فهرست مطالب مریم محمدی سیچانی

Brucellosis is one of the most common infectious diseases with a global spread. It has a high prevalence in Iran. This study aims to diagnose brucellosis caused by Brucella melitensis in the serum of patients by the amplification of omp31 gene, compared to the serological tests.

Blood samples were collected from 200 people suspected of brucellosis. The samples were evaluated by serological tests including Rose Bengal test, Wright test, Coombs-Wright test, gel agglutination test, and 2-mercaptoethanol (2ME) test. DNA extraction was done by the phenol/chloroform extraction method. Molecular detection with polymerase chain reaction (PCR) method was done using the specific primers of the Omp31 gene. Data were analyzed in SPSS software, version 23 using the analysis of variance.

Of 200 patients, 122 were female and 78 were male with a mean age of 45.17±17.43 years. The results of PCR test for the omp31 gene were positive in 14.5% of cases, which was consistent with the results of serological tests (13.8%). The sensitivity of Wright, Coombs-Wright, 2ME, and gel agglutination tests, compared to PCR, was 89.7, 75.9, 55.2 and 55.2%, respectively. Most of the affected people were housekeepers (41.5%) and urban residents (75.5%). Muscle pain (68%) and leg pain (62.3%) were the most common symptoms. Consumption of non-pasteurized dairy products was the highest risk factor (17%).

The diagnosis of brucellosis by the omp31 gene amplification has higher sensitivity and accuracy compared to the serological tests. Considering the importance of rapid and timely diagnosis of brucellosis to control its clinical complications, the molecular diagnosis method is recommended as a diagnostic method.

The growth-promoting endophytic bacteria are highly regarded as bio-fertilizers. The aim of this study was to identify safflower endophytic bacteria and to detect their effects on seed germination and plant growth. Endophytic strains were isolated from safflower roots and their auxin production and phosphate solubility were evaluated. The effects of isolates were evaluated on the safflower seed germination and growth. Then, the activity of enzymes produced by the selected isolates were investigated. The antifungal effects of endophytic isolates were also evaluated by pour plate method. Endophytic bacteria including Micrococcus luteus, Pseudomonas corrugata, Pseudomonas fluorescens, Pseudomonas brassicacearum, and Bacillus megatrium were isolated from safflower roots. In treatment with Bacillus megatrium NMR isolate, the mean of germinated seeds by exposure to the concentration of 105 cfu/ml was significantly higher than concentration of 108 cfu/ml. Coleoptile length and root length in the control group were significantly shorter than the treatment groups. There was a direct relationship between the amount of auxin produced by endophytic isolates and their ability for phosphate solubility with increasing safflower coleoptile and root length, and germinated seeds. Pseudomonas brasicacearum NMR isolate produced all the four enzymes, pectinase, amylase, protease and xylanase. The Pseudomonas fluorescence NMR with the most effectiveness inhibited the growth of Aspergillus niger by 30.76%. The isolated endophytic bacteria in the present study are suggested as stimulants of plant growth in the field due to their ability to produce auxin and to dissolve phosphate and their direct effect on safflower growth factors.

Rhizospheric bacteria are among the beneficial soil microorganisms that improve plant growth. These bacteria increase plant growth through various mechanisms such as the production of various phytohormones and the ability to solubilize phosphate. The aim of this study was to investigate the effects of rhizosphere bacteria on the growth of Carthamus tinctorius to improve its physiological and biochemical indicators. Carthamus tinctorius seeds were inoculated with five isolates of rhizosphere bacteria and were then planted the seeds in pots. Subsequently, the physiological and biochemical parameters of the plants, including the rates of auxin production, phosphate dissolving, photosynthetic pigments and the contents of proline and malondialdehyde were measured. For this purpose, a factorial experiment were conducted using a completely randomized design with three replications. The ANOVA was performed and a comparison of the means was carried out using Duncan’s multiple range test. The results indicated that the largest stem fresh weight, root fresh and dry weights observed in the treatments of using Pseudomonas fluorescens (auxin concentration of 23.55 μg/mL) and Bacillus muralis (auxin concentration of 22.27 μg/mL). In addition, all bacterial species increased the safflower seed germination rate compared to the control group. The largest malondialdehyde content was recorded in the treatment with Bacillus albus, and MDA content decreased in the treatments that produced larger amounts of auxin. In general, the finding of this research suggested that bacterial inoculation was capable to significantly affect the growth of safflower and improve its qualitative and quantitative growth parameters.

