scholarly journals Antimicrobial Activities of Leaf Extracts of Guava (Psidium guajavaL.) on Two Gram-Negative and Gram-Positive Bacteria

2013 ◽  
Vol 2013 ◽  
pp. 1-7 ◽  
Author(s):  
Bipul Biswas ◽  
Kimberly Rogers ◽  
Fredrick McLaughlin ◽  
Dwayne Daniels ◽  
Anand Yadav
Keyword(s):  
Salmonella Enteritidis ◽  
Leaf Extract ◽  
Diffusion Method ◽  
Gram Negative Bacteria ◽  
Leaf Extracts ◽  
Gram Positive ◽  
Gram Negative ◽  
Gram Positive Bacteria ◽  
Spoilage Bacteria ◽  
Guava Leaves

Aim.To determine the antimicrobial potential of guava (Psidium guajava) leaf extracts against two gram-negative bacteria (Escherichia coliandSalmonella enteritidis) and two gram-positive bacteria (Staphylococcus aureusandBacillus cereus) which are some of foodborne and spoilage bacteria. The guava leaves were extracted in four different solvents of increasing polarities (hexane, methanol, ethanol, and water). The efficacy of these extracts was tested against those bacteria through a well-diffusion method employing 50 μL leaf-extract solution per well. According to the findings of the antibacterial assay, the methanol and ethanol extracts of the guava leaves showed inhibitory activity against gram-positive bacteria, whereas the gram-negative bacteria were resistant to all the solvent extracts. The methanol extract had an antibacterial activity with mean zones of inhibition of 8.27 and 12.3 mm, and the ethanol extract had a mean zone of inhibition of 6.11 and 11.0 mm againstB. cereusandS. aureus, respectively. On the basis of the present finding, guava leaf-extract might be a good candidate in the search for a natural antimicrobial agent. This study provides scientific understanding to further determine the antimicrobial values and investigate other pharmacological properties.

Green Synthesis of Silver Nanoparticles from Aqueous Leaf Extract of 'Selaginella bryopteris' and Elucidation of its Antimicrobial Activity

2020 ◽  
Vol 16 (4) ◽  
pp. 449-459
Author(s):  
Varsha Yadav ◽  
Neha Kapoor ◽  
Soma M. Ghorai ◽  
Pradeep
Keyword(s):  
Antimicrobial Activity ◽  
Silver Nanoparticles ◽  
Leaf Extract ◽  
Diffusion Method ◽  
Gram Negative Bacteria ◽  
Gram Positive ◽  
Gram Negative ◽  
Gram Positive Bacteria ◽  
Aqueous Leaf Extract ◽  
Selaginella Bryopteris

Background: Biosynthesis of nanoparticles from aqueous leaf extract of ‘Selaginella bryopteris’ is a green chemistry approach and is considered to be one of the most efficient methods as it is devoid of toxic chemicals as well as provides natural capping agents for the stabilization of synthesized nanoparticles. ‘S.bryopteris’ also known as ‘Sanjeevani’ (in India), is thought to be prospective natural resource that possesses extraordinary pharmaceutical potential. Objective: S. bryopteris is exclusively native to India and has already been known for its expression of stress-associated genes and high levels of protective metabolites of sugars, phenolic compounds, and polyols. Its potential as an antibacterial agent is being elucidated. Methods: Different leaf extract volumes, silver nitrate (AgNO3) concentrations, and reaction time were investigated separately and the optimal conditions for the synthesis of AgNPs were suggested. The resulting AgNPs were characterized by various techniques like Ultraviolet-Visible (UV-Vis) Spectroscopy, Fourier Transform Infrared Spectroscopy (FTIR), Scanning Electron Microscopy (SEM) and XRay Diffraction (XRD). Antibacterial assays were carried out by using both agar disk and well diffusion method. Results: The AgNPs synthesized in this process were found to have efficient antimicrobial activity against both Gram-positive as well as Gram-negative bacteria. The antibacterial efficacy of S. bryopteris was consciously tried on uropathogenic Escherichia coli (Gram-negative bacteria) and Bacillus megaterium (Gram-positive bacteria) which have the self-limiting food poisoning potential along with opportunistic uropathogenic bacterial strains namely Proteus mirabilis (Gram-negative bacteria) and a non-pathogenic Micrococcus luteus (Gram-positive bacteria) for comparison. Conclusion: S. bryopteris mediated silver nanoparticles’ synthesis is attempted for being cost-effective, eco-friendly and safe for human therapeutics.

