scholarly journals The Effect of Bacteriocin Isolated From Lactobacillus rhamnosus on Pseudomonas aeruginosa Lipopolysaccharides

2021 ◽  
Vol 8 (2) ◽  
pp. 45-50
Author(s):  
Hafizeh Haghighatafshar ◽  
Reza Talebi ◽  
Amir Tukmechi
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Inhibitory Concentration ◽  
Antibacterial Effect ◽  
Antibacterial Properties ◽  
Lactobacillus Rhamnosus ◽  
Growth Period ◽  
Minimal Bactericidal Concentration ◽  
Gram Negative Bacteria ◽  
Gram Negative ◽  
Mic Value

Background: Bacteriocins are heterogeneous inhibitory substances that could affect the bacteria belonging to the same genus. Both gram-positive and gram-negative bacteria produce bacteriocins. One of the best sources of producing bacteriocins is Lactobacillus. The aim of this study was to isolate and purify bacteriocin from Lactobacillus rhamnosus and assess its effects on Pseudomonas aeruginosa and synthesis of its lipopolysaccharide. Methods: L. rhamnosus was prepared and cultured at MRS broth and incubated at 37ºC for 24 hours. Then, the medium was centrifuged for the isolation of bacteriocin and the supernatant was considered as bacteriocin. Antibacterial properties of different concentrations of bacteriocin (50, 100, 200, and 400 μg/mL) against P. aeruginosa were assayed by using agar diffusion and broth micro dilution methods. Also, the effect of bacteriocin against lipopolysaccharide synthesis in P. aeruginosa was analyzed by using one unit of minimum inhibitory concentration (MIC) for bacteriocin. Results: The results showed that all bacteriocin concentrations had antibacterial activity against P. aeruginosa. The MIC value was 31.25 μg/mL and minimal bactericidal concentration (MBC) was 62.5 μg/mL. Also, the synthesis of lipopolysaccharide decreased during P. aeruginosa growth period, and it reached zero after 5 hours. Conclusions: The results of this study showed the antibacterial effect of bacteriocin isolated from L. rhamnosus against P. aeruginosa. In addition, this bacteriocin prevented the lipopolysaccharide synthesis in P. aeruginosa.

scholarly journals Antimicrobial effect of essential oils of some Fijian medicinal plant leaves on pathogenic bacteria

2016 ◽  
Vol 34 (2) ◽  
pp. 35
Author(s):  
Prayna P. P. Maharaj ◽  
Riteshma Devi ◽  
Surendra Prasad
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Antimicrobial Agent ◽  
Essential Oils ◽  
Pathogenic Bacteria ◽  
Antibacterial Properties ◽  
Antimicrobial Activities ◽  
Diffusion Method ◽  
Gram Negative Bacteria ◽  
Gram Positive ◽  
Gram Negative

Fiji is highly populated with plants containing essential oils (EO). The essential oils extracted from the leaves of the selected Fijian leafy plants were screened against two Gram-negative bacteria (Salmonella typhimurium, Pseudomonas aeruginosa) and three Gram-positive bacteria (Staphylococcus aureus, Enterococcus faecalis and Bacillus subtilis). The agar diffusion method was used to examine the antimicrobial activities of the extracted EO. All the EO tested showed antibacterial properties against one or more strains while none of the EO was active against Pseudomonas aeruginosa. Viburnum lantana (Wayfaring tree), Annona muricata (Soursop), Coleus amboinicus (Spanish thyme) and Cinnamomum zeylancium (Cinnamon) showed good inhibition against both Gram-positive and Gram-negative bacteria and proved as worthy source of antimicrobial agent. These findings will help the Pacific population to use the studied plants leaves as antimicrobial agent.

scholarly journals QUANTITATIVE ESTIMATION AND ANTIMICROBIAL POTENTIAL OF ETHANOL EXTRACT OF DURIO ZIBETHINUS MURR. LEAVES