The aim of this study was to investigate the antimicrobial effects of kefir as a dietary supplement on the growth and infection caused by Aeromonas hydrophila in Cyprinus carpio. Totally, 72 juvenile carp weighing approximately 10-15 g were used. The fish were divided into 4 groups fed with 3, 5 and 10% kefir and the control group (without adding kefir) with three replications (six fish per replication) and were fed 3% of their body weight daily. The antimicrobial effect of kefir against A. hydrophila was investigated as well. After two weeks, the levels of IgM, ALT, AST, ALP and total protein in fish serum were evaluated. The liver, kidney and spleen tissues of fish were examined for histological study. The results showed that the 48-h kefir product had the highest antimicrobial effect against A. hydrophila. Feeding the fish with 3% kefir caused significant increases in length and weight of the fish. The statistical analyses revealed that the levels of IgM, AST, ALP and the serum total protein were not significantly different between the four groups, while the average amount of ALT in treatment 3% exhibited significant difference, which was less than the other two groups, while was not significantly different from the control. All experimental groups exposed to A. hydrophila revealed tissue damage in liver, kidney and spleen. However, tissue damage was less in treatment 3%.

 Bacteria growing in dental plaque have increasing resistant to antimicrobial agents. The present study aimed for reduction of biofilm formation by streptococcus mutans isolated from dental plaque by protease enzyme.

 Streptococcus mutans from dental plaque was isolated in Blood agar medium and then was identified by biochemical tests and sequencing of 16S rRNA coding gene. Bacterial biofilms were formed in wells of microtiter plate in Triptic Soy Broth medium supplemented with 1% sucrose after 48 hrs incubation in 37ºC. Then the volumes equal to 1.12, 2.24 and 4.4 units per well of protease was separately added to recently formed biofilms in different wells based on the manufacturer protocol and effects of them was studied on reduction of biofilms in 60, 90, 120, 150 and 210 minutes by spectrophotometer. Mean differences between independent groups were compared with Kruskal-Wallis test and SPSS25 software statistical tests and paired means were compared with Mann-Whitney test at 95% significance level.

 Streptococcus mutans was isolated from dental plaque had 98.90% similarity to LPB0225 strain and had intermediated adherence. Reduction of biofilm percentage by Streptococcus mutans LPB0225 was observed in every of units of enzyme and in every periods of times. The most biofilm percentage reduction by Streptococcus mutans LPB0225 was observed in 1.12 units of enzyme in 90 minutes with 97% reduction. Biofilm percentage reduction in 1.12 units of enzyme in 60, 150 and 210 minutes had significantly differences with each other (p value = 0.0008).

 The protease enzyme was able to reduce the dental plaque of Streptococcus mutans LPB0225. The survey on the effect of this enzyme on mixed dental plaques is suggested to control dental caries and plaques created on dentures, and to prevent periodontal diseases caused by dental plaque.

  Infections caused by resistant Pseudomonas aeruginosa strains mostly originate from hospitals, and its prevalence is increasing in many countries of the world. Therefore, many efforts have been made to find new active plant compounds as an appropriate substitute for antibiotics. The purpose of this study was to evaluate the active compounds, antibacterial and antibiofilm activity of aqueous and methanol extracts of Mazuj and Ghalghaf galls against Pseudomonas aeruginosa. This study was performed on standard strain of Pseudomonas aeruginosa and a number of clinical strains. The methanol and aqueous extract of Mazuj and Ghalghaf galls, were prepared by Soxhlet method. Antibacterial activity of the extracts was assessed by well diffusion method, minimum inhibitory concentration (MIC) by microdilution method. The anti-quorum sensing activity of methanol and aqueous extracts of Mazuj and Ghalghaf galls was investigated on anti-biofilm activity of Pseudomonas aeruginosa. The methanol and aqueous extracts of Mazuj and Ghalghaf galls showed antibacterial activity against Pseudomonas aeruginosa. The MIC values of the extracts were obtained to be 6.25 - 25 mg/ml. The extracts of Mazuj and Ghalghaf galls inhibited the formation of Pseudomonas aeruginosa biofilms in concentrations higher than 6.25. According to the results of this study, the extracts of Mazuj gall have appropriate antibacterial activity against the studied bacteria. Also, the methanol extract had higher antibacterial activity than the aqueous extract. Therefore, it is suggested that more extensive research be conducted on the identification of its antimicrobial compounds as a suitable alternative to antibiotics for the treatment of diseases.

