Commenced in January 2007
Frequency: Monthly
Edition: International
Paper Count: 129

Search results for: Listeria innocua ATCC 33092

129 Inactivation of Listeria innocua ATCC 33092 by Gas-Phase Plasma Treatment

Authors: Z. Herceg, V. Stulic, T. Vukusic, A. Rezek Jambrak

Abstract:

High voltage electrical discharge plasmas are new nonthermal developing techniques used for water decontamination. To the full understanding of cell inactivation mechanisms, this study brings inactivation, recovery and cellular leakage of L. innocua cells before and after the treatment. Bacterial solution (200 mL) of L. innocua was treated in a glass reactor with a point-to-plate electrode configuration (high voltage electrode-titanium wire, was in the gas phase and grounded electrode was in the liquid phase). Argon was injected into the headspace of the reactor at the gas flow of 5 L/min. Frequency of 60, 90 and 120 Hz, time of 5 and 10 min, positive polarity and conductivity of media of 100 µS/cm were chosen to define listed parameters. With a longer treatment time inactivation was higher as well as the increase in cellular leakage. Despite total inactivation recovery of cells occurred probably because of a high leakage of proteins, compared to lower leakage of nucleic acids (DNA and RNA). In order to define mechanisms of inactivation further research is needed.

Keywords: Listeria innocua ATCC 33092, inactivation, gas phase plasma, cellular leakage, recovery of cells

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128 Preliminary Evaluation of the Probiotic Potential of Leuconostoc mesonteroides Strain Isolated from Goat's Milk

Authors: Benyoucef Amel, Benmechernene Zineb, Kihal Mebrouk

Abstract:

One strain (V1) of Leuconostoc mesonteroides was isolated from goat’s milk collected from El Bayadh which is located in the west of Algeria and was characterized by phenotypic and biochemical methods. This strain was tested for their antimicrobial activity against indicator bacteria (Staphylococcus aureus ATCC 43300, Listeria innocua ATCC 33090, Listeria ivanovii ATCC 19119) and was evaluated for certain properties relevant to probiotic including acid resistance (pH 2 ; 3and 4), bile tolerance at 0.5%, 1% and 2%, pepsin resistance 3mg/ml at pH 2 and 3, hemolytic activity and antibiotics sensitivity. Our results revealed the strain V1 showed antagonistic activity against Staphylococcus aureus, Listeria innocua and Listeria ivanovii, due to a production of proteinous nature substances. The strain was resistant to pH 3 and 4, bile salts at 0.5%, 1% and 2% and pepsin at pH 3; and was γ-hemolytic and susceptible to four antibiotics: Chloramphenicol, pristinamycin, Clindamycin and Lincomycin. These results may be considered the strain V1 as suitable probiotic candidate.

Keywords: antimicrobial, goat‘s milk, Leuconostoc, probiotic

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127 Study of the Antimicrobial Activity of Aminoreductone against Pathogenic Bacteria in Comparison with Other Antibiotics

Authors: Vu Thu Trang, Lam Xuan Thanh, Samira Sarter, Tomoko Shimamura, Hiroaki Takeuchi  

Abstract:

Antimicrobial activities of aminoreductone (AR), a product formed in the initial stage of Maillard reaction, were screened against pathogenic bacteria. A significant growth inhibition of AR against all 7 isolates (Staphylococcus aureus ATCC® 25923™, Salmonella Typhimurium ATCC® 14028™, Bacillus cereus ATCC® 13061™, Bacillus subtilis ATCC® 11774™, Escherichia coli ATCC® 25922™, Enterococcus faecalis ATCC® 29212™, Listeria innocua ATCC® 33090™) were observed by the standard disc diffusion methods. The inhibition zone for each isolate by AR (2.5 mg) ranged from 15±0 mm to 28.3±0.4 mm in diameter. The minimum inhibitory concentration (MIC) of AR ranging from 20 mM to 26 mM was proven in the seven isolates tested. AR also showed the similar effect of growth inhibition in comparison with antibiotics frequently used for the treatment of infections bacteria, such as amikacin, ciprofloxacin, meropennem, and levofloxacin. The results indicated that foods containing AR are valuable sources of bioactive compounds towards pathogenic bacteria.

Keywords: pathogenic bacteria, aminoreductone, Maillard reaction, antimicrobial activity

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126 Phenotypic Characterization of Listeria Spp Isolated from Chicken Carcasses Marketed in Northeast of Iran

Authors: Abdollah Jamshidi, Tayebeh Zeinali, Mehrnaz Rad, Jamshid Razmyar

Abstract:

Listeria infections occur worldwide in variety of animals and man. Listeriae are widely distributed in nature. The organism has been isolated from the feces of humans and several animals, different soils, plants, aquatic environments and food of animal and vegetable origin. Listeria monocytogenes is recognized as important food-borne pathogens due to its high mortality rate. This organism is able to growth at refrigeration temperature, and high osmotic pressure. Poultry can become contaminated environmentally or through healthy carrier birds. In recent decades, prophylactic use of antimicrobial agents may be lead to emergence of antibiotic resistant organisms, which can be transmitted to human through consumption of contaminated foods. In this study, from 200 fresh chicken carcasses samples which were collected randomly from different supermarkets and butcheries, 80 samples were detected as contaminate with Listeria spp. and 19% of the isolates identified as Listeria monocytogene using multiplex PCR assay. Conventional methods were used to differentiate other species of the listeria genus. The results showed the most prevalent isolates as L. monocytogenes (48.75%). Other isolates were detected as Listeria innocua (28.75%), Listeria murrayi (20%), Listeria grayi (3.75%) and Listeria welshimeri (2.5%).The Majority of the isolates had multidrug resistance to commonly used antibiotics. Most of them were resistant to erythromycin (50%), followed by Tetracycline (44.44%), Clindamycin (41.66%), and Trimethoprim (25%). Some of them showed resistance to chloramphenicol (17.65%). The results indicate the resistance of the isolates to antimicrobials commonly used to treat human listeriosis, which could be a potential health hazard for consumers.

