Study the antimicrobial effects of artemisia santonica extract on some pathogenic bacteria

Background and aim: For rapid growing drug resistance among pathogenic microorganisms, it is essential to find new compounds with antimicrobial activity. Medicinal herbs application in traditional treatment for thousand years, make this natural compound to the best choice for antimicrobial studies. The aim of this study is to determine the antimicrobial activity of Artemisia against some important pathogenic bacteria. Material and Method: In the present study, antimicrobial activity of ethanolic and methanolic extracts of A. santonica against four pathogenic bacteria was evaluated. A. santonica dry powder was extracted with ethanol and methanol solvents in maceration method. Assessment of antimicrobial efficacies of extracts and MIC were conducted by disk diffusion manual and macro broth dilution method, respectively. Results: Both ethanolic and methanolic extracts could inhibit microorganism in this test. Staphylococcus aureus with MIC=1.56 mg/ml indicates more sensitive to the Artemisia. In addition, Bacillus cereus showed medium sensitivity. E.coli and Pseudomonas aeruginosa became involved in less sensitivity to the A. santonica extracts. Conclusion: The result of this study confirmed that A. santonica extracts were the best inhibitory effect on S. aureus. Then it can be concluded that by using herbal plant against antibiotics some antibiotic resistant problem can be resolved

Therapeutic effects of Crocus sativus: An overview of systematic reviews

Background and aims: Traditionally, plants have long been applied in the treatment of various diseases throughout the history of human life. The antimicrobial activity of plant extracts in the laboratory is studied on Gram positive and negative strains of human infectious agents. The aim of this study was to evaluate the antibacterial activity of Mentha longifolia against important human pathogens. Methods: This was an experimental study and no statistical method was used. The antimicrobial effect of ethanol extracts of Mentha longifolia were investigated on Salmonella typhimurium were determined using broth microdilution method. The broth microdilution method was used to determine the Minimal Inhibitory Concentration (MIC) and the Minimum Bactericidal Concentration (MBC). All tests were performed in Mueller Hinton broth supplemented with Tween 80 at a final concentration of 0.5%. Results: The results showed that the lowest MIC concentration was 5 mg/ml that 1 strain of Salmonella was inhibited. The highest and the lowest MBC values of extract were 40 and 10 mg/ml, respectively. Conclusion: Since the antibiotic resistant bacteria are increasing in the world, replacing the chemical and synthetic antibiotics with natural products is essential. It can be concluded from the results of this study that using herbal plant instead of antibiotics can resolve some antibiotic resistant problems

Antibacterial activity of Mentha longifolia against Salmonella typhimurium

Background and aims: Traditionally, plants have long been applied in the treatment of various diseases throughout the history of human life. The antimicrobial activity of plant extracts in the laboratory is studied on Gram positive and negative strains of human infectious agents. The aim of this study was to evaluate the antibacterial activity of Mentha longifolia against important human pathogens. Methods: This was an experimental study and no statistical method was used. The antimicrobial effect of ethanol extracts of Mentha longifolia were investigated on Salmonella typhimurium were determined using broth microdilution method. The broth microdilution method was used to determine the Minimal Inhibitory Concentration (MIC) and the Minimum Bactericidal Concentration (MBC). All tests were performed in Mueller Hinton broth supplemented with Tween 80 at a final concentration of 0.5%. Results: The results showed that the lowest MIC concentration was 5 mg/ml that 1 strain of Salmonella was inhibited. The highest and the lowest MBC values of extract were 40 and 10 mg/ml, respectively. Conclusion: Since the antibiotic resistant bacteria are increasing in the world, replacing the chemical and synthetic antibiotics with natural products is essential. It can be concluded from the results of this study that using herbal plant instead of antibiotics can resolve some antibiotic resistant problems

Screening and identification of biosurfactant producing marine bacteria from the Caspian Sea