Escherichia coli is one of the main causes of urinary tract infection in humans. The bacteria have become resistant to antibiotics and its treatment is difficult. The plasmid-dependent resistance to quinolones is increasing in the family of Enterobacteriaceae. This study aimed to assess the frequency of plasmid qnr genes in quinolone-resistant isolates of Escherichia coli causing urinary tract infection In this descriptive study, 96 isolates of Escherichia coli were identified. Antibiotic susceptibility of isolates was investigated using disc diffusion method. The presence of qnrA, qnrB, and qnrS plasmids was assessed using molecular methods with specific primers. Findings: Of the 96 isolates examined, 53 isolates (40.16%) were resistant to fluoroquinolone antibiotics. Moreover, the presence of qnrA gene in 18 isolates (33.96%), qnrB gene in 8 isolates (15.1%), and qnrS gene in 5 isolates (9.43%) of 53 isolates resistant to fluoroquinolones was confirmed via polymerase chain reaction (PCR) assay. The results of this study show that genes of plasmid-dependent qnr group have expanded in Isfahan City, Iran. The frequency of the qnrA gene relative to qnrB and qnrS is higher among quinolone-resistant Escherichia coli isolates in Isfahan.

Bacterial infections and the antibiotic resistance of pathogens are the most important challenges faced by researchers and physicians. In this study, the antibacterial and antibiofilm properties of methanol extracts of leaf, fruit, and gall of Pistacia atlantica were evaluated against some of pathogenic bacteria.
Leaf, fruit, and gall of Pistacia atlantica were collected from forests of Lorestan Province, Iran. Antibacterial properties were investigated against Staphylococcus aureus, Bacillus cereus, Enterococcus faecalis, Pseudomonas aeruginosa, and Escherichia coli through the well diffusion method. The microdilution method was used to determine the minimum inhibitory concentration and the minimum bactericidal concentration. The antibiofilm activity of methanol extract was studied in the sub-lethal concentrations on biofilm formation of Staphylococcus aureus and Pseudomonas aeruginosa using microtiter plate method.
Findings: The methanol extracts of leaf, fruit, and gall of Pistacia atlantica had significant antibacterial effects against the tested bacteria except Escherichia coli. There was a significant relationship between the antibacterial activity and the extract concentration (P The methanol extracts of different parts of Pistacia atlantica had antibacterial effects. In addition, the methanol extract reduced biofilm production of Staphylococcus aureus and Pseudomonas aeruginosa.

Chemical drugs have many side-effects, and for this reason, the approach of using medicinal plants and traditional medicine, has increased. Achillea tenuifolia is a plant belonging to the family Asteraceae. In this research, the antibacterial properties of essential oil and methanol, ethanol, chloroform, and acetone extracts of Achillea tenuifolia, were investigated against Staphylococcus aureus, Pseudomonas aeruginosa, Escherichia coli, and Enterococcus faecalis bacteria.
In this experimental study, Achillea tenuifolia flowers and leaves, were collected from Ghoroghchi mountain pass in Meymeh township in May 2014 and were dried in shadow. Flower and leaf essential oil was prepared using Clevenger apparatus. The methanol and ethanol extracts of the plant, were prepared using Soxhlet apparatus and the chloroform and acetone extracts, were prepared by maceration method. Antibacterial activity of the essential oil and the extracts was evaluated by well diffusion method. The minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC), were determined by microdilution method. Data were analyzed using one-way ANOVA, Kruskal-Wallis, and Mann-Whitney post-hoc tests. The significance level was considered to be p In this study, the essential oil of Achillea tenuifolia flowers and leaves showed antibacterial effects against Staphylococcus aureus, Pseudomonas aeruginosa, Escherichia coli, and Enterococcus faecalis at the concentrations of 20-50% (p The results of this study showed that essential oil of Achillea tenuifolia flowers and leaves has antibacterial activity, and the prepared extracts had no antibacterial properties.

