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Introduction: The present study aimed to examine the effects of Lactobacillus acidophilus and Lactobacillus plantarum probiotics separately and synergistically on the immune system, growth factors, and disease resistance in the rainbow trout. Materials and Methods: At in vitro level, bacteriocin extracts of the target bacteria were used in the antimicrobial test against the fish pathogen Aeromonas hydrophila. Next, their effects on the fish blood lymphocytes were evaluated. At in vivo level, after feeding the fish in each treatment with the lactobacilli at the concentration of 108 CFU g-1 for 60 days, the growth indices were calculated. Then, blood samples from the rainbow trout were used to analyze any increase in the number of lymphocytes. Furthermore, given the infectious challenge with the pathogen Chryseobacterium aquaticum, the survival rates of the fish were determined. Results: L. acidophilus had the best effect on the growth factors and significantly increased the number of fish blood lymphocytes (p

Abstract Background and Objectives: Escherichia coli is the most common etiologic factor of urinary tract infection, which its most important virulence factor is P fimbriae. Uropathogenic E. coli expresses various types of adhesins, such as pili adhesins (pyelonephritis-associated pili, Pap) that mediates binding to the surface of epithelial cells of the urinary tract. This study aims to identify papC and papG genes and to evaluate antibiotic resistance level in the isolated E. coli samples. Methods: In this descriptive cross-sectional study, 50 samples were collected from patients with urinary tract infection and after isolation of bacteria and DNA extraction, antibiotic susceptibility tests was performed by disc diffusion method using related antibiotics. Presence of papG and papC genes (class I, II, and III) was assessed by multiplex PCR method. Statistical data were analyzed using descriptive t-test. Results: The isolated E. coli samples were susceptible to amikacin (100%) and cefepime (72%) and resistant to ampicillin (100%) and nitrofurantoin (94%). Eighteen samples (32.7%) had papG gene, of which 17 (30.9%) samples had papGII gene and 1 sample (1.8%) had papGIII gene; papGI gene was not detected in any of the samples. Conclusion: The results of the present study showed that papC and papGI genes are the most common Pap fimbriae adhesion-encoding genes in E. coli isolated from urinary tract infection. The difference between the results of this study with those of other studies is due to geographic diversity. Keywords: Escherichia coli; Adhesion pap, Disk diffusion antimicrobial tests; Multiplex polymerase chain reaction.

Background and Objectives: Nosocomial infections are associated with complications, mortality, and imposing high costs. Staphylococcus aureus is the most common strain causing nosocomial infections. Colonization of this microorganism in the nose is also a source of spread of nosocomial infection. In this study, the prevalence of nasal carriers of this bacterium, was investigated among the staff of Hazrate Masoumeh Hospital. Methods: This analytical cross-sectional study was performed on all the staff of Hazrate Masoumeh Hospital, who were in contact with patients. A nasal sample was obtained using a sterile swap. The samples were cultured in a culture medium appropriate for staphylococcus aureus, and antibiogram was performed for positive culture sample. Data were analyzed using chi-square, independent t- and ANOVA tests. The significance level was considered to be p

Abstract Background and Objectives: Development of bacterial resistance to antibiotics has led to an increased tendency to development of new more effective and non-toxic antimicrobial compounds. In this study, the inhibitory and lethal effects of aqueous, ethanolic, and hydroalcoholic extracts of aerial parts of Salvia chorassanica were evaluated against Listeria monocytogenes, Bacillus cereus, Salmonella typhi, and Escherichia coli O:157. Methods: In this study, Kirby–Bauer disk diffusion method was used to evaluate antimicrobial activity. In this method, bacteria were cultivated as grass culture in Mueller Hinton Agar (MHA) media. To determine the minimum inhibitory concentration and minimum bactericidal concentration, micro-dilution method with ELISA and addition of phenyl tetrazolium chloride reagent, were used. Data were analyzed using one-way ANOVA and Duncan’s test at the significance level of p

