جستجوی مقالات مرتبط با کلیدواژه « عوامل ضد باکتریایی » در نشریات گروه « پزشکی »

Nosocomial infections are considered as the important parts of the treatment challenges in hospitals. The genus Artemisia is widely distributed in Iran. Their species produce antibacterial, antiviral, and antifungal compounds belonging to different groups including phenols, terpenoids, sterols and polyacetylenes. The purpose of the present study is to investigate the in vitro effects of different hydroethanolic extracts of Artemisia species against bacterial strains in nosocomial infection.

12 different extracts, including 50% and 70% hydroethanolic extracts were prepared from the aerial parts of Artemisia ciniformis, A. turanica, A. kopetdaghensis, A. khorasanica, A. vulgaris, and A. sieberi. The winterization of the extracts produced corresponding defatted extracts. The minimum inhibitory concentration (MIC) values of the extracts against the bacterial strains Staphylococcus aureus, Streptococcus pyogenes, Acinetobacter sp., Pseudomonas aeruginosa, Enterococcus faecalis, Staphylococus epidermidis, Micrococcus luteus, Klebsiella  pneumoniae and Escherichia coli were measured using the microdilution broth method. Total phenolic contents were determined by the Folin-Ciocalteu method.

Among the extracts analyzed in this experiment, the lowest MIC value was observed for the 50% hydroethanolic extract of A. turanica (0.25 mg/ml) against S. epidermidis. The largest range of bacterial sensitivity (6 strains) was related to the 50% hydroethanolic extracts of A. turanica (defatted and non-defatted) and A. kopetdaghensis (defatted). The growth of S. epidermidis was inhibited by all of the extracts. The highest total phenolic content and yield of extraction were recorded for 70% hydroethanolic extract of A. sieberi and 50% hydroethanolic extract of A. ciniformis, respectively.

The 50% hydroethanolic extract of A. turanica was superior to the other extracts in terms of the in vitro antibacterial spectrum and selective potency. A. turanica and A. kopetdaghensis are probably suitable choices for further phytochemical and antibacterial investigations.

 The use of photodynamic therapy is a relatively new approach in medical science with an old background. In this method, it is possible to use light to inactivate and destroy cells and microorganisms. In dental treatments, it can be effective in many aspects of treatment, such as the treatment of gum diseases, oral and premalignant lesions, and root canal treatment. Initially introduced as an anti-infective treatment, photodynamic therapy has become a promising treatment method due to various advances in this field.

Description: 

According to the various findings of this study, photodynamic therapy can be useful as an adjuvant treatment of gum diseases and root canal treatment as as it is a minimally invasive process and can improve the treatment outcomes. Additionally, it can be used in the treatment of premalignant and superficial lesions in the head and neck region, as well as for early diagnosis of premalignant lesions with the potential to become malignant.

 According to the recent advances regarding the use of photodynamic therapy in dental managements, today this method can be used as an adjuvant treatment in many dental procedures. In addition, further studies are needed to show the use of photodynamic therapy as an independent treatment in dental managements.

Chemical preservatives are commonly used to prevent food from quick spoiling and oxidizing. Despite their effect in increasing shelf life of foods, these compounds can have side effects. Residues of chemical compounds in foods increase microbial resistance. This study aims to investigate the antioxidant and antimicrobial properties of lemon verbena (Lippia citriodora L.) ethanolic extract against some gram-positive and gram-negative bacteria.

In this experimental study, The soaking method and ethanol solvent was used for extraction. Antioxidant activities of different concentrations of extract were assessed using DPPH (2,2-diphenyl-1-picrylhydrazyl) radical scavenging activity test and compared with butylated hydroxyanisole (BHA) as a synthetic antioxidant. Antimicrobial effect of extract on Staphylococcus aureus, Listeria innocua, Bacillus cereus, Escherichia coli, Pseudomonas aeruginosa and Salmonella typhimurium was determined by disk diffusion and well diffusion methods and measuring minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC). Experimental data were analyzed in SPSS software, version 20 using analysis of variance and the mean values were compared using Duncan’s multiple range test.