Nowadays, microorganisms have high resistance to antibiotics due to indiscriminate and unnecessary consumption. Treatment of infections caused by resistant bacteria has become difficult and expensive. Galls wild rose created by wasp's species Diplolepis mayri. This study was done to evaluate antibacterial activity of methanol, acetone and aqueous extracts of Wild Rose gall against Staphylococcus aureus and Enterococcus faecalis.
In this experimental laboratory study, the methanol, acetone and aqueous extracts of wild rose galls in 15.6, 31.3, 62.5, 125, 250 and 500 mg/dl were prepared by Soxhlet apparatus. Antibacterial activity of extracts was determined using well diffusion. MIC and MBC were determined by microdilution method. The active compounds of gall were evaluated by GC-MS.
The inhibition zone of 500 mg/ml methanol, acetone and aqueous extracts of wild rose gall were 27.3, 26.7 and 20.0, respectively. The inhibition zone of wild rose gall was similar to imipenem (antibiotics). The extract concentration was related with antibacterial activity. The gall rose methanol extract showed the highest antibacterial effect. The MIC and MBC of methanol extract against Staphylococcus aureus and Enterococcus faecalis was 62.5, 31.3 mg/ml, respectively.
This study showed that aqueous, methanol and acetone extracts of wild rose galls have strong antibacterial activity.

Elimination or reduction of petroleum hydrocarbons from natural resources such as water and soil is a serious problem of countries, particularly oil-rich countries of the world. Using white rotting fungi compost for bioremediation of soils contaminated by petroleum hydrocarbons is effective. The aim of this study is molecular identification and potential of anisolate of white rot fungi in bioremediation of petroleum contaminated soils.
Spent compost of white rotting fungi was inoculated with petroleum contaminated soil into 3%, 5% and 10% (w/w). Treatments were incubated at 25-23 °C for 3 months. Reduction of petroleum hydrocarbons in treated soil was determined by gas chromatography. Ecotoxicity of soil was evaluated by seed germination test.
Based on the genome sequence of 18s rRNA, it is revealed that this isolate is Ganoderma lucidum and this isolate is deposited as accession KX525204 in the Gene Bank database. Reduction of petroleum hydrocarbons in soil treated with compost (3, 5 and 10%) ranged from 42% to 71%. The germination index (%) in ecotoxicity tests ranged from 20.8% to 70.8%. Gas chromatography results also showed a decrease in soil Hydrocarbons compounds.
Discussion and The compost of Ganoderma lucidum, a white rot fungus, has a potential ability to remove petroleum hydrocarbons in contaminated soil. Removal of hydrocarbons was increased with increase in compost mixed with contaminated soil. Petroleum contaminated soil amended with spent compost of G.lucidum 10% during three months is appropriate to remove this pollutant.

The infections caused by Escherichia coli and Staphylococcus aureus resistant strains often originate from hospitals, and their prevalence is increasing worldwide. Therefore, many efforts are being made to find new active plant compounds as alternatives to antibiotics. In this research, the antibacterial effect of methanol and ethanol extracts of Rumex cyprius seeds against Escherichia coli and Staphylococcus aureus strains.
In this experimental study, methanol and ethanol extracts of Rumex cyprius seed, were prepared using Soxhlet apparatus. Antibacterial activity of the extracts were evaluated by well diffusion method, and minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC), were determined using microdilution method. Active compounds of the seed, were identified by gas chromatography-mass spectrometry. The data were analyzed using ANOVA and Tukey tests. The level of significance was considered p In this study, ethanol and methanol extracts of Rumex cyprius seed prevented the growth of S. aureus and E. coli. Inhibition zone diameter of the ethanol extract in concentration of 500mg/ml against E. coli and S. aureus, was 16.5 and 19mm, respectively. Inhibition zone diameter of the methanol extract in concentration of 500mg/ml against E. coli and S. aureus was 14 and 16.5mm. MIC and MBC values of ethanol and methanol extracts against E. coli and S. aureus, were obtained 62.5 and 125mg/ml, respectively. In this study, The highest compound obtained from the seeds was 1,2-Benzenedicarboxylic Acid (24.25%).
Ethanol and methanol extracts of Rumex cyprius seeds had inhibitory effect against S. aureus and E. coli. The effect of these extracts on S. aureus is more than E. coli.

