scholarly journals Determination of the antimicrobial and antibiofilm effects and ‘Quorum Sensing’ inhibition potentials of Castanea sativa Mill. extracts

2020 ◽  
Vol 48 (1) ◽  
pp. 66-78
Author(s):  
Saliha EKŞİ ◽  
Ülkü Zeynep ÜREYEN ESERTAŞ ◽  
Ali Osman KILIÇ ◽  
Nebahat EJDER ◽  
Barış UZUNOK
Keyword(s):  
Quorum Sensing ◽  
Ethyl Acetate ◽  
Antimicrobial Agents ◽  
Methanol Extract ◽  
Bacterial Species ◽  
Castanea Sativa ◽  
Diffusion Method ◽  
Biofilm Inhibition ◽  
Pao1 Strain

The rapid rise of resistance causes existing antibiotics to become dysfunctional. Therefore, search for new antimicrobial active ingredients has increased in recent years. In this study, flower extracts of Castanea sativa were examined for antimicrobial and anti-quorum sensing aspects. The antimicrobial properties of methanol, ethyl acetate, ethanol and hexane extracts of C. sativa against some gram-positive and gram-negative bacterial species, as well as yeasts (Candida albicans and Candida parapsilosis) were investigated by the agar well diffusion method. The minimum inhibition concentration (MIC) and minimum bactericidal concentrations (MBC) of C. sativa extracts were also determined. Chromobacterium violaceum ATCC 12472, C. violaceum 35352, C. violaceum VIR07 and C. violaceum CV026 indicator strains were used for determination of the quorum sensing inhibitions, and the Pseudomonas aeruginosa PAO1 strain was used for the swarming tests. Additionally, biofilm inhibition was detected by the spectrophotometric method using the P. aeruginosa PAO1 strain. Methanol, ethanol and ethyl acetate extracts of C. sativa was found to have high antibacterial and antifungal effects, while the methanol extract also had anti-quorum sensing, anti- swarming and biofilm inhibition effects, but no activity was found in the n- hexane extract. To the best of our knowledge this is the first report revealed that methanol extract obtained from C. sativa flowers induced anti-quorum sensing activities mainly inhibited the violacein production, swarming and biofilm formation. The present investigation provided evidence that the C. sativa flower extract maybe a potential source of antimicrobial agents. Therefore, much attention should be paid to C. sativa flower content, which could be used with high efficacy against microorganisms.

scholarly journals Screening Of Antibacterial Activity Of Nepeta Ciliaris Benth. Against Respiratory Tract Pathogens

1970 ◽  
Vol 8 (1) ◽  
pp. 100-103 ◽  
Author(s):  
Gautam Shiv Shankar ◽  
M Navneet ◽  
Kumar Sanjay ◽  
M Prabhat
Keyword(s):  
Respiratory Tract ◽  
Antimicrobial Agents ◽  
Inhibitory Concentration ◽  
Methanol Extract ◽  
Bacterial Species ◽  
Positive Control ◽  
Maximum Activity ◽  
Diffusion Method ◽  
Aerial Parts ◽  
Antibacterial Potential

The aim of present study was to evaluate the antibacterial potential of various extracts (petroleum ether, acetone, methanol and aqueous) of Nepeta ciliaris against selected respiratory tract pathogens. The extracts from the aerial parts of N. ciliaris at concentration of 200 mg/ml were screened against three gram-positive (Staphylococcus aureus MTCC 1144, Streptococcus pneumoniae MTCC 655 and Streptococcus pyogenes MTCC 442) and one gram-negative (Pseudomonas aeruginosa MTCC 2474) bacterial pathogens. The agar well diffusion method was adopted to examine antibacterial and minimum inhibitory concentration (MIC) values of most effective extracts against the susceptible bacteria. Erythromycin was used as positive control to determine the sensitivity of the strains. Out of the four bacterial species tested, S. pneumoniae was the most susceptible. The acetone extract exhibited maximum activity against all the tested microorganisms while methanol extract showed activity against P. aeruginosa. The MIC values ranged from 40 to 50 mg/ml for all the organisms. The N. ciliaris is potentially a good source of antimicrobial agents. DOI: http://dx.doi.org/10.3126/kuset.v8i1.6049 KUSET 2012; 8(1): 100-103

scholarly journals Antimicrobial activity and bioautographic study of antistaphylococcal components from Caesalpinia pyramidalis Tull.

