scholarly journals Selectivity of Inhibition of N-Succinyl-l,l-Diaminopimelic Acid Desuccinylasein Bacteria: The product of dapE-gene Is Not the Target ofl-Captopril Antimicrobial Activity

2011 ◽  
Vol 2011 ◽  
pp. 1-6 ◽  
Author(s):  
Narasimha Rao Uda ◽  
Marc Creus
Keyword(s):  
Antimicrobial Activity ◽  
Lysine Biosynthesis ◽  
Diaminopimelic Acid ◽  
Antimicrobial Compounds ◽  
Bacterial Strains ◽  
Gram Negative ◽  
Antibiotic Development ◽  
Gram Positive Bacteria ◽  
Good Target ◽  
Peptidoglycan Cell Wall

The emergence of bacterial strains that are resistant to virtually all currently available antibiotics underscores the importance of developing new antimicrobial compounds. N-succinyl-l,l-diaminopimelic acid desuccinylase (DapE) is a metallohydrolase involved in the meso-diaminopimelate (mDAP)/lysine biosynthetic pathway necessary for lysine biosynthesis and for building the peptidoglycan cell wall. Because DapE is essential for Gram-negative and some Gram-positive bacteria, DapE has been proposed as a good target for antibiotic development. Recently,l-captopril has been suggested as a lead compound for inhibition of DapE, although its selectivity for this enzyme target in bacteria remains unclear (Gillner et al. (2009)). Here, we tested the selectivity ofl-captopril against DapEin bacteria. Since DapE knockout strains of gram-negative bacteria are viable upon chemical supplementation with mDAP, we reasoned that the antimicrobial activity of compounds targeting DapE should be abolished in mDAP-containing media. Althoughl-captopril had modest antimicrobial activity inEscherichia coliand inSalmonella enterica, to our surprise, inhibition of bacterial growth was independent both of mDAP supplementation and DapE over-expression. We conclude that DapE is not the main target ofl-captopril inhibition in these bacteria. The methods implemented here will be useful for screening DapE-selective antimicrobial compounds directly in bacterial cultures.

scholarly journals Chemical Composition and Antimicrobial Activity of the Essential Oil from Chaerophyllum Aureum L. (Apiaceae)

2009 ◽  
Vol 4 (1) ◽  
pp. 1934578X0900400 ◽  
Author(s):  
Branislava Lakušić ◽  
Violeta Slavkovska ◽  
Milica Pavlović ◽  
Marina Milenković ◽  
Jelena Antić Stanković ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Staphylococcus Aureus ◽  
Antimicrobial Activity ◽  
Candida Albicans ◽  
Chemical Composition ◽  
Micrococcus Luteus ◽  
Bacterial Strains ◽  
Gram Negative ◽  
Gram Positive Bacteria ◽  
Aerial Parts

The essential oils of the aerial parts and fruits of Chaerophyllum aureum L., collected from two mountains in Serbia, were analyzed by GC and GC/MS. Sabinene (18.5-31.6%), p-cymene (7.9-25.4%) and limonene (1.9-10.9%) were characterized as the main constituents. The oils were tested against six bacterial strains and one strain of yeast, Candida albicans. The highest antimicrobial activity was observed against the Gram-positive bacteria Staphylococcus aureus, S. epidermidis and Micrococcus luteus, while of the Gram-negative strains, Escherichia coli was the most sensitive.

scholarly journals Antibacterial Properties of Propolis

Molecules ◽  
2019 ◽  
Vol 24 (11) ◽  
pp. 2047 ◽  
Author(s):  
Izabela Przybyłek ◽  
Tomasz M. Karpiński
Keyword(s):  
Escherichia Coli ◽  
Staphylococcus Aureus ◽  
Antimicrobial Activity ◽  
Antibacterial Properties ◽  
Bacterial Strains ◽  
Complex Composition ◽  
Gram Positive ◽  
Gram Negative ◽  
Gram Positive Bacteria ◽  
The World

Researchers are continuing to discover all the properties of propolis due to its complex composition and associated broad spectrum of activities. This review aims to characterize the latest scientific reports in the field of antibacterial activity of this substance. The results of studies on the influence of propolis on more than 600 bacterial strains were analyzed. The greater activity of propolis against Gram-positive bacteria than Gram-negative was confirmed. Moreover, the antimicrobial activity of propolis from different regions of the world was compared. As a result, high activity of propolis from the Middle East was found in relation to both, Gram-positive (Staphylococcus aureus) and Gram-negative (Escherichia coli) strains. Simultaneously, the lowest activity was demonstrated for propolis samples from Germany, Ireland and Korea.

scholarly journals Antimicrobial activity of ethanolic and aqueous extracts of medicinally used tree ferns Alsophila cuspidata and Cyathea microdonta

2018 ◽  
Vol 42 (1) ◽  
pp. 119-123
Author(s):  
Charlie Longtine ◽  
Adrian Tejedor
Keyword(s):  
Antimicrobial Activity ◽  
Diffusion Method ◽  
Gram Negative Bacteria ◽  
Aqueous Extracts ◽  
Antimicrobial Compounds ◽  
Gram Positive ◽  
Gram Negative ◽  
Gram Positive Bacteria ◽  
Neotropical Tree ◽  
Tree Ferns

