Monoterpene isolated from the essential oil of Trachyspermum ammi is cytotoxic to multidrug-resistant Pseudomonas aeruginosa and Staphylococcus aureus strains

Abstract INTRODUCTION: The aim of this study was to determine whether an herbal extract containing monoterpene exhibited activity against multidrug-resistant Staphylococcus aureus and Pseudomonas aeruginosa isolated from clinical infection samples. METHODS: The essential oil of Trachyspermum ammi (L.) Sprague ex Turrill (Apiaceae) fruit was extracted by hydrodistillation. Fruit residues were treated with hydrochloric acid and re-hydrodistilled to obtain volatile compounds. Compounds in the distilled oil were identified using gas-chromatography (GC) and GC-mass spectrometry (MS). The antibiotic susceptibility of all bacterial isolates was analyzed using both the disc diffusion method and determination of the minimum inhibitory concentration (MIC). The sensitivity of antibiotic-resistant isolates to essential oil was also determined by using the disc diffusion method and MIC determination. RESULTS: Of 26 clinical isolates, 92% were multidrug-resistant (MDR). Aromatic monoterpenes (thymol, paracymene, and gamma-terpinene) were the major (90%) components of the oil. Growth of S. aureus strains was successfully inhibited by the oil, with an inhibitory zone diameter (IZD) between 30-60mm and MIC <0.02&#956;L/mL. The oil had no antimicrobial activity against clinical isolates of P. aeruginosa; rather, it prevented pigment production in these isolates. CONCLUSIONS: This study revealed that the essential oil of Trachyspermum ammi, which contains monoterpene, has good antibacterial potency. Monoterpenes could thus be incorporated into antimicrobial ointment formulas in order to treat highly drug-resistant S. aureus infections. Our findings also underscore the utility of research on natural products in order to combat bacterial multidrug resistance

Monoterpene isolated from the essential oil of Trachyspermum ammi is cytotoxic to multidrug-resistant Pseudomonas aeruginosa and Staphylococcus aureus strains

INTRODUCTION: The aim of this study was to determine whether an herbal extract containing monoterpene exhibited activity against multidrug-resistant Staphylococcus aureus and Pseudomonas aeruginosa isolated from clinical infection samples. METHODS: The essential oil of Trachyspermum ammi (L.) Sprague ex Turrill (Apiaceae) fruit was extracted by hydrodistillation. Fruit residues were treated with hydrochloric acid and re-hydrodistilled to obtain volatile compounds. Compounds in the distilled oil were identified using gas-chromatography (GC) and GC-mass spectrometry (MS). The antibiotic susceptibility of all bacterial isolates was analyzed using both the disc diffusion method and determination of the minimum inhibitory concentration (MIC). The sensitivity of antibiotic-resistant isolates to essential oil was also determined by using the disc diffusion method and MIC determination. RESULTS: Of 26 clinical isolates, 92% were multidrug-resistant (MDR). Aromatic monoterpenes (thymol, paracymene, and gamma-terpinene) were the major (90%) components of the oil. Growth of S. aureus strains was successfully inhibited by the oil, with an inhibitory zone diameter (IZD) between 30-60mm and MIC <0.02μL/mL. The oil had no antimicrobial activity against clinical isolates of P. aeruginosa; rather, it prevented pigment production in these isolates. CONCLUSIONS: This study revealed that the essential oil of Trachyspermum ammi, which contains monoterpene, has good antibacterial potency. Monoterpenes could thus be incorporated into antimicrobial ointment formulas in order to treat highly drug-resistant S. aureus infections. Our findings also underscore the utility of research on natural products in order to combat bacterial multidrug resistance

Evaluation of Mannosidase and Trypsin Enzymes Effects on Biofilm Production of Pseudomonas aeruginosa Isolated from Burn Wound Infections.

