Unlike bacterial biofilms can be visible to the naked eye. As with many instances of bacteria they are often harmless to us but when the bacteria are dangerous the biofilm offers them protection (which is why they form such structures).
According to the National Institutes of Health, more than 65 percent of chronic inflammatory and infectious diseases are due to biofilms. According to recent studies, biofilm-related infections claim as many lives as heart attack or cancer.
Scientists think there are several reasons for this decrease in susceptibility. First, the slimy layer encasing biofilms can make it hard for disinfectants or antimicrobials to even physically reach the bacteria. Also, bacteria living in biofilms experience high stress levels while growing rather slowly, which can render most antibiotics ineffective since they only work on actively growing cells. My favorite theory is that living in a biofilm changes bacteria and their behavior; something about their mix of active genes and proteins just makes them more resilient. Whatever the contributing factors, bacteria growing in a biofilm can be up to 1,000-fold more resistant to antibiotics than the same bacteria grown planktonically.
The use of biofilms predates our use of anti-biotics but the adaptation of forming biofilm communities serves as a protection against antibiotics and so it isn’t a surprise that with more use of antibiotics more surviving bacteria will be those using biofilm strategies.
Thankfully for us, we have many researchers exploring options to help us figure out how we can protect ourselves when we need to. We are going to need many different strategies to protect us going forward. Our success will depended on thousands of scientists working on these issues.
Related: Scientists Target Bacteria Where They Live (2009) – Using Nanocomposites to Improve Dental Filling Performance (2012) – Fighting Superbugs with Superhero Bugs (2015) – The Search for Antibiotic Solutions Continues: Killing Sleeper Bacteria Cells (2013)