Biofilms are communities of bacteria that live in close proximity to each other and are surrounded by a protective layer of self-produced extracellular material. This material, composed of DNA, proteins, and polysaccharides, shields the bacteria from environmental stresses and antibiotics, making them difficult to treat.
In a study published in the journal Nature Communications, the Berkeley researchers used atomic force microscopy (AFM) to visualize and measure the mechanical properties of the biofilms produced by *Pseudomonas aeruginosa*, a bacterium that causes infections in the lungs and urinary tract. They discovered that the biofilm material had a highly structured architecture composed of nanoscale fibers that were densely packed together. This dense packing contributed to the biofilm's stiffness and resistance to mechanical forces.
The researchers also identified two proteins involved in the assembly and maintenance of the biofilm. One protein, called PslG, was required for the formation of the nanoscale fibers, while the other protein, called Pel, was necessary for the dense packing of the fibers. When the researchers genetically engineered *P. aeruginosa* to lack either of these proteins, the bacteria produced biofilms that were less stiff and more susceptible to antibiotics.
These findings suggest that PslG and Pel are promising targets for the development of new antibiotics that can disrupt the structure of biofilms and kill the bacteria within them. The researchers are now working to design and test new antibiotics based on these proteins.