2012 ◽  
Vol 48 (1) ◽  
pp. 147-154 ◽  
Author(s):  
Antonio Marcos Saraiva ◽  
Cristiane Lopes Saraiva ◽  
Admário Marques Gonçalves ◽  
Rogério Ribeiro Soares ◽  
Fabrício de Oliveira Mendes ◽  
...  
Keyword(s):  
Antimicrobial Activity ◽  
Ethyl Acetate ◽  
Antimicrobial Agents ◽  
Inhibitory Concentration ◽  
Methanol Extract ◽  
Diffusion Method ◽  
Phytochemical Study ◽  
Multiresistant Strains ◽  
Active Substances ◽  
Ethyl Acetate Extracts

The antimicrobial activity of dry methanol and ethyl acetate extracts for the leaves, bark of the stem, peel of the root, flower, fruit and seed of Caesalpinia pyramidalis Tull. (catingueira) was performed against seventeen isolates of Staphylococcus aureus MRSA multiresistant strains, which included two isolates of S. aureus MSSA and two ATCC strains. The antimicrobial activity was tested by the agar diffusion method and the Minimum Inhibitory Concentration (MIC) was determined. The dry methanol extract of the root showed good antimicrobial activity with a MIC of less than 0.5 mg.mL-1. The dry ethyl acetate extracts exhibited lower antimicrobial activity, which might be explained by solubility problems and less diffusion in the agar medium. Results of the bioautographies also confirmed inhibition halos corresponding to the active substances present in the leaves, as well as in the flower of C. pyramidalis. The phytochemical study of the leaves, bark of the stem, peel of the root, flower and fruit of extracts from C. pyramidalis confirmed the presence of a number of known antimicrobial agents including ursolic acid, quercetin, catechin, ellagic acid, sitosterol, flavonoids, proanthocyanidins and gallic acid.

scholarly journals Effect of Essential Oils on the Inhibition of Biofilm and Quorum Sensing in Salmonella Enteritidis 13076 and Salmonella Typhimurium 14028

Antibiotics ◽  
2021 ◽  
Vol 10 (10) ◽  
pp. 1191
Author(s):  
Yuliany Guillín ◽  
Marlon Cáceres ◽  
Rodrigo Torres ◽  
Elena Stashenko ◽  
Claudia Ortiz
Keyword(s):  
Quorum Sensing ◽  
Essential Oils ◽  
Salmonella Enterica ◽  
Salmonella Enteritidis ◽  
Antimicrobial Agents ◽  
Multidrug Resistant ◽  
Transcriptional Analysis ◽  
Bacterial Cells ◽  
Sem Images ◽  
Biofilm Inhibition

The emergence of multidrug-resistant microorganisms represents a global challenge that has led to a search for new antimicrobial compounds. Essential oils (EOs) from medicinal aromatic plants are a potential alternative for conventional antibiotics. In this study, the antimicrobial and anti-biofilm potential of 15 EOs was evaluated on planktonic and biofilm-associated cells of Salmonella enterica serovar Enteritidis ATCC 13076 (S. enteritidis) and Salmonella enterica serovar Typhimurium ATCC 14028 (S. typhimurium). In total, 4 out of 15 EOs showed antimicrobial activity and 6 EOs showed anti-biofilm activity against both strains. The EO from the Lippia origanoides chemotype thymol-carvacrol II (LTC II) presented the lowest minimum inhibitory concentration (MIC50 = 0.37 mg mL−1) and minimum bactericidal concentration (MBC = 0.75 mg mL−1) values. This EO also presented the highest percentage of biofilm inhibition (>65%) on both microorganisms, which could be confirmed by scanning electron microscopy (SEM) images. Transcriptional analysis showed significant changes in the expression of the genes related to quorum sensing and the formation of the biofilm. EOs could inhibit the expression of genes involved in the quorum sensing mechanism (luxR, luxS, qseB, sdiA) and biofilm formation (csgA, csgB, csgD, flhD, fliZ, and motB), indicating their potential use as anti-biofilm antimicrobial agents. However, further studies are needed to elucidate the action mechanisms of essential oils on the bacterial cells under study.