Keywords: listeria species, L. monocytogenes, antibiotic resistance, chicken carcass

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125 Control of Listeria monocytogenes ATCC7644 in Fresh Tomato and Carrot with Zinc Oxide Nanoparticles

Authors: Oluwatosin A. Ijabadeniyi, Faith Semwayo

Abstract:

Preference for consumption of fresh and minimally processed fruits and vegetables continues to be on the upward trend however food-borne outbreaks related to them have also been on the increase. In this study the effect of zinc oxide nanoparticles on controlling Listeria monocytogenes ATCC 7644 in tomatoes and carrots during storage was investigated. Nutrient broth was inoculated with Listeria monocytogenes ATCC 7644 and thereafter inoculated with 0.3mg/ml nano-zinc oxide solution and 1.2mg/ml nano-zinc oxide solution and 200ppm chlorine was used as a control. Whole tomatoes and carrots were also inoculated with Listeria monocytogenes ATCC 7644 after which they were dipped into zinc oxide nanoparticle solutions and chlorine solutions. 1.2 mg/ml had a 2.40 log reduction; 0.3mg/ml nano-zinc oxide solution had a log reduction of 2.15 in the broth solution. There was however a 4.89 log and 4.46 reduction by 200 ppm chlorine in tomato and carrot respectively. Control with 0.3 mg/ml zinc oxide nanoparticles resulted in a log reduction of 5.19 in tomato and 3.66 in carrots. 1.2 mg/ml nanozinc oxide solution resulted in a 5.53 log reduction in tomato and a 4.44 log reduction in carrots. A combination of 50ppm Chlorine and 0.3 mg/ml nanozinc oxide was also used and resulted in log reductions of 5.76 and 4.84 respectively in tomatoes and carrots. Treatments were more effective in tomatoes than in carrots and the combination of 50ppm Chlorine and 0.3 mg/ml ZnO resulted in the highest log reductions in both vegetables. Statistical analysis however showed that there was no significant difference between treatments with Chlorine and nanoparticle solutions. This study therefore indicates that zinc oxide nanoparticles have the potential for use as a control agent in the fresh produce industry.

Keywords: Listeria monocytogenes, nanoparticles, tomato, carrot

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124 Incidence of Listeria monocytogenes in Ready-To-Eat Food Sold in Johannesburg, South Africa

Authors: Hattie Hope Makumbe, Bhekisisa Dlamini, Frederick Tabit

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Listeria monocytogenes is one of the most important foodborne pathogens associated with ready-to-eat (RTE) food. This study investigated the incidence of Listeria monocytogenes in 80 RTE food sold in the formal (dairy and processed meat) and informal markets (vegetable salads, beef stew, and rice) of Johannesburg, South Africa. High Enterobacteriaceae, S. aureus, and E. coli counts were obtained, which ranged from 1.9-7.5 log CFU/g. Listeria monocytogenes microbial counts in the food samples ranged from 3.5-6.0 log colony forming unit per gram except in cooked rice. The Listeria monocytogenes isolates were identified using biochemical tests and confirmed with the Biolog identification system and PCR analyses. The percentage incidence for Listeria monocytogenes in ready to eat food was 12.5%. When Minimum Inhibitory Concentrations were under consideration, all disinfectants were effective against Listeria monocytogenes strains. For antimicrobial work, rates of resistance amongst the antibiotics ranged from 17-100%. Therefore, more effective preventive control strategies for Listeria monocytogenes are needed to reduce the prevalence of the pathogen in RTE food that is sold in Johannesburg.

Keywords: Listeria monocytogenes, Listeria species, ready to eat food, sanitiser efficacy

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123 Purification of Eicosapentaenoic Acid (EPA) and Docosahexaenoic Acid (DHA) from Fish Oil Using HPLC Method and Investigation of Their Antibacterial Effects on Some Pathogenic Bacteria

Authors: Yılmaz Uçar, Fatih Ozogul, Mustafa Durmuş, Yesim Ozogul, Ali Rıza Köşker, Esmeray Kuley Boğa, Deniz Ayas

Abstract:

The aim of this study was to purified eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), that are essential oils from trout oil, using high-performance liquid chromatography (HPLC) method, bioconverted EPA and DHA into bioconverted EPA (bEPA), bioconverted DHA (bDHA) extracts by P. aeruginosa PR3. Moreover, in vitro antibacterial activity of bEPA and bDHA was investigated using disc diffusion methods and minimum inhibitory concentration (MIC). EPA and DHA concentration of 11.1% and 15.9% in trout oil increased in 58.64% and 40.33% after HPLC optimisation, respectively. In this study, EPA and DHA enriched products were obtained which are to be used as valuable supplements for food and pharmaceutical purposes. The bioconverted EPA and DHA exhibited antibacterial activities against two Gram-positive bacteria (Listeria monocytogenes ATCC 7677 and Staphylococcus aureus ATCC 29213) and six Gram-negative bacteria (Pseudomonas aeruginosa ATCC 27853, Escherichia coli ATCC 25922, Klebsiella pneumoniae ATCC700603, Enterococcus faecalis ATCC 29212, Aeromonas hydrophila NCIMB 1135, and Salmonella Paratyphi A NCTC 13). Inhibition zones and MIC value of bEPA and bDHA against bacterial strains ranged from 7 to 12 mm and from 350 to 2350 μg/mL, respectively. Our results suggested that the crude extracts of bioconversion of EPA and DHA by P. aeruginosa PR3 can be considered as promising antimicrobials in improving food safety by controlling foodborne pathogens.

Keywords: High-Performance Liquid Chromatography (HPLC), docosahexaenoic acid, DHA, eicosapentaenoic acid, EPA, minimum inhibitory concentration, MIC, Pseudomonas aeruginosa PR3

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122 Chemical Composition and Antibacterial Activity of the Essential Oils from Bunium alpinum and Bunium incrassatum

Authors: Hayet El Kolli, Hocine Laouer

Abstract:

Bunium in the world comprises about 50 to 100 species, mostly distributed in: Algeria, Italy, Pakistan, Iran, and South Africa. Bunium species have several uses like: Bunium persicum which is commonly used as antispasmodic, carminative, anti-obesity and lactogage. This plant have been widely used as an additive in food stuff such as in bread cooking, rice and yoghurt for its carminative, anti-dyspepsia and antispasmodic effect. The B. paucifolium oil has a wide spectrum of action against moulds, yeast and bacteria. The chemical compositions of Bunium incrassatum and Bunium alpinum essential oils were carry out by GC and GC/MS. Therefore, antibacterial activity of two oils was investigated by disk diffusion method against Pseudomonas aeruginosa ATCC 27853, Escherichia coli ATCC 25922, Salmonella typhimurium ATCC 1331, Staphylococcus aureus ATCC 25923, Klebsiella pneumoniae ATCC 700603, Bacillus cereus ATCC 10876, Enterococcus faecalis ATCC 49452, Lysteria monocytogenes ATCC 15313, Citrobacter freundii ATCC 8090, Proteus mirabilis ATCC 35659. A moderate antibacterial activity was found. In conclusion, it is found that essential oils of the two species are rich in sesquiterpens and other oxygenated compounds. These compounds have been reported to show bactericidal activity and the presence of phenolic compounds makes them useful antioxidants so that results confirm some ethnopharmacologique applications of these two oils of Bunium.

