scholarly journals Purification and Evaluation of N-benzyl Cinnamamide from Red Seaweed Gracilaria fisheri as an Inhibitor of Vibrio harveyi AI-2 Quorum Sensing

Marine Drugs ◽  
2020 ◽  
Vol 18 (2) ◽  
pp. 80 ◽  
Author(s):  
Kulwadee Karnjana ◽  
Saksit Nobsathian ◽  
Chumporn Soowannayan ◽  
Wei Zhao ◽  
Ya-Jie Tang ◽  
...  
Keyword(s):  
Quorum Sensing ◽  
Biofilm Formation ◽  
Inhibitory Concentration ◽  
Vibrio Harveyi ◽  
Ethanol Extract ◽  
Red Seaweed ◽  
In Vitro Activity ◽  
Activity Assay ◽  
Pure Compounds

Previously, we reported that the ethanol extract from red seaweed Gracilaria fisheri effectively decreased biofilm formation of Vibrio harveyi. In this study, the anti-biofilm active compounds in the ethanol extract were isolated and their structures identified. The anti-biofilm fractionation assay for minimum inhibitory concentration (MIC) produced two fractions which possessed maximal inhibitory activities toward the biofilm formation of V. harveyi strains 1114 and BAA 1116. Following chromatographic separation of the bioactive fractions, two pure compounds were isolated, and their structures were elucidated using FTIR, NMR, and HR-TOF-MS. The compounds were N-benzyl cinnamamide and α-resorcylic acid. The in vitro activity assay demonstrated that both compounds inhibited the biofilm formation of V. harveyi and possessed the anti-quorum sensing activity by interfering with the bioluminescence of the bacteria. However, the N-benzyl cinnamamide was more potent than α-resorcylic acid with a 10-fold lesser MIC. The present study reveals the beneficial property of the N-benzyl cinnamamide from the ethanol extract as a lead anti-microbial drug against V. harveyi.

scholarly journals Modulation of Campylobacter jejuni Motility, Adhesion to Polystyrene Surfaces, and Invasion of INT407 Cells by Quorum-Sensing Inhibition

2020 ◽  
Vol 8 (1) ◽  
pp. 104 ◽  
Author(s):  
Katarina Šimunović ◽  
Dina Ramić ◽  
Changyun Xu ◽  
Sonja Smole Možina
Keyword(s):  
Quorum Sensing ◽  
Campylobacter Jejuni ◽  
Biofilm Formation ◽  
Vibrio Harveyi ◽  
Foodborne Pathogen ◽  
Wild Type ◽  
Natural Extracts ◽  
Ethanolic Extracts ◽  
Pure Compounds ◽  
Moderate Positive Correlation

Campylobacter jejuni is a major foodborne pathogen, and the LuxS-mediated quorum-sensing (QS) system influences its motility, biofilm formation, invasion, host colonization, and virulence. QS therefore represents a target for the control of C. jejuni. The aim of this study was to investigate the correlation of QS inhibition with changes in C. jejuni motility, adhesion to polystyrene surfaces, and adhesion to and invasion of INT407 cells. This was achieved by studying (i) the luxS-deficient mutant and (ii) treatment of C. jejuni with 20 natural extracts as six essential oils, 11 ethanolic extracts, and three pure compounds. Compared to the wild-type, the ΔluxS mutant showed decreased motility, adhesion to polystyrene surfaces, and invasion of INT407 cells. The anti-QS effects of the treatments (n = 15/20) were assayed using Vibrio harveyi BB170 bioluminescence. Moderate positive correlation was shown between C. jejuni QS reduction and reduced motility (τ = 0.492, p = 0.024), adhesion to polystyrene surfaces (τ = 0.419, p = 0.008), and invasion (r = 0.394, p = 0.068). The best overall effect was achieved with a Sedum rosea (roseroot) extract, with 96% QS reduction, a 1.41 log (96%) decrease in adhesion to polystyrene surfaces, and an 82% decrease in invasion. We show that natural extracts can reduce motility, adhesion to polystyrene surfaces, and invasion of INT407 cells by C. jejuni through modulation of the LuxS (QS) system.