scholarly journals Test for the antibacterial inhibition of kaffir lime leaf (Citrus hysteric D.C) extract against pathogen bacteria in improving food safety

2021 ◽  
Vol 883 (1) ◽  
pp. 012056
Author(s):  
S J Nendissa ◽  
D M Nendissa
Keyword(s):  
Antibacterial Activity ◽  
Food Safety ◽  
Salmonella Typhimurium ◽  
Pathogenic Bacteria ◽  
Leaf Extract ◽  
Diffusion Method ◽  
Gram Negative Bacteria ◽  
Gram Positive ◽  
Gram Negative ◽  
Gram Positive Bacteria

Abstract Kafir lime leaf (Citrus hystrix) is a plant from the citrus tribe that has long been known by community as flavor ingredient. To support its use and increase its application in supporting food safety, a test the inhibition of on kaffir lime leaf extract against pathogenic bacteria, namely Gram Negative Bacteria (Escherichia coli, Salmonella typhimurium) and Gram Positive bacteria (Staphylococcus aereus, P. aeroginosa). Making kaffir lime leaf extract (Citrus hystrix) was done by weighing 150g of lime leaf powder, then immersing in 96% ethanol solution and leaving for + 3 days. Kaffir lime leaf extract was dissolved with sterile distilled aquades to obtain a concentration of 5%, 10% and 15%. The antibacterial activity of kaffir lime leaf extract was tested by diffusion method using disc paper to determine of the bacterial growth inhibition area. The results showed that kaffir lime extract had antibacterial activity inhibition of 12,78 mm of S. aereus, 9 mm of E.coli, 7,12 mm of S. typhimurium and 9,3 mm of P. aeroginosa. Kaffir lime leaf extract has inhibition effectiveness for gram positive bacteria Staphylococcus aereus and gram negative bacteria E. coli, Salmonella typhimurium, P. aeroginosa. Thus, kaffir lime leaf extract can be used as a decontaminant agait theses 4 type of bacteria, especially Staphylococcus aereus which has a strong inhibitory power, so it can maintain quality and increase the safety of mead based foods

Antibacterial activity of magnesium oxide nanoparticles prepared by Calcination method

2019 ◽  
Vol 10 (03) ◽  
Author(s):  
Elaf Ayad Kadhem ◽  
Miaad Hamzah Zghair ◽  
Sarah , Hussam H. Tizkam, Shoeb Alahmad Salih Mahdi ◽  
Hussam H. Tizkam ◽  
Shoeb Alahmad
Keyword(s):  
Antibacterial Activity ◽  
Magnesium Oxide ◽  
Diffusion Method ◽  
Oxide Nanoparticles ◽  
Gram Negative Bacteria ◽  
Gram Positive ◽  
Gram Negative ◽  
Gram Positive Bacteria ◽  
Magnesium Oxide Nanoparticles ◽  
Agar Disc

magnesium oxide nanoparticles (MgO NPs) were prepared by simple wet chemical method using different calcination temperatures. The prepared NPs were characterized by Electrostatic Discharge (ESD), Scanning Electron Microscope (SEM) and X-ray Diffraction (XRD). It demonstrates sharp intensive peak with the increase of crystallinty and increase of the size with varying morphologies with respect to increase of calcination temperature. Antibacterial studies were done on gram negative bacteria (E.coli) and gram positive bacteria (S.aureus) by agar disc diffusion method. The zones of inhibitions were found larger for gram positive bacteria than gram negative bacteria, this mean, antibacterial MgO NPs activity more active on gram positive bacteria than gram negative bacteria because of the structural differences. It was found that antibacterial activity of MgO NPs was found it has directly proportional with their concentration.

