The Effect of Size and Taper of Apical Preparation in Reducing Intra-Canal Bacteria: A Quantitative SEM Study

Introduction: Bacteria and their byproducts are major etiologic factors in endodontic diseases. Prevention or reduction of root canal bacterial contamination is the main aim of endodontic treatment. The purpose of this in vitro study was to evaluate the effect of size and taper of master apical file (MAF) in reducing bacteria from the apical third of the curved canals using a quantitative scanning electron microscope (SEM) study. Methods and Materials: Eighty-nine human mandibular first molars with curved MB canals (20º-35º) were divided into one control group (n=5) (without rotary instrumentation) and 6 experimental groups (n=14). The canals were prepared using RaCe rotary files to the MAF sizes 25/0.04, 25/0.06, 30/0.04, 30/0.06, 35/0.04 and 35/0.06, in groups 1 to 6, respectively. All the experimental groups were finally rinsed with 2 mL of 17% EDTA followed by 3 mL of 5.25% NaOCl. The mesial roots were split longitudinally. Remaining bacteria in the apical third of MB canals were evaluated using SEM (2000×). Data analysis was performed using one way ANOVA with Tukey’s post hoc test. The level of significance was set at 0.05. Results: All the experimental groups showed significant bacterial reduction (P<0.001). Although the greater size and/or taper resulted in decrease in bacteria, differences between the groups were not significant. Conclusion: Based on this in vitro study the MAF #25/0.04 had no significant difference compared to other groups with greater apical size/taper; all groups could effectively reduce intra-canal bacteria

Identification of Bioactive Compounds in the Extracts of Brown Algae Sargassum (Sargassum angustifulium) and Padina )Padina distromatic( and Evaluation of Antimicrobial, Antioxidant and Enzymatic Properties

IntroductionSargassum and Padina are two genera of brown algae that are widely scattered in temperate regions. Sargassum species are categorized as tropical and sub-tropical brown seaweed which are valuable sources of bioactive compounds including dietary fibers, carotenoids, vitamins, and minerals. These brown algae demonstrate diverse biological activities such as antioxidant, antimicrobial, and anti‑Alzheimer, due to the presence of flavonoids, triterpenoids, flavonoids, sterols, polyphenols, and pheophytine. The genus Padina is scattered in many environmental conditions, mainly in the tropical marine waters, and belongs to the family Dictyotaceae. Some bioactive components isolated from Padina species have been demonstrated hypoglycemic, hypolipidemic, anti-obesity, hepatoprotective, cardioprotective, immunostimulatory, and antimicrobial activities., The aim of this study was to prepare an extract from two species of algae Padina and Sargsum by massaging and ultrasound assisted-methods  as well as analyzing their compounds and investigating the antioxidant, antimicrobial and enzymatic properties of the extracts. According to the obtained results, ultrasound assisted method was a suitable method for extraction. This extract can be used as a combination of antioxidant, antimicrobial, anti-Alzheimer's and nitrate reducing agent in food additives. Materials and MethodsChemical materials were supplied by Sigma-Aldrich GmbH (Sternheim, Germany). The algal species utilized in the current investigation; namely, Padina distromatic and Sargassum angustifolium were collected from the coastal region of Chabahar bandar, Sistan and Baluchistan Province, Iran. To eliminate all the impurities and extraneous materials, they were washed by using distilled water and then dried at ambient temperature (24-48 h) until the constant weight. Extraction by maceration was compared with the extraction using ultrasonic assisted method. Determination of chemical compounds was parformed using GC-MS device. Investigation of antioxidant properties and total polyphenol and flavonoid content were also performed. The degree of free radical scavenging was done according to DPPH method. Evaluation of antimicrobial effect of algae extracts were the main challenges in our research. S. aureus ATCC25923, Listeria innocua ATCC 33090, E. coli ATCC 25922 and S. typhi ATCC 6539 were used for antimicrobial test. Determination of minimum growth inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) were performed using wells in agar.The enzymatic activity was also determined. In this study, the activity of acetylcholinesterase was investigated using the method introduced by Ellman et al. (1961) and also the activity of nitric oxidase was determined using a kit protocol (Nvand-Iran). Factorial experiment in the form of a completely randomized design was used to analyze the data. Duncan's multiple range test was used to determine the difference between the means at the 95% confidence level, and SAS software version 2.9 will used for statistical analysis. Results and DiscussionThe current study investigated the antioxidant, antibacterial, anti-inflammatory, and anti-Alzheimer’s attributes of two brown algae namely Padina distromatic and Sargassum angustifolium which were collected from the coastal region of Chabahar Bandar, Iran. The results clearly indicated that the type of algae and extraction techniques used in this investigation highly affected phytochemical compositions, antioxidant, AChE inhibitory, scavenging, and antimicrobial activities. Considering both extraction yield and phytochemical components, extraction by ultrasound assisted method provided better results. Among all algal extracts, UPE presented the highest AChE inhibitory activity, and antibacterial activity and USE presented the highest antioxidant activities, total phenols and flavonoids, reflecting the presence of various bioactive components. The extracts of two various seaweeds utilized in the current study highlighted considerable inhibitory action against four pathogenic bacteria. According to the observations of the antibacterial assay, S. aureus was the most sensitive microorganism, while L. innocua was revealed as the most resistant bacteria to the extracts of P. distromatic and S. angustifolium. Further, the chemical components responsible for the antioxidant, AChE inhibitory, and antibacterial power were confirmed by GC-MS analysis. The findings of the current investigation confirmed the potential of the health benefits and therapeutic effect of brown marine algae. Thus, the extract of P. distromatic and S. latifolium could be an effective supplement to be incorporated into the products’ formulation in the food and pharmaceutical industries as well as in medication to alleviate several disorders such as Alzheimer

