Question: What are biofilms?

Katie Fala answered on 13 Nov 2019: last edited 13 Nov 2019 9:32 pm

Thanks for your question Hazel (and ContagiousKeva)! Biofilms are masses of bacteria that grow attached to a surface or one another, they are sometimes described as bacterial cities or fortresses as you can often find many different species of bacteria and fungi living side by side! They can be sticky or hard, as the bacteria produce different things to protect themselves like carbohydrates, proteins and strands of DNA. In the picture below (thanks BioNinja) you can an example of biofilm that has formed on toothbrush bristles. You can make out some individual, rod-shaped cells at the higher magnification but also see tangled matter which are those substances made by the bacteria to stick to oneanother and the surface.

Most bacteria in nature are thought to live in this way, living in a biofilm affords the bacteria protection to cleaning processes, or antibiotics or even our immune cells. Some examples of biofilms that are particularly worrying are biofilms that form on our teeth, ones that grow in chronic wounds or medical devices like hip implants as they can be very dangerous for the patient, and biofilms inside pipes in food processing plants as they can allow dangerous bacteria to contaminate the food we eat. In the lab I am studying compounds that may stop such bacteria from talking to oneanother, which could in turn stop them from making biofilms or make them more susceptible to antibiotics, even when living in biofilms.