Biofilm-mediated antibiotic tolerance in bacterial pathogens: Integrated molecular networks and novel therapeutic avenues

The stable structure of biofilms and the characteristics of the bacteria within them make biofilms an important barrier for bacteria to resist external stress, and a key factor contributing to the difficulty of eradicating clinical infections. This article reviews the multi-stage formation process of biofilms, the various mechanisms of antibiotic tolerance and resistance (such as physical barriers, metabolic adaptations, horizontal gene transfer, etc.), as well as the integrated regulatory roles of molecular networks like quorum sensing (QS) and cyclic diguanosine monophosphate (c-di-GMP). These multiple protective mechanisms in biofilms compose a closed "structure-function" loop system. In the past few years, the emergence of new anti-biofilm intervention approaches (matrix-degrading enzymes, phage therapy, nanomaterials, gene editing, etc.) revealed the possibility to break the limitations of conventional antibiotics by compromising structural integrity or interfering with signaling pathways, providing new ideas for drug-resistance infection control.