Evaluation of Anti-bacterial and Anti-quorum Sensing Potential of Essential Oils Extracted by Supercritical CO₂ Method Against Pseudomonas aeruginosa

Abstract

Pseudomonas aeruginosa is an important opportunistic pathogen causing widespread infections by numerous virulence factors. The present investigation was to evaluate the antimicrobial and anti-quorum sensing (anti-QS) activities of essential oils (EOs) from Cuminum cyminum, Zingiber officinale, Myristica fragrans, Syzygium aromaticum, Cinnamomum verum, Rosmarinus officinalis, and Curcuma longa against the wild strain of Chromobacterium violaceum CV12472, clinical strain of P. aeruginosa (MM-1) and P. aeruginosa PAO1. All the EOs have shown antimicrobial activity against CV12472. Among these, five EOs namely C. cyminum, S. aromaticum, C. verum, R. officinalis and C. longa have shown anti-QS activity as evidenced by inhibition of violacein production. S. aromaticum and C. verum have shown promising anti-QS activity at very low concentration of 0.006 %, v/v and 0.01 %, v/v respectively. The study also analysed against the PAO1 and P. aeruginosa (MM-1). The MM-1 strain was resistant to the tested broad-spectrum β-lactam and cephalosporin antibiotics. Among the seven EOs, MICs of S. aromaticum and C. verum were found to be 0.78 %, v/v and also they have shown anti-QS activities at 0.39 %, v/v and 0.097 %, v/v as confirmed by the decreased pyocyanin production in the MM-1 strain. C. verum and S. aeromaticum inhibited the swarming motility of the tested P. aeruginosa strains. The present study suggested that the active principle from essential oils can be used as efficient herbal medicine for blocking the QS against the resistant clinical strains of P. aeruginosa.

Keywords:

• Pseudomonas aeruginosa
• Chromobacterium violaceum CV12472
• Essential oils
• Violacein
• Pyocyanin