scholarly journals Uji Aktivitas Antibakteri Ekstrak Metanol dan Fraksi Daun Kenikir (Cosmos caudatus Kunth) terhadap Salmonella typhi

2020 ◽  
Vol 8 (3) ◽  
pp. 177
Author(s):  
Achmad Syarifudin Noor ◽  
Bawon Triatmoko ◽  
Nuri Nuri
Keyword(s):  
Antibacterial Activity ◽  
Typhoid Fever ◽  
Ethyl Acetate ◽  
Methanol Extract ◽  
Inhibition Zone ◽  
Salmonella Typhi ◽  
Diffusion Method ◽  
Disk Diffusion Method ◽  
Water Fraction ◽  
Zone Diameter

The leaves of kenikir are known to have many benefits, one of which can be used as medicine. Kenikir leaves are reported to have antibacterial activity against the bacteria Salmonella typhi (S.typhi). S. typhi is a bacterium that causes typhoid fever. Typhoid fever is still an endemic disease in Asian countries, especially Indonesia. Typhoid fever became the third largest disease in Indonesia in 2010. The study related to the antibacterial activity of kenikir leaf fraction to S. typhi has never been reported. Therefore, it is necessary to conduct research related to the antibacterial activity of extracts and leaf fractions of kenikir to compare their potential against S. typhi. The study was conducted using the disk diffusion method using 5 series of concentrations namely 5%, 10%, 15%, 20%, and 30%. Tests were carried out on methanol extract, hexane, ethyl acetate, and methanol-water fraction. The results showed that highest inhibition zone diameter is 7,75 mm which is reached by methanol extract. The order of the highest inhibiting zone diameter are extract, hexane, ethyl acetate, and methanol-water fraction.

scholarly journals DETERMINATION OF THE ANTIOXIDANT ACTIVITY OF PRASMAN LEAF EXTRACTS (AYAPANA TRIPLINERVIS [VAHL]) AND THE TOTAL FLAVONOID AND PHENOL CONTENTS OF THE MOST ACTIVE EXTRACTS

2020 ◽  
pp. 107-111
Author(s):  
YUNITRIANTI ◽  
BERNA ELYA ◽  
ARIKADIA NOVIANI
Keyword(s):  
Antioxidant Activity ◽  
Ethyl Acetate ◽  
Methanol Extract ◽  
Total Flavonoid ◽  
Dpph Assay ◽  
Frap Assay ◽  
Methanol Extracts ◽  
Uv Visible ◽  
Antioxidant Effects

Objective: Prasman (Ayapana triplinervis [Vahl]) is a plant that can eliminate free radicals through its antioxidant effects. However, little research hasbeen conducted to explore the antioxidant activity of the plant.Methods: A. triplinervis (Vahl) leaves, which were determined by the Indonesian Institute of Sciences (LIPI) Bogor, were used in this study. Meanwhile,extraction was performed using n-hexane, ethyl acetate, and methanol as the solvents. Based on the 2,2-diphenyl-1-picrylhydrazyl (DPPH) assay usinga UV–visible spectrophotometer and based on ferric reducing antioxidant power (FRAP) assay using a microplate reader.Results: Based on the DPPH assay using a UV–visible spectrophotometer, n-hexane, ethyl acetate, and methanol extracts with a final concentrationof 25 μg/mL inhibited DPPH radical production by 38.91, 51.03, and 54.06%, respectively. Using the percent inhibition, the IC50 for the ethyl acetateand methanol extracts were 28.71 and 23.472 μg/mL, respectively. Based on FRAP assay using a microplate reader, the n-hexane, ethyl acetate, andmethanol extracts had ferrous equivalent antioxidant capacity values of 460, 828.99, and 940.22 μmol/g, respectively. The methanol extract had thegreatest antioxidant activity. The ethyl acetate and methanol extracts at the initial concentrations contained total phenol levels of 12.06 and 42.11 mgGAE/g extract, respectively, as well as total flavonoid levels of 3.24 and 3.41 mg QE/g extract, respectively.Conclusion: Based on the determination of phenol and flavonoid levels, the methanol extract had the greatest antioxidant effects.

