GSE210382
BosR: a novel biofilm-specific regulator in Pseudomonas aeruginosa
Biofilms are the most common cause of bacterial infections in humans and notoriously hard to treat due to their ability to withstand antibiotics and host immune defenses. To overcome the current lack of effective antibiofilm therapies and guide future design, the identification of novel gene targets is crucial. In this regard, transcriptional regulators have been proposed as promising targets for antimicrobial drug design, since they simultaneously affect multiple genes, typically lack human orthologs, and can be inactivated by small molecules that prevent dimerization. Therefore, a Transposon insertion sequencing approach was employed to systematically identify regulatory genes phenotypically affecting biofilm growth in Pseudomonas aeruginosa PA14. A screen of a pool of 300,000 transposon insertion mutants identified 349 genes involved in biofilm growth on hydroxy apatite, including 47 regulators. Detection of 19 regulatory genes participating in well-established biofilm pathways validated the results. An additional 28 novel prospective biofilm regulators suggested the requirement of multiple one-component transcriptional regulators. Defect phenotypes were confirmed for five one-component transcriptional regulators PA14_43720, PA14_56430, PA14_36180, arsR and merD as well as the protein kinase yeaG, which have not been implicated in biofilm growth before. Promisingly, the transcriptional regulator PA14_43720 displayed a conserved role in biofilm growth since its ortholog in P. aeruginosa strain PAO1 was also required for biofilm growth. Overall, our results highlighted that the gene network driving biofilm growth is complex and involves regulators beyond the primarily studied groups of two-component systems and cyclic diguanylate signaling proteins. Overall design: TnSeq experiments on PA14 grown under different conditions, namely planktonic and biofilm, for 96 hours. Additionally, the TnSeq pool was characterized at T0 as a reference condition. Each condition included three biological replicates.