Biofilms are a type of bacterial community caused by cells adhering to a surface, multiplying and embedding themselves in a matrix that they secrete. This ability to produce a matrix has likely evolved because it helps protect bacteria from harsh conditions and has been shown to increase bacteria’s resistance to antimicrobial products. Thus, biofilms can contain harmful bacteria that are difficult to remove.
Biofilms lead to serious hygiene problems in the medical field and in food industry because they affect the quality and safety of our food. The most common method of biofilm prevention is cleaning and disinfecting surfaces before bacteria have the chance to firmly attach. However, cleaning procedures do not penetrate the biofilm matrix, so they do not kill the cells and need to be performed frequently to prevent attachment. Using antimicrobials as disinfectants selects for resistant bacteria through natural selection (Simoes 2010).
It is imperative that different strategies to destroy biofilms are explored. In our project, we use the host bacteria Caulobacter crescentus to secrete proteins known to inhibit biofilm formation and destroy preexisting biofilm: DspB and Esp.
Genetically engineering Caulobacter to secrete proteins that inhibit biofilm formation and break down biofilm avoids the issue of antimicrobials selecting for resistant bacteria because these proteins do not kill the cells, but rather target the biofilm itself. With the use of proteins, selection for mutants will be indirect and therefore slower and less likely to occur. In addition, no manual labor is required to remove biofilms with the use of proteins. Active manual removal of biofilms works, but it needs to be done so frequently that it is inconvenient and labor intensive. We propose that these engineered Caulobacter be included in regular cleaning products in the hopes that the proteins they secrete will break down preexisting biofilm.