The LiaFSR-SpxA2 regulatory axis governs bile salt resistance and virulence in group B Streptococcus

transcription in response to bile salt stress, defining a novel LiaFSR-SpxA2 regulatory pathway playing a role in bile salt resistance in GBS. Importantly, this LiaFSR-SpxA2 regulatory axis plays a role in colonization and virulence in a tilapia infection model. Collectively, our work defines the LiaFSR-SpxA2 axis as a central regulator of membrane homeostasis that is critical for GBS to overcome innate host defenses, thereby facilitating intestinal colonization and the progression to systemic disease.