Marine microorganisms have unique physiological properties and novel metabolites such as biosurfactant to live in extreme habitats (e.g. oil polluted environment). The aim of this study was to characterize some biosurfactant-producing bacteria collected from sediment and seawater samples from the Caspian Sea. These bacteria were isolated using enrichment method in ONR7a medium with crude oil as sole carbon source. Five screening tests were used for selection of the bacteria including hemolysis in blood agar, oil spreading, drop collapse, emulsification activity and bacterial adhesion to hydrocarbon test (BATH). The bacteria isolated were identified using molecular methods. Eighteen biosurfactant-producing bacteria (from 44 different colonies isolated) were selected and 9 isolates were screened as predominant biosurfactant producer belonging to Pseudomonas stutzeri (Strain S1-4-2), P. balearica (Strain S1-4-1), Pseudomonas sp. (Strain S2-1), P. stutzeri (Strain R3-2), P. chloritidismutans (Strain K4-1), Achromobacter xylosoxidans (Strain K4-3), Acinetobacter radioresistens (Strain S1-2), Acinetobacter calcoaceticus (Strain K4-2) and Citrobacter freundii (Strain R3-1). The largest clear zone diameters for oil spreading method observed for P. balearica strain S1-4-1 (14 mm). Also, this strain has the best emulsification activity (100 %); surface hydrophobicity (BATH: 77 %) and reduction of surface tension (34.5 mN m-1 ). Thus, this strain selected as the best isolated strains. The results of this study confirmed that there is sufficient diversity of biosurfactant-producing bacteria in the Caspian Sea and the environmental problem can be resolved by application of these bacteria in petrochemical waste water

Study of plasmid profile and alkane hydroxylase genes in crude-oil degrading bacteria isolated from the Persian Gulf

610-615Bioremediation, using microorganisms, especially hydrocarbon-degrading bacteria are inexpensive and eco-friendly methods to reduce oil pollutions. Plasmids containing hydrocarbon-degrading genes encode the enzymes necessary for the derivative pathways are important for bioremediation. The aim of the present work was to study the plasmid profile of bacterial strains isolated from crude-oil contaminated sites in the Persian Gulf in previous researches. In this study, plasmids were extracted from 21 strains using alkaline lysis method. Then, alkane hydroxylase gene groups (I, II, III) were detected in extracted plasmids using specific primers by PCR. The results of this study indicated that eight crude oil degrading strains out of 21 had plasmid. The results of PCR amplification confirmed that 50 % of plasmid containing strains had alkane hydroxylase gene group (I), 75 percent of them had alkane hydroxylase gene group (III) and none of them had alkane hydroxylase gene group (II)

Biosurfactants produced by Bacillus subtilis A1 and Pseudomonas stutzeri NA3 reduce longevity and fecundity of Anopheles stephensi and show high toxicity against young instars

Anopheles stephensi acts as vector of Plasmodium parasites, which are responsible for malaria in tropical and subtropical areas worldwide. Currently, malaria management is a big challenge due to the presence of insecticide-resistant strains as well as to the development of Plasmodium species highly resistant to major antimalarial drugs. Therefore, the present study focused on biosurfactant produced by two bacteria Bacillus subtilis A1 and Pseudomonas stutzeri NA3, evaluating them for insecticidal applications against malaria mosquitoes. The produced biosurfactants were characterized using FT-IR spectroscopy and gas chromatography-mass spectrometry (GC-MS), which confirmed that biosurfactants had a lipopeptidic nature. Both biosurfactants were tested against larvae and pupae of A. stephensi. LC50 values were 3.58 (larva I), 4.92 (II), 5.73 (III), 7.10 (IV), and 7.99 (pupae) and 2.61 (I), 3.68 (II), 4.48 (III), 5.55 (IV), and 6.99 (pupa) for biosurfactants produced by B. subtilis A1 and P. stutzeri NA3, respectively. Treatments with bacterial surfactants led to various physiological changes including longer pupal duration, shorter adult oviposition period, and reduced longevity and fecundity. To the best of our knowledge, there are really limited reports on the mosquitocidal and physiological effects due to biosurfactant produced by bacterial strains. Overall, the toxic activity of these biosurfactant on all young instars of A. stephensi, as well as their major impact on adult longevity and fecundity, allows their further consideration for the development of insecticides in the fight against malaria mosquitoes