Detection of antibiotic-resistant bacteria and resistance genes SHV, TEM, and CTX-M in drinking waters in Tehran, Iran

Nowadays, a difficult problem has been disrupting people's health through treated and untreated water, namely the existence of antibiotic-resistant bacteria in these environments. The first is such organisms’ ability to acquire resistance genes through genetic elements, and the second seems to be the substances’ potential toxicity. The health index of supply water is lacking for bacteria such as coliform bacteria, Escherichia coli, Pseudomonas aeruginosa, and intestinal enterococci. The study's main aim was to figure out how these bacteria function as antibiotic resistance pools, not only to find resistant genes like SHV, TEM, and CTX-M but also to depict the dendrogram of clones in water supply samples in Tehran. Over the course of a year, 17 strains of P. aeruginosa were analyzed. In this study, 94.1% of the isolates tested positive for the TEM gene, while only one isolate tested positive for the CTX-M gene, and none tested positive for the SHV gene. This research shows that P. aeruginosa is not as common in drinkable water as previously thought. Nevertheless, it appears that P. aeruginosa can spread acquired antibiotic resistance vertically rather than horizontally. HIGHLIGHTS Pseudomonas aeruginosa is not as common in drinkable water in Tehran.; P. aeruginosa can spread acquired antibiotic resistance vertically rather than horizontally.; One isolate of Bacillus, two isolates of Enterococcus, one isolate of P. mendocina, and 13 isolates of P. aeruginosa were isolated.

Comparison the antimicrobial effect of methanolic total extracts and petroleum ether fractions of flowering aerial parts of Glaucium vitellinum Boiss. & Buhse and Gaillonia aucheri Jaub. & Spach

Background: With increasing use of antibiotics, the number and type of microbial resistance to antibiotics have been raised and at result the need for synthesis of new antimicrobials or acquire new sources of antimicrobial is indisputable. In this study the antimicrobial effects of the flowering aerial parts of Glaucium vitellinum and Gaillonia aucheri were investigated.Materials and Methods: The antimicrobial effect of mentioned extracts against Escherichia coli PTCC 1399, Pseudomonas aeruginosa PTCC 1430, Salmonella typhimurium PTCC 1639, Staphylococcus aureus PTCC 1431 and Candida albicans PTCC 5027 were evaluated by disk diffusion and the microdilution method based on CLSI protocol 2012.Results: No any zone of inhibition were detected by disk diffusion method against tested microbes for Glaucium vitellinum. After deletion of agar interference, the minimal inhibitory concentration (MIC) was determined by broth microdilution method for two plants. None of tested extracts were effective against Gram negative tested bacteria except alkaloid fraction of G. vitellinum which was effective against S. typhi. In contrast, the extracts and fractions of both plans were effective against tested gram positive bacteria especially S. aureus.Conclusion: The best result of MIC was detected for alkaloid fraction of G. vitellinum (0.09 mg/ml) Vs. G. aucheri (125 mg/ml) against S.aureus