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Showing 11 results for Bacteria

Abdolhosein Moghbel, Ahmad Farjzadeh, Nasrin Aghel, Homayoon Agheli, Nafiseh Raisi,
Volume 5, Issue 14 (10-2011)
Abstract

Background: Compounds present in both green and black teas have been shown to inhibit the growth and activity of bacteria associated with mouth infections. The aim of this study was to assess the effects of green tea leaves extract on the aerobic mouth bacterial load.
Methods: A total of 25 volunteer female students, aged 20-25 years, were selected and then evaluated by green tea extract and mouthwashes containing 0.2, 0.5, and 1% tannin, as the most effective antibacterial complex in green tea. Then a comparative study was conducted on a green tea mouthwash containing 1% tannin with 10% ethanol, a alcohol free mouthwash, and a green tea herbal mouthwash with a chlorhexidine 0.2% sample, as and chemical brand.
Results: Green tea mouthwash containing 1% tannin was more effective than other concentrations (P<0.05). There were no meaningful differences between the green tea mouthwashes containing 10% alcohol and alcohol free, as well as the herbal and chemical chlorhexidine 0.2% (P>0.05).
Conclusion: The herbal green tea mouthwash could reduce the aerobic mouth bacterial load and may prevent plaque formation on teeth and come over halitosis due to infection of the bacteria. Also, it is a safe and nontoxic mouthwash especially for children and pregnant women.
Mehdi Hassanshahian,
Volume 10, Issue 4 (6-2016)
Abstract

Background: Organic agricultural pesticides are so stable in ecosystems and biosphere. These compounds affect soil conditions and agricultural products. The aim of this study was isolation of diazinon-degrading bacteria from Kerman pistachio orchards, Southeastern Iran.

Methods: Diazinon-degrading bacteria were enriched in Bushnell-Hass medium. Identification and sequencing of prevalent degrading strains was performed using PCR based on amplifying of 16s rDNA.

Results: The soil of pistachio orchard has some degrading bacteria that are suitable for elimination of diazinon from soil and environment. Three diazinon-degrading bacteria strains belong to: Pseudomonas putida strain D3, P. fluorescens strain D1 and Achromobacter piechaudii strain D8. The best degrading strain (D1), up to 100 ppm, illustrated a good growth, whereas more than this concentration, the growth was reduced. The results of Gas-Chromatography (GC) confirmed the decomposition of organic pesticide by degrading-bacteria.

Conclusion: The results of Gas-Chromatography (GC) confirmed the decomposition of organic pesticide by degrading-bacteria.

Using these strains and other biological reclamation methods we can eliminate bio-environmental problems.


Siavash Kamyar , Mohammadhosein Movassaghghazani,
Volume 11, Issue 6 (11-2017)
Abstract

Background: Mycotoxins naturally occur in foods. Aflatoxins can cause serious health problems in consumers. Nowadays, biological detoxification method is considered to decrease the aflatoxins level in foods. The aim of this study was to evaluate the effect of kefir starter microorganisms to decrease the aflatoxin M1 (AFM1) levels in milk.
Methods: The study was carried out at Shabestar branch, Islamic Azad University in 2016. AFM1 at three levels 150, 200 and 250 ng/L was added to milk samples. Then a pool of lactic acid bacteria (LAB), yeasts and full kefir starter culture was added to milk samples. After cool storage of samples in 4 °C for 7 d, all samples were collected and the level of AFM1 determined by HPLC method. All samples were prepared in triplicate.
Results: The highest reduction percentage of AFM1 was observed in yeast (65.33%-68.89%) and LAB pool (65%). Samples with full kefir starter showed the reduction percent range of 11.67-34.66% that was lower in compare with other treatment groups.
Conclusion: These findings support the ability of LAB and yeasts to bind to aflatoxins in foods. Kefir drink in countries with high contamination by AFM1 in milk can be a safe dairy product choice for consumers.
 