scholarly journals In Vitro Effect of Copper (I) Complex [Cu(NN1)2](ClO4) on Vibrio harveyi BB170 Biofilm Formation

2021 ◽  
Vol 9 (11) ◽  
pp. 2273
Author(s):  
Sarita Soto-Aguilera ◽  
Brenda Modak ◽  
Maialen Aldabaldetrecu ◽  
Carla P. Lozano ◽  
Juan Guerrero ◽  
...  
Keyword(s):  
Biofilm Formation ◽  
Pathogenic Bacteria ◽  
Inhibitory Concentration ◽  
Vibrio Harveyi ◽  
Laser Scanning Microscopy ◽  
Confocal Laser ◽  
Minimal Bactericidal Concentration ◽  
Vitro Effect ◽  
Harveyi Bb170

Biofilm formation in pathogenic bacteria is an important factor of resistance to antimicrobial treatments, allowing them to survive for a long time in their hosts. In the search for new antibiofilm agents, in this work we report the activity of a copper (I) complex, [Cu(NN1)2]ClO4, synthesized with Cu (I) and NN1, an imine ligand 6-((quinolin-2-ylmethylene)amino)-2H-chromen-2-one, a derivate of natural compound coumarin. The antibacterial and antibiofilm capacity was evaluated in Vibrio harveyi BB170 used as model bacteria. Antibacterial activity was measured in vitro by minimal inhibitory concentration (MIC), minimal bactericidal concentration (MBC) and half-maximal inhibitory concentration (IC50) determination. Antibiofilm capacity of copper (I) complex was analyzed by different concentrations of IC50 values. The results showed that the sub-IC50 concentration, 12.6 µg/mL of the copper (I) complex, was able to reduce biofilm formation by more than 75%, and bacterial viability was reduced by 50%. Inverted and confocal laser scanning microscopy showed that the [Cu(NN1)2]ClO4 complex affected the biofilm structure. Therefore, the copper (I) complex is effective as an antibiofilm compound in V. harveyi BB170.

In vitro antibiofilm efficacy of Piper betle against quorum sensing mediated biofilm formation of luminescent Vibrio harveyi

2017 ◽  
Vol 110 ◽  
pp. 232-239 ◽  
Author(s):  
Ramanathan Srinivasan ◽  
Sivasubramanian Santhakumari ◽  
Arumugam Veera Ravi
Keyword(s):  
Quorum Sensing ◽  
Biofilm Formation ◽  
Vibrio Harveyi ◽  
Piper Betle

In Vitro Antibacterial activity of ethanolic extract of Myrsine africana against laboratory Strains of Pathogenic Organisms

2016 ◽  
Vol 5 (04) ◽  
pp. 4512
Author(s):  
Jackie K. Obey ◽  
Anthoney Swamy T* ◽  
Lasiti Timothy ◽  
Makani Rachel
Keyword(s):  
Antibacterial Activity ◽  
Minimum Inhibitory Concentration ◽  
Inhibitory Concentration ◽  
Ethanolic Extract ◽  
Ethanol Extract ◽  
E Coli ◽  
Zones Of Inhibition ◽  
In Vitro Antibacterial Activity ◽  
Myrsine Africana

The determination of the antibacterial activity (zone of inhibition) and minimum inhibitory concentration of medicinal plants a crucial step in drug development. In this study, the antibacterial activity and minimum inhibitory concentration of the ethanol extract of Myrsine africana were determined for Escherichia coli, Bacillus cereus, Staphylococcus epidermidis and Streptococcus pneumoniae. The zones of inhibition (mm±S.E) of 500mg/ml of M. africana ethanol extract were 22.00± 0.00 for E. coli,20.33 ±0.33 for B. cereus,25.00± 0.00 for S. epidermidis and 18. 17±0.17 for S. pneumoniae. The minimum inhibitory concentration(MIC) is the minimum dose required to inhibit growth a microorganism. Upon further double dilution of the 500mg/ml of M. africana extract, MIC was obtained for each organism. The MIC for E. coli, B. cereus, S. epidermidis and S. pneumoniae were 7.81mg/ml, 7.81mg/ml, 15.63mg/ml and 15.63mg/ml respectively. Crude extracts are considered active when they inhibit microorganisms with zones of inhibition of 8mm and above. Therefore, this study has shown that the ethanol extract of M. africana can control the growth of the four organisms tested.