The amounts of phenols and flavonoids in the ethanolic extract of were 96.47±0.35 mg of gallic acid/g of extract and 31.07±0.42 mg of quercetin/g of extract, respectively. The half-maximal inhibitory concentration of lemon verbena extract was 11.79±0.76 μg/mL, while it was 10.16±0.29 μg/mL for BHA. In both disk diffusion and well diffusion methods, with the increase of the concentration of extract, the inhibition zone diameter increased. The ethanolic extract of lemon verbena at the concentration of 12.5 mg/mL had no inhibitory effect on gram-negative bacteria growth. In both methods, the extract had the greatest effect on S. aureus. The MIC of ethanolic extract ranged from 8 to 128 mg/mL, depending on the type of bacteria (gram-positive or gram-negative).

The ethanolic extract of lemon verbena has higher antimicrobial effects on gram-positive bacteria. Therefore, it can be used in food and pharmaceutical industries as a natural antimicrobial agent. Considering the increasing resistance of bacteria to chemical antibiotics, more studies on lemon verbena and its antibacterial compounds are needed for treating infections.

In the past decades, problems in treating infections caused by resistant pathogenic bacteria were coupled with an increased focus on herbal active ingredients. The aim of this study was to evaluate the anti-biofilm, antibacterial and antioxidant effects of S. khuzestanica and to determine its chemical composition.

Satureja khuzestanika leaf was prepared from the Natural Resources Center of Isfahan Province. The antibacterial effect of extracts and essential oils was determined by well diffusion method and their minimum inhibitory concentration (MIC) were determined by microdilution method on Staphylococcus aureus and Pseudomonas aeruginosa strains. The antioxidant activity was also investigated by measuring the reduction of radical capacity. The chemical composition of the plant was determined by gas chromatography-mass spectrometry.

The MIC of methanolic extract and essential oil of S. khuzestanica were 12.5 and 31.25 mg/ml for S. aureus, respectively. In all cases, there was a direct relationship between the diameter of the growth inhibition zone and the concentrations of the plant extracts. The essential oil of the plant at a concentration of 50 mg/ml inhibited 100% of the biofilm production of both bacteria. Essential oil also had the highest antioxidant activity with 86% inhibition of DPPH. The level of antioxidant activity of extracts showed a significant increase with increasing the concentrations (P < 0.001). Carvacrol with 32.61% was the main compound of S. khuzestanica and then Cymene, Terpinene and Bisabolone was more than other compounds.

The results showed that S. khuzestanika essential oil and extracts have antibacterial effect against S. aureus and antibiofilm effect on S. aureus and P. aeruginosa. This plant contains compounds with antimicrobial activity and antioxidant properties.

Irrational use of antibiotics can lead to increased drug resistance. The Anatomical Therapeutic Chemical/ Defined Daily Dose (ATC/DDD) system is a tool to monitor medication use, evaluate the improvements in drug consumption quality, and make comparisons between international and other levels in this regard. This study aimed to determine the status of antibiotic prescription in hospitals in Qom, Iran.

This cross-sectional study was performed on 1200 medical records of the patients using a multi-stage sampling method in 2019. The data were collected through a researcher-made questionnaire to seek demographic information and antibiotics used by patients, as well as ATC/DDD based on the DDD/100 bed-days index. Furthermore, the data were analyzed in SPSS software (version 20) through descriptive statistics and analysis of variance.

The results showed no significant relationship between the number of prescribed antibiotics and the hospitalization season (P>0.05). The majority of the antibiotics were injectable (93.5%) prescribed by surgical specialists (50.70%). Gynecology and Children's hospitals obtained the highest (18.4%) and the least (12.4%) level of antibiotic prescription, respectively. The daily recommended doses for every 100 days of bed rest for the most common antibiotics were Amikacin (21.81), Ceftriaxone (33. 62), Ampicillin (19. 34), Meropenem (6.10), and Vancomycin (11.28).

The results show that Amikacin, Ceftriaxone, Ampicillin, Meropenem, and Vancomycin were the most common antibiotics used in the present study accounting for more than 70% of the total antibiotics administered. The DDD/100 bed-days of the most commonly used antibiotics were higher than those reported by the World Health Organization.