Keywords: Bunium alpinum, Bunium incrassatum, apiaceae, essential oil, sesquiterpens, phenols, antibacterial, antioxidant activities

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121 Identification of the Antimicrobial Effect of Liquorice Extracts on Gram-Positive Bacteria: Determination of Minimum Inhibitory Concentration and Mechanism of Action Using a luxABCDE Reporter Strain

Authors: Madiha El Awamie, Catherine Rees

Abstract:

Natural preservatives have been used as alternatives to traditional chemical preservatives; however, a limited number have been commercially developed and many remain to be investigated as sources of safer and effective antimicrobials. In this study, we have been investigating the antimicrobial activity of an extract of Glycyrrhiza glabra (liquorice) that was provided as a waste material from the production of liquorice flavourings for the food industry, and to investigate if this retained the expected antimicrobial activity so it could be used as a natural preservative. Antibacterial activity of liquorice extract was screened for evidence of growth inhibition against eight species of Gram-negative and Gram-positive bacteria, including Listeria monocytogenes, Listeria innocua, Staphylococcus aureus, Enterococcus faecalis and Bacillus subtilis. The Gram-negative bacteria tested include Pseudomonas aeruginosa, Escherichia coli and Salmonella typhimurium but none of these were affected by the extract. In contrast, for all of the Gram-positive bacteria tested, growth was inhibited as monitored using optical density. However parallel studies using viable count indicated that the cells were not killed meaning that the extract was bacteriostatic rather than bacteriocidal. The Minimum Inhibitory Concentration [MIC] and Minimum Bactericidal Concentration [MBC] of the extract was also determined and a concentration of 50 µg ml-1 was found to have a strong bacteriostatic effect on Gram-positive bacteria. Microscopic analysis indicated that there were changes in cell shape suggesting the cell wall was affected. In addition, the use of a reporter strain of Listeria transformed with the bioluminescence genes luxABCDE indicated that cell energy levels were reduced when treated with either 12.5 or 50 µg ml-1 of the extract, with the reduction in light output being proportional to the concentration of the extract used. Together these results suggest that the extract is inhibiting the growth of Gram-positive bacteria only by damaging the cell wall and/or membrane.

Keywords: antibacterial activity, bioluminescence, Glycyrrhiza glabra, natural preservative

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120 Antibacterial Activity of the Essential Oil of Origanum glandulosum on Bacterial Strains of Hospital Origin Most Implicated in Nosocomial Infections

Authors: A. Lardjam, R. Mazid, S. Y. Boudghene, A. Izarouken, Y. Dali, N. Djebli, H. Toumi

Abstract:

Origanum glandulosum is an aromatic plant, common in Algeria and widely used by local people for its medicinal properties. The essential oil from this plant, which grows in the west of Algeria, was studied to evaluate and determine its antibacterial activity. The extraction of the essential oil was performed by water steam distillation; the yield obtained from the aerial parts (1.78 %) is interesting, its chromatographic profile revealed by TLC showed the presence of phenolic compounds thymol and carvacrol. The evaluation of the activity of the essential oil of Origanum glandulosum on bacterial strains of hospital origin, ATCC, MRB, and HRB, most implicated in nosocomial infections (Staphylococcus aureus ATCC 25923, Staphylococcus aureus ATCC 43300, Enterococcus faecalis ATCC 29212, Escherichia coli ATCC 25922, Pseudomonas aeruginosa ATCC 27853, Staphylococcus aureus resistant to meticillin, Enterococcus faecium, VA R and R TEC, Acinetobacter baumanii, IMP R and R CAZ, Klebsiella pneumonia carbapenemase-producing) by the method of aromatogramme and micro atmosphere, shows that the antibacterial potency of this oil is very high, expressed by significant inhibition diameters on all strains except Pseudomonas aeruginosa, and low MICs and is characterized by a bactericidal action.

Keywords: antibacterial activity, essential oil, HRB, MBR, nosocomial infections, origanum glandulosum

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119 The Effect of Some Macrofungi Extracts on Cytoplasmic Membrane of Multidrug Resistant Bacteria by Flow Cytometry

Authors: Yener Tekeli, Hayri Baba

Abstract:

The natural active compounds found in medicinal plants are belong to various chemical structures including polyphenolic compounds, flavonoids, essential oils, and vitamins and some of these compounds have anticancer, antioxidant, and antimicrobial activity. However, these compounds have been little known about mechanisms to confer antibacterial drug resistance. In this study; some macrofungi extracts (Pholiota lucifera, Gnaoderma applanatum and Pleurotus ostreatus) were investigated for their abilities to enhance bacterial permeability by flow cytometry. This experiments exhibited enhancement of these extracts to disrupt the cytoplasmic membrane of living bacterial (Listeria innocua and Escherichia coli) cells. These experiments were designed to detect uptake of PI&SYT by enhancing with a ranged concentration of herb extracts.

Keywords: antimicrobial activity, flow cytometry, macrofungi, multidrug resistant

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118 Synthesis and in-Vitro Biological Activity of Novel Gallic Acid Derivatives

Authors: Hossein Mostafavi

Abstract:

A diversity of biological activities and pharmaceutical uses have been attributed to gallic acid derivatives such as antibacterial, anticancer, anti inflammatory. A series of gallic acid derivatives were synthesized, and their structure was confirmed by FT-IR, HNMR, CNMR, elemental analysis. In vitro biological activity of compounds was determined against Proteus vulgaris ATCC 7829, Escherichia coli ATCC 25922, as (Gram-negative) bacteria and bacillus cereus ATCC 11778, Staphylococus aureus ATCC 6538 as (Gram-positive) bacteria. Antibacterial susceptibility tests were done by use of the paper disc diffusion method on Mueller Hinton agar (Merck). Chloramiphenicol, Penicilline, Streptomycin and Tetracycline were standard reference antibiotics. The zone of inhibition against bacteria was measured after 24 hours at 37 °C. Compounds 3, 4, 5 were the main antibacterial compounds against Gram-negative bacteria but not Gram-positive.

