Adaptation for <i>Staphylococcus aureus</i> to hosts via insertion mutation in the accessory gene regulator <i>agrC</i> gene: decreased virulence and enhanced persistence capacity

In clinical antimicrobial therapy, bacterial strains often develop resistance to antimicrobial agents. Additionally, mutations in their gene regulatory networks can increase their persistence, especially in immunocompromised patients. This study identified an insertion mutation in the accessory gene regulator, <i>agrC</i> gene, carried by a <i>Staphylococcus aureus</i> strain isolated from the blood of a febrile patient, leading to the functional loss of AgrC. Further research revealed that despite the reduced virulence of the mutated strain, it significantly bolstered the capacity to adapt and endure within the host during prolonged infections. This was evidenced by increased adhesion and biofilm formation capabilities, development of antimicrobial tolerance, and decreased ATP levels linked to persistence. Therefore, monitoring these mutations in <i>S. aureus</i> is crucial clinically, as they can complicate treatment strategies.