جستجوی مقالات مرتبط با کلیدواژه "antimicrobial" در نشریات گروه "دامپزشکی"

Edible films have gained significant attention as carriers of antioxidant and antimicrobial compounds. Essential oils and aqueous extracts of red pepper, known for their antimicrobial properties in food systems, can be incorporated into the matrix of edible films. This study aimed to investigate the antimicrobial activity of calcium pectinate edible films containing essential oil and aqueous extract of red pepper against four major foodborne pathogenic bacteria, including Staphylococcus aureus, Listeria monocytogenes, Escherichia coli (O157:H7), and Salmonella enteritidis, using the disc diffusion method. Disks with a diameter of 9 mm were prepared from calcium pectinate-based films containing 0.5% and 1% essential oil and 2% aqueous extract of red pepper and placed under sterile conditions on pre-inoculated BHI agar plates. The diameter of the inhibition zones was considered as an indicator of the antimicrobial activity of the films. Statistical analysis was performed using Sigma Plot software. The results demonstrated that the designed films effectively inhibited the tested pathogens. Composites containing red pepper essential oil exhibited a remarkable ability to restrict the growth of foodborne pathogenic bacteria at both concentrations. However, the film containing only 0.5% essential oil did not form an inhibition zone against Salmonella enteritidis, indicating no inhibitory effect at this concentration. Additionally, the addition of aqueous extract of red pepper further enhanced the antibacterial properties of the essential oil-containing films. These findings suggest that essential oil and aqueous extract of red pepper can be employed as natural preservatives in calcium pectinate edible films for food packaging applications.

Salmonella is one of the important  food borne diseases, worldwide. Egg and meat are among the most important incriminated foods to cause salmonella infection in Iran. This study was designed to investigate possible inhibitory effects of ethanolic extract of basil on Salmonella in mayonnaise sauce. Salmonella is killed with baking food but there is problem with foods like sauce which contain raw egg and is not used any procedure for baking them while producing. The purpose of this project was to investigate the possibility to use ethanol extract of basil to control Salmonella Typhimurium in sauce. In the study, first of all the anti-bacterial property of ethanol extract of basil was tested. So, by appearing result test for final investigation densities of extract was purposed 0.25, 0.5 and 0.75%. Then anti-bacterial property of ethanol extract of basil on growth of salmonella in mayonnaise sauce for a period of 30 days in condition of 25oc and 4oc was investigated.The results of statistical studies showed that the three concentrations studied significantly (p <0.05) compared to the control sample reduced the growth of Salmonella Typhimurium during storage and with increasing the concentration of the extract increased the antibacterial activity of the extract so that the extract Basil with a concentration of 7500 ppm was significantly lower than other treatments in most cases (p<0.05). Sensory evaluation test was performed by 5-point hedonic method and the results of sensory analysis of appearance and color in different treatments were not significantly different from each other. Regarding the flavour, texture and total acceptability of the sauce, the lowest sensory score was related to the treatment with a concentration of 0.75%. Based on the obtained results, the amount of bacteria in both temperatures decreased in all treatments and this decrease was little in the control treatment and its antibacterial activity increased with increasing the concentration of the extract.

This study aims to compare the antimicrobial properties of nisin and natamycin in pasteurized liquid egg whites. After breaking and processing the eggs and performing operations such as filtration and homogenization, the egg white liquid undergoes pasteurization at 56-57 °C for 10 minutes with a flow rate of 1800 m3/s. Following pasteurization, the liquid is mixed with 0.08% and 0.1% solutions of nisin and natamycin in packaging tanks. Microbial tests are conducted at 0, 7, 14, and 30 days of storage. Based on the results, the antimicrobial effect of both natural preservatives nisin and natamycin in the microbial tests of total count, coliform, mold, and yeast have a significant difference at the probability level of 5%. In the total count test, 0.1% nisin on the seventh day exhibits the lowest total count (1.71 log CFU/gr), while the control sample on the 30th day shows the highest (4/49 log CFU/gr). For natamycin, 0.1% on the seventh day and 0.08% on the seventh day have the lowest counts (2.63 log CFU/gr and 2.67 log CFU/gr) respectively, and the control sample on the 30th day has the highest (4.5 log CFU/gr). No microorganism growth is observed in samples containing nisin and natamycin for coliform, mold, yeast, Escherichia coli, Staphylococcus aureus, and salmonella tests. Nisin demonstrates a more intense reduction in total count compared to natamycin, indicating superior antimicrobial properties and increased shelf life over time.