Keywords: gallic acid derivatives, antibacterial, antibiotics, inhibition

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117 The Effect of Probiotic Bacteria on Aflatoxin M1 Detoxification in Phosphate Buffer Saline

Authors: Sumeyra Sevim, Gulsum Gizem Topal, Mercan Merve Tengilimoglu-Metin, Mevlude Kizil

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Aflatoxin M1 (AFM1) is a major toxic and carcinogenic molecule in milk and milk products. Therefore, it poses a risk for public health. Probiotics can be biological agent to remove AFM1. The aim of this study is to evaluate the effect of probiotic bacteria on AFM1 detoxification in phosphate buffer saline. The PBS samples artificially contaminated with AFM1 at concentration 100 pg/ml were prepared with probiotics bacteria that including monoculture (L. plantarum, B. bifidum ATCC, B. animalis ATCC 27672) and binary culture (L. bulgaricus + S. thermophiles, B. bifidum ATCC + B. animalis ATCC 27672, L. plantarum+B. bifidum ATCC, L. plantarum+ B. animalis ATCC 27672). The samples were incubated at 37°C for 4 hours and stored for 1, 5 and 10 days. The toxin was measured by the ELISA. The highest levels of AFM1 binding ability (63.6%) in PBS were detected yoghurt starter bacteria, while L. plantarum had the lowest levels of AFM1 binding ability (35.5%) in PBS. In addition, it was found that there was significant effect of storage on AFM1 binding ability in all groups except the one including B. animalis (p < 0.05). Consequently, results demonstrate that AFM1 detoxification by probiotic bacteria has a potential application to reduce toxin concentrations in yoghurt. Moreover, probiotic strains can react with itself as synergic or antagonist.

Keywords: aflatoxin M1, ELISA, probiotics, storage

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116 Interventions to Control Listeria Monocytogenes on Sliced Mushrooms

Authors: Alanna Goodman, Kayla Murray, Keith Warriner

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The following reports on a comparative study on the efficacy of different decontamination technologies to decrease Listeria monocytogenes inoculated onto white sliced mushrooms and assesses the fate of residual levels during posttreatment storage under aerobic conditions at 8uC. The treatments were chemical (hydrogen peroxide, peroxyacetic acid, ozonated water, electrolyzed water, chitosan, lactic acid), biological (Listeria bacteriophages), and physical (UV-C, UV:hydrogen peroxide). None of the treatments achieved .1.2 log CFU reduction in L. monocytogenes levels; bacteriophages at a multiplicity of infection of 100 and 3% (vol/vol) hydrogen peroxide were the most effective of the treatments tested. However, growth of residual L. monocytogenes during posttreatment storage attained levels equal to or greater than levels in the nontreated controls. The growth of L. monocytogenes was inhibited on mushrooms treated with chitosan, electrolyzed water, peroxyacetic acid, or UV. Yet, L. monocytogenes inoculated onto mushrooms and treated with UV:hydrogen peroxide decreased during posttreatment storage, through a combination of sublethal injury and dehydration of the mushroom surface. Although mushrooms treated with UV:hydrogen peroxide became darker during storage, the samples were visually acceptable relative to controls. In conclusion, of the treatments evaluated, UV:hydrogen peroxide holds promise to control L. monocytogenes on mushroom surfaces.

Keywords: listeria monocytogenes, sliced mushrooms, bacteriophages, UV, sanitizers

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115 Microwave Sanitization of Polyester Fabrics

Authors: K. Haggag, M. Salama, H. El-Sayed

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Polyester fabrics were sanitized by exposing them to vaporized water under the influence of conventional heating or microwave irradiation. Hydrogen peroxide was added the humid sanitizing environment as a disinfectant. The said sanitization process was found to be effective towards two types of bacteria, namely Escherichia coli ATCC 2666 (G –ve) and Staphylococcus aureus ATCC 6538 (G +ve). The effect of the sanitization process on some of the inherent properties of polyester fabrics was monitored.

Keywords: polyester, fabric, sanitization, microwave, bacteria

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114 Comparison between Two Groups of Pathogenic Bacteria under Different Essential Oil Extract of Ocimum basilicum L.

Authors: A. M. Daneshian Moghaddam, J. Shayegh, J. Dolghari Sharaf

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This study was conducted to assessment the antibacterial activities of different part of basil essential oil on the standard gram-negative bacteria include Escherichia coli, Pseudomonas aeruginosa, Salmonella typhi, and gram-positive ones including Bacillus cereus, Staphylococcus aureus, and Listeria monocytogen. The basil essential oil was provided from two part of plant (leaf and herb) at the two different developmental stage. The antibacterial properties of basil essential oil was studied Also agar disk diffusion, minimal inhibition concentration (MIC) and minimum bactericidal concentration (MBC) were detected. The results of agar disk diffusion tests showed the inhibition zones as follow: Listeria monocytogen 17.11-17.42 mm, St. aureus 29.20-30.56 mm, B. cereus 14.73-16.06 mm, E. coli 21.60-23.58 mm, Salmonella typhi 21.63-24.80 mm and for P. aeruginosa the maximum inhibition zones were seen on leaf essential oil. From the herb part of basil almost similar results were obtained: Listeria monocytogen 17.02-17.67 mm, St. aureus 29.60-30.41 mm, B. cereus 10.66-16.11 mm, E. coli 17.48-23.54 mm, Salmonella typhi 21.58-21.64 mm and for P. aeruginosa the maximum inhibition zones were seen. The MICs for gram-positive bacteria were as: B. cereus ranging 36-18 μg/mL, S. aureus 18 μg/mL, Listeria monocytogen 18-36 μg/mL and for gram-negative bacteria of E. coli, Salmonella typhi and P. aeruginosa were 18-9 μg/mL.

Keywords: basil (Ocimum basilicum) essential oil, gram-positive and gram negative bacteria, antibacterial activity, MIC, MBC

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113 Antibacterial Activity of Bacillus thuringiensis Activated Delta-endotoxins

Authors: R. Gounina-Allouane, N. Ouali, F. Z. Berrabah, A. Bentaleb

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For a long time, the Gram-positive spore-forming bacteria Bacillus thuringiensis (Bt) has been widely used in biological control against devastating and disease vectors insects. This is due to the insecticidal activity of its crystalline parasporal inclusion (crystals) predominantly comprised of one or more proteins (Cry and Cyt proteins) also called δ-endotoxins, produced during sporulation. The shape and composition of Bt crystals vary among strains and crystalline proteins are extremely varied (more than 475 cry gene were discovered). The insecticidal activity of Bt crystals is very well studied, thus their insecticidal mode of action is well established, however, their antimicrobial effect is largely unknown. The lack of data on the antimicrobial effect of crystalline proteins of Bt and the need for searching new antimicrobial molecules encouraged us to carried out this study. The antibacterial effect of δ-endotoxines produced by two Bt stains; a strain isolated from soil at northern of Algeria (Bt 7.2.B), and a strain isolated from a bioinsecticide (Bacillus thuringiensis var aizawai), activated by proteolysis, was assayed on clinical bacterial strains and ATCC collection ones respectively. Gram positive and negative clinical bacterial strains (Escherichia coli, Klebsiella pneumonaie, Pseudomonas aeruginosa, Staphylococcus aureus) were sensitive to activated Bt 72B endotoxins. Similarly, bacterial strains from ATCC collection (Escherichia coli ATCC 25922, Pseudomonas aerugenosa ATCC 27853, Staphylococcus aureus ATCC 25923) were sensitive to activated B. thuringiensis var aizawai δ-endotoxines. The activated δ-endotoxins were separated by SDS-PAGE.

