Maryam Pezeshki Najafabadi, Maryam Mohammadi-Sichani, Mohammad Javad Kazemi, Mohammad Sadegh Shirsalimian, Majid Tavakoli
Biofilm formation of Pseudomonas aeruginosa makes up a sizeable proportion of hospital-acquired infections, because bacteria in biofilms can resist antibiotic treatment. The extracellular polymeric substance of P. aeruginosa biofilm is an imprecise collection of extracellular polysaccharides, proteins and microbial cells. Rumex dentatus belongs to polygonaceae family. This family can be found in Middle East. The aim of this present study was to assess the effect of various concentrations of methanol extract of Rumex dentatus on biofilm formation of Pseudomonas aeruginosa after 48 h and 72 h. In this experimental study we collected Rumex dentatus from Khoramabad, Iran. The working extracts were 250, 125, 62.5, 31.25, 15.62, 7.81, 3.9, 1.95, 0.97 and 0.48 mg/ml. We used microtiter plate method to grow P. aeruginosa biofilm and assess the antibiofilm activity of plant extract. The composition of methanol extract obtained from Rumex dentatus was studied by gas chromatography. The minimum biofilm inhibitory concentration (MBIC) for P. aeruginosa found to be 250 mg/ml. GC-MS analyses indicated that these fractions contained a variety of compounds including Bicyclo (3.1.1) heptan- 3 -one, 2, 6, 6- trimethyl, Bicyclo (3.1.1) heptan, 6, 6- dimethyl and Eucalyptol. There were consequential correlations between antibiofilm activity and the concentration of extracts after 48 and 72 h.