scholarly journals Extraction and Fractionation Effects on Antiplasmodial Activity and Phytochemical Composition of Palicourea hoffmannseggiana

2021 ◽  
Vol 8 (01) ◽  
pp. e34-e42
Author(s):  
Leticia Hiromi Ohashi ◽  
Douglas Costa Gontijo ◽  
Maria Fernanda Alves do Nascimento ◽  
Luciano Ferreira Margalho ◽  
Geraldo Célio Brandão ◽  
...  
Keyword(s):  
Growth Inhibition ◽  
Scale Up ◽  
Indole Alkaloid ◽  
Ethanol Extract ◽  
Parasite Growth ◽  
In Vitro Activity ◽  
Acid Base ◽  
Leaf Extracts ◽  
Leaf Powder

AbstractThe present study on Palicourea hoffmannseggiana, which was collected at Marapanim, state of Pará, Brazil, comprises the preparation of different stem and leaf extracts and fractions. Ethanol, hydroethanol, and water extracts were prepared by several methods and evaluated for in vitro activity against resistant Plasmodium falciparum (W2 strain), disclosing a low parasite growth inhibition effect (< 50%). Dereplication by UPLC-DAD-ESI−MS of the leaf ethanol extract showed the presence of two known alkaloids, lyalosidic and strictosidinic acids, along with a sinapoyl ester of lyalosidic acid, with m/z 719.33 [M+H]+, which is possibly a new monoterpene indole alkaloid representative. Sequential liquid-liquid acid-base alkaloid separations from the leaf ethanol extract as well as directly from leaf powder afforded fractions of increased parasite growth inhibition, reaching up to 92.5±0.7%. The most bioactive fractions were shown to contain the β-carboline alkaloids harmane and 4-methyl-β-carboline, along with N-methyl-tryptamine and N-acetyl-tryptamine, while monoterpene indole alkaloids were detected in inactive fractions of these processes. The present results demonstrate that these preliminary fractionation methods can lead to significantly active fractions supporting an adequate scale-up to carrying out the isolation of anti-plasmodial compounds.

scholarly journals In vitro activity of allicin combined with two antibiotics on intestinal Shigella

2017 ◽  
Vol 6 (1) ◽  
pp. 25-29 ◽  
Author(s):  
Yuchi Jia ◽  
Xiaomei Wu
Keyword(s):  
Intestinal Tract ◽  
Inhibitory Concentration ◽  
Synergistic Effects ◽  
Antagonistic Effect ◽  
Additive Effects ◽  
In Vitro Activity ◽  
Antibacterial Effects ◽  
Combined Application ◽  
Combined Use

Abstract Objective We aimed to evaluate the combined antibacterial effects of allicin in combination with levofloxacin and ceftriaxone on Shigella isolated from the intestinal tract in vitro. Materials and Methods Using a checkerboard design, broth microdilution assay was used to test the effects of the compounds on the organism. We also determined the MIC of the two groups of antibacterial drugs against 30 strains of Shigella and calculated the fractional inhibitory concentration (FIC) index, to judge the combination effect. Result After the combined application of allicin and ceftriaxone the MIC decreased significantly. Distribution of the FIC index was as follows: FIC ≤0.5, accounting for 10%; 0.5< FIC ≤1.0, accounting for 60%; 1 < FIC ≤2, accounting for 30%; FIC >2, percentage is zero. After combined application of allicin and levofloxacin, distribution of FIC index was as follows: FIC≤0.5, ratio is zero; 0.5< FIC ≤1, accounting for 56.7%; 1 < FIC ≤2, accounting for 43.3%; FIC >2, ratio is zero. Conclusion After the combined use of ceftriaxone, levofloxacin, and allicin, most of the tests showed synergistic effects and additive effects on Shigella, while some of them showed no correlation and no antagonistic effect.