Maryam Kouhkan, Ali Souldozi, Reza Talebi ,
Volume 12, Issue 1 (1-2018)
Abstract

Background: In this study, we evaluated antibacterial and antifungle activity of these derivatives against gram positive (Staphylococcus aureus, Bacillus subtilis, B. cereus), gram negative (Proteus vulgaris) bacteria and fungale (Candida albicans, C. tropicalis and C. glabrata).
Methods: The broth macro dilution and well agar diffusion methods were used for determination of inhibition zoom (IZ) and minimum inhibitory concentration (MIC) during preliminary evaluation of antimicrobial activity.
Results: The (MIC) values of tested compounds revealed that all compounds were active against Staphylococcus oureus and exhibited the same antibacterial activity in comparison to ceftizoxim (MIC=125µg/mL). The results of antifungal screening showed that all the compounds were potent antimicrobial activity against tested pathogenic fungi (MIC=250 to1000 µg/ml). Compounds (6a) and (6b) showed the maximum activity with MIC value of 250 µg/ml against all tested fungi, but compound (6h) showed poor antifungal activity against all fungi. MIC values for title compounds were similar to MIC results for fluconazol. 
Conclusions: All the compounds are potent antifungal and antibacterial activity against tested microorganism.
Abubakar Awwal Yusuf , Bashir Lawal , Mumeen Abdulganeey Yusuf , Emisi Omotayo Omonije , Arogbokun Opeyemi Adejoke , Feyisara Habibat Raji, Dannana Luke Wenawo ,
Volume 12, Issue 3 (4-2018)
Abstract

Background: Xylopia aethiopica is highly reputed for its numerous medicinal properties. In the present study, antioxidant, antimicrobial, and toxicity profile of methanol seed extract of Nigerian X. aethiopica in rat were evaluated.
Methods: Phytochemical compositions were evaluated using standard procedures. The antibacterial study was carried out using agar well diffusion method, while antioxidant activities were evaluated by DPPH and FRAP assay. Twenty-five rats (5 each) were given 0, 75, 150, 300 and 600 mg/kg bwt of the extract orally for 28 days.
Results: The extract had total phenolic and total flavonoid contents of 15.98±0.03mg GAE/g and 2.29±0.02 mg/g CE respectively. The extract had IC50 values of 52.45±3.05 µg/mL and 73.45±3.89 μg/mL in DPPH and FRAP assay respectively. The E. coli showed the highest susceptibility (20.27±0.90mm) while P. aeuruginisa showed the least (15.08±0.20mm). The MIC ranged from 25-50 µg/mL while MBC ranged between 50µg/mL and 100 µg/mL. In comparison with the control rats, the levels of serum creatinine, bicarbonate total proteins, albumin, and ALP were significantly higher in rat dosed 600 mg/kg bwt while urea decreases in rat dose 300 and 600 mg/kg. However, serum concentration of ALT, AST, bilirubin, Na+, K+ and Cl- compared favorably (P>0.05) with control at all doses.
Conclusion: The study revealed the antioxidant and antimicrobial activities of Nigerian X. aethiopica, the extract at 75, 150 and 300 mg/kg/b.wt did not provoke toxic effects to the animals’ liver and kidney; however, caution should be exercised when using as a prolonged oral remedy at high doses.
Uwakwe Simon Onoja , Nwachukwu Romanus Ekere , Joy Uzoamaka Ezugwu , Remigius Ibe Onoja ,
Volume 12, Issue 4 (7-2018)
Abstract

Background: Food poisoning resulting from microbial and heavy metals pollution is commonplace. These contaminants do not only reduce the nutritional value of the food but are in many cases toxic. In this study, the proximate composition, bacterial quality and some heavy metals (Cd, Pb, Hg) concentration in three common fish species (Claria gariepinus, Heterobrachus bidorsalis and Channa obscura) found in flood basin of Omambala River in Anambra, Nigeria were evaluated from 2016  to 2017.
Methods: Wet digestion was used for the samples preparation and AOAC methods were adopted for the proximate analysis. Standard aerobic pour-platetechniques were used for bacterial enumeration while heavy metal concentrations were determinedusing Atomic Absorption Spectrophotometer (AAS).
Results: All the fish species had high protein, moisture, lipid, ash and minerals contents. Mean bacteria count of 3.36x106cfu/g was observed in C. gariepinus while C. obscura had mean bacterial count of 3.23x106cfu/g and H. bidorsalis had mean bacterial count of 3.40x106cfu/g. C. gariepinus had a cadmium and lead concentration of 0.012±0.012mg/kg,and 0.0043±0.0012mg/kg respectively while C.obscura had 0.010 ± 0.005mg/kg and 0.037 ±0.013mg/kg of cadmium and lead. H.bidorsalis had 0.011 ± 0.002mg/kg, and 0.048 ± 0.005mg/kg of cadmium and lead respectively.
Conclusion: All the fish species are good sources of nutrient. The microbial and heavy metals concentrations were within the acceptable international limits for heavy metals in foods. However, the presence of these toxicants in the samples is a source of concern in relation to the health of the consumers.
Sheriff Itopa Umar, Bashir Lawal, Bala Alkali Mohammed, Cyril Ifeanyi Obiekezie, Abdulsalam Hassan Adewuyi, Shukurat Bisola Babalola, Stephen Damaola Ariyeloye,
Volume 13, Issue 4 (10-2019)
Abstract