Lentinula edodes mushroom is the edible and medicinal mushroom. The flavor, pleasant odor and pharmaceutical attribute it has been noted. In different country experimental cultivation of Lentinula edodes has been carried out using wood shavings with or without Coffee pulp, sugar cane bagasse, and straw from several cereals. The purpose of this study is investigation about optimal growth conditions of Lentinula edodes under laboratory conditions. The experiment designed based on taghuchi design by 8 different composts with 3 different woods on process of mycelium growth and compost weight increasing with 3 replicates. Results showed the compost that contains molasses, wheat straw and wheat bran had the most rate growth on the compost weight increasing and mycelium growth. Also the compost with just wood chips not have any nutrient material had shown the minimum result of mycelium growth. Analysis of data shows that the different types of woods have no significant effect on mycelium growth. However, molasses and wheat bran addition have significant effect on mycelium growth.

Enteropathogenic Escherichia coli strains cause a wide range of gastrointestinal infections, especially in developing countrirs. The aim of this study was to evaluate of the antibacterial effect of methanol and aqueous extracts of Vaccinium arctostaphylos fruit on entropathogenic Escherichia coli in vitro.
In this experimental study, methanol and aqueous extracts of Vaccinium arctostaphylos fruit were prepared by two methods, maceration and soxhlet. Antimicrobial effects of these extracts were examined by agar diffusion method on two strains of Escherichia coli (ATCC: 8739, ATCC: 25922) and 12 clinical strains of enteropathogenic Escherichia coli. Minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) were determined by microdilution method. Analysis of variance and t-independent tests wee used to comoare the means.
All of the studied strains of Escherichia coli were sensitive to the methanol and aqueous extracts of Vaccinium arctostaphylos fruit. The mean zones of inhibition produced by the extracts were obtained in the range of 10.6-18.8 mm. Statistical analysis showed that there is a significant relationship between the increase in extracts’ concentrations and inhibition zone diameters (p According to the results of this study, methanol and aqueous extracts of Vaccinium arctostaphylos fruit had inhibitory effect on enteropathogenic Escherichia coli.

Salmonella infections، or salmonellosis such as typhoid، bacteremia، enterocolitis are the major health problem worldwide، especially in developing countries including Iran. This study aimed to evaluate the antibacterial effect of methanol and aqueous extracts of Vaccinium arctostaphylos fruit against Salmonella spp. The present study is an experimental one Methanol and aqueous extracts of Vaccinium arctostaphylos fruit were prepared by maceration and Soxhlet method. Antimicrobial effects of the extracts were evaluated by agar diffusion method against Salmonella typhi (PTCC: 1609) and six clinical strains of Salmonella. Minimal inhibitory concentration (MIC) and minimal bactericidal concentration (MBC) were determined by micro-dilution method. All of the studied strains were sensitive to the aqueous and methanol extracts of Vaccinium arctostaphylos fruit. The mean zones of inhibition were obtained in ranging from 6. 6 to 26. 6 mm. Statistical analysis showed a significant difference between the mean diameters of inhibition zone and increased extracts concentrations (p<0. 001). The MIC values were ranged from 50-200 mg/ml، whereas the MBC values from 100- 400 mg/ml. Methanol and aqueous extracts of Vaccinium arctostaphylos fruit had inhibitory activity against Salmonella spp.