Keywords: Bacillus thuringiensis, crystals, cry proteins, δ-endotoxins, antibacterial activity

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112 Antibacterial Activity of Bacillus thuringiensis Cristalline Parasporal Proteins

Authors: R. Gounina-Allouane, N. Ouali, F. Z. Berrabah, A. Bentaleb

Abstract:

For a long time, the Gram-positive spore-forming bacteria Bacillus thuringiensis (Bt) has been widely used in biological control against devastating and disease vectors insects. This is due to the insecticidal activity of its crystalline parasporal inclusion (crystals) predominantly comprised of one or more proteins (Cry and Cyt proteins) also called δ-endotoxins, produced during sporulation. The shape and composition of Bt crystals vary among strains and crystalline proteins are extremely varied (more than 475 cry gene were discovered). The insecticidal activity of Bt crystals is very well studied, thus their insecticidal mode of action is well established, however, their antimicrobial effect is largely unknown. The lack of data on the antimicrobial effect of crystalline proteins of Bt and the need for searching new antimicrobial molecules encouraged us to carried out this study. The antibacterial effect of δ-endotoxines produced by two Bt stains; a strain isolated from soil at northern of Algeria (Bt 7.2.B), and a strain isolated from a bioinsecticide (Bacillus thuringiensis var aizawai), activated by proteolysis, was assayed on clinical bacterial strains and ATCC collection ones respectively. Gram positive and negative clinical bacterial strains (Escherichia coli, Klebsiella pneumonaie, Pseudomonas aeruginosa, Staphylococcus aureus) were sensitive to activated Bt 72B endotoxins. Similarly, bacterial strains from ATCC collection (Escherichia coli ATCC 25922, Pseudomonas aerugenosa ATCC 27853, Staphylococcus aureus ATCC 25923) were sensitive to activated B. thuringiensis var aizawai δ-endotoxines. The activated δ-endotoxins were separated by SDS-PAGE.

Keywords: Bacillus thuringiensis, crystals, cry proteins, δ-endotoxins, antibacterial activity

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111 In vitro Antioxidant, Anticancer Properties and Probiotic Characteristics of Selected Lactic Acid Bacteria Strains

Authors: M. G. Shehata, S. A. El Sohaimy, Marwa M. Abu-Serie, Nourhan M. Abd El-Aziz

Abstract:

Probiotic strains can potentially be used as bio-preservatives and functional food supplement. Eight lactic acid bacteria strains (LAB) Lactobacillus brevis NRRL B-4527; Streptococcus thermophilus BLM 58; Pediococcusacidilactici ATCC 8042; Lactobacillus rhamnosus CCUG 1452; Lactobacillus curvatus ATCC 51436; Lactococcuslactis sub sp. lactisDSM 20481; Lactobacillus plantarum DMSZ 20079 and Lactobacillus plantarumTF103 were selected to screen the antioxidant, anticancer potential and probiotic properties. LAB strains exhibited good probiotic, antioxidant properties and showed antagonistic activity against food-borne pathogenic (Bacillus subtilis DB 100 host; Candida albicans ATCCMYA-2876; Clostridium botulinum ATCC 3584; Escherichia coli BA 12296; Klebsiellapneumoniae ATCC12296; Salmonella senftenberg ATCC 8400 and Staphylococcus aureus NCTC 10788). Further, in vitro probiotic properties of eight strains displayed excellent acid tolerance, bile tolerance, simulated gastrointestinal juice tolerance, in vitro adhesion ability for HT-29 cell line. The antioxidant effect of intracellular and cell-free extract of lactic acid bacteria strains was evaluated by various antioxidant assays, namely, resistance to hydrogen peroxide, DPPH radical scavenging, ABTS radical scavenging, and hydroxyl radical scavenging (HRS). The results showed that intracellular and cell-free supernatant of S. Thermophilus BLM 58, L. lactissubsp.lactis DSM 20481, P. acidilactici ATCC 8042, L. brevis NRRL B-4527 strains possess excellent antioxidant capacity. The intracellular of S. Thermophilus BLM 58 and P. acidilactici ATCC 8042 also showed excellent anticancer activity against Caco-2, MCF-7, HepG-2, and PC-3. Antioxidative property of selected lactic acid bacteria strains would be useful in the functional food manufacturing industry. They could beneficially affect the consumer by providing dietary source of antioxidants.

Keywords: anticancer activity, antioxidant activity, functional food, lactic acid bacteria, probiotic

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110 Anti-Bacterial Activity Studies of Derivatives of 6β-Hydroxy Betunolic Acid against Selected Stains of Gram (+) and Gram (-) Bacteria

Authors: S. Jayasinghe, W. G. D. Wickramasingha, V. Karunaratne, D. N. Karunaratne, A. Ekanayake

Abstract:

Multi-drug resistant microbial pathogens are a serious global health problem, and hence, there is an urgent necessity for discovering new drug therapeutics. However, finding alternatives is a one of the biggest challenges faced by the global drug industry due to the spiraling high cost and serious side effects associated with modern medicine. On the other hand, plants and their secondary metabolites can be considered as good sources of scaffolds to provide structurally diverse bioactive compounds as potential therapeutic agents. 6β-hydroxy betunolic acid is a triterpenoid isolated from bark of Schumacheria castaneifolia which is an endemic plant to Sri Lanka which has shown antibacterial activity against both Staphylococcus aureus (ATCC 29213) and methicillin-resistant S. aureus with Minimum Inhibition Concentration (MIC) of 16 µg/ml. The objective of this study was to determine the anti-bacterial activity for the derivatives of 6β- hydroxy betunolic acid against standard strains of Staphylococcus aureus (ATCC 29213 and ATCC 25923), Enterococcus faecalis (ATCC 29212), Escherichia coli (ATCC 35218 and ATCC 25922), Pseudomonas aeruginosa (ATCC 27853), carbepenemas produce Kebsiella pneumonia (ATCC BAA 1705) and carbepenemas non produce Kebsiella pneumonia (ATCC BAA 1706) and four stains of clinically isolated methicillin resistance S. aureus and Acinetobacter. Structural analogues of 6β-hydroxy betunolic acid were synthesized by modifying the carbonyl group at C-3 to obtain olefin and oxime, the hydroxyl group at C-6 position to a ketone, the carboxylic acid at C-17 to obtain amide and halo ester and the olefin group at C-20 position to obtain epoxide. Chemical structures of the synthesized analogues were confirmed with spectroscopic data and antibacterial activity was determined through broth micro dilution assay. Results revealed that 6β- hydroxy betunolic acid shows significant antibacterial activity only against the Gram positive strains and it was inactive against all the tested Gram negative strains for the tested concentration range. However, structural modifications into oxime and olefin at C-3, ketone at C-6 and epoxide at C-20 decreased its antibacterial activity against the gram positive organisms and it was totally lost with the both modifications at C-17 into amide and ester. These results concluded that the antibacterial activity of 6β- hydroxy betunolic acid and derivatives is predominantly depending on the cell wall difference of the bacteria and the presence of carboxylic acid at C-17 is highly important for the antibacterial activity against Gram positive organisms.

