Antibacterial Activity of Kaolin–Silver Nanomaterials: Alternative Approach to the Use of Antibiotics in Animal Production

According to the search for alternatives to replace antibiotics in animal production suggested in the antimicrobial resistance action plans around the world, the objective of this work was to evaluate the bactericidal effect of kaolin–silver nanomaterial for its possible inclusion as an additive in animal feed. The antibacterial activity of the C3 (kaolin–silver nanomaterial) product was tested against a wide spectrum of Gram-negative and Gram-positive bacteria (including multidrug resistant strains) by performing antibiograms, minimal inhibitory concentration (MIC) and minimal bactericidal concentration (MBC), as well as growth inhibition curves against seven strains causing infections in animals. The C3 product generated inhibition halos in all the tested strains, and a higher activity against Gram-negative bacteria was found, with MBC values ranged from 7.8 µg/mL (P. aeruginosa) to 15.6 µg/mL (E. coli and Salmonella). In contrast, it was necessary to increase the concentration to 31.3 µg/mL or 250 µg/mL to eliminate 99.9% of the initial population of S. aureus ATCC 6538 and E. faecium ATCC 19434, respectively. Conversely, the inhibition growth curves showed a faster bactericidal activity against Gram-negative bacteria (between 2 and 4 h), while it took at least 24 h to observe a reduction in cell viability of S. aureus ATCC 6538. In short, this study shows that the kaolin–silver nanomaterials developed in the framework of the INTERREG POCTEFA EFA183/16/OUTBIOTICS project exhibit antibacterial activity against a wide spectrum of bacteria. However, additional studies on animal safety and environmental impact are necessary to evaluate the effectiveness of the proposed alternative in the context of One Health.

Download Full-text

rial activity of Ilex paraguariensis (Yerba Mate) against Gram-positive and Gram-negative bacteria

The Journal of Infection in Developing Countries ◽

10.3855/jidc.10380 ◽

2018 ◽

Vol 12 (09) ◽

pp. 712-719 ◽

Cited By ~ 2

Author(s):

Tania Noureddine ◽

Ziad El Husseini ◽

Ali Nehme ◽

Roula Abdel Massih

Keyword(s):

Antibacterial Activity ◽

Aqueous Extract ◽

Clinical Isolates ◽

Ilex Paraguariensis ◽

Minimal Bactericidal Concentration ◽

Yerba Mate ◽

Gram Negative Bacteria ◽

Gram Positive ◽

Gram Negative ◽

Stems And Leaves

Introduction: The stems and leaves of Ilex paraguariensis are popularly used for tea infusions in South America and the Middle East. The health benefits have been previously studied, revealing anti-mutagenic, anti-oxidant, hepatoprotective, hypocholesteremic and glycemic improvement. Limited research was performed on the antibacterial activity of the aqueous extract of Yerba Mate on standard and clinical isolates of Gram-positive and Gram-negative bacteria. Methodology: Commercial Ilex paraguariensis stems and leaves were ground and extracted with sterile deionized water at 70°C. Four ATCC bacterial strains and twenty-five bacterial clinical strains were used for testing. To obtain the minimal inhibitory concentration (MIC), the Yerba Mate aqueous solution was serially diluted according to the microdilution method. For the minimal bactericidal concentration (MBC), the tubes with clear broth were sub-cultured. To identify the types of ESBLs present in the clinical isolates, a multiplex PCR was performed. Results: An antibacterial activity was observed against most of tested strains, with a greater activity against Gram-positive bacteria. MIC and MBC values ranged between 0.468 mg/mL and 15 mg/mL of aqueous extract of Yerba Mate. Conclusion: The aqueous extract of the stems and leaves of Ilex paraguariensis extracted at 70°C showed a significant antibacterial activity. There was no correlation found between the different molecular resistance profiles and the antibacterial activity range.

Download Full-text

Study on Antibacterial Activity of Common Spices

Nepal Journal of Science and Technology ◽

10.3126/njst.v12i0.6518 ◽

2012 ◽

Vol 12 ◽

pp. 312-317 ◽

Cited By ~ 2

Author(s):

Dinesh Maharjan ◽

Anjana Singh ◽

Binod Lekhak ◽

Shaila Basnyat ◽

Lekhnath S Gautam

Keyword(s):