Clean water is vital to both human life and preservation of ecosystems. The goal of this study was to investigate the antibacterial effects of ZnO nanoparticles and filters coated with different sizes of ZnO nanoparticles on Escherichia coli (ATCC: 25922) and Enterococcus faecalis (ATCC: 11700) as the predominant bacteria in contaminated water. The antibacterial effects of ZnO nanoparticles (5 and 100 nm in size) at concentrations of 12.5, 25.0, 50.0, and 100.0 mg/ml were determined using the well diffusion method in vitro. Minimum inhibitory concentrations and minimal bactericidal concentrations of ZnO nanoparticles were determined by the broth micro-dilution method. In another part of the study, ZnO nanoparticles were coated on polypropylene filters using the precipitation method to investigate their removal efficiency. Filtration of contaminated water was performed using a standard number of the bacteria being tested. ZnO nanoparticles (5 nm) at a concentration of 100.0 mg/ml showed maximum sensitivity against E.coli and Enterococcus faecalis by inhibition zones of 14.00±1.73 and 11.67±1.52 mm, respectively. Maximum inhibitory concentration of ZnO nanoparticles was determined as 25mg/ml. A significant relationship was found between antibacterial activity and ZnO nanoparticles concentration (P. value <0.001). It may be claimed that treatment with polypropylene filters coated with ZnO nanoparticles (5nm) is an effective process for controlling bacterial growth and eliminating E.coli.

Burn is one of the most devastating conditions encountered in medicine. Burn wounds are appropriate environments for growth of bacteria, including Pseudomonas aeruginosa. The aim of this study was to investigate the antibacterial properties of zinc oxide nanoparticles on growth inhibition of Pseudomonas aeruginosa. In this experimental study, 25 burn wound samples were collected from patients hospitalized in Imam Musa Kazem hospital, Isfahan in 2012. After culturing and diagnostic tests, Pseudomonas aeruginosa was detected. The antibiotic resistance pattern was determined for amikacin, ciprofloxacin, ceftriaxone, cefepime, cefotaxime, tobramycin, imipenem, piperacillin, gentamicin, and ceftizoxime using standard Kirby-bauer disk diffusion method. Antibacterial activity of zinc oxide nanoparticles in sizes of 5 and 100nm were evaluated using well diffusion method in concentrations of 100.00, 50.00, 25.00, 12.50, 6.25, and 3.13mg/ml. The data were analyzed using ANOVA and Chi-square tests. The significance level was considered as p<0.001. In this investigation, Pseudomonas aeruginosa showed sensitivity to piperacillin, tobramycin, and gentamicin. Zinc oxide nanoparticles in size of 5 nm at the concentration of 25, 50, 100mg/ml and in size of 100nm at the concentration of 100mg/ml had antibacterial activity against Pseudomonas aeruginosa isolated from burn wounds. The results of this study showed that zinc oxide nanoparticles have inhibitory effect on Pseudomonas aeruginosa. Also, the inhibitory effect of zinc oxide nanoparticles increases with increasing nanoparticle concentration and decreasing nanoparticle size.

Background and Dental caries is a pathological infectious disease. It begins with the formation of dental plaques which is a structurally and functionally organized biofilm. Streptococcus mutans is the most important bacterium in the formation of dental plaque and dental caries. This study aimed at evaluating the antibacterial and antibiofilm activity of Quercus infectoria galls against Streptococcus mutans. The bacterial strain used in this study was Streptococcus mutans (ATCC: 25923). Extracts were prepared by Soxehlet apparatus and maceration. They were then dissolved in sterile distilled water to a final concentration of 0.16 to 10.00 mg/ml. The antimicrobial activities of the extracts were determined using well diffusion method. The antibiofilm activities of the extracts were examined in a microdilution assay using TTC. Statistical analysis was performed in SPSS V.18. The methanol, ethanol, and acetone extracts of Quercus infectoria galls showed strong inhibitory effects against Streptococcus mutans. The MIC values of extracts were similar and ranged from 160µg/ml to 320µg/ml, whereas the MBC values ranged from 320µg/ml to 640µg/ml. Aqueous extracts of oak galls did not show antimicrobial activity. The extracts of Quercus infectoria galls strongly inhibited the formation of Streptococcus mutans biofilms at concentrations higher than 19.5µg/ml. The extracts of Quercus infectoria galls displayed similarities in their antibacterial activity against Streptococcus mutans. Also, they were found effective in preventing biofilm formation of Streptococcus mutans. The galls of Quercus infectoria are considered potentially good sources of antimicrobial agent.