Keywords: antibacterial activity, 6β- hydroxy betunolic acid, broth micro dilution assay, structure activity relationship

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109 Antimicrobial Activity of Sour Cherry Pomace

Authors: Sonja Djilas, Aleksandra Velićanski, Dragoljub Cvetković, Siniša Markov, Eva Lončar, Vesna Tumbas Šaponjac, Milica Vinčić

Abstract:

Due to high content of bioactive compounds, sour cherry possesses antioxidant and antimicrobial activity. Additionally, waste material from industrial processing of sour cherry is also a good source of bioactive compounds. The aim of this study was to screen the antimicrobial activity and determine the minimal inhibitory (MIC) and minimal bactericidal concentrations (MBC) of sour cherry pomace extract. Tested strains were Gram-negative bacteria (Escherichia coli ATCC 25922, Salmonella typhimurium ATCC 14028 and wild isolates Escherichia coli and Salmonella sp.), Gram-positive bacteria (Staphylococcus aureus ATCC 11632, Bacillus cereus ATCC 10876 and wild isolates Staphylococcus saprophyticus and Bacillus sp.) and yeasts (Saccharomyces cerevisiae 112, Hefebank Weihenstephan and Candida albicans ATCC 10231). Antimicrobial activity was tested by disc-diffusion method and agar-well diffusion method. MIC and MBC were determined by microdilution method. Screening tests showed that Gram-negative bacteria were resistant to tested extract, with exception of Salmonella typhimurium and Salmonella sp. for which only zones of reduced growth appeared. However, Gram-positive bacteria were more sensitive where the highest clear zones appeared with 100 µl of extract applied. There was no activity against tested yeasts. MIC and MBC values were in the range 3.125-37.5 mg/ml and 6.25-100 mg/ml, respectively. The most susceptible strain was Staphylococcus aureus while the most resistant was Bacillus sp. where MBC was not found in tested concentration range. Sour cherry pomace possesses high antibacterial potential, which indicates that this waste material is a promising source of bioactive compounds and could be used as a functional food ingredient.

Keywords: antimicrobial activity, sour cherry, pomace, bioactive compounds

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108 Same-Day Detection Method of Salmonella Spp., Shigella Spp. and Listeria Monocytogenes with Fluorescence-Based Triplex Real-Time PCR

Authors: Ergun Sakalar, Kubra Bilgic

Abstract:

Faster detection and characterization of pathogens are the basis of the evoid from foodborne pathogens. Salmonella spp., Shigella spp. and Listeria monocytogenes are common foodborne bacteria that are among the most life-threatining. It is important to rapid and accurate detection of these pathogens to prevent food poisoning and outbreaks or to manage food chains. The present work promise to develop a sensitive, species specific and reliable PCR based detection system for simultaneous detection of Salmonella spp., Shigella spp. and Listeria monocytogenes. For this purpose, three genes were picked out, ompC for Salmonella spp., ipaH for Shigella spp. and hlyA for L. monocytogenes. After short pre-enrichment of milk was passed through a vacuum filter and bacterial DNA was exracted using commercially available kit GIDAGEN®(Turkey, İstanbul). Detection of amplicons was verified by examination of the melting temperature (Tm) that are 72° C, 78° C, 82° C for Salmonella spp., Shigella spp. and L. monocytogenes, respectively. The method specificity was checked against a group of bacteria strains, and also carried out sensitivity test resulting in under 10² CFU mL⁻¹ of milk for each bacteria strain. Our results show that the flourescence based triplex qPCR method can be used routinely to detect Salmonella spp., Shigella spp. and L. monocytogenes during the milk processing procedures in order to reduce cost, time of analysis and the risk of foodborne disease outbreaks.

Keywords: evagreen, food-born bacteria, pathogen detection, real-time pcr

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107 Isolation, Characterization and Application of Bacteriophages on the Biocontrol of Listeria monocytogenes in Soft Cheese

Authors: Vinicius Buccelli Ribeiro, Maria Teresa Destro, Mariza Landgraf

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Bacteriophages are one of the most abundant replicating entities on Earth and can be found everywhere in which their hosts live and there are reports regarding isolation from different niches such as soil and foods. Since studies are moving forward with regard to biotechnology area, different research projects are being performed focusing on the phage technology and its use by the food industry. This study aimed to evaluate a cocktail (LP501) of phages isolated in Brazil for its lytic potential against Listeria monocytogenes. Three bacteriophages (LP05, LP12 and LP20) were isolated from soil samples and all of them showed 100% lysis against a panel of 10 L. monocytogenes strains representing different serotypes of this pathogen. A mix of L. monocytogenes 1/2a and 4b were inoculated in soft cheeses (approximately 105 cfu/cm2) with the phage cocktail added thereafter (1 x 109 PFU/cm2). Samples were analyzed immediately and then stored at 10°C for ten days. At 30 min post-infection, the cocktail reduced L. monocytogenes counts approximately 1.5 logs, compared to controls without bacteriophage. The treatment produced a statistically significant decrease in the counts of viable cells (p < 0.05) and in all assays performed we observed a decrease of up to 4 logs of L. monocytogenes. This study will make available to the international community behavioral and molecular data regarding bacteriophages present in soil samples in Brazil. Furthermore, there is the possibility to apply this new cocktail of phages in different food products to combat L. monocytogenes.