Background and Aims: One of the most important childhood infections is urinary tract infection (UTI). In order to prevent serious complications of UTI in children such as hypertension and renal failure, definitively diagnose and prompt treatment are essential. Since bacteria of the family Enterobacteriaceae are known to be the most common causes of UTI, the present study aimed to determine the frequency and antimicrobial resistance patterns of them in children with UTI. Materials and Methods: The present study was conducted on urine samples of children with UTI referred to Children`s Medical Center of Tehran during one year. The urine samples were cultured on selective media and the bacteria were identified by biochemical tests. Antibiotic resistance pattern of isolates were investigated by disk diffusion method. Results and Discussion: Out of 1348 positive urines for Enterobacteriaceae bacteria, more cases of UTI were observed in outpatient (1050, 77.89%) than in hospitalized patients (298, 22.11%). E.coli was the most common bacteria isolated among family Enterobacteriaceae, with prevalence of 76%. The clinical isolates had the most sensitivity to Amikacin and Piperacillin-Tazobactam, respectively (93%), and (98%) and resistance to Cephalothin (80%). Considering the prevalence of urinary tract infections, especially in children under 2 years and also in girls, the knowledge of local resistance pattern and well-timed eligible treatment are imperative. Accordingly, Amikacin and Piperacillin-Tazobactam are recommended for empirical treatment in children with UTI.

Background and Objectives: The medical herb Poulk is used for the treatment of infectious diseases in urinary tract, vagina, respiratory tract, rheumatism, ear infections, and other inflammatory conditions. In this study, the antibacterial effect of methanolic and aqueous extracts of Poulk on bacterial infection of urine, was investigated. Methods: In this experimental study, techniques for determining minimum inhibitory concentration (MIC) of bacterial growth, minimum bactericidal concentration (MBC), and disk diffusion were used to investigate the antibacterial effects of Poulk on the mentioned bacteria. Data were analyzed using analysis of variance and Duncan’s tests. Significance level was considered p

Background: Staphylococcus aureus is the most important cause of nosocomial infections acquired in the community. Protein A is a major component of Staphylococcus aureus cell wall. In analysis of the nucleotide sequence Protein A encoding spa, locus x consists of 24 base pairs which repeat with high polymorphism. In this study, the spa gene of Staphylococcus aureus isolated from clinical specimens were obtained from patients admitted to the hospital and healthy carriers. Methods: In a cross-sectional study, a total of 200 samples were collected. One hundred fifty samples were obtained from hospitalized patients and 50 samples obtained from staff nasal swabs in Hamadan University Hospitals from October 2013 to August 2014. Disk diffusion antibiotic susceptibility tests performed. The antibiotics studied were Vancomycin (30 µg), Cefoxitin (15 µg) Gentamicin (10 µg), Tetracycline (30 µg), Trimethoprim/sulfamethoxazole (25 µg), Ciprofloxacin (5 µg), Erythromycin (15 µg), Clindamycin (2 µg), Rifampin (5 µg). The tests performed according to the guidelines of clinical and laboratory standards institute (CLSI). It also detect the mecA gene of Methicillin-resistant Staphylococcus aureus strains (MRSA) and genes spa which encodes the protein A by polymerase chain reaction (PCR). The PCR products using a polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) method with enzyme Rsa I (Afa I) were prepared. Results: This methicillin-resistant Staphylococcus aureus strain (MRSA) had the highest sensitivity and resistance to ciprofloxacin and clindamycin. Totally, 8 amplicon with different sizes for the spa gene were identified. A total of 9 patterns polymerase chain reaction- restriction fragment length polymorphism (PCR-RFLP) were found. Some of these patterns between Staphylococcus aureus isolated from clinical specimens and nasal carriers were common. Conclusion: There is a similar pattern of spa gene among patients admitted to the hospital and staff, according to our findings. Analysis of the patterns can reduced transmission of infection in both hospital staff and patients. Also it can help the physicians for correct management of infections.