scholarly journals Peptide Mix from Olivancillaria hiatula Interferes with Cell-to-Cell Communication in Pseudomonas aeruginosa

2019 ◽  
Vol 2019 ◽  
pp. 1-12
Author(s):  
Edward Ntim Gasu ◽  
Hubert Senanu Ahor ◽  
Lawrence Sheringham Borquaye
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Quorum Sensing ◽  
Biofilm Formation ◽  
Antimicrobial Agents ◽  
Cell Communication ◽  
Microtiter Plate ◽  
Antibiofilm Activity ◽  
Dependent Manner ◽  
Biofilm Inhibition ◽  
Swarming Motility

Bacteria in biofilms are encased in an extracellular polymeric matrix that limits exposure of microbial cells to lethal doses of antimicrobial agents, leading to resistance. In Pseudomonas aeruginosa, biofilm formation is regulated by cell-to-cell communication, called quorum sensing. Quorum sensing facilitates a variety of bacterial physiological functions such as swarming motility and protease, pyoverdine, and pyocyanin productions. Peptide mix from the marine mollusc, Olivancillaria hiatula, has been studied for its antibiofilm activity against Pseudomonas aeruginosa. Microscopy and microtiter plate-based assays were used to evaluate biofilm inhibitory activities. Effect of the peptide mix on quorum sensing-mediated processes was also evaluated. Peptide mix proved to be a good antibiofilm agent, requiring less than 39 μg/mL to inhibit 50% biofilm formation. Micrographs obtained confirmed biofilm inhibition at 1/2 MIC whereas 2.5 mg/mL was required to degrade preformed biofilm. There was a marked attenuation in quorum sensing-mediated phenotypes as well. At 1/2 MIC of peptide, the expression of pyocyanin, pyoverdine, and protease was inhibited by 60%, 72%, and 54%, respectively. Additionally, swarming motility was repressed by peptide in a dose-dependent manner. These results suggest that the peptide mix from Olivancillaria hiatula probably inhibits biofilm formation by interfering with cell-to-cell communication in Pseudomonas aeruginosa.

scholarly journals Phytochemical Screening and in vitro Antimicrobial Activity of Cyperus rotundus Leaf Extracts

2021 ◽  
Vol 4 (1) ◽  
pp. 43-52
Author(s):  
EO Agbo ◽  
JO Ogenyi ◽  
CA Adah ◽  
CT Agber
Keyword(s):  
Staphylococcus Aureus ◽  
Antimicrobial Activity ◽  
Candida Albicans ◽  
Ethyl Acetate ◽  
Plant Extracts ◽  
Methanol Extract ◽  
Cyperus Rotundus ◽  
Diffusion Method ◽  
Methanol Extracts ◽  
Study Results

Cyperus rotundus, a member of family Cyperaceae is a perennial, stoloniferous herb. The study investigated the secondary metabolites present in the leaf of Cyperus rotundus and antimicrobial activities of the hexane, ethyl acetate and methanol extracts. Phytochemical analysis revealed the presence of saponins, alkaloids, phenolic compounds, tannins, steroids, flavonoids, cardiac glycosides and terpenoids. The qualitative test of the extracts show the presence of steroid only in the hexane extract; flavonoid, cardiac glycoside in both the ethyl acetate and methanol extracts; saponin and tannin and phenolics in just the methanol extract. While alkaloid was present in all the extracts, terpenoid was absent in all. Antimicrobial activity of plant extracts were monitored using the agar disk-diffusion method against strains gram-positive bacterial: Staphylococcus aureus, Pseudomonas aeruginosa; and gram-negative bacteria: Escherichia coli, Salmonela typhi, and strains of fungi: Candida albicans and Aspergillus niger. The antimicrobial activity of the extracts was monitored at different concentrations of 50, 25, 12.5 and 6.25 mg/mL prepared from the stock concentration (100mg/mL) by serial dilution; with standard drugs: ciprofloxacin and fluconazole. The inhibition of the test organisms were concentration dependent. The methanol extract showed significantly higher Inhibition Zone (IZ) and Activity Index (AI) against the microbes at all concentrations compared to the ethyl acetate and hexane extracts due to the much phytochemicals (saponins, tanins, phenols, flavonoids, cardiac glycocides and alkaloids) found present in its extract. The overall study results signify the potential of Cyperus rotundus as a source of therapeutic agents. The methanol extract showed the best activity against both bacterial and fungal pathogens at the highest concentration of 100 mg/mL, especially the most susceptible bacteria: Staphylococcus aureus (IZ of 25.0±1.5; AI of 0.96) and Candida albicans (IZ of 25.5±0.5; AI of 0.91). At MIC, MBC and MFC of 6.25 mg/mL and 12.5 mg/mL, the plant extracts showed effective bactericidal and fungicidal effect against the test microbes.