Keywords: bacteriophages, biocontrol, listeria monocytogenes, soft cheese

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106 Chemical Compositon and Antimicrobial Activity of Daucus aristidis Coss. Essential Oil in Pre-Flowering Stage from Algeria

Authors: M. Lamamra, H. Laouer, A. Adjaoud, Sahli Farida

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Essential oils can have significant antimicrobial activities and can successfully replace antibiotics that show their ineffectiveness against resistant germs. The chemical composition of the essential oil obtained by hydrodistillation from the aerial part of Daucus aristidis (Apiaceae) at the pre-flowering stage was investigated for the first time, by GC and GC-MS and evaluated for in vitro antimicrobial activity by the disk diffusion method. The Main components of D. aristidis oil were α-pinene (20.13%), cedrol (20.11%), and E- asarone (18.53%). The oil exhibited an antibacterial activity against almost strains tested except for Klebsiella pneumoniae ATCC 700603 K6 and Enterococcus faecalis ATCC 49452, the oil of D. aristidis had no activity against all fungi tested.

Keywords: α-pinene, antimicrobial activity, Daucus aridtidis, essential oil

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105 Microbiological Analysis of Biofuels in Order to Follow Stability on Room Temperature

Authors: Radovan Cobanovic, Milica Rankov Sicar

Abstract:

Biodiesel refers to a vegetable oil - or animal fat-based diesel fuel consisting of long-chain alkyl (methyl, ethyl, or propyl) esters. It is derived by alcoholysis of triacylglycerols (triglycerides) from various lipid based materials that can be traditionally categorized into the following main groups: vegetable oils, animal fats, waste and algal oils. The goal of this study was to evaluate microbiological stability of biodiesel samples since it has been made from vegetable oil or animal fat which was stored on room temperature. For the purposes of this study, analyzes were conducted on six samples of biodiesel first at zero sample at the reception day than fifth, thirtieth, sixtieth, ninetieth and one hundred twentieth day from the day of reception. During this period, biodiesel samples were subjected to microbiological analyses (Salmonella spp., Listeria monocytogenes, Enterobacteriaceae and total plate count). All analyses were tested according to ISO methodology: Salmonella spp ISO 6579, Listeria monocytogenes ISO 11290-2, Enterobacteriaceae ISO 21528-1, total plate count ISO 4833-1. The results obtained after the analyses which were done according to the plan during the 120 days indicate that are no changes of products concerning microbiological analyses. Salmonella spp., Listeria monocytogenes, Enterobacteriaceae were not detected and results for total plate count showed values < 10 cfu/g for all six samples. On the basis of this monitoring under defined storage conditions at room temperatures, the results showed that biodiesel is very stable as far as microbiological analysis were concerned.

Keywords: biodiesel, microbiology, room temperature, stability

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104 Effect of Environmental Conditions on E. Coli o157:h7 Atcc 43888 and L. Monocytogenes Atcc 7644 Cell Surface Hydrophobicity, Motility and Cell Attachment on Food-Contact Surfaces

Authors: Stanley Dula, Oluwatosini A. Ijabadeniyi

Abstract:

Biofilm formation is a major source of materials and foodstuffs contamination, contributing to occurrence of pathogenic and spoilage microbes in food processing resulting in food spoilage, transmission of diseases and significant food hygiene and safety issues. This study elucidates biofilm formation of E. coli O157:H7 and L. monocytogenes ATCC 7644 grown under food related environmental stress conditions of varying pH (5.0;7.0; and 8.5) and temperature (15, 25 and 37 ℃). Both strains showed confluent biofilm formation at 25 ℃ and 37 ℃, at pH 8.5 after 5 days. E. coli showed curli fimbriae production at various temperatures, while L. monocytogenes did not show pronounced expression. Swarm, swimming and twitching plate assays were used to determine strain motilities. Characterization of cell hydrophobicity was done using the microbial adhesion to hydrocarbons (MATH) assay using n-hexadecane. Both strains showed hydrophilic characteristics as they fell within a < 20 % interval. FT-IR revealed COOH at 1622 cm-1, and a strong absorption band at 3650 cm-1 – 3200 cm-1 indicating the presence of both -OH and -NH groups. Both strains were hydrophilic and could form biofilm at different combinations of temperature and pH. EPS produced in both species proved to be an acidic hetero-polysaccharide.

Keywords: biofilm, pathogens, hydrophobicity, motility

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103 Effect of Temperature on the Production of Fructose and Bioethanol from Date’s Syrup using S. cerevisiae ATCC 36859

Authors: M. A. Zeinelabdeen, A. E. Abasaeed, M. H. Gaily, A. K. Sulieman, M. D. Putra

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The effect of temperature on the production of fructose and bioethanol from date syrup via selective fermentation by S. cerevisiae ATCC 36859 strain was studied. Various temperatures have been tested (27, 30 and 33 ᵒC). The fermentation experiments were conducted in a water shaker bath at the three temperatures under testing and 120 rpm. The results showed that a high fructose yield can be achieved at all temperatures under testing while the optimal is 27 ᵒC with 84% fructose yield. A high ethanol yield can be obtained for all temperatures under testing. However; the maximum biomass concentration and ethanol yield (86.22%) were obtained at 30 ᵒC.

Keywords: dates, ethanol, fructose, fermentation, S. cerevisiae

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102 Exploratory Tests of Crude Bacteriocins from Autochthonous Lactic Acid Bacteria against Food-Borne Pathogens and Spoilage Bacteria

Authors: M. Naimi, M. B. Khaled

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The aim of the present work was to test in vitro inhibition of food pathogens and spoilage bacteria by crude bacteriocins from autochthonous lactic acid bacteria. Thirty autochthonous lactic acid bacteria isolated previously, belonging to the genera: Lactobacillus, Carnobacterium, Lactococcus, Vagococcus, Streptococcus, and Pediococcus, have been screened by an agar spot test and a well diffusion assay against Gram-positive and Gram-negative harmful bacteria: Bacillus cereus, Bacillus subtilis ATCC 6633, Escherichia coli ATCC 8739, Salmonella typhimurium ATCC 14028, Staphylococcus aureus ATCC 6538, and Pseudomonas aeruginosa under conditions means to reduce lactic acid and hydrogen peroxide effect to select bacteria with high bacteriocinogenic potential. Furthermore, crude bacteriocins semiquantification and heat sensitivity to different temperatures (80, 95, 110°C, and 121°C) were performed. Another exploratory test concerning the response of St. aureus ATCC 6538 to the presence of crude bacteriocins was realized. It has been observed by the agar spot test that fifteen candidates were active toward Gram-positive targets strains. The secondary screening demonstrated an antagonistic activity oriented only against St. aureus ATCC 6538, leading to the selection of five isolates: Lm14, Lm21, Lm23, Lm24, and Lm25 with a larger inhibition zone compared to the others. The ANOVA statistical analysis reveals a small variation of repeatability: Lm21: 0.56%, Lm23: 0%, Lm25: 1.67%, Lm14: 1.88%, Lm24: 2.14%. Conversely, slight variation was reported in terms of inhibition diameters: 9.58± 0.40, 9.83± 0.46, and 10.16± 0.24 8.5 ± 0.40 10 mm for, Lm21, Lm23, Lm25, Lm14and Lm24, indicating that the observed potential showed a heterogeneous distribution (BMS = 0.383, WMS = 0.117). The repeatability coefficient calculated displayed 7.35%. As for the bacteriocins semiquantification, the five samples exhibited production amounts about 4.16 for Lm21, Lm23, Lm25 and 2.08 AU/ml for Lm14, Lm24. Concerning the sensitivity the crude bacteriocins were fully insensitive to heat inactivation, until 121°C, they preserved the same inhibition diameter. As to, kinetic of growth , the µmax showed reductions in pathogens load for Lm21, Lm23, Lm25, Lm14, Lm24 of about 42.92%, 84.12%, 88.55%, 54.95%, 29.97% in the second trails. Inversely, this pathogen growth after five hours displayed differences of 79.45%, 12.64%, 11.82%, 87.88%, 85.66% in the second trails, compared to the control. This study showed potential inhibition to the growth of this food pathogen, suggesting the possibility to improve the hygienic food quality.