Introduction: Copper nanoparticles (CuNPs) are used in various industries, including pharmaceutical and biomedical sciences, agricultural and food chemistry, electronics and environmental applications, due to their novel optical, chemical, photoelectrochemical, and electronic properties as well as antimicrobial activities. The aim of the present study was to evaluate the ability of endophytic bacteria to synthesize CuNPs. Materials and Methods: Eighteen endophytic bacteria (CN1-CN18) were isolated from the root and crown rot of the bean. The agar dilution method was used to determe the intrinsic tolerance of endophytic bacterial isolates to copper ions. Characterization of CuNPs was performed using different methods including ultraviolet–visible spectroscopy (UV–Vis), field emission scanning electron microscope (FE-SEM), Fourier transform infrared (FTIR), X-ray energy diffraction spectroscopy (EDS), and powder X-ray diffraction (XRD). The antimicrobial activity of the copper nanoparticles was investigated by the agar well diffusion method. Results: The results of the study indicated that isolate CN10 was able to reduce CuCl2 to CuNPs. Based on the obtained phenotypic data and 16s rDNA sequence analysis (similarity above 99%), the isolate was identified as Pseudomonas grimontii. Additionally, spherical CuNPs with an average size of 24.8 nm were synthesized by resting cells of strain CN10 under 3 mM of copper chloride, pH 7.0, agitation 100 rpm, and 96 hours of incubation. The results of antimicrobial tests showed that the produced CuNPs exhibited the highest inhibitory effects on Xanthomonas campestris (19.2 mm) and the lowest inhibitory effects on Staphylococcus aureus (9.4 mm). Discussion and Conclusion: The current study is the first report on the synthesis of CuNPs using a resting cell of Pseudomonas grimontii. The results suggested the synthesis of CuNPs using endophytic bacteria as a promising tool for the production of CuNPs in a controlled shape and size. [ABSTRACT FROM AUTHOR]

Background and Aims: One of the most important childhood infections is urinary tract infection (UTI). In order to prevent serious complications of UTI in children such as hypertension and renal failure, definitively diagnose and prompt treatment are essential. Since bacteria of the family Enterobacteriaceae are known to be the most common causes of UTI, the present study aimed to determine the frequency and antimicrobial resistance patterns of them in children with UTI. Materials and Methods: The present study was conducted on urine samples of children with UTI referred to Children`s Medical Center of Tehran during one year. The urine samples were cultured on selective media and the bacteria were identified by biochemical tests. Antibiotic resistance pattern of isolates were investigated by disk diffusion method. Results and Discussion: Out of 1348 positive urines for Enterobacteriaceae bacteria, more cases of UTI were observed in outpatient (1050, 77.89%) than in hospitalized patients (298, 22.11%). E.coli was the most common bacteria isolated among family Enterobacteriaceae, with prevalence of 76%. The clinical isolates had the most sensitivity to Amikacin and Piperacillin-Tazobactam, respectively (93%), and (98%) and resistance to Cephalothin (80%). Considering the prevalence of urinary tract infections, especially in children under 2 years and also in girls, the knowledge of local resistance pattern and well-timed eligible treatment are imperative. Accordingly, Amikacin and Piperacillin-Tazobactam are recommended for empirical treatment in children with UTI. [ABSTRACT FROM AUTHOR]

Background: Staphylococcus aureus is the most important cause of nosocomial infections acquired in the community. Protein A is a major component of Staphylococcus aureus cell wall. In analysis of the nucleotide sequence Protein A encoding spa, locus x consists of 24 base pairs which repeat with high polymorphism. In this study, the spa gene of Staphylococcus aureus isolated from clinical specimens were obtained from patients admitted to the hospital and healthy carriers. Methods: In a cross-sectional study, a total of 200 samples were collected. One hundred fifty samples were obtained from hospitalized patients and 50 samples obtained from staff nasal swabs in Hamadan University Hospitals from October 2013 to August 2014. Disk diffusion antibiotic susceptibility tests performed. The antibiotics studied were Vancomycin (30 μg), Cefoxitin (15 μg) Gentamicin (10 μg), Tetracycline (30 μg), Trimethoprim/sulfamethoxazole (25 μg), Ciprofloxacin (5 μg), Erythromycin (15 μg), Clindamycin (2 μg), Rifampin (5 μg). The tests performed according to the guidelines of clinical and laboratory standards institute (CLSI). It also detect the mecA gene of Methicillin-resistant Staphylococcus aureus strains (MRSA) and genes spa which encodes the protein A by polymerase chain reaction (PCR). The PCR products using a polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) method with enzyme Rsa I (Afa I) were prepared. Results: This methicillin-resistant Staphylococcus aureus strain (MRSA) had the highest sensitivity and resistance to ciprofloxacin and clindamycin. Totally, 8 amplicon with different sizes for the spa gene were identified. A total of 9 patterns polymerase chain reaction- restriction fragment length polymorphism (PCR-RFLP) were found. Some of these patterns between Staphylococcus aureus isolated from clinical specimens and nasal carriers were common. Conclusion: There is a similar pattern of spa gene among patients admitted to the hospital and staff, according to our findings. Analysis of the patterns can reduced transmission of infection in both hospital staff and patients. Also it can help the physicians for correct management of infections. [ABSTRACT FROM AUTHOR]

