Observation of the extension and retraction of bacterial type i pili under cutting flow

In this work we study the mechanical properties of type I pili in bacteria adhered to a surface and exposed to changing flow conditions. We compare our results with the ones obtained in previous studies with individual pili, and we suggest a hypothesis that explains the observed differences. We modeled the pili as a chain that follows the model of a 'freely jointed chain' and validate it with our experimental data. We finally make a parallel of the mechanical properties of bacterial pili with the properties of the mechanism used by mussels to stay adhered under marine waves.

Dilia Rangel, Nathaly Melina Marin Medina