What Are Biofilms and Why Are They So Hard to Remove?

Biofilms are everywhere. They are highly resilient, difficult to remove, and implicated in a staggering 80% of infections. But what exactly are they?

Biofilms can be formed by a single bacterial species but usually consist of many different types along with fungi, algae, protozoa, and debris. They are bound together in a thick, gluey substance that can adhere to a wide range of surfaces, including metals, plastics, soil, and biological tissue.

Why Biofilms Are Difficult to Remove

Once established, biofilms are challenging to eliminate. A biofilm forms in multiple layers, so when you apply a disinfectant, you may damage the top layer but fail to reach organisms deeper inside. To completely remove a biofilm, you must eliminate every single organism and remove the conditions that allowed growth in the first place. If even a few organisms remain, they can quickly recolonize when conditions are right.

Biofilms are resistant to removal and tolerant to many disinfectants. Their layered structure shields bacterial cells, meaning standard cleaning and sanitizing methods may not fully eliminate them. They can also spread easily, contaminate nearby areas, and cause illnesses.

Biofilms tend to form on surfaces that are not cleaned frequently enough. They can anchor themselves to many types of materials.

How to Combat Biofilms

Regular, scheduled cleaning is the most effective way to disrupt the conditions that allow biofilms to grow. Physical agitation is also required for removal. The optimal approach is to perform routine cleaning first and then follow with a sanitizing process to dislodge the biofilm.

Surfaces Prone to Biofilm Growth

Some surfaces are more prone to biofilm colonization than others. Textured plastics, for example, provide ideal surfaces for adhesion. Standard cleaning may remove surface soil but won’t effectively clean the three-dimensional texture. Residue can remain in the “valleys,” and if moisture or nutrients are present, bacteria can feed on them and reestablish quickly.

Preventing biofilm formation is easier than removing established biofilms. Effective measures include proper design, preventative maintenance, and the use of antimicrobial surfaces or devices. These can include biostatic or biocidal surface treatments and nano-coatings that inhibit biofilm attachment.

Effective Methods for Biofilm Removal

Traditional mop, bucket, and wipe-clean methods are generally ineffective against biofilms. Superior results have been demonstrated using cleaning tools such as microfiber cloths and dry steam vapor machines.