In this research, the physicochemical and antimicrobial properties of propolis from honeybee beehives around Mashhad and the content of active compounds in propolis were determined by high pressure liquid chromatography (HPLC) both quantitatively and qualitatively. Physicochemical properties of the propolis sample (such as ash, moisture, soluble solids and insoluble solids and existing metal elements) were measured. The total phenolic and flavonoids compounds in the ethanolic extract of propolis were 40.126 mg/g (gallic acid) and 26.46 mg/g (quercetin), respectively. Antimicrobial tests showed that the minimum inhibitory concentration (MIC) of the extract against Staphylococcus aureus was 100 mg/mL, while in the applied concentration MIC did not achieve against Escherichia coli. Also, the results of the minimum bactericidal concentration (MBC) test indicated that propolis extract on Staphylococcus aureus had only inhibitory effects. Evaluation of the content of phenolic and flavonoid compounds in propolis extract by HPLC indicated that the flavonoid compounds included flavones (13.33 mg/g), flavonoids (6.375 mg/g), flavonols (8.235 mg/g) and flavanones (16.825 mg/g). Based on the results, propolis can be used in various food and pharmaceutical industries. [ABSTRACT FROM AUTHOR]

Biodegradable edible biopolymers derived from renewable agricultural sources offer a promising alternative to synthetic plastics. This study focused on preparing agar-carboxymethyl cellulose films containing glycerol (20-60%) and potassium sorbate (0-20%). Film properties such as thickness, water vapor permeability, water solubility, moisture absorption, water drop contact angle, and color characteristics were evaluated. The films were also tested for antibacterial and anti-mold properties against three bacterial species and two mold species. Results indicated that the composition of glycerol and potassium sorbate significantly influenced film solubility and moisture absorption (p< 0.05). The films exhibited high water drop contact angles, indicating low hydrophilicity. Potassium sorbate and glycerol notably affected the color parameters (L, a, b, and yellow index) of the films. Antimicrobial tests revealed effective antibacterial and antifungal properties, with the level of potassium sorbate showing a significant impact (p < 0.05) on these properties. In conclusion, utilizing cost-effective biopolymers and incorporating antimicrobial agents like potassium sorbate not only supports environmental sustainability but also enhances film properties and inhibits microbial growth.

Extracts and essential oils of medicinal plants have many bioactive agents, including phenolic compounds with significant antioxidant and antimicrobial properties. Choosing the suitable extraction method affects the quantity and quality of antioxidant and antimicrobial compounds. The aim of this study was to evaluate the efficiency of ultrasound waves in extracting phenolic, antioxidant and antimicrobial compounds of Caper fruit. Response surface methodology (RSM) and Box–Behnken design were used to optimize the extraction factors, including extraction time (10, 25, 40 min) and ultrasound intensity (40, 70, 100 %) with ethanolic solvent (70 %). From the results of the tests performed with the response surface methodology, ultrasound intensity was recognized as the most effective factor in extracting phenolic, antioxidant and antimicrobial compounds of Caper fruit and by increasing time and ultrasound intensity, the extraction of these compounds increased. The optimum conditions for extraction of antioxidant and antimicrobial compounds of Caper fruit were determined extraction time 36 minutes and ultrasound intensity 91 percent. In these optimum conditions, the amount of total phenolic contents and IC50 index of ethanolic extracts extracted from Caper fruit were obtained 23.63 mg/g and 45.30 μg/mg, respectively, the optimum amount of minimum inhibitory concentration of coagulase positive Staphylococcus aureus and Bacillus cereus were obtained 0.19 and 6.07 mg/ml, respectively, and the optimum amount of minimum batericidal concentration of coagulase positive Staphylococcus aureus was obtained 11.81 mg/ml. Also, the extracts extracted at time 36 minutes and ultrasound intensity 91 percent had the ability to inhibit the activity of Escherichia coli O157: H7 and Pseudomonas aeruginosa at concentrations of 25 and 25 mg/ml, respectively, and had the batericidal ability of Bacillus cereus, Escherichia coli O157: H7 and Pseudomonas aeruginosa at concentrations of 25, 50 and 50 mg/ml, respectively. [ABSTRACT FROM AUTHOR]