Antimicrobial activity of Pycnarrhena cauliflora (Miers.) Diels. methanol extract

2021 ◽  
Vol 2 (2) ◽  
Author(s):  
Eti Nurwening Sholikhah ◽  
Maulina Diah ◽  
Mustofa ◽  
Masriani ◽  
Susi Iravati ◽  
...  
Keyword(s):  
Antimicrobial Activity ◽  
Methanolic Extract ◽  
Biological Activities ◽  
Positive Control ◽  
Diffusion Method ◽  
Gram Negative Bacteria ◽  
Gram Positive ◽  
Gram Negative ◽  
Gram Positive Bacteria ◽  
Methanolic Extracts

Pycnarrhena cauliflora (Miers.) Diels., local name sengkubak, is one of indigenous plants from West Kalimantan that has been used as natural flavor. Pycnorrhena cauliflora is one of species of Menispermaceae family which is rich in bisbenzylisoquinoline alkaloids. This alkaloids are known to have various biological activities including antiprotozoal, antiplasmodial, antifungal and antibacterial activities. This study aimed to investigate antimicrobial activity of  the P. cauliflora (Miers.) Diels. methanolic extracts against gram-positive and gram-negative bacteria. The methanolic extract of P. cauliflora (Miers.) Diels., root, leaf and stem were prepared by maceration. The disk-diffusion method was then used to determine the antimicrobial activity of the extracts against Streptococcus pyogenes, S. mutants, Staphylococcus aureus, S. epidermidis, Salmonella typhi, Shigella flexneri, Pseudomonas aeruginosa and Escherichia coli after 18-24 h incubation at 37 oC. Amoxicillin was used as positive control for gram-positive bacteria and ciprofloxacin was used as gram-negative bacteria. The inhibition zones were then measured in mm. Analysis were conducted in duplicates. The results showed in general the methanolic extracts of P. cauliflora (Miers.) Diels. root (inhibition zone diameter= 10-23 mm) were more active than that leaf (0-15 mm) and stem (0-17 mm) extracts against gram-positive bacteria. The zone inhibition diameter of amoxicillin as positive control was 8-42 mm. In addition, the methanolic extracts of P. cauliflora (Miers.) Diels. root (12-17 mm) were also more active than that leaf (0-12 mm) and stem (0-12 mm) extracts against gram-negative bacteria. The zone inhibition diameter of ciprofloxacin as positive control was 33-36 mm. In conclusion, the methanolic extract of P. caulifloria (Miers.) Diels. root is the most extract active against both gram-positive and gram-negative bacteria. Further study will be focused to isolate active compounds in the methanolic extract of the root.

scholarly journals The Efficacy of Psidium guajava Linn Leaf Extractsfrom Selangor Region Against Gram-Positive and Gram-Negative Bacteria

2018 ◽  
Vol 54 (4) ◽  
pp. 294
Author(s):  
S Zuhaira ◽  
Noorhaniz Mohd Nizam ◽  
PM Ridzuan
Keyword(s):  
Methanol Extract ◽  
Psidium Guajava ◽  
Diffusion Method ◽  
Future Research ◽  
Phytochemical Analysis ◽  
Gram Negative Bacteria ◽  
Leaf Extracts ◽  
Gram Positive ◽  
Gram Negative ◽  
Freeze Dried

Antibiotic is a type of medication that helps in fighting bacterial infection. Treating bacterial infections in clinical setting become more complicated and costly due to drug resistance. This study was conducted to determine the antibacterial potential of Psidium guajava Linn leaf extracts against Gram-positive and Gram-negative bacteria. P. guajava Linn leaf was obtained from Research Orchards at University Putra Malaysia (UPM). Leaves were extracted using three types of extracts; hot, cold and methanol extract. Freeze dried was used in this study and temperature was set at -104°C for 24 hours. Antibacterial testing was determined using disc diffusion and well diffusion method. Antibacterial activity was evaluated by measuring the inhibitory zone of the tested bacteria. Phytochemical analysis was conducted by adding few drop of diluted NaOH (Sodium Hydroxide) solution to detect the active flavanoid from leaves extract. Antimicrobial activity showed all extracts were effective against Gram-positive and Gram-negative bacteria. Phytochemical analysis of P. guajava Linn leaf extracts showed the methanol extract indicating the presence of tannins, phenols, flavonoids, terpenoids, glycosides and saponins. Results showed that P. guajava Linn leaf was effective against Gram-positive and Gram-negative bacteria, and pythochemical analysis also exhibited a few active compounds that were determined. P. guajava Linn leaf had potential natural product that may be used for further analysis in the future research.

