood stream infections, of
these patients 20-30% die¹. 
Staphylococcus epidermidis is
frequently involved in nosocomial (hospital-related) bacterial biofilm
infections associated with contaminated medical devices.  This work will present measurements of
the impact of fluid flow on S.
epidermidis biofilm formation by analyzing the bacterial microstructure in the
biofilm with confocal laser scanning microscopy (CLSM). Of particular interest
are the shear rates of the experiments, which were set in ranges that approximate
physiological conditions.  3D image
volumes acquired by the CLSM were analyzed with image processing tools to
extract material properties of the structures formed such as the mean
separation between bacterial cells in the biofilm.  This microscopic structural information complements the more
typical morphological studies of biofilm structure which do not resolve
individual cells.  The
intercellular structure probed here is of interest to investigate fundamental
questions about the life cycle of biofilms including their growth, fracture and
erosion.  The evolution of these
properties with time, as well as their correlation with flow conditions is
discussed.

¹http://www.cdc.gov/ncidod/eid/vol7no2/wenzel.ht