2017 ◽  
Vol 10 (9) ◽  
pp. 251
Author(s):  
Sridevi Chigurupati ◽  
Jahidul Islam Mohammad ◽  
Shantini Vijayabalan ◽  
Narmatha Devi Vaipuri ◽  
Kesavanarayanan Krishnan Selvarajan ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Pseudomonas Aeruginosa ◽  
Quantitative Estimation ◽  
Antibacterial Properties ◽  
Diffusion Method ◽  
Gram Negative Bacteria ◽  
Human Pathogens ◽  
Gram Negative ◽  
Antimicrobial Potential ◽  
Durio Zibethinus

Objectives: Current research is aimed to investigate the natural antimicrobial potential of Durio zibethinus murr. ethanol leaves extract (DZL).Methods: DZL was subjected to the preliminary phytochemical screening along with quantitative analysis of phenols and flavonoids. Minimum Inhibitory Concentration (MIC) and Minimum Bactericidal Concentration (MBC) were recorded. The agar well diffusion method was used to measure the antibacterial activity against gram positive and gram negative bacteria. The microorganisms used for the study were the ATCC strains of Bacillus subtilis, Enterococcus faecalis, Staphylococcus aureus, Streptococcus pyogenes, Neisseria gonorrhoeae, Pseudomonas aeruginosa and Escherichia coli.Results: DZL exhibited the highest MIC of 0.1mg/mL and MBC of 0.25 mg/mL against gram negative bacteria, Pseudomonas aeruginosa and Escherichia coli. At MIC of 0.1mg/mL, DZL displayed significant zone of inhibition against Pseudomonas aeruginosa and Escherichia coli compared to gentamycin.Conclusion: This research has shown that DZL has natural antibacterial properties against gram negative human pathogens.

scholarly journals A Mini Review of Antibacterial Properties of ZnO Nanoparticles

2021 ◽  
Vol 9 ◽  
Author(s):  
Sergey V. Gudkov ◽  
Dmitriy E. Burmistrov ◽  
Dmitriy A. Serov ◽  
Maxim B. Rebezov ◽  
Anastasia A. Semenova ◽  
...  
Keyword(s):  
Zinc Oxide ◽  
Zinc Oxide Nanoparticles ◽  
Antibacterial Effect ◽  
Antibacterial Properties ◽  
World Health ◽  
Oxide Nanoparticles ◽  
Gram Negative Bacteria ◽  
Gram Negative ◽  
E Coli ◽  
Antibacterial Potential

The development of antibiotic resistance of bacteria is one of the most pressing problems in world health care. One of the promising ways to overcome microbial resistance to antibiotics is the use of metal nanoparticles and their oxides. In particular, numerous studies have shown the high antibacterial potential of zinc oxide nanoparticles (ZnO-NP) in relation to gram-positive and gram-negative bacteria. This mini-review includes an analysis of the results of studies in recent years aimed at studying the antibacterial activity of nanoparticles based on zinc oxide. The dependence of the antibacterial effect on the size of the applied nanoparticles in relation to E. coli and S. aureus is given. The influence of various ways of synthesis of zinc oxide nanoparticles and the main types of modifications of NP-ZnO to increase the antibacterial efficiency are also considered.

scholarly journals Antibacterial activity of wood distillate from residual virgin chestnut biomass

2020 ◽  
Author(s):  
Francesco Misuri ◽  
Laura Marri
Keyword(s):  
Antibacterial Activity ◽  
Inhibitory Concentration ◽  
Sustainable Use ◽  
Antibacterial Properties ◽  
Gram Negative Bacteria ◽  
Bacterial Cells ◽  
Gram Negative ◽  
Concentration Test ◽  
Mic Minimum Inhibitory Concentration ◽  
Wall Components

Abstract The antibacterial properties of a wood distillate obtained from residual virgin chestnut biomass were investigated by means of quantitative MIC (minimum inhibitory concentration) test and a whole-cell assay that specifically responds to different classes of antimicrobials on the basis of the mode of action. Results indicate that wood distillate is active against gram-positive and gram-negative bacteria related to human and/or fish diseases with a mechanism, which could mainly affect wall components and plasma membrane of the bacterial cells. These findings highlight the possible sustainable use of chestnut residues as a source of bioactive natural compounds with antibacterial properties.

