Broccoli Can Silence Bacteria

Research shows that natural isothiocyanates in broccoli can stop the chemical communication of Pseudomonas aeruginosa, which is implicated in cystic fibrosis and AIDS complications. Many microbes rely on this communication, called quorum sensing, to form biofilms or activate virulence. As antibiotic resistance rises in pathogens such as methicillin-resistant Staphylococcus aureus (MRSA) and P. aeruginosa, researchers are increasingly interested in combating bacterial pathogens by interfering with their chemical communication. Scientists at Ben-Gurion University of the Negev, in Israel, led by chemical biologist Michael M. Meijler found that two broccoli isothiocyanates—sulforaphane and erucin—interfere with P. aeruginosa chitchat by binding to important proteins involved in the communication machinery (MedChemComm, DOI: 10.1039/c2md20196h). Sulforaphane and erucin join a toolbox of bacterial conversation stoppers that may one day be used to fight pathogens. This is not the first time sulfur-rich compounds have been found to interfere with quorum sensing. Isothiocyanates and disulfides from horseradish and garlic have also been shown to block bacterial conversations. Meij­ler’s team notes that P. aeruginosa is not a common broccoli pathogen, but the related bacterium P. fluorescens is.