How flow shapes bacterial biofilms

EPFL biophysicists have taken a systematic look into how bacterial biofilms are affected by fluid flow. The findings can give us clues about the physical rules guiding biofilm architecture, but also about the social dynamics that shape evolution. Although we tend to think of them as solitary sojourners of the world, bacteria are actually very social organisms. In fact, the vast majority of bacteria live on surfaces by forming "biofilms": three-dimensional communities hosting thousands to millions of bacteria of such bustling activity that scientists describe them as "bacterial cities". Bacteria form biofilms by attaching to each other on a wide variety of surfaces: the bottom of oceans, lakes or rivers, medical equipment and even internal organs, like the intestine, lungs, and teeth - the latter is the familiar dental plaque, a large source of income for dentists. In short, biofilms are the preferred lifestyle of bacteria. They grow wide and thick, forming a new, social dynamic among their member microorganisms, while also defending them: biofilms can be notoriously inaccessible to antibiotics, which is why they have drawn a lot of medical research.