Replacing naturally occurring bioactive substances, such as microbial metabolites, with synthetic preservative compounds, and getting access to their beneficial properties, is expanding every day. Meanwhile, the focus of many researchers' attention has been on bacteriocins, which have multiple physiological functions, including antibacterial and anticancer properties. In this study, the enterocin production genes of Enterococcus isolates from two fermented dairy products (Motal cheese and Tarkhineh) were tracked using a molecular method. The kinetics of bacteriocin-like substance production, as well as its stability (at high temperatures, different pH levels, and under different enzyme influences), were investigated. The antagonistic (well diffusion method) and anticancer (with MTT colorimetric technique) characteristics of enterocins generated by these isolates were also investigated in two human cancer cell lines. The results of the PCR test showed that isolates of Enterococcus faecium AUT-7KB and Enterococcus faecalis KUMS-T48 contained all three studied enterocin production genes, and the bacteriocin-like metabolites of these strains had strong antagonistic effects on Listeria monocytogenes and Bacillus cereus. These metabolites had high stability at different pH and became ineffective under the influence of protease enzymes (trypsin and pepsin), which indicated their protein nature. Additionally, metabolites of the KUMS-T48 isolate showed strong cytotoxic effects on two cancer cell lines, AGS and HT-29. According to the findings of the current research, enterocins of the E. faecalis KUMS-T48 strain are suggested as a suitable candidate for further anti-tumor studies, such as in vivo studies, after complete investigations of safety aspects.

Salmonellosis is one of the most important common diseases of livestock and humans worldwide. With the prevalence of antibiotic resistance, the tendency to use medicinal plants to control microorganisms has increased. The aim of this research was to investigate the antibacterial effects of the essential oils of Thymus vulgaris and salmonella typhimurium (ATCC=14028). For this purpose, first, the essential oils of the mentioned plants were extracted by steam distillation using a Clovenger machine. Then, using the microdilution broth method, the Minimum Inhibitory Concentration (MIC) and the Minimum Bactericidal Concentration (MBC) of essential oils alone and in combination, as well as drug sensitivity or resistance testing based on the well diffusion method in agar against the standard strain of Salmonella typhimurium bacteria, were determined in comparison with three common antibiotics in veterinary medicine. The MIC was calculated for thyme (0.25), mixed essential oil (0.50), doxycycline (0.0078) and oxytetracycline (<0.00195) μg/ml. The MBC for them was 0.25, 0.50, 0.0156 and >0.00195 respectively. Dill essential oil and erythromycin antibiotic had no antimicrobial effect against Salmonella typhimurium. The highest effect was related to oxytetracycline (with a growth inhibition diameter of 27 mm) and the lowest effect was related to thyme essential oil (with a growth inhibition diameter of 10 mm). Unlike dill essential oil, garden thyme essential oil has a significant antibacterial effect.

Some yeasts, such as Z. bisporis and P. occidentalis, still need further study to determine their functional characteristics and how to use them in the food and pharmaceutical industries. The purpose of this study is the investigation of the functional and antioxidant properties of Z. bisporis and P.occidentalis isolated from Kombucha.

for this purpose, antioxidant capacity by 1,1-diphenyl-2-picrylhydrazyl radical method (DPPH) and functional properties (survival under simulated conditions of the gastrointestinal system, hydrophobicity, auto aggregation and antioxidant properties, antimicrobial activity against food-borne pathogenic bacteria such as Staphylococcus aureus, Yersinia enterocolitica, Bacillus cereus and Escherichia coli was investigated by spot method.

The results of this research showed that Z.bisporis and P.occidentalis have excellent antioxidant activity of about 67.67 and 69.18 percent, auto aggregation capacity of about 92.44 and 87.30 percent. After 24 hours and high hydrophobicity activity has provided about 87.51 and 86.127 percent. Also, the survival percentage of these isolates under the simulated conditions of the gastric juice was about 54.87 and 88.87%, under the simulated conditions of the duodenum, it was 97.09 and 94.40%. Z. bisporis studied in this test had antimicrobial activity against Yersinia enterocolitica, but did not show any activity against the tested microorganisms.