Background: Increasing bacterial resistance to usual antibacterial agents is a major problem of health care systems. Controlling the spread of bacteria within a hospital is thus a constant challenge. In this study, we investigated antimicrobial activity of copper oxide (CuO) and zinc oxide (ZnO) nanoparticles against Escherichia coli ATCC 25922 and Staphylococcus aureus ATCC 25923 bacteria. Methods: In this study, sensitivity coefficients and death kinetics of nanoparticles were used to evaluate the antimicrobial characteristics of ZnO and CuO nanoparticles against Escherichia coli and Staphylococcus aureus. Antimicrobial tests were performed with 108 CFU/ml of each bacterium at baseline. At first, minimum inhibitory concentration (MIC) was determined. Then, nanoparticle suspension of one and two times of MIC was used to determine death kinetics and sensitivity coefficient at treatment time of 0 to 360 minutes. Findings: In reaction with Staphylococcus aureus, ZnO nanoparticles (size: 20 nm) had the highest susceptibility (Z = 0.033 ml/μg) while CuO nanoparticles (size: 60 nm) had the lowest susceptibility (Z = 0.0032 ml/μg). The process of Escherichia coli and Staphylococcus aureus death in CuO and ZnO suspension was assumed to follow first-order kinetic. The survival ratio of bacteria decreased with increasing treatment time. An increase in the concentration of nanoparticles enhanced bactericidal properties. Conclusion: The sensitivity of Staphylococcus aureus to ZnO and CuO nanoparticles was higher than Escherichia coli. The results of this study demonstrated that ZnO has a strong antimicrobial effect compared to CuO. [ABSTRACT FROM AUTHOR]

[1]Introduction: Economic losses can occur due to the growth of fungi on foods that lead to food spoilage and plant diseases. Fruits and vegetables are often exposed to microbial activity, caused by pathogenic fungi, during post-harvest storage. Diseases of food origin are a growing public health problem. Thus, food safety has become a major public concern as microbial contamination increases the risk of foodborne illnesses and shortens the shelf life of foods. Infection with fungi such as Aspergillus, Rhizopus, and Penicillium species is considered as the primary cause of rapid spoilage of fresh produce, which reduces their quality and shelf life. Synthetic fungicides have been applied to solve this problem for many years. Nonetheless, the adverse effects of synthetic chemicals on human health and the emergence of fungicide-resistant strains have motivated the scientists and food industries to find out safe preservatives to control postharvest rot/diseases. On this point, natural antimicrobial agents such as plant extracts and essential oils are gaining more and more interest. In this study, we used Levisticum officinale Koch essential oil, which its antimicrobial and antioxidant activity has been reported in literatures. Materials and Methods: L. officinale Koch essential oil was obtained by hydrodistillation method and its total phenol content, total flavonoids, antioxidant activity (based on DPPH and ABTS free radical scavenging and β-carotene bleaching tests) and its antifungal effect against fungi causing apple and orange rotting (Alternaria alternata, Penicillium expansum, Penicillium digitatum, Penicillium italicum, and Botrytis cinerea) were examined according to antimicrobial tests of disk diffusion agar, well diffusion agar, minimum inhibitory concentration, and minimum fungicidal concentration. Results and Discussion:L. officinale Koch essential oil contained 61.27 ± 0.34 mg GAE/g and 20.14 ± 0.21 mg QE/g total phenol and flavonoids, respectively. Its antioxidant activity, based on DPPH free radical scavenging, ABTS free radical scavenging, and β-carotene bleaching inhibition were 69.72 ± 0.65%, 78.54 ± 0.3% and 57.50 ± 0.41%, respectively. L. officinale Koch essential oil was effective against all fungal species and the highest susceptibility was observed for Penicillium expansum. According to the results, L. officinale Koch essential oil can be used as a natural antifungal agent to prevent post-harvest diseases of fruits and vegetables.

