Background: Acinetobacter baumannii is a Gram-negative, obligate anaerobic, non-fermented and non-motile bacterium. Acinetobacter baumannii has become a particularly important organism in the Intensive Care Unit (ICU). Acinetobacter baumannii plays a significant role in nosocomial infections. Multidrug- resistant A. baumannii is recognized to be among the most difficult antimicrobial-resistant Gram-negative bacilli to be controlled and treated. For this reason, we examined the efficacy of nanosilver material against different types of bacteria.Methods: Silver nanoparticles with sizes of 20 nm were obtained from the Pishtazan nanotechnology (Mashhad-Iran). Then, silver nanoparticles serial dilutions (40000, 20000, 10000, 5000, 2500, 1250, 625, 312 ppm) were prepared in nutrient broth medium and 1.5 x 106 bacteria were added to each tube. After 24 h incubation at 37oC, the MIC (minimum inhibitory concentration) and MBC (minimum bactericide concentration) were determinate by sub-culturing and colony counting on Mueller Hinton agar. Also, we evaluated the ANTIBACTERIAL properties of nano silver by disk diffusion and well diffusion methods (30 ml 10,000 ppm solution per well and per disk) in this research. This study ANTIBACTERIAL activity of silver nanoparticles was tested for 20 clinical Acinetobacter baumannii (collected from Imam Reza Hospital in Tabriz) as a standard strain.Results: The MIC and MBC of silver nanoparticles (20 nm) were 1200 ppm and 2500 ppm for all clinical isolated Acinetobacter baumannii. The zone of dick diffusion and well diffusion methods respectively were 9 mm and 7 mm. The MIC and MBC results obtained for clinical isolates Acinetobacter baumannii showed no significant difference.Conclusion: Acinetobacter baumannii is susceptible to silver nanoparticles. Also the same MIC and MBC in multiple clinical strains suggest that there is no resistance to silver nanoparticles in Acinetobacter baumannii.

Microorganisms play a major role in initiation and perpetuation of pulpal and periapical diseases. Therefore, elimination of the microorganisms present in the root canal system is the fundamental objective of endodontic treatment. The use of mechanical debridement, chemical irrigation or other antimicrobial protocols and intra-canal medicaments are critical to attain this goal. The aim of this article was to review the antimicrobial agents and their properties in endodontics.

Indiscriminate and excessive uses of antibiotics may be lead promotethe emergence of antibiotic-resistant microorganisms and side effects in patients. Therefore the researchers recently have focused on the use of natural resources, especially medicinal plants.Ruta graveolens is a kind of medical plants which contains antifungal and ANTIBACTERIAL components and use in traditional medicine in Iran and other nations. The main goal of this research was investigation of antimicrobial effects of aquatic and alcoholic extracts of this plant on Gram-positive and Gramnegative bacteria and four Candida albicans selected. For this aim ANTIBACTERIAL and antifungal activities of Ruta graveolens extracts on Staphylococcus aureus (PTCC 1431), Bacillus subtilis (PTCC 1720), Escherichia coli (PTCC 1763) and Pseudomonasaeroginosa (PTCC 1599) and four Candida albicans isolated form Denture stomatitiswere evaluated by measurement of minimum inhibitory concentration (MIC) and minimum bactericidal and fungacidal concentration (MBC, MFC), disc diffusion and well diffusion methods. The results indicated that aquatic, methanolic and ethanolic extracts with different MIC and MBC have been effective on growth selected bacteria and Candida albicans.

