BatR: A novel regulator of antibiotic tolerance in Pseudomonas aeruginosa biofilms

Pseudomonas aeruginosa is a multidrug-resistant opportunistic human pathogen. Chronic infections are associated with biofilms, conferring resistance to antibiotics and complicating treatment strategies. This study focuses on understanding the role of the uncharacterized gene PA3049, upregulated under biofilm conditions. In the context of P. aeruginosa biofilms, PA3049 plays a role in withstanding antimicrobial challenges both in vitro and in clinically validated infection models. Under sub-inhibitory concentrations of antibiotic, the deletion of PA3049 resulted in reduced pyocyanin production and altered abundance of enzymes controlling denitrification, pyoverdine, and hydrogen cyanide biosynthesis. Notably, PA3049 directly interacts with two kinases implicated in stress response, inactivating their active sites. Renamed as the Biofilm antibiotic tolerance Regulator (BatR), PA3049 is a key player in P. aeruginosa biofilm maintenance and antimicrobial tolerance. These findings contribute to understanding the complex bacterial lifestyle in biofilms, shedding light on a previously uncharacterized gene with significant implications for combating multidrug-resistant infections. IMPORTANCEP. aeruginosa is a multidrug-resistant ESKAPE pathogen that causes chronic biofilm-based infections and is a leading cause of mortality in cystic fibrosis (CF) patients. Understanding the molecular mechanisms underlying P. aeruginosa biofilm resilience and antimicrobial resistance is crucial for developing effective therapeutic interventions. This study focuses on characterizing the gene PA3049, now known as the biofilm antibiotic tolerance Regulator (batR). BatR plays a central role within P. aeruginosa biofilms, orchestrating adaptive responses to antimicrobial challenges. Our work sheds light on the contribution of batR to biofilm biology and its relevance in lung infections, where subinhibitory antibiotic concentrations make BatR pivotal for bacterial survival. By advancing our understanding of P. aeruginosa biofilm regulation, this study holds significant promise for the development of innovative approaches against biofilm-associated infections to mitigate the growing threat of antimicrobial resistance.