Keywords: exploratory test, lactic acid bacteria, crude bacteriocins, spoilage, pathogens

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101 Search of Сompounds with Antimicrobial and Antifungal Activity in the Series of 1-(2-(1H-Tetrazol-5-yl)-R1-phenyl)-3-R2-phenyl(ethyl)ureas

Authors: O. Antypenko, I. Vasilieva, S. Kovalenko

Abstract:

Investigations for new effective and less toxic antimicrobials agents are always up-to-date. The tetrazole derivatives are quite interesting objects as for synthesis as well as for pharmacological screening. Thus, some derivatives of tetrazole demonstrated antimicrobial activity, namely 5-phenyl-tetrazolo[1,5-c]quinazoline was effective one against Staphylococcus aureus and Esherichia faecalis (MIC = 250 mg/L). Besides, investigation of the 9-bromo(chloro)-5-morpholin(piperidine)-4-yl-tetrazolo[1,5-c]quinazoline’s antimicrobial activity against Esherichia coli and Enterococcus faecalis, Pseudomonas aeruginosa and Staphylococcus aureus revealed that sensitivity of Gram-positive bacteria to the compounds was higher than that of Gram-negative bacteria. So, our previously synthesized, 31 derivatives of 1-(2-(1H-tetrazol-5-yl)-R1-phenyl)-3-R2-phenyl(ethyl)ureas were decided to test for their in vitro antibacterial activity against Gram-positive bacteria (Staphylococcus aureus ATCC 25923, Enterobacter aerogenes, Enterococcus faecalis ATCC 29212), Gram-negative bacteria (Pseudomonas aeruginosa ATCC 9027, Escherichia coli ATCC 25922, Klebsiella pneumoniae 68) and antifungal properties against Candida albicans ATCC 885653. Agar-diffusion method was used for determination of the preliminary activity compared to well-known reference antimicrobials. All the compounds were dissolved in DMSO at a concentration of 100 μg/disk, using inhibition zone diameter (IZD, mm) as a measure for the antimicrobial activity. The most active turned to be 3 structures, that inhibited several bacterial strains: 1-ethyl-3-(5-fluoro-2-(1H-tetrazol-5-yl)phenyl)urea (1), 1-(4-bromo-2-(1H-tetrazol-5-yl)-phenyl)-3-(4-(trifluoromethyl)phenyl)urea (2) and 1-(4-chloro-2-(1H-tetrazol-5-yl)phenyl)-3-(3-(trifluoromethyl)phenyl)urea (3). IZM (mm) was 40 (Escherichia coli), 25 (Klebsiella pneumonia) for compound 1; 12 (Pseudomonas aeruginosa), 15 (Staphylococcus aureus), 10 (Enterococcus faecalis) for compound 2; 25 (Staphylococcus aureus), 15 (Enterococcus faecalis) for compound 3. The most sensitive to the activity of the substances were Gram-negative bacteria Pseudomonas aeruginosa. While none of compound effected on Candida albicans. Speaking about, reference drugs: Amikacin (30 µg/disk) showed 27 and Ceftazide (30 µg/disk) 25 against Pseudomonas aeruginosa. That is, unfortunately, higher than studied 1-(2-(1H-tetrazol-5-yl)-R1-phenyl)-3-R2-phenyl(ethyl)ureas. Obtained results will be used for further purposeful optimization of the leading compounds in the more effective antimicrobials because of the ever-mounting problem of microorganism’s resistance.

Keywords: antimicrobial, antifungal, compounds, 1-(2-(1H-tetrazol-5-yl)-R1-phenyl)-3-R2-phenyl(ethyl)ureas

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100 The Antibacterial and Anticancer Activity of Marine Actinomycete Strain HP411 Isolated in the Northern Coast of Vietnam

Authors: Huyen T. Pham, Nhue P. Nguyen, Tien Q. Phi, Phuong T. Dang, Hy G. Le

Abstract:

Since the marine environmental conditions are extremely different from the other ones, so that marine actinomycetes might produce novel bioactive compounds. Therefore, actinomycete strains were screened from marine water and sediment samples collected from the coastal areas of Northern Vietnam. Ninety-nine actinomycete strains were obtained on starch-casein agar media by dilution technique, only seven strains, named HP112, HP12, HP411, HPN11, HP 11, HPT13 and HPX12, showed significant antibacterial activity against both gram-positive and gram-negative bacteria (Bacillus subtilis ATCC 6633, Staphylococcus epidemidis ATCC 12228, Escherichia coli ATCC 11105). Further studies were carried out with the most active HP411strain against Candida albicans ATCC 10231. This strain could grow rapidly on starch casein agar and other media with high salt containing 7-10% NaCl at 28-30oC. Spore-chain of HP411 showed an elongated and circular shape with 10 to 30 spores/chain. Identification of the strain was carried out by employing the taxonomical studies including the 16S rRNA sequence. Based on phylogenetic and phenotypic evidence it is proposed that HP411 to be belongs to species Streptomyces variabilis. The potent of the crude extract of fermentation broth of HP411that are effective against wide range of pathogens: both gram-positive, gram-negative and fungi. Further studies revealed that the crude extract HP411 could obtain the anticancer activity for cancer cell lines: Hep-G2 (liver cancer cell line); RD (cardiac and skeletal muscle letters cell line); FL (membrane of the uterus cancer cell line). However, the actinomycetes from marine ecosystem will be useful for the discovery of new drugs in the furture.

Keywords: marine actinomycetes, antibacterial, anticancer, Streptomyces variabilis

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