In the present study, the antimicrobial tests of patchouli oil were studied by using molecular docking technology and antimicrobial test in vitro. Five biological macromolecule enzymes, required by the bacteria in the process of biosynthesis were selected as target molecules. Five antibiotics benzylpenicillin, sulfadiazine, trimethoprim, rifampicin and ciprofloxacin, which are generally acknowledged as ANTIBACTERIAL drugs, were selected as reference compounds. The 3 three-dimensional (3D) structures of the 5 reference compounds and 26 compounds from patchouli oil were established by using surflex-dock software (8.1). And the 3D structures of five biological macromolecule enzymes derived from Protein Data Bank (PDB). Molecular docking was carried out between the 31 chemical compounds (ligands) and the 5 enzymes (receptors) by using surflex-dock function. Furthermore, the ANTIBACTERIAL effects of 31 chemical compounds were investigated by the scoring function after molecular docking was completed. By comparing the scoring result of 26 compounds in patchouli oil with 5 compared components, we inferred ANTIBACTERIAL activity in about 26 compounds in patchouli oil. On the other hand, six frequently-used pathogenic bacteria were selected for antimicrobial test in vitro, patchouli oil and its two major compounds: (-)-patchouli alcohol and pogostone, which their contents exceeded 60% in patchouli oil samples, were selected ANTIBACTERIAL agents. Minimum inhibitory concentration (MIC) and Minimum bactericidal concentration (MBC) were also determined. Molecular docking technology and antimicrobial test in vitro proved that patchouli oil had strong antimicrobial effects. Particularly, pogostone and (-)-patchouli alcohol have potent antimicrobial activity.

Objective(s): The present work shows the green synthesis of silver nanoparticles using C. roseus extract and its antioxidant, free radicals scavenging and ANTIBACTERIAL activities. Methods: The C. roseus extract synthesized silver nanoparticles (CrAgNPs) were characterized by X-ray diffractometry, Scanning Electron Microscopy, Transmission Electron Microscopy and Fourier Transform Infra Red spectroscopy. The antioxidant, hydrogen peroxide scavenging, hydroxyl radicals scavenging, superoxide scavenging and reducing power activity of CrAgNPs were determined by DPPH, hydrogen peroxide scavenging, hydroxyl radicals scavenging, superoxide scavenging and reducing power assay methods. The ANTIBACTERIAL activity of CrAgNPs was analyzed by Agar dilution, Minimum Inhibitory Concentration methods. Results: The CrAgNPs were synthesized by C. roseus extract and silvernitrate. The synthesis of silver nanoparticles was confirmed by color changes and UVvisible spectrophotometer analysis. The CrAgNPs were crystalline, variable size, elemental and spherical shape. The C. roseus extract and CrAgNPs have antioxidant, hydrogen peroxide scavenging, hydroxyl radicals scavenging, superoxide scavenging and reducing power activity. The zone of inhibition and MIC value of CrAgNPs confirmed the ANTIBACTERIAL activity. The CrAgNPs have greater ANTIBACTERIAL activity than C. roseus extract against the S. Typhi and P. vulgaris. The MIC results of CrAgNPs confirmed that CrAgNPs was highly effective against the S. Typhi and P. vulgaris bacteria. Conclusions: Phenols and flavonoids of C. roseus extract reduced the silvernitrate into silver nanoparticles. The CrAgNPs were crystalline, spherical shape, variable particles size and elemental. The C. roseus extract and CrAgNPs have antioxidant, hydrogen peroxide scavenging, hydroxyl radicals scavenging, superoxide scavenging, reducing power activity and ANTIBACTERIAL activity.

Background: Nowadays, adding natural food preservatives is one of the methods for increasing shelf-life. The aim of this study was evaluation of ANTIBACTERIAL effects Tarragon (Artemisia dracunculus) essential oil (TEO) in beef burger product.Methods: In this experimental study, essential oil of the Tarragon was isolated by hydro distillation. Then, TEO was analyzed by gas chromatography-flame ionization detector (GCFID) and gas chromatography/mass spectrometry (GC-MS). The effect of different concentrations of Tarragon essential oil (0.00, 0.062, 0.125 and 0.25%) in 4±1oC temperature and storage time up to 12 days was evaluated anti Staphylococcus aureus activity in beef burger.Results: The monoterpenes hydrocarbons constitute the major fraction of the TEO (95.91%) and the sesquiterpene hydrocarbons were the minor fraction (0.46%). The minimum inhibitory concentrations (MIC) and minimum bactericidal concentrations (MBC) for Staphylococcus aureus were between 62.4to 250 mg/mL, respectively. The Tarragon essential oil 0.25% in storage temperature (4±1oC) decreased growth rate of S. aureus in beef burger (p<0.05).Conclusion: Therefore, this essential oil might be used as an ANTIBACTERIAL agent in meat products such as beef burger.