A novel imaging technique sheds new light on bacterial mobility and adhesion.

A novel imaging technique sheds new light on bacterial mobility and adhesion.

A scientific endeavour carried out by two French groups belonging to INSERM and CNRS at Aix-Marseilles University shows for the very first time that both bacterium adhesion to and bacterium motion on a surface are driven by the same mechanism. Those findings result from collaborative work with Nanolane, a French company that specialises in optical characterisation. Nanolane has devised a new generation of advanced microscope slides specifically for this type of investigation.

Up until now, it was believed that the motion of a bacterium on a surface was caused by projection of a polymeric material referred to as slime that would be produced at the bacterium rear. The Marseilles-based scientists’ work, recently published in America’s famous Proceedings of the National Academy of Sciences, proves that slime is being generated at spots spread out all along a bacterium’s body as opposed to the rear as seemed to be agreed upon in the scientific literature. The role played by this slime appears to be two-fold: it works as a glue so that a bacterium can stick to a surface, and it facilitates bacterium motion by lubricating the surface-to-bacterium contact.
It is because of the picture quality SEEC microscopy provides by substituting Surf slides for ordinary microscope slides that the above-mentioned conclusions were drawn. Surfs are the new generation of microscope slides that Nanolane developed, they have the power to let a reflected light microscope image samples in an aqueous medium with a sensitivity level of under one nanometre!
This discovery adds a fundamental element to what is already known about bacterial motion and therefore about the evils bacteria are responsible for: diseases, decays and so on. It can be hoped that thanks to this new knowledge medical scientists will be in a position to put together more effective kinds of treatment for bacteria-induced disorders. Let us recall that bacterial diseases: cholera, typhoid fever, pneumonia, dysentery, leprosy and so forth cause several million yearly deaths worldwide.

Contacts :
M.P.Valignat, INSERM-CNRS, University Aix-Marseilles, Marie-Pierre.Valignat@inserm.fr;
N.Médard, Nanolane, nicolas.medard@eolane.com

Source:
‘Wet-Surface-Enhanced Ellipsometric Contrast Microscopy identifies slime as a major adhesion factor during bacterial surface motility’,A. Ducret, M-P. Valignat, F. Mouhamar, T. Mignot, O. Theodoly, Proc Natl Acad Sci U S A. 2012 June 19, 2012 vol. 109 no. 25 10036-10041.
http://www.pnas.org/content/early/2012/05/31/1120979109.full.pdf+html