Antimicrobial Activity ◽

Antibacterial Activity ◽

Essential Oil ◽

Minimal Bactericidal Concentration ◽

Gram Negative Bacteria ◽

Gram Negative ◽

Methanol Extracts ◽

Gram Positive Bacteria ◽

Medicinal Value ◽

Common Spices

Spices have been shown to possess medicinal value, in particular, antimicrobial activity. They are used as householdmedicines as well as preservatives of food materials. This study compares the sensitivity of some human pathogenicbacteria to various spice extracts viz. essential oils, acetone and methanol extracts by agar well diffusion method.Of the different spices tested clove, ajowan and cinnamon were found to possess relatively higher antimicrobialactivities. Essential oil of cinnamon showed broad spectrum of inhibition against all tested bacteria while essentialoil of ajowan and clove inhibited 90% and 70% bacteria respectively. Acetone and methanol extracts of cloveshowed better antibacterial activity among the spices. The MBC value ranged from 0.39 to 25mg/ml. The lowestMBC (minimal bactericidal concentration) value was given by essential oil of cinnamon against E.coli, S. aureusand S. Typhi. Gram positive bacteria were found to be more sensitive to spices than Gram negative bacteria. Spices might have a great potential to be used as antimicrobial agents.DOI: http://dx.doi.org/10.3126/njst.v12i0.6518 Nepal Journal of Science and Technology 12 (2011) 312-317

Download Full-text

In-vitro Antioxidant and Antibacterial Activity of Methanolic Extract of Shorea robusta Gaertn. F. Resin

International Journal of Pharmaceutical and Phytopharmacological Research ◽

10.24896/eijppr.2016641 ◽

2016 ◽

Vol 6 (4) ◽

pp. 68

Author(s):

Sushma Vashisht ◽

Manish Pal Singh ◽

Viney Chawla

Keyword(s):

Antibacterial Activity ◽

Methanolic Extract ◽

Diffusion Method ◽

Gram Negative Bacteria ◽

Disc Diffusion ◽

Gram Positive ◽

Gram Negative ◽

Shorea Robusta ◽

Dose Dependent ◽

Resin Extract

The methanolic extract of the resin of Shorea robusta was subjected to investigate its antioxidant and antibacterial properties its utility in free radical mediated diseases including diabetic, cardiovascular, cancer etc. The methanol extract of the resin was tested for antioxidant activity using scavenging activity of DPPH (1,1-diphenyl-2-picrylhydrazil) radical method, reducing power by FeCl3 and antibacterial activity against gram positive and gram negative bacteria using disc diffusion method. The phytochemical screening considered the presence of triterpenoids, tannins and flavoniods. Overall, the plant extract is a source of natural antioxidants which might be helpful in preventing the progress of various oxidative stress mediated diseases including aging. The half inhibition concentration (IC50) of resin extract of Shorea robusta and ascorbic acid were 35.60 µg/ml and 31.91 µg/ml respectively. The resin extract exhibit a significant dose dependent inhibition of DPPH activity. Antibacterial activity was observed against gram positive and gram negative bacteria in dose dependent manner.Key Words: Shorea robusta, antioxidant, antibacterial, Disc-diffusion, DPPH.

Download Full-text

Antibacterial activity of magnesium oxide nanoparticles prepared by Calcination method

International Journal of Pharmaceutical Quality Assurance ◽

10.25258/ijpqa.10.3.25 ◽

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.

Download Full-text

Structure-Activity Relationship and Antimicrobial Evaluation of N-Phenylpyrazole Curcumin Derivatives

Current Bioactive Compounds ◽

10.2174/1573407215666190124115010 ◽

2020 ◽

Vol 16 (4) ◽

pp. 481-488

Author(s):

Heli Sanghvi ◽

Satyendra Mishra

Keyword(s):

Antibacterial Activity ◽

Gram Negative Bacteria ◽

Pyrazole Derivatives ◽

Gram Positive ◽

Gram Negative ◽

E Coli ◽

Curcumin Derivatives ◽

Structure Activity ◽

Electron Donating Groups ◽

Derivatives Of

Background: Curcumin, one of the most important pharmacologically significant natural products, has gained significant consideration among scientists for decades since its multipharmacological activities. 1, 3-Dicarbonyl moiety of curcumin was found to be accountable for the rapid degradation of curcumin molecule. The aim of present work is to replace 1, 3-dicarbonyl moiety of curcumin by pyrazole and phenylpyrazole derivatives with a view to improving its stability and to investigate the role of substitution in N-phenylpyrazole curcumin on its antibacterial activity against both Gram-positive as well as Gram-negative bacteria. Methods: Pyrazole derivatives of curcumin were prepared by heating curcumin with phenyhydrazine/ substituted phenyhydrazine derivatives in AcOH. The residue was purified by silica gel column chromatography. Structures of purified compounds were confirmed by 1H NMR and Mass spectroscopy. The synthesized compounds were evaluated for their antibacterial activity by the microdilution broth susceptibility test method against gram positive (S. aureus) and gram negative (E. coli). Results: Effects of substitution in N-phenylpyrazole curcumin derivatives against S. aureus and E. coli were studied. The most active N-(3-Nitrophenylpyrazole) curcumin (12) exhibits twenty-fold more potency against S. aureus (MIC: 10μg/mL)) and N-(2-Fluoroophenylpyrazole) curcumin (5) fivefold more potency against E. coli (MIC; 50 μg/mL) than N-phenylpyrazole curcumin (4). Whereas, a remarkable decline in anti-bacterial activity against S. aureus and E. coli was observed when electron donating groups were incorporated in N-phenylpyrazole curcumin (4). Comparative studies of synthesized compounds suggest the effects of electron withdrawing and electron donating groups on unsubstituted phenylpyrazole curcumin (4). Conclusion: The structure-activity relationship (SAR) results indicated that the electron withdrawing and electron donating at N-phenylpyrazole curcumin played key roles for their bacterial inhibitory effects. The results of the antibacterial evaluation showed that the synthesized pyrazole derivatives of curcumin displayed moderate to very high activity in S. aureus. In conclusion, the series of novel curcumin derivatives were designed, synthesized and tested for their antibacterial activities against S. aureus and E. coli. Among them, N-(3-Nitrophenylpyrazole curcumin; 12) was most active against S. aureus (Gram-positive) and N-(2-Fluoroophenylpyrazole) curcumin (5) against E. coli (Gram-negative) bacteria.

