Amineh Sadat Tajani - Pharmaceutical Control Department, School of Pharmacy, Mashhad University of Medical Sciences, Mashhad, Iran
Elham Jangi - School of Pharmacy, Mashhad University of Medical Sciences, Mashhad, Iran
Razieh Ghodsi - Medical Chemistry Department, School of Pharmacy, Mashhad University of Medical Sciences, Mashhad, Iran
Vahid Soheili - Pharmaceutical Control Department, School of Pharmacy, Mashhad University of Medical Sciences, Mashhad, Iran
Bibi Sedigheh Fazly Bazzaz - Pharmaceutical Control Department, School of Pharmacy, Mashhad University of Medical Sciences, Mashhad, Iran

Introduction and Objectives: The Pseudomonas aeruginosa quorum-sensing (QS) is a complicated network of genome-wide regulation, activated in response to bacterial population density. One of the main components is the auto-regulating Pseudomonas quinolone signal (PQS) system that controls the construction of several virulence factors and biofilm-related factors. Therefore, inhibiting the QS circuitry is a promising approach for anti-virulence agents with much lowered resistance development possibility. Materials and Methods: Here, we tested a member of NSAID (Non-Steroidal Anti-Inflammatory Drugs) family, ketoprofen, in silico and in vitro as an anti-quorum sensing compound due to its chemical structure similarity to the natural P. aeruginosa signaling molecules (PQS). Its effect was assessed with colorimetric method by spectrophotometer against biofilm formation and several virulence factors production, besides evaluation of the synergistically effect with tobramycin. Moreover, its influence on the other major QS pathways (las and rhl) was also depicted. Results: Our study revealed that ketoprofen decreased the expression of virulence factors including pyocyanin, protease, pyoverdine and also lactonic compounds, inhibited the biofilm formation and reduced the effective dose of tobramycin against P. aeruginosa PAO1. Conclusion: As it was anticipated, ketoprofen is a quorum quenching compound and could be utilize in order to attenuate Pseudomonas aeruginosa pathogenicity.

Pseudomonas aeruginosa, quorum-sensing, ketoprofen, biofilm, virulance factor