BackgroundMaytenus heterophylla (M. heterophylla) is commonly used in African traditional medicine for the management of various ailments. The present study evaluated the antioxidant, antimicrobial and safety properties of the Flavonoid extract of M. heterophylla in Wister rats.
Methods: The Flavonoid was subjected to antibacterial study via agar well diffusion method, and antioxidant study using 2, 2′-diphenyl-1-picrylhydrazyl (DPPH) and ferric reducing antioxidant properties (FRAP) assays. Subacute toxicity were carried out by the oral administration of the extract at a daily dose of 50 or 100mg/kg for 28 days.
Results: The extract produced significant antioxidants activities with IC50 of 33.07±0.84 µg/mL & 38.08±0.89 μg/mL in DPPH and FRAPS models respectively. It produced a dose-dependent inhibition of S. aureus, E.coli, P. aeruginosa, K. pneumonia and S. Typhi with MIC between 12.5µg/mL to 25µg/mL. The flavonoid was safe on acute exposure to rats (LD50> 5000 mg/kg). However, the  chronic exposure significantly (p<0.05) decreased the creatinine, bilirubin concentrations and increased  aspartate transaminase (AST) activities while the total protein, albumin, alanine transaminase (ALT), alkaline phosphatise (ALP), urea, chloride, potassium and sodium concentrations were comparable with those in the controls. The organs-body weights ratios also compared well with the controls (p<0.05).
Conclusions: The findings showed that the Flavonoid extract of M. heterophylla was relatively non-toxic following acute or chronic exposures at 50-100 mg/kg. The flavonoid extract may potentially serve as a candidate agent for the development of an anti-microbial drug and to enhance the antioxidant capacity in rats.
 
Hani Keshavarz Alikhani, Jamil Zargan, Ali Bidmeshkipour, Ashkan Haji Nour Mohammadi, Mohammad Hosseinpour, Ahmad Heydari, Abbas Hajizadeh,
Volume 14, Issue 2 (5-2020)
Abstract

Background: The venoms of some scorpions are rich in bioactive components that may be used in the development and discovery of new antibacterial drugs. The venoms have many components, such as neurotoxins, salts, proteins and peptides with therapeutic properties, and can rapidly eliminate a broad range of bacteria. This study evaluated the anti-bacterial activity of Odontobuthus bidentatus’ crude venom against typical Gram-positive and negative bacteria, such as Staphylococcus aureus, Bacillus subtilis, and Escherichia coli.
Methods: The antibacterial effects of the crude venom were evaluated using Minimal Inhibitory Concentration (MIC) and MTT assays and its IC50 value was determined, using GraphPad software. 
Results: The crude venom significantly inhibited the growth of both Gram-positive and negative bacteria. Also the MTT results showed that the crude venom significantly reduced the viability of E. Coli, S. Aureus, and B. Subtilis bacteria compared with that for the controls. The IC50 values of the venom for E.coli, S.aureus, and B.subtilis were 30.19, 17.64, and 24.13 µM, respectively. 
Conclusion: The findings suggest that the venom of O. bidentatus scorpion has antibacterial properties. Also, our results offer preliminary clues toward the development of new antibacterial agents and new drugs with high therapeutic potentials for use in animals and humans.

