Molecular Mechanisms of DNase Inhibition of Early Biofilm Formation Pseudomonas aeruginosa or Staphylococcus aureus: A Transcriptome Analysis

In vitro studies have shown that DNase can inhibit biofilm formation of Pseudomonas aeruginosa and Staphylococcus aureus. However, the underlying molecular mechanisms are not well understood. The aim of this study was to investigate the mechanism of DNase I of inhibition the early biofilm formation of P. aeruginosa or S. aureus on a transcriptional level. We used an RNA-sequencing transcriptomic approach to investigate the underlying mechanism of the inhibition of early biofilm formation of DNase I. A total of 1171 differentially expressed genes (DEGs) of P. aeruginosa and 1016 DEGs of S. aureus enriched in a variety of biological processes and pathways were identified. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analysis showed that, the DEGs were mainly involved in two-component system, biofilm formation, and flagellar assembly of P. aeruginosa, and in biosynthesis of secondary metabolites, microbial metabolism in diverse environments, and biosynthesis of amino acids of S. aureus. The transcriptional data were validated by quantitative real-time polymerase chain reaction (RT-qPCR), and the results showed that the expression profiles of 22 major genes were consistent with transcriptome analysis. Our results suggested that DNase I may inhibit early biofilm formation by downregulating gene expression of flagellar assembly and type VI secretion system of P. aeruginosa, and downregulating gene expression of capsular polysaccharide and amino acids metabolism of S. aureus. We believe that our study offers insights into the mechanisms of DNase treatment-based inhibition of early biofilm formation of P. aeruginosa or S. aureus.