Biological effects of essential oils and extracts
S. Moslemi; N. Kashef
Abstract
Bacterium Pseudomonas aeruginosa is an opportunistic human pathogen and one of the most important causes of nosocomial infections in a wide range of immunocompromised patients including those with malignancies, cystic fibrosis, and burns. This bacterium produces many virulence factors and is highly resistant ...
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Bacterium Pseudomonas aeruginosa is an opportunistic human pathogen and one of the most important causes of nosocomial infections in a wide range of immunocompromised patients including those with malignancies, cystic fibrosis, and burns. This bacterium produces many virulence factors and is highly resistant to lots of common antibiotics due to its biofilm formation. The production of many virulence factors in this bacterium is under the control of quorum sensing systems (QS). The QS is an attractive target for the development of novel therapeutics. Eugenol is the major component of clove (Eugenia caryophylata) oil. The previous studies have shown its antibacterial activities. This study aimed to determine the in vitro anti-QS activity of eugenol on QS-regulatedbiofilm formation and virulence factors production in P. aeruginosa strains. The minimum inhibitory concentration (MIC) of eugenol was determined against two strains of this bacterium ATCC 27853 and PAO1, and three clinical isolates. Then the effect of eugenol on bacterial proliferation was determined by monitoring the growth curve. The biofilm formation, the production of exopolysaccharide (EPS), pyocyanins, rhamnolipids, the motility of swimming, swarming, and twitching were evaluated after the eugenol treatment. The MICs against two strains of the bacterium ATCC 27853 and PAO1 were obtained 0.3% and 0.6% (v/v), respectively. Different concentrations of eugenol (≤0.15%) significantly reduced the production of virulence factors including pyocyanin and rhamnolipid. The biofilm formation, EPS production, and swarming, swimming, and twitching motility were also reduced after the eugenol treatment. In general, according to the results of this study, the use of eugenol, as a potent QS inhibitor and anti-biofilm agent, could be an effective therapeutic strategy against P. aeruginosa infections.
N. Saidi; H. Saderi; E. Taghian; F. Sefidkon; I. Rasooli; R. Mohammad Salehi; P. Owlia
Abstract
Pseudomonas aeruginosa is one of the most common opportunistic bacteria in nosocomial infections, which has a significant resistance to antimicrobials. Due to the restrictions in the use of antibiotics, the tendency to replace them with natural products has increased. In this study, the antimicrobial ...
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Pseudomonas aeruginosa is one of the most common opportunistic bacteria in nosocomial infections, which has a significant resistance to antimicrobials. Due to the restrictions in the use of antibiotics, the tendency to replace them with natural products has increased. In this study, the antimicrobial effect of four species of Satureja essential oils (S. mutica, S. bachtiarica, S. rechingeri and S. khuzestanica) on virulence factors of P. aeruginosa was evaluated. The minimum inhibitory concentration of Satureja essential oils was determined by microdilution broth method against standard strains of P. aeruginosa including PAO1 and 8821M. In the following, the effect of sub-minimum inhibitory concentrations (sub-MIC) of essential oils was investigated on virulence factors of this bacterium including motility, biofilm formation and alginate, elastase, and alkaline protease production of these two strains. All four Satureja essential oils had antimicrobial effects against the standard strains of P. aeruginosa, and also sub-MIC concentrations of the essential oils significantly reduced the virulence factors production of these strains. In this study, the suitable antagonistic effects of Satureja essential oils were observed against P. aeruginosa standard strains. By further study, these essential oils can be used as an antimicrobial compound against this bacterium.
L. Moein Najafabadi; P. Owlia; S. Mousavi Nadoushan; I Rasooli; H. Saderi; F. Sefidkon; M.H. Salari
Abstract
Pseudomonas aeruginosa is an important opportunistic pathogen with many virulence factors. In this study, the effects of sub-MICs of three essential oils on alginate production, biofilm formation, swimming, twitching and adhesion in P. aeruginosa have been evaluated. The plants (Zataria multiflora Boiss.,Myrtus ...
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Pseudomonas aeruginosa is an important opportunistic pathogen with many virulence factors. In this study, the effects of sub-MICs of three essential oils on alginate production, biofilm formation, swimming, twitching and adhesion in P. aeruginosa have been evaluated. The plants (Zataria multiflora Boiss.,Myrtus communis L. and Eucalyptus camaldulensis Dehnh.) were dried in shadow and were hydro-distilled for 90 minutes. Minimal inhibitory concentrations (MIC) of essential oils were determined by macrodilution method. The virulence factors in the mucoid P. aeruginosa 8821M were determined in the presence of sub-MICs (1/2, 1/4 and 1/8) of essential oils. The MICs of essential oils against P. aeruginosa for Z. multiflora, M. communis and E. camaldulensis oils were obtained 64, 64 and 64µg/mL, respectively. The results showed that all oils at 1/2 and 1/4 MICs significantly reduced all tested virulence factors. At 1/8 MICs, Z. multiflora oil had significantly reduced virulence factors, but another oils had different effects. This study showed that sub-MIC levels of Z. multiflora, M. communis and E. camaldulensisessentialoils affected alginate production, biofilm formation, swimming, twitching and adhesion in P. aeruginosa and it is probable to use these medicinal plants for treating.
P. Owlia; H. Saderi; S.A. Tabatabaei Nezhad; M. Naseri; M.B. Rezaee
Volume 20, Issue 2 , July 2004, , Pages 171-180
Abstract
Pseudomonas aeruginosa is important opportunistic pathogen and to produce widespread infections by numerous virulence factors. Treatment of Pseudomonas infection is very difficult, because resistance to antibiotics is increasing. The purpose of this study was evaluation of antimicrobial effects of extract ...
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Pseudomonas aeruginosa is important opportunistic pathogen and to produce widespread infections by numerous virulence factors. Treatment of Pseudomonas infection is very difficult, because resistance to antibiotics is increasing. The purpose of this study was evaluation of antimicrobial effects of extract of Ruta graveolens on P. aeruginosa (28852ATCC). MIC and MBC of extract were evaluated and change of number of bacteria in the present of 1%, 2%, 4% and 8% of R. graveolens extract was compared with the change of number of bacteria in the present of 0.00078 and 0.00156mg/ml gentamicin. The results showed that MIC and MBC of R. graveolenc extract were equal of 10% of concentration. Comparison of change of number of bacteria had shown that the effect of 8% of extract of R. graveolens after 4 h is equal of 0.00156mg/ml gentamicin after 2h. According to the results we can probably to use of R. graveolens against Pseudomonas infections, but we need more study and research.