scholarly journals Phytochemical Investigation and Antimicrobial Activity of Hexane, Ethyl Acetate and Methanol Fractions from Stem Bark of Icacina Trichantha Oliv. (Icacinaceae)

2020 ◽  
Vol 7 (1) ◽  
pp. 7-12
Author(s):  
Ojah Emmanuel Onah ◽  
Kachi Jolly Babangida
Keyword(s):  
Ethyl Acetate ◽  
Methanol Extract ◽  
Antimicrobial Properties ◽  
Ethyl Acetate Fraction ◽  
Hexane Fraction ◽  
Diffusion Method ◽  
Economic Losses ◽  
Phytochemical Screening ◽  
E Coli ◽  
Micro Organisms

Background: Micro-organisms are responsible for the transmission of a large number of diseases. It is hard to comprehend the amount of diseases, deaths and economic losses caused by micro-organisms alone. Plants are good sources of eco-friendly and readily available antimicrobial agents. Purpose: The aim of this study was to evaluate the chemical constituents and antimicrobial characteristics of three fractions from ethnomedicinal Icacina trichantha. Oliv. (Icacinaceae).Methods: Methanol extract from Icacina trichantha. Oliv was obtained by maceration and fractionated successively using hexane, and ethyl acetate. The antimicrobial properties of Icacina trichantha. Oliv was assessed using agar cup diffusion method on MRSA, P. aeruginosa, S. typhi, C. krusei, S. dysenteriae, S. pyrogenes, E. coli, K. pneumoniae, C. albicans, and C. tropicalis. Phytochemical screening on fractions was also evaluated using standard methods.Results: Phytochemical screening on fractions revealed the presence of saponins, alkaloids, steroids, tannins, and glycosides. Agar diffusion assay on fractions showed growth inhibitory effect on all the organisms except P. aeruginosa, S. typhi, and C. tropicalis. The MIC revealed that n-hexane fraction was active against MRSA, S. pyrogenes, E. coli, K. pneumonia, C. albicans and C. krusei at 10 mg/mL while S. dysenteriae was active at 5 mg/mL. The ethyl acetate fraction was active against all the organisms at a concentration of 5 mg/mL except P.aeruginosa, S.typhi and C.tropicalis. Methanol fraction showed activity of 5 mg/mL against MRSA, S. pyrogenes, E. coli, S. dysenteriae, C. albicans and C. krusei except for K. pneumoniae with activity at 10 mg/mL. Minimum bactericidal concentration/fungicidal concentration MBC/MFC evaluated on the n-hexane fraction revealed that MRSA, S. pyrogenes, E. coli, K. pneumoniae, S. dysenteriae, C. albicans, and C. krusei were activeat 20 mg/mL, while the ethyl acetate fraction had MBC/MFC of 10 mg/mL against all the organisms except P. aeruginosa, S. typhi, C. tropicalis. Methanol extract had MBC/MFC of 10 mg/mL against MSRA, E.coli and S. dysenteriae whereas S. pyrogenes, K. pneumoniae, C. albicans and C. krusei had MBC/MFC at 20 mg/mL.Conclusion: Icacina trichantha. Oliv. contain constituents with concentration dependent antimicrobial properties based on type of organism. The plant could be useful in the prevention and treatment of multi-resistant disease causing microorganisms.