Introduction: Copper nanoparticles (CuNPs) are used in various industries, including pharmaceutical and biomedical sciences, agricultural and food chemistry, electronics and environmental applications, due to their novel optical, chemical, photoelectrochemical, and electronic properties as well as antimicrobial activities. The aim of the present study was to evaluate the ability of endophytic bacteria to synthesize CuNPs. Materials and Methods: Eighteen endophytic bacteria (CN1-CN18) were isolated from the root and crown rot of the bean. The agar dilution method was used to determe the intrinsic tolerance of endophytic bacterial isolates to copper ions. Characterization of CuNPs was performed using different methods including ultraviolet–visible spectroscopy (UV–Vis), field emission scanning electron microscope (FE-SEM), Fourier transform infrared (FTIR), X-ray energy diffraction spectroscopy (EDS), and powder X-ray diffraction (XRD). The antimicrobial activity of the copper nanoparticles was investigated by the agar well diffusion method. Results: The results of the study indicated that isolate CN10 was able to reduce CuCl2 to CuNPs. Based on the obtained phenotypic data and 16s rDNA sequence analysis (similarity above 99%), the isolate was identified as Pseudomonas grimontii. Additionally, spherical CuNPs with an average size of 24.8 nm were synthesized by resting cells of strain CN10 under 3 mM of copper chloride, pH 7.0, agitation 100 rpm, and 96 hours of incubation. The results of antimicrobial tests showed that the produced CuNPs exhibited the highest inhibitory effects on Xanthomonas campestris (19.2 mm) and the lowest inhibitory effects on Staphylococcus aureus (9.4 mm). Discussion and Conclusion: The current study is the first report on the synthesis of CuNPs using a resting cell of Pseudomonas grimontii. The results suggested the synthesis of CuNPs using endophytic bacteria as a promising tool for the production of CuNPs in a controlled shape and size.

Introduction: In addition to its protective role, dressings not only prevent infection, but also accelerate wound healing process. In this study, the influence of optimizing the properties of the calendered needle-punched nonwoven fabrics using the finishing materials of Honey, Aloe Vera, Chitosan and Nano Argentum Nitrate for the end-usage as dressing has been investigated. Methods: The prepared samples of the needle-punched nonwoven fabrics were firstly calendered and then, tested for the fundamental expected physical characteristics in the dressing purpose, i.e. crease recovery magnitude, air permeability, etc. in order to distinct initial optimized sample. In the following, the antimicrobial finishing process was carried out on the primary sample by the four studied finishing materials. The finished samples were finally analyzed simultaneously from the antimicrobial aspect and also, for the same physical properties of the dressing, as tested before, to distinguish the ultimate optimized sample. The bacteria of Staphylococcus aureus and Escherichia coli (E.coli) were also employed for antimicrobial tests. Results: The results demonstrated that combination of four finishing materials of Nano Silver 1%, Aloe-Vera 20%, Honey 7% and Chitosan 1% improved desired properties for wound dressing application in comparison to the other samples from one side and, showed no cellular toxicity and allergy from the other side. The FTIR’s results also implied stretching bonding of hydroxyl group in 3200-3400 wavenumber. Conclusion: The needle-punched nonwoven fabric finished by the recommended antimicrobial materials can be considered as wound dressing, regarding to sufficient physical properties and hygienic condition.

In this research, the physicochemical and antimicrobial properties of propolis from honeybee beehives around Mashhad and the content of active compounds in propolis were determined by high pressure liquid chromatography (HPLC) both quantitatively and qualitatively. Physicochemical properties of the propolis sample (such as ash, moisture, soluble solids and insoluble solids and existing metal elements) were measured. The total phenolic and flavonoids compounds in the ethanolic extract of propolis were 40.126 mg/g (gallic acid) and 26.46 mg/g (quercetin), respectively. Antimicrobial tests showed that the minimum inhibitory concentration (MIC) of the extract against Staphylococcus aureus was 100 mg/mL, while in the applied concentration MIC did not achieve against Escherichia coli. Also, the results of the minimum bactericidal concentration (MBC) test indicated that propolis extract on Staphylococcus aureus had only inhibitory effects. Evaluation of the content of phenolic and flavonoid compounds in propolis extract by HPLC indicated that the flavonoid compounds included flavones (13.33 mg/g), flavonoids (6.375 mg/g), flavonols (8.235 mg/g) and flavanones (16.825 mg/g). Based on the results, propolis can be used in various food and pharmaceutical industries.

