Unveiling the role of <i>srbA</i> sRNA in biofilm formation by regulating <i>algU</i>, <i>mucA</i>, <i>rhlA</i>, and <i>rsmA</i> in <i>Pseudomonas aeruginosa</i>

The survival and increasing antimicrobial resistance of various bacteria, including clinically relevant opportunistic pathogen, Pseudomonas aeruginosa, largely depends on their biofilm architectural strength, that makes a challenge to eradicate it. Small RNAs (sRNAs) have been identified as the key modulators in regulating the expression and function of different transcriptional regulators, and the components of regulatory networks involved in bacterial biofilm formation. This study was focused to identify the regulatory role of the srbA sRNA in controlling biofilm formation in P. aeruginosa. srbA was found to be upregulated in both substratum-attached and colony biofilms compared to planktonic growth conditions. Further analysis revealed that srbA overexpressing strain produced more biofilm, whereas a significant reduction in biofilm formation was noted due to srbA deletion. Interestingly, it was also predicted from the study that srbA might regulate the expression of AlgU/MucA, the sigma and anti-sigma factor, involved in biofilm developmental network. Additionally, srbA showed possible interference on the expression of two other important biofilm regulatory genes, rhlA and rsmA. Overall, this research highlights the critical role of srbA sRNA as a central regulator of biofilm formation, and possibly the pathogenicity of P. aeruginosa. These findings might offer potential avenues for developing targeted therapeutic strategies to mitigate biofilm-related infections caused by P. aeruginosa.