scholarly journals Promising Antimicrobial Properties of Bioactive Compounds from Different Honeybee Products

Molecules ◽  
2021 ◽  
Vol 26 (13) ◽  
pp. 4007
Author(s):  
Magdalena Ratajczak ◽  
Dorota Kaminska ◽  
Eliza Matuszewska ◽  
Elżbieta Hołderna-Kedzia ◽  
Jarosław Rogacki ◽  
...  
Keyword(s):  
Royal Jelly ◽  
Antimicrobial Agents ◽  
Inhibitory Concentration ◽  
Antibacterial Properties ◽  
Antimicrobial Properties ◽  
Bee Venom ◽  
Gram Negative Bacteria ◽  
Gram Negative ◽  
The Subject ◽  
The Impact

Bee products have been known for centuries for their versatile healing properties. In recent decades they have become the subject of documented scientific research. This review aims to present and compare the impact of bee products and their components as antimicrobial agents. Honey, propolis, royal jelly and bee venom are bee products that have antibacterial properties. Sensitivity of bacteria to these products varies considerably between products and varieties of the same product depending on their origin. According to the type of bee product, different degrees of activity were observed against Gram-positive and Gram-negative bacteria, yeasts, molds and dermatophytes, as well as biofilm-forming microorganisms. Pseudomonas aeruginosa turned out to be the most resistant to bee products. An analysis of average minimum inhibitory concentration values for bee products showed that bee venom has the strongest bacterial effectiveness, while royal jelly showed the weakest antibacterial activity. The most challenging problems associated with using bee products for medical purposes are dosage and safety. The complexity and variability in composition of these products raise the need for their standardization before safe and predictable clinical uses can be achieved.

scholarly journals Effect of leaves Extracts of Duranta repens on growth and activity of some types of Pathogenic Bacteria and Some types of Fungi

2009 ◽  
Vol 6 (1) ◽  
pp. 29-42 ◽  
Author(s):  
Baghdad Science Journal
Keyword(s):  
Pathogenic Bacteria ◽  
Inhibitory Concentration ◽  
Minimum Bactericidal Concentration ◽  
Inhibition Zone ◽  
Diameter Growth ◽  
Gram Negative Bacteria ◽  
Organic Extract ◽  
Gram Negative ◽  
Gram Positive Bacteria ◽  
Mic Value

A study were conducted to examinate the effect of organic and aqueous (Hot, Cold) Extracts from leaves of Duranta repens on the growth and activities of the following types of Bacteria:- Staphylococcus aureus,Streptococcus pyogens ,Escherichia coli,Klebsilla pneumonia, in addition to the yeast Candida albicans and the fungi Aspergullis niger ,Aspergulls flavus.The result showed that gram Positive Bacteria is more sensitive to the extracts than gram negative bacteria with Minimum inhibitory concentration (MIC) value (50,25,50,100)% and Minimum Bactericidal Concentration (MBC) value (100,50,200,100)% for all types Bacteria respectively . The most active extract against A.niger ,A,flavus was cold and hot aqueous extract from the leaves with diameter growth of colony value of ( 0.93,0.37)cm for A.niger in 20 % concentration compared with organic extract (0.26)cm, and the inhibition zone value of cold and hot extract to A.flavus (0.90,0.80)cm respectively compared with organic extract (7.056)cm.

scholarly journals The Effect of Eruca sativa extract on Gram Posative and Negative Bacteria

2007 ◽  
Vol 4 (3) ◽  
pp. 375-378
Author(s):  
Baghdad Science Journal
Keyword(s):  
Antibacterial Effect ◽  
In Vitro Study ◽  
Minimal Bactericidal Concentration ◽  
Natural Material ◽  
Gram Negative Bacteria ◽  
Eruca Sativa ◽  
Gram Positive ◽  
Gram Negative ◽  
Gram Positive Bacteria