Antimicrobial potentials, phytochemical screening and determination of bioactive compounds from Three Indian folk medicinal plants

2020 ◽  
Vol 16 ◽  
Author(s):  
V. Vanitha ◽  
S. Vijayakumar ◽  
S. Rajalakshmi
Keyword(s):  
Antimicrobial Activity ◽  
Ethyl Acetate ◽  
Leaf Extract ◽  
Antimicrobial Agents ◽  
Ethyl Acetate Extract ◽  
Diffusion Method ◽  
Dilution Method ◽  
Phytochemical Analysis ◽  
Leaf Extracts ◽  
Ft Ir

Aim: To investigate the antimicrobial efficacy of various solvents leaf extracts of Aegle marmelos, Plumbago zeylanica and Rhinacanthus nasutus against human pathogenic organisms such as Acinetobacter baumannii, Salmonella enteriditis, Bacillus cereus, Streptococcus pneumonia, Mycobacterium tuberculosis and Aspergillus fumigatous by agar well diffusion method. Background: Also, this is the first time report on MIC and MBC/MFC activities and identify the phytochemicals and functional groups using HPLC, GC-MS and FT-IR analysis. Objective: Minimum inhibitory concentration (MIC), minimum bactericidal (MBC/MFC) values were also carried out by the micro dilution method. Methods: Ethyl acetate extract of P. zeylanica showed better antimicrobial activity against the tested pathogens, especially for S. pneumoniae (40 mm) followed by ethyl acetate extract of R. nasutus (36 mm) against S. pneumoniae. While least inhibition was observed for aqueous extract of P.zeylanica against S. enteritis (10 mm). Results: The MIC ranged from 3.75 µg/ml to 60µg/ml and MBC/MFC 7.5 µg/ml to 60 µg/ml. Phytochemical analysis exhibited the presence of alkaloids, steroids, saponins, flavonoids, tannins, terpenes, phenolics and cardiac glycoside in all samples of selected plant extracts. Tannins, phenolics and glycoside were found only in the ethyl acetate extract of P.zeylanica. HPLC and GC-MS analysis of ethyl acetate leaf extract of P. zeylanica exposed ten major peaks and eleven compounds respectively. Chemical nature of the leaf extract was analysed by FT-IR spectrum. Conclusion: Ethyl acetate leaf extract of P. zeylanica showed better antimicrobial activity than other extracts as well as standard drugs. Therefore, this plant could be studied in detail for the identification of active biomolecules for antimicrobial agents.

Quorum Sensing Regulation as a Target for Antimicrobial Therapy

2021 ◽  
Vol 21 ◽  
Author(s):  
Caterine Henríquez Ruiz ◽  
Estefanie Osorio-Llanes ◽  
Mayra Hernández Trespalacios ◽  
Evelyn Mendoza-Torres ◽  
Wendy Rosales ◽  
...  
Keyword(s):  
Quorum Sensing ◽  
Molecular Mechanisms ◽  
Bacterial Resistance ◽  
Antimicrobial Agents ◽  
Bacterial Species ◽  
Cell Communication ◽  
Structural Evolution ◽  
Structural Diversity ◽  
Signal Molecules ◽  
Bacterial Survival

: Some bacterial species use a cell-to-cell communication mechanism called Quorum Sensing (QS). Bacteria release small diffusible molecules, usually termed signals which allow the activation of beneficial phenotypes that guarantee bacterial survival and the expression of a diversity of virulence genes in response to an increase in population density. The study of the molecular mechanisms that relate signal molecules with bacterial pathogenesis is an area of growing interest due to its use as a possible therapeutic alternative through the development of synthetic analogues of autoinducers as a strategy to regulate bacterial communication as well as the study of bacterial resistance phenomena, the study of these relationships is based on the structural diversity of natural or synthetic autoinducers and their ability to inhibit bacterial QS, which can be approached with a molecular perspective from the following topics: i) Molecular signals and their role in QS regulation; ii) Strategies in the modulation of Quorum Sensing; iii) Analysis of Bacterial QS circuit regulation strategies; iv) Structural evolution of natural and synthetic autoinducers as QS regulators. This mini-review allows a molecular view of the QS systems, showing a perspective on the importance of the molecular diversity of autoinducer analogs as a strategy for the design of new antimicrobial agents.

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