Comparison of the in Vitro Activity of Daptomycin and four other Antimicrobial Agents against Staphylococci Associated with CAPD Peritonitis

1988 ◽  
Vol 8 (4) ◽  
pp. 277-279
Author(s):  
Wendy L. Vaudry ◽  
Claudia Gratton ◽  
Kinga Kowalewska ◽  
Wanda M. Wenman
Keyword(s):  
Peritoneal Dialysis ◽  
Minimum Inhibitory Concentration ◽  
Continuous Ambulatory Peritoneal Dialysis ◽  
Antimicrobial Agents ◽  
Inhibitory Concentration ◽  
Vitro Activity ◽  
In Vitro Activity ◽  
Coagulase Negative Staphylococci ◽  
Vancomycin Resistant

The minimum inhibitory concentration (MIC) of daptomycin was compared with that of four other antimicrobial agents against clinically relevant staphylococci. Sixtyfive isolates were obtained from patients on continuous ambulatory peritoneal dialysis (CAPD) who contracted peritonitis. These isolates comprised 29 S. Sureus strains (all sensitive to oxacillin); 25 S. epidermidis strains (14 sensitive and 9 resistant to oxacillin); and 11 unspeciated coagulase-negative staphylococci (2 sensitive and 11 resistant to oxacillin). All of the oxacillin susceptible strains were inhibited by ≤2 mg/L of the five antibiotics tested. The oxacillin resistant staphylococci were also resistant to cefuroxime and variably resistant to cefamandole, but were uniformly susceptible to both vancomycin and daptomycin. Daptomycin possesses equivalent in vitro activity to vancomycin against strains of S. Sureus and coagulase negative staphylococci associated with CAPD peritonitis. If vancomycin resistance becomes a significant problem in these patients, and daptomycin is shown to be active against vancomycin resistant organisms, then it would have potential usefulness as an alternative to vancomycin in the treatment of peritonitis caused by multiply -resistant staphylococci.

scholarly journals Synthesis, In Silico, and In Vitro Evaluation of Long Chain Alkyl Amides from 2-Amino-4-Quinolone Derivatives as Biofilm Inhibitors

Molecules ◽  
2019 ◽  
Vol 24 (2) ◽  
pp. 327 ◽  
Author(s):  
Mariana Espinosa-Valdés ◽  
Sara Borbolla-Alvarez ◽  
Ana Delgado-Espinosa ◽  
Juan Sánchez-Tejeda ◽  
Anabelle Cerón-Nava ◽  
...  
Keyword(s):  
Quorum Sensing ◽  
Biofilm Formation ◽  
Active Sites ◽  
Multidrug Resistant ◽  
Health Concern ◽  
Resistant Bacteria ◽  
Biofilm Inhibition ◽  
Amide Derivatives ◽  
Long Chain

Infection from multidrug resistant bacteria has become a growing health concern worldwide, increasing the need for developing new antibacterial agents. Among the strategies that have been studied, biofilm inhibitors have acquired relevance as a potential source of drugs that could act as a complement for current and new antibacterial therapies. Based on the structure of 2-alkyl-3-hydroxy-4-quinolone and N-acylhomoserine lactone, molecules that act as mediators of quorum sensing and biofilm formation in Pseudomonas aeruginosa, we designed, prepared, and evaluated the biofilm inhibition properties of long chain amide derivatives of 2-amino-4-quinolone in Staphylococcus aureus and P. aeruginosa. All compounds had higher biofilm inhibition activity in P. aeruginosa than in S. aureus. Particularly, compounds with an alkyl chain of 12 carbons exhibited the highest inhibition of biofilm formation. Docking scores and molecular dynamics simulations of the complexes of the tested compounds within the active sites of proteins related to quorum sensing had good correlation with the experimental results, suggesting the diminution of biofilm formation induced by these compounds could be related to the inhibition of these proteins.

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