Today, in traditional medicine, plants are used in treatment of some diseases because of their antimicrobial activity. The problems in treatment of infections caused by resistant microbial strains are a reason for more precise investigation on herbal plants. The aim of this study was to determine antibacterial activity of essential oil of Artemisia deserti flowers against some gram-positive and gram-negative bacteria. In this study, antibacterial activity of essential oil of Artemisia deserti flowers was investigated against standard strains of Staphylococcus aureus, Enterococcus faecalis, Escherichia coli, and Pseudomonas aeruginosa. Determination of antibacterial activity, Minimum Inhibitory Concentration (MIC) and Minimum Bactericidal Concentration (MBC) were performed using well diffusion and microdilution methods, respectively. Data were analyzed using statistical tests, including Duncan's post hoc test and two-way analysis of variance. The Significance Level Was Considered p<0.05. In this study, essential oil of Artemisia deserti flowers inhibited the growth of Staphylococcus aureus, Enterococcus faecalis, and Escherichia coli. The diameter of inhibition zone for essential oil of Artemisia deserti flowers was in the range of 8.3 to 45.0mm. The diameter of inhibition zone had a direct relationship with the concentration of essential oil (p<0.001). The lowest MIC was 2.5%. This essential oil had no activity against Pseudomonas aeruginosa. The results of this study indicated that essential oil of Artemisia deserti flowers has inhibitory activity against pathogenic bacteria, especially gram-positive ones, and this herbal essential oil can be useful as a pharmaceutical composition.

Streptococcus mutans is a major cause of dental caries and tooth damage. The purpose of this study was to evaluate the effect of the Stevioside and Stevia rebaudiana leaf extracts on the growth of Streptococcus mutans. In this study, the aqueous and acetone extracts of Stevia rebaudiana were extracted by the maceration method, and methanol and ethanol extracts were prepared by a Soxhlet apparatus. Stevioside was purchased from Malaysia. The agar-well diffusion method was used to determine the antibacterial activity of Stevioside and Stevia extracts. Minimal Inhibitory Concentration (MIC) was determined by the microdilution method. The antibacterial effects of Stevioside and Stevia extracts together and in combination with Penicillin were compared through variance analysis. The results indicated the inhibitory effects of methanol extracts at MIC= 25 mg/ml, ethanol extract at MIC=3.13 mg/ml, and acetone extract at MIC=1.56 mg/ml on growth of Streptococcus mutans. The aqueous extract of Stevia rebaudiana and Stevioside could not inhibit the growth of Streptococcus mutans. The alcoholic and acetone extracts of Stevia rebaudiana may be used as pharmaceuticals and preservatives in controlling the growth of Streptococcus mutans.

There is a long period between harvested beets and their transfer to the sugar factory. Sugar beet crop is damaged and injured during harvest and transport which provides a suitable place for various saccharoliytic microorganisms growth in terms of temperature, moisture, pH and glucose concentration. In this study, samples were randomly selected from the roots stored in spring 2010 and also the processed syrup in one of the sugar factories in Isfahan, to isolate and identify microorganisms. After washing and disinfecting the root’s surface, infected pieces were taken from different parts of tissue. After preparation of dilution series, isolation and identification of microorganisms were carried out using standard microbiological methods. In the next stage, the impact of the ethanolic extract of the honey bee prepolis as an antimicrobial agent was studied under the controlled environment on the isolated bacteria and fungi. And, its effect was compared with two disinfecting materials, i.e. sodium hypochlorite and calcium hypochlorite. Different kinds of gram-positive bacilli and cocci, including genus Bacillus, Leuconostoc, Staphylococcus and Streptococcus from bacteria, and several types of fungi constitute Paecilomyces, Chrysosporium, Pencillium, Fusarium and Pythiumwere isolated, purified and identified. Pathogenic bacteria such as Staphylococcus aureus and Staphylococcus saprophyticus were detected among the isolated bacteria. Bacterial counting in heated syrup showed the presence of bacterial spores and the re- growth of bacteria as 53 colony forming units per ml. after emergence. The bacterial population remained in heated syrup was belonged to the Bacillus species. These bacteria are called as ‘ human opportunistic pathogens’ and some of them are allergens. Therefore, it is important to control their population instored sugar beet which can improve the quality of the crop and health parameters. Ethanol extract from bee Propolis had significant effect on isolated microorganisms, so that the minimum lethal concentration of Propolis was 6 times less than sodium hypochlorite and 12 times less than calcium hypochlorite.

