Biofilms

‘Biofilms are elaborate structures of bacterial communities attached to a surface and supported by a self-produced matrix mainly constituted of polysaccharides, nucleic acids, proteins, lipids and water’ (Hanot et al, 2025). First observed by Dutch microscopist Anthony van Leeuwenhoek (1632–1723), he saw ‘aggregated microbes in the “scurf of the teeth” and “particles scraped off his tongue”’ (Hølby, 2017).

The importance of biofilm infections in medicine was first recognised in the early 1970s ‘by the observation of heaps of Pseudomonas aeruginosa cells in sputum and lung tissue from chronically infected cystic fibrosis patients’ (Hølby, 2017).

Research attempts to identify new antimicrobial agents that kill micro-organisms in biofilms more effectively than existing antibiotics: designing drugs that prevent microbial adhesion or disrupt intercellular communication; developing biofilm dispersants; and ‘combining agents with different mechanisms of action’ (Stewart, 2015).

Biofilms allow bacterial growth on abiotic surfaces and the health implications of this ability were underlined when Belfast Health Trust took possession of a five-storey maternity hospital in March 2024, but high concentrations of Pseudomonas aeruginosa were discovered in water pipe outlets ‘a month later after a four-week operating exercise. Responding to a Freedom of Information request, the Trust said pseudomonas has been detected in several of its buildings since 2013 but declined to detail any impact on patients' (BBC News, 2024).