scholarly journals Chemical Composition and Antibacterial Activity of the Essential Oil of Espeletia nana

2012 ◽  
Vol 7 (5) ◽  
pp. 1934578X1200700 ◽  
Author(s):  
Alexis Peña ◽  
Luis Rojas ◽  
Rosa Aparicio ◽  
Libia Alarcón ◽  
José Gregorio Baptista ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Antibacterial Activity ◽  
Chemical Composition ◽  
Essential Oil ◽  
Diffusion Method ◽  
Gram Negative Bacteria ◽  
Gram Positive ◽  
Disk Diffusion Method ◽  
Gram Negative ◽  
Gram Positive Bacteria

The essential oil of the leaves of Espeletia nana Cuatrec, obtained by hydrodistillation, was analyzed by GC-MS, which allowed the identification of 24 components, which made up 99.9% of the oil. The most abundant compounds were α-pinene (38.1%), β-pinene (17.2%), myrcene (15.0%), spathulenol (4.2%), bicyclogermacrene (4.0%), α-zingiberene (4.0%), and γhimachalene (3.7%). Antibacterial activity was tested against Gram-positive and Gram-negative bacteria using the agar disk diffusion method. Activity was observed only against Gram-positive bacteria. MIC values were determined for Staphylococcus aureus ATCC 25923(200 μg/mL) and Enterococcus faecalis ATCC 29212 (600 μg/mL).

scholarly journals Analysis of Phytochemical Constituents and Biological Activity of Taxus Wallichiana Zucc. Dolakha District of Nepal

2018 ◽  
Vol 6 (2) ◽  
pp. 110-114
Author(s):  
Bimala Subba
Keyword(s):  
Biological Activities ◽  
Radical Scavenging ◽  
Diffusion Method ◽  
Gram Negative Bacteria ◽  
Zone Of Inhibition ◽  
Gram Positive ◽  
Gram Negative ◽  
Gram Positive Bacteria ◽  
Pharmacologically Active ◽  
Taxus Wallichiana

Phytochemical and biological activities of methanolic extract of Taxus wallichiana Zucc. (Leaf, stem) were carried out. The brine shrimp bioassay showed T. wallichiana is pharmacologically active. The antibacterial potential was studied against one gram positive bacteria (Staphylococcus aureus) and one gram negative bacteria (Escherichia Coli) using Agar Well Diffusion Method. Stem of T. wallichiana showed significant zone of inhibition against gram positive bacteria while the leaf of T. wallichiana did not show significant zone of inhibition against both gram positive and gram negative bacteria. Antioxidant activity was evaluated by 2, 2-diphenyl-1-picryl hydrazyl (DPPH) free radical scavenging activity and FRAP assay. Both assay showed that T. wallichiana leaves has high antioxidant activities.Int. J. Appl. Sci. Biotechnol. Vol 6(2): 110-114

scholarly journals Antibacterial Activities of Xanthium Strumarium L.

2018 ◽  
Vol 29 ◽  
pp. 70-77 ◽  
Author(s):  
Anjana Devkota ◽  
Ritu Kumari Das
Keyword(s):  
Antibacterial Activity ◽  
Pathogenic Bacteria ◽  
Antibacterial Activities ◽  
Diffusion Method ◽  
Xanthium Strumarium ◽  
Distilled Water ◽  
Leaf Extracts ◽  
Gram Positive ◽  
Gram Negative ◽  
Gram Positive Bacteria

