How Biofilms Work

By: Marianne Spoon

Biofilms and Medical Problems

Biofilm formation that occurs in an indwelling catheter, such as this one show on an electron micrograph, may lead to staph infections.
Biofilm formation that occurs in an indwelling catheter, such as this one show on an electron micrograph, may lead to staph infections.
Image Courtesy CDC/Rodney M. Donlan, Ph.D; Janice Carr

Have you ever wondered why getting your teeth cleaned at the dentist is necessary? You already brush your teeth on your own, right?

With more than 500 individual species of bacteria in our mouths, it's safe to say biofilms may pose a problem if we let them [sources: Cromie; Montana State University CBE]. Brushing your teeth removes dental plaque, a type of biofilm on teeth, yet removing it from hard-to-reach areas near our gum lines is often left to the expertise of a dental hygienist. If left on our teeth, dental plaque can lead to cavities and periodontitis -- the medical term for gum infection.


Outside your mouth, biofilm-related health problems are more common than you might think. What's alarming about biofilm infections is the fact that some aren't easy to get rid of and can be tolerant of antimicrobial treatments such as antibiotics. This means some medicines won't work for people who are ill from biofilm infections. Biofilms can cause a variety of health problems, ranging from a common earache to a specific bacterial infection found in people living with a genetic disease called cystic fibrosis.

But biofilms are particularly an area of concern for patients with implanted medical devices. They have been found on some devices more than others, including:

  • Catheters, or tubes inserted in the body to deliver treatment or remove bodily fluids (especially central venous catheters and urinary catheters)
  • Prosthetic joints
  • Mechanical heart valves
  • Pacemakers
  • Contact lenses
  • Endotracheal tubes, used to help breathing or administer anesthesia
  • Intrauterine devices used as contraceptives

In hospital settings, microbes that form biofilms usually enter a patient's body from being transferred on the implant or inside the patient from the patient himself, visitors or hospital staff beforehand. Certain types of biofilms, such as those from the genus Staphylococcus, are more harmful because they release toxins and can be highly resistant to antibiotics, especially if they form biofilms in a patient's body (see How Staph Infections Work to read more).

Getting rid of biofilms, especially staph bacteria, can be a challenge for patients with implants, but there are a few options. Sometimes removing the implant will do the trick, unless the biofilm has formed on live tissue [source: Donlan]. Other techniques include applying stronger doses of antimicrobial drugs to the surface of the implant before it's placed inside a patient or experimenting with implants lined with silver, which has antimicrobial properties.

Unfortunately, there's no universal treatment for medical biofilms in the long run. Preventing biofilms from forming in the first place is the most promising tactic. Patients should always consult their doctors about possible treatments for biofilm infections.

The human body isn't the only arena in our battle against unwanted biofilms. Read on to learn how these persistent clusters negatively affect industry settings and the environment.