„BaKillus“ – Engineering a pathogen-hunting microbe

Increasing bacterial resistance to classical antibiotics remains a serious threat and urges the development of novel pathogen-killing strategies. Exploiting bacterial communication mechanisms such as quorum sensing is a promising strategy to specifically target certain pathogens. The major aim of this project is the introduction of a genetic circuit enabling Bacillus subtilis to actively detect, attach to, and eventually kill Staphylococcus aureus and Streptococcus pneumoniae. Initially, we will introduce the autoinducer-sensing two-component systems of S. aureus and S. pneumoniae into B. subtilis. to create a pathogen-detecting strain. By utilizing quorum sensing-dependent promoters, we will then trigger pathogen-killing strategies like the production of antimicrobial peptides or biofilm degradation. As a safety measure a delayed suicide-switch guarantees non-persistence of genetically modified B. subtilis in the absence of pathogens. We envision the use of BaKillus as a smart, cheap and simple-to-use medical device for diagnostics and targeted treatment of multiresistant superbugs.