Zingerone inhibit biofilm formation and improve antibiofilm efficacy of ciprofloxacin against Pseudomonas aeruginosa PAO1

Abstract

Multidrug resistant opportunistic pathogen Pseudomonas aeruginosa produces surface-associated communities called biofilms, which protect pathogen by forming a complex permeability barrier for antibiotics and immune cells. Biofilm formation contributes to persistent and chronic infections caused by P.aeruginosa. Extensive use of antibiotics to treat biofilm associated infections has culminated in the emergence of multiple drug-resistant strains. Hence novel strategies are urgently required to address this issue. Since phytochemicals are valuable source of antibacterial agents, these can be explored for antibiofilm activity. Therefore, the present study was planned to evaluate the inhibition of biofilm formation in presence of zingerone alone and its ability to increase the susceptibility of the pathogen to ciprofloxacin. Scanning electron microscopy of catheter surface showed thinner biofilm of P.aeruginosa in presence of zingerone. Evaluation of motility phenotypes indicated significant reduction (p < 0.05) in swimming, swarming and twitching motility. Further, biofilm was inhibited and eradicated in presence of zingerone alone and in combination with ciprofloxacin. Highly significant inhibition (p < 0.001) was observed when phytochemical and antibiotic were used as adjunct therapy. These findings prove zingerone as potential phytotherapeutic agent which in future can be employed to formulate preventive strategies against biofilm associated infections caused by P.aeruginosa.

Keywords: Antibiotic resistance; Biofilm; Ciprofloxacin; Motility phenotype; Zingerone.