Since some sealants can  control cariogenic microorganisms, therefore the evaluation of antibacterial  effect of different sealants are the subject of this study.  in this experimental study,  the plates were divided into 5 groups.Group I control:two plates including Blood Agar with Mutans Streptococcus (SM) & the other MRS with Lactobacillus Acidophilus (LA).Group II:6 plates Blood Agar culture with two wells and inoculation of SM with addition of two fissure sealants; Clinpro 3M with fluoride &flowable composite 3M without fluoride.In group III all the steps were the same as group IIexcept that in which fissure sealants used were  Conseal F with flouride& Eco-s without fluoride.In groups IV & V all the steps were the same as groups II & III respectively except that MRS culture media with inoculation of Lactobacillus Acidophilus was used.The diameter of the growth inhibition halo (zone of inhibition) was measured using calipers. The experiment was repeated for three consecutive days with 26 plates  and the results were recorded every 48 hours.The data were analyzed using Two-way ANOVA  The diameter of growth inhibition halo for Clinpro 3M in the medium where Streptococcus mutans was cultured was 27/29+ 3/59mm&where Lactobacillus Acidophilus was cultured was 12/37+ 1/46mm which differed from other three materials significantly. (p<0.000)
Conclution: It seems, Clinpro 3M had the most inhibitory effect on Streptococcus mutans and , Lactobacillus acidophilus  growth.

Bloodstream infections are the most important causes of morbidity and mortality in hospitalized patients. Blood culture plays an important role in identifying most of bacterial agents of bloodstream infections. Knowledge about bacterial agents of bloodstream infections and also antibiotic resistance of these bacteria are important. Antibiotic resistance among bacterial agents of bloodstream infection including Acinetobacter, Klebisella, Pseudomonas, Escherichia coli, Enterobacter, Enterococcus, Staphylococcus aureus and Staphylococcus coagulase negative (CoNS) is one of the major challenges faced by physicians in treating. Therefore, this study was aimed to determine the frequency and antibiotic resistant patterns of bacterial isolates from hospitalized patient's blood cultured samples in the hospital, Tehran, Iran.
This research is a descriptive and retrospective study based on recorded data in Shariati hospital laboratory and under the supervision of Tehran University of Medical Sciences. The bacterial isolates were collected from positive blood cultures from October 2013 to March 2014. The frequency of bacterial isolates were determined by phenotypic and biochemical tests. The antibiotic resistance patterns of isolated bacteria were found by disk diffusion agar method. The diameters of inhibition zone were recorded and interpreted according to Clinical and Laboratory Standards Institute (CLSI) 2013.
The frequency of bacterial isolates was determined among 595 positive blood cultures as followed: 41% Pseudomonas, 20% Staphylococcus epidermidis, 10% Escherichia coli, 6% Acinetobacter lwoffii, 6% Staphylococcus aureus, 5% Stenotrophomonas, 3% Acinetobacter baumannii. The antibiogram test showed that 96.2% of Acinetobacter lwoffii, 92.8% of Acinetobacter baumannii, 66% of Pseudomonas aeruginosa, 85.7% of Staphylococcus epidermidis, 65% of Staphylococcus aureus, 75% of Klebsiella, 73.7% of Escherichia coli, and 50% of Stenotrophomonas were resistant to imipenem, piperacillin, piperacillin, erythromycin, erythromycin, ciprofloxacin, trimethoprim-sulfamethoxazole, and ceftazidime respectively.
The most prevalent bacterial isolate among the blood cultures of patients was Pseudomonas. The patients more than 50 years were more susceptible to blood stream infections. The most bacteria were isolated from the internal medicine department of hospital. The antibiotic resistance was also increasing especially in Acinetobacter, Staphylococcus coagulase negative, Escherichia coil and Klebsiella

Nowadays, biosynthesis of nanoparticles is considered because of its low energy requirements and risk. In present study, silver nanoparticles produced by two species of lichens “Usnea articulata” and “Ramalina sinensis”. Furthermore, the antibacterial effects of nanoparticles were studied.
To produce silver nanoparticles, lichens aqueous extract was placed in the vicinity of 1mmol of the silver nitrate solution. The production of nanoparticles was studied by spectroscopy, X-ray diffraction (XRD), and transmission electron microscopy (TEM). The antibacterial effect of the produced silver nanoparticles was investigated by agar well diffusion method against Escherichia coli¡ Pseudomonas aeruginosa¡ Bacillus subtilis, and Staphylococcus aureus.
The biosynthesized nanoparticles by two types of lichens had a maximum absorption at the wavelengths of 450 and 480 nm. Also, the presence of silver nanoparticles was confirmed by XRD method. The size of silver nanoparticles produced by Usnea articulata was about 10 to 50 nm and the nanoparticles produced by Ramalina sinensis around was 50 to 80 nm. The antibacterial test of the nanoparticles showed a good inhibitory effect against all four bacteria.
Lichens can be a good choice to produce silver nanoparticles, due to the abundance, fast growth, and environmental sustainability. The results of present study showed that biosynthesized silver nanoparticles had an effective inhibitory activity against bacteria. Therefore, these nanoparticles can be used in various industries.

