جستجوی مقالات مرتبط با کلیدواژه « Minimum Bactericidal Concentration » در نشریات گروه « پزشکی »

To fight food pathogenic microorganisms, it is necessary to search for new antimicrobial compounds. Marine sponges are potential sources of new antimicrobial agents due to secondary metabolites. This study investigated the antibacterial effect of methanolic extract of H. implexa sea sponge collected from Chabahar.

This study investigated at two concentrations of 3 and 5 mg/ml of the methanolic extract against two foodstuffs bacteria of Escherichia coli and Pseudomonas aeruginosa by disc diffusion sensitivity test, minimum inhibitory concentration (MIC), and minimum bactericidal concentration (MBC). Statistical analysis was done with One-Way Analysis of Variance and comparison of means with Tukey's test.

According to the results, the highest effects were obtained on concentrations of 5 mg/ml with 11.03±1.7 and 12.033±0.702 mm diameters of non-growth halos for Escherichia coli and Pseudomonas aeruginosa, respectively, and showed significant difference by Gentamycin (p<0.05). The minimum inhibitory concentration of H. impelxa sponge organic extract in Escherichia coli and Pseudomonas aeruginosa was observed at 1 and 3 mg/ml concentration, respectively. Minimum bactericidal concentration observed in Escherichia coli at 3 mg/ml concentration and no effect on Pseudomonas aeruginosa strain observed.  

 Based on the results, H. impelxa sea sponge extract has a good antibacterial effect on pathogenic bacteria of Escherichia coli and Pseudomonas aeruginosa. Therefore, the extract of this sponge can be further studied for use in food packaging.

Removing pharmaceutical substances from wastewater is essential due to their high stability and toxic effects on humans and other living organisms before they enter the environment. Green-synthesized nanocomposites possess significant abilities to degrade pharmaceutical compounds and exhibit antibacterial effects. Therefore, this study aimed to investigate the photocatalytic and antibacterial effects of a green-synthesized magnetic nanocomposite.

In this experimental study, the photocatalytic process was conducted on a solution containing tetracycline to examine the photocatalytic capabilities of the synthesized nanocomposite. The antibacterial effect of the nanocomposite was also assessed on Gram-negative and Gram-positive bacteria using the broth dilution method.

The results of the tetracycline antibiotic photocatalytic degradation test showed a removal rate of 87.95% under the following conditions: pH = 7, nanocomposite dose = 0.26 g/L, contact time = 54 min, and initial TC concentration of 10 mg/L. The minimum inhibitory concentration (MIC) of the synthesized nanocomposite was determined to be 1.25 mg/mL for Staphylococcus aureus bacteria and 5 mg/mL for Escherichia coli and Klebsiella bacteria. The minimum bactericidal concentration (MBC) against Escherichia coli and Staphylococcus aureus bacteria was found to be 5 mg/mL.

In addition to the inhibitory and bactericidal capabilities of the manganese-ferrite-based nanocomposite, it can be utilized as a powerful catalyst for the degradation of tetracycline antibiotics in aqueous solutions

Marrubium plants have long been used as a traditional medicine in treatment of diseases. The aim of this study was to evaluate the antimicrobial effects of Marrubium parviflorum extracts and fractions.

In this experimental study, solvent extraction from aerial parts of the plant was done by Soxhlet method. The antimicrobial effect of the extracts was evaluated on six strains of gram-positive bacteria, four strains of gram-negative bacteria, and one strain of fungus. Also, effective extracts were fractionated by various chromatographic methods and their antimicrobial effects were investigated.

Chloroform extract of M. parviflorum was found to be effective against Micrococcus luteus, Staphylococcus epidermidis, and Bacillus cereus with a growth inhibition zone diameter (DIZ) of 16.6, 14.6, and 11.6 mm, respectively, and MBC 100 mg/ml. Methanolic extract also showed considerable antimicrobial effects against Proteus mirabilis and Psudomonas aeruginosa. Among the fractions obtained, 10%, 20%, 40%, and 60% fractions of the chloroform extract and 20% and 40% fractions of the methanolic extract showed the highest antimicrobial effect. The superior values ​​of MBC and DIZ in fractions indicate the condensation of certain antimicrobial compounds in some fractions and higher sensitivity of gram-positive bacteria compared with gram-negative bacteria.

Among the extracts studied, the chloroform and the methanolic extracts of M. parviflorum exhibited the strongest antimicrobial effect and Micrococcus luteus was the most sensitive microorganism.

Emergence of resistance to antimicrobial medications has led to the use of medicinal herbs for the treatment of infections. In this regard, this study aimed to investigate the antimicrobial effects of three extracts (i.e., ethanol/methanol, water, and acetone) of Melissa officinalis and Impatiens walleriana on four species of bacteria.

The selected bacteria, including Staphylococcus aureus, Escherichia coli, Bacillus subtilis, and Enterococcus were first activated in the culture medium of broth neutrinos. Subsequently, a suspension equivalent to half McFarland was prepared from the activated bacteria. Antimicrobial activities of the extracts were evaluated by microdilution broth and disc diffusion methods to determine the minimum inhibitory and bactericidal concentration values.

Based on the results, the Impatiens walleriana acetone extract had the most antimicrobial effects on all four species of bacteria. Moreover, acetone and ethanol/methanol extracts of Impatiens walleriana had more antimicrobial effects on E. coli than ethanol/methanol and water extracts of Melissa officinalis. In case of S. aureus, the water and ethanol/methanol extracts of both plants had almost the same minimum bactericidal and inhibitory concentration values. Finally, it can be said that all three Melissa officinalis extracts had better antimicrobial effects on Enterococcus and B. subtilis than the three Impatiens walleriana extracts.

Among all extracts, acetone extract of Impatiens walleriana showed the highest antibacterial property. Given the results and the increasing resistance of bacteria to antibiotics, it is suggested to use antibacterial compounds of plants for the treatment of infectious diseases; nevertheless, further studies should be carried out in this regard.