https://www.selleckchem.com/products/cmc-na.html is considered a dangerous pathogen, as it causes many human diseases, besides that it is resistant to almost all types of antibacterial agents. So, new strategies to overcome infection have evolved to attenuate its virulence factors and inhibit its quorum-sensing (QS) activity. This study investigated the effect of tyrosol and EDTA as anti-quorum-sensing and antivirulence agents against PAO1. Anti-quorum activity of sub-minimum inhibitory concentrations (sub-MICs) of tyrosol and EDTA was tested using (CV 12,472) biosensor bioassay. Miller assay was used to assess the inhibition of QS signal molecules by β-galactosidase activity determination. Also, their effects on the production of protease, lipase, lecithinase, and motility were tested. The inhibitory effects of these molecules on QS regulatory genes and exotoxins genes expression were evaluated by real-time PCR. Tyrosol and EDTA at sub-MICs inhibited the production of violacein pigment. Both compounds inhibited QS molecules production and their associated virulence factors (protease, lipase, lecithinase, and motility) (P≤ 0.05). Besides, the expression levels of QS regulatory genes ( and ) and exotoxins genes ( ) were significantly reduced (P≤ 0.05). Both tyrosol and EDTA can be used to fight infection as anti-quorum-sensing and antivirulence agents at their sub-MICs. Both tyrosol and EDTA can be used to fight P. aeruginosa infection as anti-quorum-sensing and antivirulence agents at their sub-MICs. The last few decades have witnessed a rapid and global increase in multidrug-resistant bacteria (MDR) emergence. The aim of the current study is to isolate the most common MDR bacteria from dairy farms and beef slaughterhouses followed by evaluation of their antimicrobial resistance pattern and assessment of the antibacterial activity of AgNPs-H O as an alternative to conventional antibiotics. In this regard, 200 samples were collected from two dairy farms and one beef