Antibacterial activities of Xanthium strumarium L. (Asteraceae) was carried out in laboratory. Distilled water and methanol extracts of the leaves of plant was prepared. The antibacterial activity was studied against six pathogenic bacteria, three gram negative: Klebsiella pneumoniae (ATCC 15380), Proteus mirabilis (ATCC 49132), Escherichia coli (ATCC 25922) and three gram positive: Bacillus subtilis (ATCC 6633), Enterococcus faecalis (ATCC 29212), Staphylococcus aureus (ATCC 25932) at different concentrations (50 mg/ml, 100 mg/ml, 150 mg/ml, 200 mg/ ml, 250 mg/ml) of leaf extracts of X. strumurium. The phytochemical screening depicted the presence of terpenoids, saponins, flavonoids, tannins and alkaloids. The antibacterial activity of extracts was determined by disc diffusion method and zone of inhibition (ZOI) was measured. Gram negative bacteria was found more resistant than gram positive bacteria. The most susceptible bacterium was S. aureus while the most resistant bacterium was E. coli. Methanolic extract was found more effective than distilled water. These findings suggest that extracts obtained from leaves of X. strumurium possess biobactericidal potential, which can suitably be exploited for making antibacterial drugs.J. Nat. Hist. Mus. Vol. 29, 2015, Page: 70-77

scholarly journals Analysis of Phytoconstituents and Biological Activities on The Selected Medicinal Plants of Dolakha and Sindhualchowk District of Nepal

2018 ◽  
Vol 22 (2) ◽  
pp. 140-147 ◽  
Author(s):  
Bimala Subba ◽  
Susila Thapa
Keyword(s):  
Antioxidant Activities ◽  
Biological Activities ◽  
Radical Scavenging ◽  
Diffusion Method ◽  
Gram Negative Bacteria ◽  
Gram Positive ◽  
Antioxidant Power ◽  
Gram Negative ◽  
Gram Positive Bacteria ◽  
Pharmacologically Active

Phytochemical and biological activities of methanolic extract of seven plants viz. Scindapsus officinalis Schott. , Lepisorus loriformis, Nicotiana tabacum L., Clematis buchananiana DC., Astilbe rivularis D. Don, Potentilla fulgens Wall. ex Hook and Taxus wallichiana Zucc. were carried out. The brine shrimp bioassay showed that N. tabacum, A. rivularis, and P. fulgens were pharmacologically active. The antibacterial potential was studied against Staphylococcus aureus (gram positive bacteria) and Escherichia coli (gram negative bacteria) using Agar Well Diffusion Method. Roots of P. fulgens showed inhibition against gram positive bacteria while the rhizome of A. rivularis showed inhibition against both gram positive and gram negative bacteria. Antioxidant activity was evaluated by 2, 2-diphenyl-1-picryl hydrazyl (DPPH) free radical scavenging activity and ferric reducing antioxidant power FRAP assay. Both assays showed that P. fulgens has high antioxidant activities with (IC50 =15.57 ± 3.6) lower than standard ascorbic acid.  Journal of Institute of Science and TechnologyVolume 22, Issue 2, January 2018, Page: 140-147

Biogenic Gold Nanoparticles and its Antibacterial Activities: Houttuynia Cordata Leaf Extract

2014 ◽  
Vol 1051 ◽  
pp. 392-397
Author(s):  
T.V.M. Sreekanth ◽  
In Yong Eom
Keyword(s):  
Gold Nanoparticles ◽  
Leaf Extract ◽  
Antibacterial Activities ◽  
Gram Negative Bacteria ◽  
Gram Positive ◽  
Houttuynia Cordata ◽  
Gram Negative ◽  
Gram Positive Bacteria ◽  
Visible Spectra ◽  
Uv Visible

Gold nanoparticles (AuNPs) can be prepared in a number of chemical techniques, which are not environmentally friendly. Biosynthesis of nanoparticles by plant extracts is currently under exploitation. In this work, we describe an eco-friendly technique for green synthesis of AuNPs from AuCl4 solution using the Houttuynia cordata leaf extract as reducing agent. The AuNPs were characterized using UV-Visible spectroscopy, SEM, TEM, FTIR and AFM. The UV-Visible spectra indicate a strong plasma resonance that is located at 535 nm. The antibacterial activity of AuNPs was performed on various gram positive and gram negative bacteria. The AuNPs showed more inhibitory activity on gram negative than gram positive bacteria.

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