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Biofilm Control

Spotting Biofilms

Microorganisms like bacteria or yeasts hate solitude; they tend to collect in clumps–from a few micrometers to several millimeters in size–called biofilms. This makes them more resistant to cleaning products and antibiotics. In hospital environments, for example, biofilms are the cause of approximately 60% of hospital-acquired infections. To combat these aggregates, Thierry Jouenne’s team in Rouen1,2 has been contributing to some very encouraging tests on a new screening process developed by the start-up company Biofilm Control. This will enable a large-scale screening of different antibiotics to combat the formation of biofilms.
Set up in 2004 by Thierry Bernardi, and based in Clermont-Ferrand, Biofilm Control has developed the Biofilm Ring Test–a simple and rapid method to evaluate the formation of biofilms. Testing is carried out using a 96-well plastic microplate placed on a magnet. A solution of bacteria and magnetizable particles is deposited in each well (the tiny indentations on the plate). If no biofilm is present, the particles submitted to the magnetic field will clump at the bottom of the well and form a spot. But if a biofilm builds up, the particles are gradually immobilized. Fewer particles then react to the magnetic field, the spot is less pronounced and will even disappear when a biofilm has fully formed. The density of the spot is then detected by an appropriate reading device. It is this screening technique that the CNRS researchers are currently experimenting in Rouen.


© Chavant et al (2007) J Microbiol Methos 68:605-612

A solution of bacteria and magnetizable particles is deposited in each well, underneath which a magnet is placed. If no biofilm is present, the particles clump in the center to form a spot detected by a special riding device.

This method has numerous advantages. Less complex than standard procedures, it can be automated and give results in just a few minutes. At a rate of several thousand tests a day, it will help determine the efficiency of different antibiotics by observing whether their addition to a well prevents or delays the formation of a biofilm.
But not all biofilms are dangerous: The agrifood and cosmetics industries exploit the ability of microorganisms to synthesize specific polymers during their formation in a biofilm. Used as texture or gelling agents, these compounds are used for making a wide range of products including lipstick, ice cream, or even cakes. “This technique will let us study thousands of biofilms, and in the long run, we hope to make new polymers available to industrials,” concludes Bernardi.
Emmanuel Thévenon

For more

Notes :

1. Laboratoire “Polymères, biopolymères, membranes” (CNRS / Univ. Rouen / INSA Rouen).
2. With INSA in Lyon and the Institut Pasteur in Paris.

Contacts :

Thierry Jouenne
Laboratoire “Polymères, biopolymères, membranes,” Rouen.


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