A biofilm is a layer of mucus that is produced by microorganisms, which are embedded in this layer themselves. Biofilm-producing bacteria pose a medical problem.
The slimy layer consisting of sugar and proteins protects the embedded bacteria against the immune system
and increases their insensibility against antibiotics. Bacteria on surfaces like teeth or medical implants organize themselves into communities, which are able to communicate with each other. Medically relevant biofilm-producing pathogens are staphylococci
, pseudomonads and streptococci.