Biofilm formation is one of the most important and widespread areas of research today. Not that it is a new subject: biofilms were known of as early as 1684, when Antonie van Leeuwenhoek of Delft, a developer of some of the early microscopes, remarked on the vast accumulation of micro-organisms he was able to see in dental plaque.
Since that time biofilms have been linked to a wide variety of microbial infections in the human body, including illnesses such as urinary tract infections, cystic fibrosis and, most recently reported, Lupus. They are also thought to play a large part in catheter infections, coatings that form on contact lenses, as well as joint prostheses and heart valves, and they can also affect wound healing. One of the most high profile biofilm dangers is from Legionella bacteria, which are known to grow under certain conditions in biofilms in which they are protected against disinfectants.
Contrary to conventional sanitary/hygienic concepts of using high temperatures and harsh disinfectants, biofilms have evolved specifically to live in harsh environments, such as high temperatures and acidic pHs. Research has shown that when removing them from industrial or hospital pipework, a calculated combinational approach is usually required.
It appears that whatever we throw at biofilms they can counter. Scientists Yu Yang and Pedro Alvarez at the Department of Civil and Environmental Engineering, Rice University, US, have carried out research that suggests sublethal exposure to silver nanoparticles (AgNPs), like those used in many antimicrobials, can counter-productively promote development of biofilms (Environ. Sci. Technol. Lett. 2015, DOI: 10.1021/acs.estlett.5b00159).
The researchers postulate that enhanced biofilm development by exposure to low AgNP concentrations might accelerate biofouling and biocorrosion and harbour pathogens that pose a risk to public health.
Let’s hope we won’t still be pondering the question of biofilm eradication 300 years hence.