Management of acute and chronic wounds has significantly altered in the last decade but little attention has been paid to the solution used for cleansing the wounds. Therefore, the present study aimed to compare the effects of tap water, distilled water, and normal saline for wound cleansing in emergency department.
This is a double-blind randomized clinical trial with a 10-day follow up. Patients who had superficial wounds were randomly divided into 3 treatment groups: normal saline, distilled water, and tap water. The wounds were cleansed using a 20 - 60 milliliter syringe with an 18 gauge needle. All the patients were discharged with the same antibiotic and were followed 48 hours and 10-day to determine the presence or absence of infection symptoms. The evaluated outcomes were infection incidence in the first 48 hours and 10 days after being discharged.
1200 patients were included in the present study (57% male, average age 25.5 ± 11.0 years). 43 (3.5%) patients showed infection symptoms in the first 48 hours. Ten (2.5%) patients were in normal saline treated group, 15 (3.7%) patients were in distilled water group, and 18 (4.4%) patients were in tap water treated group (p=0.32). 13 (3.2%) patients in normal saline group, 20 (4.9%) patients in distilled water group and 23 (5.6%) in the tap water group did not take their antibiotics. Prevalence of infection were higher in patients who did not take antibiotics (p The results of the present study showed that the prevalence of infection in using the 3 agents (normal saline, distilled water and tap water) for cleansing wounds was similar. Therefore, drinking water could be considered as an alternative for cleansing wounds.

Introduction and Pseudomonas aeruginosa is a key opportunistic pathogen causing severe acute and chronic nosocomial infections in immunocompromised or catheterized patients. It is prevalent in burn wound infections and it is generally multi-drug resistant. This study evaluated antimicrobial activity of ZnO and catechin and EDTA on the most common pathogen bacteria Pseudomonas aeroginusa by standard microdilution test depend on NCCLS. Zinc acetate dehydrate and Ethilen glycol (EG) were dissolved in 50 ml Distilled water with 10/1 ratio (Zn/EG). The solution were heated at 80 0C until little the gel of zinc acetate was obtained. Then gel was dried in the oven for 12h. Dried gel is calcinated at 300 0C for 24h Size and type of these Nanoparticles was characterized by scanning electron microscopy (SEM) and X-Ray-: Diffraction (XRD). pseudomonas aeroginusa strain (ATCC 27853) were cultured on nutrient agar medium (NA) for 24h at 370C. The microbial Suspension (1×106 cells/ml) was prepared. Minimum Inhibitory Concentration (MIC) test for ZnO and EDTA and Catechin were evaluated by microdilution test. Evaluation of Morphology and measurement of the size of the ZnO showed that nanoparticles were spherical with 30- 90 nm diameter. MIC of ZnO and EDTA and Catechin on pseudomonas aeroginusa was respectively 0.0003, 24.92 and 7.24 µg/ml. In this study we synthesized the ZnO nanoparticles with chemical method and we found that it has antimicrobial activity in low concentration compared with Catechin and EDTA. We offered that catechin and ZnO nanoparticles are good candidate for eliminating some contamination including of Pseudomonas aeroginusa in medical industrial.

Infection diseaseshave always been an important concern of human being and attracted theattention of a large number of professionals from the medical and laboratory community. On the other hand, antibiotic treatment can bring about microbial resistance and many side effects. Therefore, using medical plants with fewer side effects can be of great help in the treatment of these infections. The aim of this study was to examine antimicrobial effects of the flowers and leaves of methanol extract of Achilleawilhelmsii on the growth of some pathogenic bacteria. In this study, methanol extracts were obtained by Soxhlet apparatus and Rotary and were tested invitro against 4 bacteria species: Bacillus cereus, Staphylococcus aureus, Pseudomonas aeroginosa, Escherchia coli. Several concentrations of flowers and leaves of methanol extracts (20,30,50,400 mg/ml) were prepared by using DMSO solvent and then antimicrobial activity was tested using Agar well diffusion and dilution Test. Data were analyzed using Chi-square and AVONA statistical tests (p