A compound produced by certain bacteria can break down biofilms — the tight-knit communities that some bacteria form on surfaces to protect themselves from antimicrobial attack.

Researchers in Massachusetts identified the compound, norspermidine, in Bacillus subtilis. Jon Clardy at Harvard Medical School in Boston, Richard Losick at Harvard University in Cambridge and their colleagues found that norspermidine acts in concert with a previously identified mix of amino acids to break down established biofilms of B. subtilis and to prevent biofilm formation in B. subtilis, Escherichia coli and Staphylococcus aureus. Using high-resolution microscopy, the researchers showed that norspermidine interacts directly with the sugar-based molecules that hold the biofilm together. Mutant bacterial strains unable to make both norspermidine and the amino acids form long-lived biofilms.

Synthetic chemicals modelled on norspermidine could be used to combat biofilms in industrial and medical settings, the authors say.

Cell 149, 693–707 (2012)