presents a study, recently published in PNAS, that deals with the role
of bacterium-generated slime (extracellular mucus forming films of 0.1
to 5nm in thickness) on bacterial adhesion and ability to move.
These results were obtained by two French groups from INSERM and
CNRS at Aix-Marseille University in collaboration with Nanolane. They
show for the first time live observations of bacterial slime whilst the
bacteria are in motion.
SEEC of slime deposition by bacteria
This feat was made possible thanks to T-Surfs, innovative
contrast-enhancing slides specially designed for nanometric
characterization with a conventional inverted light microscope. T-Surfs
are intended to help study biological samples, biofilms, organic layers
in liquid or in air. In addition, they are compatible with most of the
nano-analytical devices and instruments (microfluidics, Fluorescence,
The study reveals that slime (extracellular mucus) is secreted by
bacteria at a constant rate, independent of the bacterium speed.
Furthermore, it is demonstrated that secretion takes place underneath
the bacterium and not at its ends. These brand new results are in
opposition to previous works which most often indicated direct
involvement of the extracellular matrix on bacterial motility through a
mode of propulsion caused by the secretion of the matrix at the 'rear'
of a bacterium.
For the first time, the relationship between the production of
extracellular matrices and time of residence of bacteria is clearly
established thanks to SEEC microscopy. This discovery adds a new and
possibly fundamental element as far as understanding the roles of
bacteria and extracellular matrices in cancer biology, bacteriology,
and many other fields.