Researchers have discovered toxic protein particles, shaped like umbrellas, that soil bacteria known as Streptomyces secrete to squelch competitors in their crowded microbial communities, especially others of their own species. What makes these newly detected antibacterial toxins different is that, unlike the Streptomyces' small-molecule antibiotics, umbrella toxins are large complexes composed of multiple proteins. They are also far more specific in the bacteria they target. They tend to go after bacteria that form branching filaments, an usual growth pattern among bacteria. The scientists are intrigued by the potential clinical clinical applications of this discovery, because they suspect the pathogens that cause tuberculosis and diphtheria might be sensitive to umbrella toxins.