In this study، antibacterial behavior of nanoparticles of titania and nanoparticles of silver-doped titania were evaluated against Streptococcus mutans and were compared with three pathogen bacteria. Initially، the nanoparticles of titania and nanoparticles of silver-doped titania were synthesized by sol-gel method. The powders were characterized by X-ray diffraction (XRD)، Transmission Electron Microscopy (TEM) and Energy-Dispersive Spectroscopy (EDS) techniques. Then، Agar dilution was used to evaluate antibacterial properties of silver- doped titania nanoparticles against Streptococcus mutans and three types of pathogen bacteria. Phase structure evaluation showed anatase phase of titania in all silver-dopped titania nanoparticles. The particle size of titania and silver particles were determined 30 and 15 nanometers، respectively. The antibacterial results showed that Minimum Inhibition Concentration (MIC) of 3 mg/ml for silver-doped titania nanoparticles with different percentages of silver could inhibit bacteria growth، while nanoparticles of titania in fluorescent light indicated reducing growth of bacteria. Furthermore، MIC of 4 mg/ml was achieved for silver-doped titania nanoparticles with 5 mole percent sliver against the other pathogen bacteria and for other specimens observed growth of bacteria. These results showed that silver could increase antibacterial properties of titania. This is due to presence of silver nanoparticles and also the effect of silver on the photocatalyst properties increased antibacterial properties.

Nowadays، bacterial infections and antibiotic resistance of their etiologic agents are among the most important challenges facing the health systems. Therefore the application of antimicrobial agents with natural origin has been deeply studied recently. The aim of this study is to evaluate antibacterial effects of aqueous extracts of Ghalghaf and Mazuj galls on gram-negative bacteria. The antibacterial activity of aqueous extract of two galls on the bacterial strains from clinical samples with multi-drug resistance (Pseudomonas aeruginosa، Acinetobacter baumannii، Escherichia coli) and reference bacterial strains were determined using agar dilution and agar diffusion methods. The aqueous extracts of both galls showed antibacterial activity against all studied bacterial strains. Inhibition zone diameter for aqueous extracts of Ghalghaf and Mazuj are in the ranges of 8-20 and 8-26 mm respectively. The size of the inhibition zone diameter was directly proportional to the concentration of extracts (p< 0. 05). The lowest amount of MIC related to aqueous extract of mazuj gall (0. 128 mg / ml). This study showed that two galls of Mazuj and Ghalghaf are contained of antibacterial compounds that could be used against multi-drug-resistant gram negative bacteria. Therefore the antibacterial activity of other extracts of these galls and pharmacologic studies are necessary.

Quercus infectoria gall (Oak) has a long history of use as a medicinal plant. Andricus moreae galls arise on young branches of Quercus infectoria as a result of attack by bees. In this research، the antibacterial activity of methanol and acetone extracts of gall (Quercus infectoria) against Staphylococcus aureus، Bacillus cereus، B. subtilis strains was evaluated. this empirical-experimental study was carried out in Autumn،2011. Getlls were collected from Lorestan oak forests and then were dried and grinded. Acetone and methanol extracts of the galls were prepared by maceration. The viscosities of 50،25،12. 5،6. 25،3. 12 and 1. 56 mg/ml were provided from methanol and aceton extracs by serial dilution method. The agar plate well diffusion method was used for antibacterial assay of different samples. Broth microdillution method was used for evaluate MIC and MBC of extracts. Data was analyzed by SPSS-16 software. All extracts demonstrated significant inhibitory effect against selected bacterial strains. There were statistically significant correlations between antibacterial activity and extracts concentration (p<0. 05). Antibacterial activity of Andricus moreae gall methanol and acetone extracts against Staphylococcus aureus was more than Bacillus cereus، B. subtilis. The MIC values of the Andricus moreae gall extracts ranged from 1. 56 mg/ml to 3. 13 mg/ml whereas the MBC values ranged from 3. 13mg/ml to 6. 25 mg/ml. Methanol and acetone extracts of Andricus moreae were effective against all of tested bacteria. These findings show that methanol and acetone extracts of galls of Quercus infectoria may can be suggested as a natural antibacterial treatment.