Role of rgsA in Oxidative Stress Resistance in Pseudomonas aeruginosa.

Pseudomonas aeruginosa is a common opportunistic pathogen that causes infections in vulnerable patients including those with metabolic disorders, hematologic diseases, and malignancies, and in those who have undergone surgery. In addition, P. aeruginosa exhibits high intrinsic resistance to numerous antibiotics and tends to form biofilms rendering it even more refractory to treatment. Among the mechanisms used by P. aeruginosa to adapt to environmental stresses are those involving small regulatory RNAs (sRNAs), which are 40-500 nucleotides long and are ubiquitous in bacteria. sRNAs play important regulatory roles in various vital processes in diverse bacteria, with their quantity and diversity of regulatory functions exceeding those of proteins. In this study, we show that deletion of the sRNA, rgsA, decreased the growth rate of P. aeruginosa. Furthermore, ΔrgsA P. aeruginosa exhibited decreased ability to resist the stress induced by exposure to different concentrations and durations of peroxides in both planktonic and biofilm growth modes compared with the wild-type strain. These results highlight the role of rgsA in the defense of P. aeruginosa against oxidative stress.