Medicinal plants are important components of traditional medicine and sources of novel antimicrobial compounds against drug resistance pathogen strains. This study tested the antimicrobial activity of ethanolic and aqueous extracts of medicinally used Neotropical tree ferns Cyathea microdonta and Alsophila cuspidata against gram positive bacteria and gram negative bacteria using the Kirby-Bauer disc diffusion method. Highest antimicrobial activity was observed in ethanolic extracts, and extracts were more active against gram positive bacteria than gram negative bacteria. No difference was observed in antimicrobial activity between species or between extracts made from the leaves, stipe, or caudex. These results suggest that the traditional use of tree fern mucilage as a topical agent for cuts and leishmaniasis lesions may reduce risk of secondary infection with skin bacteria such as Staphylococcus aureus, and that Neotropical Cyatheaceae are a potential source of novel antimicrobial compounds.

scholarly journals Antimicrobial activity of ethanolic and aqueous extracts of medicinally used tree ferns Alsophila cuspidata and Cyathea microdonta

2018 ◽  
Vol 42 ◽  
pp. 119
Author(s):  
Charlie Longtine ◽  
Adrian Tejedor
Keyword(s):  
Antimicrobial Activity ◽  
Diffusion Method ◽  
Gram Negative Bacteria ◽  
Aqueous Extracts ◽  
Antimicrobial Compounds ◽  
Gram Positive ◽  
Gram Negative ◽  
Gram Positive Bacteria ◽  
Neotropical Tree ◽  
Tree Ferns

Medicinal plants are important components of traditional medicine and sources of novel antimicrobial compounds against drug resistance pathogen strains. This study tested the antimicrobial activity of ethanolic and aqueous extracts of medicinally used Neotropical tree ferns Cyathea microdonta and Alsophila cuspidata against gram positive bacteria and gram negative bacteria using the Kirby-Bauer disc diffusion method. Highest antimicrobial activity was observed in ethanolic extracts, and extracts were more active against gram positive bacteria than gram negative bacteria.  No difference was observed in antimicrobial activity between species or between extracts made from the leaves, stipe, or caudex.  These results suggest that the traditional use of tree fern mucilage as a topical agent for cuts and leishmaniasis lesions may reduce risk of secondary infection with skin bacteria such as Staphylococcus aureus, and that Neotropical Cyatheaceae are a potential source of novel antimicrobial compounds.   

SYNTHESIS, CHARACTERIZATION AND BIOLOGICAL EVALUATION OF 3-FORMYL INDOLE BASED SCHIFF BASES

2018 ◽  
Vol 7 (6) ◽  
Author(s):  
Singh Gurvinder ◽  
Singh Prabhsimran ◽  
Dhawan R. K.
Keyword(s):  
Antimicrobial Activity ◽  
Spectral Analysis ◽  
Schiff Bases ◽  
Antimicrobial Agents ◽  
Biological Evaluation ◽  
Fungal Strain ◽  
Bacterial Strains ◽  
Standard Drug ◽  
Gram Negative ◽  
E Coli

In order to develop new antimicrobial agents, a series of 3-formyl indole based Schiff bases were synthesized by reacting 3-formyl indole(indole-3-carboxaldehyde) with substituted aniline taking ethanol as solvent. The reaction was carried in the presence of small amount of p-toluene sulphonic acid as catalyst.All the synthesized compounds were characterized by IR, 1H-NMR spectral analysis. All the synthesized compounds were evaluated for antimicrobial activity against two gram positive bacterial strains (B. subtilisand S. aureus) and two gram negative bacterial strains (P. aeruginosaand E. coli) and one fungal strain (C. albicans). All the synthesized compounds were found to have moderate to good antimicrobial activity. The  standard drug amoxicillin, fluconazole were used for antimicrobial activity. Among the synthesized compounds, the maximum antimicrobial activity was shown by compounds GS04, GS07, GS08 and GS10.

Antimicrobial Activity of Iron-Halide Complexes Against Gram-Positive and Gram-Negative Bacteria

2020 ◽  
Author(s):  
Nusrat Abedin ◽  
Abdullah Hamed A Alshehri ◽  
Ali M A Almughrbi ◽  
Olivia Moore ◽  
Sheikh Alyza ◽  
...  
Keyword(s):  
Antimicrobial Activity ◽  
Antimicrobial Resistance ◽  
Extracellular Dna ◽  
Antibiofilm Activity ◽  
Gram Negative Bacteria ◽  
Bacterial Strains ◽  
Gram Positive ◽  
Gram Negative ◽  
Antimicrobial Substances ◽  
Mammalian Cell Lines

