Effect of novel non-coding small RNA111 of Pseudomonas aeruginosa on bacterial virulence.

Pseudomonas aeruginosa is an important gram-negative pathogen that often causes skin, respiratory, and bloodstream infections. The virulence of P. aeruginosa is regulated by sRNAs through a complex network, which is still incompletely understood. This study employed transcriptome sequencing (RNA-Seq) to screen sRNA 111, and real-time quantitative PCR was conducted for validation. In addition, an overexpression strain of sRNA111 was constructed and the effects of overexpression of sRNA111 on virulence factors such as biofilm formation, pyocyanin, swarming motility, inflammatory factors, and biofilm-associated factors were analyzed. The results revealed that sRNA111 might be closely related to the formation of P. aeruginosa biofilm. Compared to the vector, sRNA111 was found to enhance P. aeruginosa biofilm formation while also suppressing swarming motility, invasive ability, and adhesion capability. Meanwhile, sRNA111 up-regulated the expression of biofilm-related genes, such as Anr, pel family, polB, recA, etc., more significantly in the biofilm environment compared with the wild strain. In addition, sRNA111 effectively promoted the expression of inflammatory factors in the biofilm environment compared with the planktonic environment. These results implied that sRNA111 regulates the formation of P. aeruginosa biofilm and other virulence factors and further modulates the process of infection immunity.