The antibacterial effect of (Eruca sativa) extract was evaluated by an in vitro study testing the growth of various Gram-Positive and Gram-Negative bacteria . The bactericidal activity of this extract was analyzed by serial dilution in tubes. This study,found that Gram-Negative and Gram-Positive bacteria susceptible to very low eruca concentrations. On the other hand, Gram-positive bacteria were more susceptible than Gram-negative bacteria, the minimal bactericidal concentration of Gram-positive bacteria was 5 mg ml-1 but minimal bactericidal concentration of Gram-negative bacteria was 10 mg ml-1 that mean duble inhibation concentration of Gram-positive bacteria . this study suggest that Eruca sativa leaves have inhibation effect on Gram-Posative and Gram-Negative bacteria and Eruca sativa was natural material with little side effect.

scholarly journals Antibacterial activity of grapefruit peel extracts and green-synthesized silver nanoparticles

2021 ◽  
pp. 1330-1341
Author(s):  
Mbarga M. J. Arsène ◽  
I. V. Podoprigora ◽  
Anyutoulou K. L. Davares ◽  
Marouf Razan ◽  
M. S. Das ◽  
...  
Keyword(s):  
Silver Nanoparticles ◽  
Antibacterial Activity ◽  
Inhibitory Concentration ◽  
Antibacterial Properties ◽  
Gram Negative Bacteria ◽  
Gram Negative ◽  
E Coli ◽  
Gram Positive Bacteria ◽  
Grapefruit Peel ◽  
Green Synthesized Silver Nanoparticles

Background and Aim: The gradual loss of efficacy of conventional antibiotics is a global issue. Plant material extracts and green-synthesized nanoparticles are among the most promising options to address this problem. Therefore, the aim of this study was to assess the antibacterial properties of aqueous and hydroalcoholic extracts of grapefruit peels as well as their inclusion in green-synthesized silver nanoparticles (AgNPs). Materials and Methods: Aqueous and hydroalcoholic extracts (80% v/v) were prepared, and the volume and mass yields were determined. The synthesis of AgNPs was done in an eco-friendly manner using AgNO3 as a precursor. The nanoparticles were characterized by ultraviolet–vis spectrometry and photon cross-correlation spectroscopy. The antibacterial activity of the extracts was tested on three Gram-positive bacteria (Staphylococcus aureus ATCC 6538, clinical Enterococcus faecalis, and S. aureus) and two Gram-negative bacteria (two clinical Escherichia coli) using various concentrations of extracts (100, 50, 25, 12, and 5 mg/mL and 5% dimethyl sulfoxide as negative control). Minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) were determined using the microdilution method. Modulation of cefazoline and ampicillin on resistant E. coli and S. aureus strains was added to the mixture design response surface methodology with extreme vertices design, with the diameters of inhibition and the fractional inhibitory concentration index as responses and factors, respectively. The antibiotic, the ethanolic extract, and water varied from 0.1 MIC to 0.9 MIC for the first two and from 0 to 0.8 in proportion for the third. Validating the models was done by calculating the absolute average deviation, bias factor, and accuracy factor. Results: The volume yield of the EE and aqueous extract (AE) was 96.2% and 93.8% (v/v), respectively, whereas their mass yields were 7.84% and 9.41% (m/m), respectively. The synthesized AgNPs were very uniform and homogeneous, and their size was dependent on the concentration of AgNO3. The antibacterial activity of the two extracts was dose-dependent, and the largest inhibition diameter was observed for the Gram-positive bacteria (S. aureus ATCC 6538; AE, 12; EE, 16), whereas AgNPs had a greater effect on Gram-negative bacteria. The MICs (mg/mL) of the AEs varied from 3.125 (S. aureus ATCC 6538) to 12.5 (E. coli 1 and E. coli 2), whereas the MICs of the EEs varied from 1.5625 (S. aureus 1, S. aureus ATCC 6538, and E. faecalis) to 6.25 (E. coli 1). There was a significant difference between the MICs of AEs and EEs (p=0.014). The MBCs (mg/mL) of the AEs varied from 12.5 (S. aureus ATCC 6538) to 50 (S. aureus 1), whereas those of the EEs varied from 6.25 (S. aureus 1) to 25 (E. coli 1 and E. faecalis). Ethanolic grapefruit extracts demonstrated an ability to modulate cefazolin on E. coli and S. aureus but were completely indifferent to ampicillin on E. coli. Conclusion: Grapefruit peel extracts and their AgNPs exhibit antibacterial properties that can be exploited for the synthesis of new antimicrobials and their EEs may be efficiently used synergistically with other antibiotics against bacteria with intermediate susceptibility.