Biofilm is an important virulence factor in Pseudomonas aeruginosa and has a substantial role in antibiotic resistance and chronic burn wound infections. New therapeutic agents against P. aeruginosa, degrading biofilms in burn wounds and improving the efficacy of current antimicrobial agents, are required. In this study, the effects of α-mannosidase, β-mannosidase and trypsin enzymes on the degradation of P. aeruginosa biofilms and on the reduction of ceftazidime minimum biofilm eliminating concentrations (MBEC) were evaluated. All tested enzymes, destroyed the biofilms and reduced the ceftazidime MBECs. However, only trypsin had no cytotoxic effect on A-431 human epidermoid carcinoma cell lines. In conclusion, since trypsin had better features than mannosidase enzymes, it can be a promising agent in combatting P. aeruginosa burn wound infections

Evaluation of Mannosidase and Trypsin Enzymes Effects on Biofilm Production of Pseudomonas aeruginosa Isolated from Burn Wound Infections

Biofilm is an important virulence factor in Pseudomonas aeruginosa and has a substantial role in antibiotic resistance and chronic burn wound infections. New therapeutic agents against P. aeruginosa, degrading biofilms in burn wounds and improving the efficacy of current antimicrobial agents, are required. In this study, the effects of α-mannosidase, β-mannosidase and trypsin enzymes on the degradation of P. aeruginosa biofilms and on the reduction of ceftazidime minimum biofilm eliminating concentrations (MBEC) were evaluated. All tested enzymes, destroyed the biofilms and reduced the ceftazidime MBECs. However, only trypsin had no cytotoxic effect on A-431 human epidermoid carcinoma cell lines. In conclusion, since trypsin had better features than mannosidase enzymes, it can be a promising agent in combatting P. aeruginosa burn wound infections

Antibiotic susceptibility of the P.aeruginosa isolates by disk diffusion method.

<p>Antibiotic susceptibility of the P.aeruginosa isolates by disk diffusion method.</p

Influence of the most effective concentrations of alpha-mannosidase (0.02 unit/ml), beta-mannosidase (0.02 unit/ml), citrate buffer (100mM, pH 4.5) and trypsin (0.75μg/ml) on the viability of A-431 human epidermoid carcinoma cell lines after 24h incubation.

<p>No enzyme column represents control positive of the test. The relative cell viability (%) was computed by this formula: [A]_test/ [A]_control ×100. The experiment was performed 2 times in duplicates. Error bars represent standard errors.</p

The effect of selected concentration of enzymes alpha-mannosidase, beta-mannosidase, and trypsin on the biofilms of <i>P</i>. <i>aeruginosa</i> isolates.

<p>The experiment was performed once in triplicates. Error bars represent standard errors.</p

The effects of combinations ofalpha-mannosidase and beta-mannosidase enzymes on the biofilm of <i>P</i>. <i>aeruginosa</i> strain 3.

<p>alpha- mannosidase and beta- mannosidase enzymes were used at the concentration of 0.02 unit/ml. Combination1: The wells were treated with 0.02 unit/ml of enzyme alpha- mannosidase and then after 1h were treated with the same concentration of enzyme beta- mannosidase. Combination 2: The wells were treated with 0.02 unit/ml of enzyme beta- mannosidase and then after 1h were treated with the same concentration of enzyme alpha-mannosidase. The test was conducted once in triplicates. Error bars represent standard errors.</p

Morphology of the A-431 human epidermoid carcinoma cell lines after 24h incubation with alpha-mannosidase, beta-mannosidase and trypsin enzymes.

<p><b>A.</b> alpha-mannosidase (0.02 unit/ml). <b>B.</b> beta-mannosidase (0.02 unit/ml). <b>C.</b> citrate buffer)100mM, pH 4.5). <b>D.</b> trypsin (0.75 μg/ml). <b>E.</b> Control positive (cells with no enzyme treatment). The experiment was performed 2 times in duplicates.</p

The combined effects of enzymes and ceftazidime on the MBEC values of ceftazidime.

<p>The combined effects of enzymes and ceftazidime on the MBEC values of ceftazidime.</p