According to the obtained results, it is suggested to use more of these strains as a natural source of antioxidant and probiotic supplement in the production of food and pharmaceutical products after completing additional tests.

This study aimed to investigate the antioxidant and antimicrobial properties of Echinacea purpurea, which is used as an antiseptic, immune system booster, antimicrobial, antioxidant and anti-poisoning herbaceous plant. Antioxidant and antimicrobial properties, total phenolic compounds and DPPH radical scavenging of the extract were measured. Antimicrobial properties of the extract were assessed using well-diffusion method. The components of the extract were identified using gas chromatography-mass spectrometry (GC MS). The data were analyzed using SPSS and Duncan's statistical test. The plant extract showed high level of phenolic compounds. The DPPH radical scavenging of the extract was tested at concentrations of 0.22, 0.25, 0.27, 0.31, 0.35, 0.41, 0.50 g/ml. The concentration of IC50 indicated sufficient inhibitory potential of the extract. The diameter (means ± SD) of the growth inhibition zone for Staphylococcus aureus, Escherichia coli and Aspergillus niger was estimated at 4.67 ± 1.24, 3.11 ± 0.84 and 1.78 ± 0.89 mm, respectively. Based on well-diffusion assay, S. aureus was found more sensitive than E. coli, and E. coli was more sensitive than A. niger. Using the gas chromatography-mass spectrometry, 81.38% of the total extract compounds were identified. Important components of the extract consisted of germacrene D (21.67%), paracetamol (5.53%), Bernoulli (4.58%), respectively. The results showed that Echinacea extract had excellent antioxidant and antimicrobial effects.

Hypericum perforatum is a medicinal plant of the genus Hypercasia that has phenolic and flavonoid compounds with high antimicrobial and antioxidant properties. The present study was performed to evaluate the antimicrobial effects of the methanolic extract of Hypericum perforatum on food-borne bacteria. Aerial part of Hypericum perforatum was prepared from the research farm, and after approval by experts, it was dried and powdered and used to prepare methanolic extract. The diameter of the growth inhibition zone of Pseudomonas aeruginosa, Escherichia coli and Staphylococcus aureus was assessed using disk diffusion and compared with antibiotics. Minimum inhibitory concentration (MIC) and Minimum Bacterial Concentration (MBC) of methanolic extract of Hypericum perforatum were evaluated on the target bacteria using ELISA plate. The diameter of the growth inhibition zone of bacteria against the methanolic extract of Hypericum perforatum ranged from 9.33±0.45 to 15.28±0.60 mm. Application of 100 mg/ml concentration of methanolic extract of Hypericum perforatum caused the highest diameter of the growth inhibition zone of Pseudomonas aeruginosa (12.27±0.53 mm), Escherichia coli (13.20±0.59 mm) and Staphylococcus aureus (15.28±0.60 mm). The antimicrobial effects of methanolic extract of fenugreek were dose-dependent (P <0.05). The lowest and highest levels of MIC and MBC of methanolic extract of Hypericum perforatum were obtained for Staphylococcus aureus (0.0010 and 0.0019, respectively) and Escherichia coli (0.50 and 1.00, respectively). The diameter of the growth inhibition zone of bacteria treated with methanolic extract of Hypericum perforatum was higher compared to some antibiotic discs.

Plants are valuable sources of different antioxidant and antimicrobial compounds. The composition and structure of the functional groups of essential oils and extracts play an important role in their antioxidant and antimicrobial activity. Prosopis farcta is a spice of Leguminosae family and Mimosoideae subfamily, an aborigine to the dry and semi-dried regions of Asia, Africa and America. In this study, the root extract of Prosopis farcta prepared by soxhlet extractor and ethanol 70% solvent. The extraction yield was estimated at 1.85%. Total phenol and flavonoids compounds were calculated 178.14 ± 0.17 mg Gallic acid/g and 94.33 ± 0.77 mg Quercetin/g, respectively. Phenolic compounds comprised 11.98% of the total chemical composition of the extract. IC50 for root extract and BHT (synthetic antioxidant) was determined 2.45 μg/ml and 1.98 μg/ml, respectively. In the β-carotene-linoleic acid system, the average antioxidant activity reported 39.25% for root extract and 57.13% for the BHT. Among 250, 500 and 1000 ppm concentrations of the extract, 1000 ppm showed the best antioxidant effect in soybean oil for 12 days storage at 50°C. Staphylococcus aureus (with MIC 200 µg/ml and MBC 350 µg/ml) showed the most sensitivity in comparison with the two gram-negative bacteria, Salmonella Typhimurium and Escherichia coli. The results of this study showed that the hydro-ethanolic root extract of Prosopis farcta had suitable antimicrobial and antioxidant activity.