Mahboobeh Talebi Mehrdar,
Volume 14, Issue 3 (7-2020)
Abstract

Background: Antibacterial proteins are widely expressed in snake venoms. Previously, we have isolated two immunodominant proteins with molecular weights of 14 and 65 kD from the snake venom of Naja naja oxiana (N. oxiana). It was demonstrated that they had potent inhibitory effects against gram-positive bacteria, S. aureus and B. subtilis but were less effective against gram-negative bacteria, such as E. coli and P. aeruginosa. This study aimed at investigating the potential antibacterial effects of the two proteins against Bacillus anthracis and Streptococcus pneumoniae.
Methods: The proteins were identified by SDS-PAGE and western blot analysis, and isolated by Gel Electrophoresis (Electro-elution). The antibacterial effects were tested against the strains of Bacillus anthracis and Streptococcus pneumoniae, using broth microdilution and disc-diffusion assays. For comparison, the antibacterial effects of standard antibiotics, such as Gentamicin, Ampicillin, Penicillin, Amoxicillin and Ciprofloxacin were also tested on the same B. anthracis and S. pneumoniae batches under identical laboratory conditions.
Results: The two proteins showed high immunogenicity and strongly inhibited the growth of gram-positive bacteria, B. anthracis, and to a lesser extent S. pneumoniae.
Conclusion: The isolated proteins demonstrated strong antibacterial effects against Gram-positive bacteria, B. anthracis and S. pneumoniae, in addition to their previously known effects against S. aureus and B. subtilis.

Priyanka Bist, Sangeeta Choudhary,
Volume 16, Issue 1 (1-2022)
Abstract

Background: Heavy metal containing wastes reaches to the food chain either directly or indirectly. These ingested toxic elements manifest direct impact on the gut ecosystem and its overall functioning. The present study explores the alteration in mice gut bacteria on exposure to mixture of toxic heavy metals through drinking water. 
Methods: Twelve experimental groups of Swiss albino male and female mice were exposed to the metal mixture of varying concentrations. Profiling of gut bacterial flora was done by periodical collection of fecal samples via culture-based technique. Redox status of all experimental animals was analyzed in blood samples collected on the day 30.
Results: In comparison to the controls, nearly a 10-fold decline in colony forming units/ml was observed at higher modal concentrations (50× & 100×) at the end of 15 days, but 100-fold reduced bacterial count was recorded following 30 days of dosing. Sex specific significant alteration in the bacteria count and diversity was also observed. Overall experimental results showed a heavy metal dose-dependent decline in bacterial count and loss in diversity. Disturbance in the oxidative stress markers was recorded in response to high dose of metal mixture. In group receiving 100× dose, malondialdehyde levels were increased in the erythrocytes (P<0.05), and all of the other antioxidant parameters were decreased (P<0.05), except for reduced glutathione in both male and female mice. 
Conclusion: The present work is the first report on the multiple heavy metals induced gut microbiota alterations and its correlation to oxidative stress.
Ali Almasi, Mitra Mohammadi, Rouhollah Shokri, Zahra Najafi, Mohammad Javad Shokoohizadeh,
Volume 16, Issue 4 (10-2022)
Abstract

Background: Studies suggest that sulfur may react with plants or monocellular organisms, such as fungi, to produce toxic agents. It has been theorized that sulfur enters cells and affects their respiration. This study reports on a phototroph development that leads to the diminution and/or production of sulfur and release of hydrogen sulfide from public ponds.
Methods: This study was conducted in anoxic stabilization ponds at a dimension of 1×0.25×1 (m), with a hydraulic retention time of 6 days. The ponds’ water was tested during the dark and light cycles. The experiments were carried out by factorial design and measured three variables: volumetric organic loading, sulphate concentrations and temperature.
Results: Cyanobacteria and Rhodobacter species were the most abundant phototroph cellular organisms. The mean value of total sulfur and un-ionized hydrogen sulfide concentration were 74 mg/L and 21 mg/L, respectively, at the volumetric organic loading of 100 g BOD5/m3 per day. The efficiencies of biochemical and chemical oxygen removal were 71.9% and 59.1%, respectively. The mean proliferation rate of photosynthetic sulfur bacteria was 3.4×106 cells/ml.
Conclusion: photosynthetic sulfur bacteria significantly reduced the sulfur concentration generated in the ponds. The illumination of bright light enhanced the sulfur reduction by the photosynthetic sulfur bacteria in the wastewater of the anoxic stabilization ponds.
 


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