Antimicrobial and cytotoxic activity of Macrophomina phaseolina isolated from gummosis infected citrus reticulata

2013 ◽  
pp. 125-133
Author(s):  
Rubal C Das ◽  
Rajib Banik ◽  
Robiul Hasan Bhuiyan ◽  
Md Golam Kabir
Keyword(s):  
Escherichia Coli ◽  
Staphylococcus Aureus ◽  
Brine Shrimp ◽  
Inhibitory Concentration ◽  
Lethal Dose ◽  
Macrophomina Phaseolina ◽  
Chloroform Extract ◽  
Citrus Reticulata ◽  
Gram Negative Bacteria ◽  
Gram Negative

Macrophomina phaseolina is one of the pathogenic organisms of gummosis disease of orange tree (Citrus reticulata). The pathogen was identified from the observation of their colony size, shape, colour, mycelium, conidiophore, conidia, hyaline, spore, and appressoria in the PDA culture. The crude chloroform extracts from the organism showed antibacterial activity against a number of Gram positive and Gram-negative bacteria. The crude chloroform extract also showed promising antifungal activity against three species of the genus Aspergillus. The minimum inhibitory concentration (MIC) of the crude chloroform extract from M. phaseolina against Bacillus subtilis, Staphylococcus aureus, Escherichia coli, and Shigella sonnie were 128 ?gm, 256 ?gm, 128 ?gm and 64 ?gm/ml respectively. The LD50 (lethal dose) values of the cytotoxicity assay over brine shrimp of the crude chloroform extract from M. phaseolina was found to be 51.79 ?gm/ml. DOI: http://dx.doi.org/10.3329/cujbs.v5i1.13378 The Chittagong Univ. J. B. Sci.,Vol. 5(1 &2):125-133, 2010

scholarly journals MexAB-OprM Efflux Pump Interaction with the Peptidoglycan of Escherichia coli and Pseudomonas aeruginosa

2021 ◽  
Vol 22 (10) ◽  
pp. 5328
Author(s):  
Miao Ma ◽  
Margaux Lustig ◽  
Michèle Salem ◽  
Dominique Mengin-Lecreulx ◽  
Gilles Phan ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Pseudomonas Aeruginosa ◽  
Cell Division ◽  
Membrane Proteins ◽  
Outer Membrane ◽  
Efflux Pump ◽  
Gram Negative Bacteria ◽  
Gram Negative ◽  
Active Efflux

One of the major families of membrane proteins found in prokaryote genome corresponds to the transporters. Among them, the resistance-nodulation-cell division (RND) transporters are highly studied, as being responsible for one of the most problematic mechanisms used by bacteria to resist to antibiotics, i.e., the active efflux of drugs. In Gram-negative bacteria, these proteins are inserted in the inner membrane and form a tripartite assembly with an outer membrane factor and a periplasmic linker in order to cross the two membranes to expulse molecules outside of the cell. A lot of information has been collected to understand the functional mechanism of these pumps, especially with AcrAB-TolC from Escherichia coli, but one missing piece from all the suggested models is the role of peptidoglycan in the assembly. Here, by pull-down experiments with purified peptidoglycans, we precise the MexAB-OprM interaction with the peptidoglycan from Escherichia coli and Pseudomonas aeruginosa, highlighting a role of the peptidoglycan in stabilizing the MexA-OprM complex and also differences between the two Gram-negative bacteria peptidoglycans.

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