Download Full-text

Light mediated, switchable, antibacterial activity of cerium dioxide nanoparticles on gram positive and gram negative bacteria

10.1063/5.0029978 ◽

2020 ◽

Author(s):

Rekhachandran Prasanna Ramachandran ◽

Archana Valliyamma ◽

Nitha Nellithanathu Thomas ◽

Mangalaraja Ramalinga Viswanathan ◽

Boby Theophilofe Edwin ◽

...

Keyword(s):

Antibacterial Activity ◽

Cerium Dioxide ◽

Gram Negative Bacteria ◽

Gram Positive ◽

Gram Negative

Download Full-text

Proteomic response of Escherichia coli to a membrane lytic and iron chelating truncated Amaranthus tricolor defensin

BMC Microbiology ◽

10.1186/s12866-021-02176-4 ◽

2021 ◽

Vol 21 (1) ◽

Author(s):

Tessa B. Moyer ◽

Ashleigh L. Purvis ◽

Andrew J. Wommack ◽

Leslie M. Hicks

Keyword(s):

Escherichia Coli ◽

Antibacterial Activity ◽

Antimicrobial Peptides ◽

Mechanism Of Action ◽

Gram Negative Bacteria ◽

Amaranthus Tricolor ◽

Core Motif ◽

Gram Negative ◽

E Coli ◽

Membrane Lysis

Abstract Background Plant defensins are a broadly distributed family of antimicrobial peptides which have been primarily studied for agriculturally relevant antifungal activity. Recent studies have probed defensins against Gram-negative bacteria revealing evidence for multiple mechanisms of action including membrane lysis and ribosomal inhibition. Herein, a truncated synthetic analog containing the γ-core motif of Amaranthus tricolor DEF2 (Atr-DEF2) reveals Gram-negative antibacterial activity and its mechanism of action is probed via proteomics, outer membrane permeability studies, and iron reduction/chelation assays. Results Atr-DEF2(G39-C54) demonstrated activity against two Gram-negative human bacterial pathogens, Escherichia coli and Klebsiella pneumoniae. Quantitative proteomics revealed changes in the E. coli proteome in response to treatment of sub-lethal concentrations of the truncated defensin, including bacterial outer membrane (OM) and iron acquisition/processing related proteins. Modification of OM charge is a common response of Gram-negative bacteria to membrane lytic antimicrobial peptides (AMPs) to reduce electrostatic interactions, and this mechanism of action was confirmed for Atr-DEF2(G39-C54) via an N-phenylnaphthalen-1-amine uptake assay. Additionally, in vitro assays confirmed the capacity of Atr-DEF2(G39-C54) to reduce Fe3+ and chelate Fe2+ at cell culture relevant concentrations, thus limiting the availability of essential enzymatic cofactors. Conclusions This study highlights the utility of plant defensin γ-core motif synthetic analogs for characterization of novel defensin activity. Proteomic changes in E. coli after treatment with Atr-DEF2(G39-C54) supported the hypothesis that membrane lysis is an important component of γ-core motif mediated antibacterial activity but also emphasized that other properties, such as metal sequestration, may contribute to a multifaceted mechanism of action.

Download Full-text

Two structurally diverse Zn-based coordination polymers with excellent antibacterial activity

CrystEngComm ◽

10.1039/c8ce00394g ◽

2018 ◽

Vol 20 (24) ◽

pp. 3353-3362 ◽

Cited By ~ 16

Author(s):

Ian R. Colinas ◽

Mauricio D. Rojas-Andrade ◽

Indranil Chakraborty ◽

Scott R. J. Oliver

Keyword(s):

Antibacterial Activity ◽

Structural Properties ◽

Coordination Polymers ◽

Gram Negative Bacteria ◽

Gram Positive ◽

Gram Negative

Two novel Zn-based coordination polymers with unique structural properties display an exceptional antibacterial activity against Gram-positive and Gram-negative bacteria.

Download Full-text