Nowadays, many studies have been conducted to substitute the chemical preservatives with naturally occurring compounds, including plant essential oils. In this research, Golpar essential oil was added to Dough samples at concentrations of 0 (control), 100, 250, 500 and 1000 ml/l and after packaging, were stored at refrigerator for 40 days. The samples were subjected to microbial (enumeration of yeasts and molds, yoghurt starter bacteria and coliforms), chemical (acidity, pH, fat and solids-non-fat) as well as sensory characteristics (taste and odor) assays. Results showed that with the increasing of the essence concentration, the populations of yeast and mold were reduced (P

Application of natural preservatives to protect foods from microbial spoilage and to control the occurrence of foodborne pathogens has become an important issue worldwide. The aim of this study was to investigate the inhibitory effect of Basil (Ocimum basilicum L.) essence of Staphylococcus aureus, Escherichia coli and Rhodotorula rubra. The basil essence was extracted by hydro-distillation using Clevenger apparatus. The components of the essence was analyzed by GC/MS. Afterwards, using micro-dilution method the Minimum Inhibitory Concentration (MIC) and Minimum Bactericidal Concentration (MBC) for S. aureus, E. coli and R. rubra was estimated. Based on results, 43 various components were detected in basil essence, namely benzene (20.97%), E-citral (12.845%), Z-citral (6.137%), methyl chavicol (7.68%) and thymol (7.79%). MIC and MBC for was 0.25 mg/ml for E. coli and R. rubra, meanwhile it was estimated at 0.5 mg/ml for S. aureus. Taking into account the various components of basil essence as well as their antimicrobial properties, it was concluded that, with considering the natural properties of each food type, basil essence can be used as a food preservative.

Due to the increasing resistance of pathogenic bacteria to common antibiotics and antimicrobial agents, researchers are finding antimicrobial agents with plant origin as alternative drugs. Antioxidants are the main factors in neutralizing free radicals and prevent the spread of chronic diseases and destruction of many foods. After preparing the ethanolic extract from leaves of Eucalyptus camaldulensis Dehnh by maceration method, the antimicrobial effect of it was determined on Staphylococcus aureus and Escherichia coli isolated from women’s urogenital tract infections and food stuff and Salmonella pullorum and Salmonella gallinarum isolated from birds cases by minimal inhibitory concentration (MIC) and minimal bactericidal concentration (MBC) methods. The antioxidant and reducing power effects of ethanolic extract of Eucalyptus camaldulensis Dehnh were studied by DPPH(2,2-diphenyl-1-picryl-hydrazyl-hydrate) assay. The least to most antimicrobial effects of ethanolic extract of Eucalyptus camaldulensis Dehnh were seen against Salmonella pullorum, Escherichia coli, Staphylococcus aureus and Salmonellagallinarum, respectively. Antioxidant effect and reducing power of ethanolic extract of Eucalyptus camaldulensis Dehnh were recorded less than BHT (Butylatedhydroxytoluene) in equal concentration (p

Regarding the harmful effects of chemical foods preservatives on human body, it is crucial to find out safe antimicrobials among essential oils and herbs. This study aimed to address the effects of different essential oils on various bacterial species through a systematic review. A wide range of published papers in national and international data bases have been searched for the relevant articles. For this reason, the keywords used in searching were: "essential oils in food", "antimicrobial effect" and "vegetable oils". Among 462 retrieved articles, 76 papers were selected for further reviewing based on their title and abstracts. Based on results, the antimicrobial effects of different essential oils on pathogenic and spoilage organisms were compared. Moreover, the most effective as well as the least effective essential oils on microbial growth were identified. It was concluded that essential oils are more effective on gram positive bacteria rather than gram negatives. Besides, it was evident that some essential oils negatively affected the useful organisms such as lactobacilli.