Hypothesis: In order to achieve safe and high-quality food products, the use of suitable packaging materials with excellent physical and chemical properties is a key requirement. Pollution resulting from packaging materials made of oil-based plastics and the problems associated with burning, disposal and recycling of these plastic products have attracted the attention of researchers to find appropriate solutions in recent years. Carboxymethyl cellulose (CMC) is one of the important polysaccharide polymers with capability of producing transparent films with relatively good mechanical and inhibition properties that have been used broadly in studies concerning the food stuff packaging. Methods: Nanocomposite films have been prepared by solution casting method in the presence of clay nanoparticles. Pure and modified montmorillonite noanoparticles and Cloisite 30B along with silver and copper were used for improving the functional properties of carboxymethyl cellulose nanobiocomposite films.Findings: It was observed that the clay nanoparticles incorporated into the nanocomposite films increased the UV absorption and mechanical properties and reduced the vapor permeability of the films. The XRD results showed that the silver was successfully inserted into the gallery space of the nanoclay, because the basal spacing of Ag-modified Cloisite 30B increased from 1.841 nm to 1.855 nm. Also, the compatibility of the nanoparticles with carboxymethyl cellulose was examined by SEM images. The SEM micrographs showed that the Cloisite 30B nanoparticles displayed better interface compatibility with CMC films than Na-montmorillonite. The results of antimicrobial tests showed that the nanobiocomposite film containing 4 wt% of Ag-modified Cloisite 30B exhibited maximum antimicrobial property against Staphylococcus aureus and Escherichia coli bacteria.

This study was aimed to fabricate a novel active edible coating with remarkable antioxidant and antimicrobial activity to ameliorate the beef shelf-life. For this purpose, the essential oil of Avishan-e- Baghi was firstly extracted by hydrodistillation method and its in-vitro antioxidant and antibacterial properties were then evaluated. The essential oil had a potentially high antioxidant activity and it was able to reduce the growth of bacteria Escherichia coli, Staphylococcus aureus, Salmonella typhimurium, and Pseudomonas aeruginosa. The essential oil was then mixed with Barhang-e- Sagheerseed mucilage to fabricate an active edible coating. The edible coating was used to coat beef and increase its shelf-life. The use of edible coating containing different concentration of essential oil significantly (p<0.05) inhibit the fat oxidation extent (primary and secondary products) and increase in total viable count, psychrotrophic bacteria, and coliforms in beef samples, and improved its shelflife up to 6-day storage at refrigeration condition. In general, the Avishan-e-Baghiessential oil-loaded Barhang-e-Sagheerseed mucilage-based edible coating could be used to control the lipid oxidation and microbial growth, as well as, to improve the shelf-life of meat products or other food products. [ABSTRACT FROM AUTHOR]

Background: Increasing bacterial resistance to usual antibacterial agents is a major problem of health care systems. Controlling the spread of bacteria within a hospital is thus a constant challenge. In this study, we investigated antimicrobial activity of copper oxide (CuO) and zinc oxide (ZnO) nanoparticles against Escherichia coli ATCC 25922 and Staphylococcus aureus ATCC 25923 bacteria. Methods: In this study, sensitivity coefficients and death kinetics of nanoparticles were used to evaluate the antimicrobial characteristics of ZnO and CuO nanoparticles against Escherichia coli and Staphylococcus aureus. Antimicrobial tests were performed with 108 CFU/ml of each bacterium at baseline. At first, minimum inhibitory concentration (MIC) was determined. Then, nanoparticle suspension of one and two times of MIC was used to determine death kinetics and sensitivity coefficient at treatment time of 0 to 360 minutes. Findings: In reaction with Staphylococcus aureus, ZnO nanoparticles (size: 20 nm) had the highest susceptibility (Z = 0.033 ml/μg) while CuO nanoparticles (size: 60 nm) had the lowest susceptibility (Z = 0.0032 ml/μg). The process of Escherichia coli and Staphylococcus aureus death in CuO and ZnO suspension was assumed to follow first-order kinetic. The survival ratio of bacteria decreased with increasing treatment time. An increase in the concentration of nanoparticles enhanced bactericidal properties. Conclusion: The sensitivity of Staphylococcus aureus to ZnO and CuO nanoparticles was higher than Escherichia coli. The results of this study demonstrated that ZnO has a strong antimicrobial effect compared to CuO. Keywords: Susceptibility, Kinetic, Zinc oxide, Copper oxide, Nanoparticle, Escherichia coli, Staphylococcus aureus