Antimicrobial resistance (AMR) has become one of the more serious threats to the global health. The emergence of bacteria resistant to antimicrobial substances decreases the potencies of current antibiotics. Consequently, there is an urgent and growing need for the developing of new classes of antibiotics. Three prepared novel iron complexes have a broad-spectrum antimicrobial activity with minimum bactericidal concentration (MBC) values ranging from 3.5 to 10 mM and 3.5 to 40 mM against Gram-positive and Gram-negative bacteria with antimicrobial resistance phenotype, respectively. Time-kill studies and quantification of the extracellular DNA confirmed the bacteriolytic mode of action of the iron-halide compounds. Additionally, the novel complexes showed significant antibiofilm activity against the tested pathogenic bacterial strains at concentrations lower than the MBC. The cytotoxic effect of the complexes on different mammalian cell lines show sub-cytotoxic values at concentrations lower than the minimum bactericidal concentrations.

scholarly journals Enaminone-Derived Pyrazoles with Antimicrobial Activity

2019 ◽  
Vol 2019 ◽  
pp. 1-10
Author(s):  
Mashooq Ahmad Bhat ◽  
Mohamed A. Al-Omar ◽  
Ahmed M. Naglah ◽  
Abdul Arif Khan
Keyword(s):  
Antimicrobial Activity ◽  
Gram Negative Bacteria ◽  
Significant Activity ◽  
Disc Diffusion ◽  
Initial Screening ◽  
Gram Positive ◽  
Gram Negative ◽  
Disc Diffusion Assay ◽  
Gram Positive Bacteria ◽  
Diffusion Assay

A series of pyrazoles derived from the substituted enaminones were synthesized and were evaluated for antimicrobial activity. All the compounds were characterized by the spectral data and elemental analysis. The synthesized compounds were initially screened for their antimicrobial activity against ATCC 6538, NCTC 10400, NCTC 10418, and ATCC 27853. During initial screening, compounds (P1, P6, and P11) presented significant antimicrobial activity through disc diffusion assay. These compounds were further evaluated for antimicrobial activity at different time points against Gram-positive and Gram-negative bacteria and presented significant activity for 6 hours. The activity was found to be greater against Gram-positive bacteria. In contrast at 24 hours, the activity was found only against Gram-positive bacteria except compound (P11), showing activity against both types of bacteria. Compound (P11) was found to have highest activity against both Gram-positive and Gram-negative bacteria.

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 Ultrasonic Irradiation: Synthesis, Characterization, and Preliminary Antimicrobial Activity of Novel Series of 4,6-Disubstituted-1,3,5-triazine Containing Hydrazone Derivatives

2016 ◽  
Vol 2016 ◽  
pp. 1-9 ◽  
Author(s):  
Hessa H. Al-Rasheed ◽  
Monirah Al Alshaikh ◽  
Jamal M. Khaled ◽  
Naiyf S. Alharbi ◽  
Ayman El-Faham
Keyword(s):  
Antimicrobial Activity ◽  
Ultrasonic Irradiation ◽  
New Products ◽  
Conventional Heating ◽  
Pyridine Derivative ◽  
Gram Negative Bacteria ◽  
Bacterial Strains ◽  
Gram Positive ◽  
Gram Negative ◽  
Antimicrobial And Antifungal Activities

Novel series of 4,6-disubstituted-1,3,5-triazines containing hydrazone derivatives were synthesized employing ultrasonic irradiation and conventional heating. The ultrasonication gave the target products in higher yields and purity in shorter reaction time compared with the conventional method. IR, NMR (H 1 and C 13), elemental analysis, and LC-MS confirmed the structures of the new products. The antimicrobial and antifungal activities were evaluated for all the prepared compounds against some selected Gram-positive and Gram-negative bacterial strains. The results showed that only two compounds 7i (pyridine derivative) and 7k (4-chlorobenzaldehyde derivative) displayed biological activity against some Gram-positive and Gram-negative bacteria, while the rest of the tested compounds did not display any antifungal activity.

scholarly journals Anticancer and Antimicrobial Activity Evaluation of Cowpea-Porous-Starch-Formulated Silver Nanoparticles

2021 ◽  
Vol 2021 ◽  
pp. 1-13
Author(s):  
Shiara Ramdath ◽  
John Mellem ◽  
Londiwe Simphiwe Mbatha
Keyword(s):  
Antimicrobial Activity ◽  
Silver Nanoparticles ◽  
Cell Viability ◽  
High Dose ◽  
Bacterial Strains ◽  
Gram Positive ◽  
Gram Negative ◽  
Anticancer Drug Delivery ◽  
Ic50 Values ◽  
Biosynthesized Agnps

Health issues involving inadequate treatment of diseases such as cancer and microbial infections continue to be the subject of much ongoing recent research. Biosynthesized silver nanoparticles (AgNPs) were characterized using Transmission Electron Microscopy (TEM), Zeta Sizer, Ultraviolet (UV), and Fourier Transform Infrared (FTIR) spectroscopy. Their antimicrobial activity was evaluated on selected Gram-positive and Gram-negative bacterial strains, using the disc diffusion and broth dilution assays. Cell viability profiles were evaluated using MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) and apoptosis studies on selected human noncancer and cancer cells. The biosynthesized AgNPs were evaluated to be spherical clusters, with sizes between 40 and 70 nm. The absorption peak at 423 nm and the presence of polyphenols confirmed the synthesis and stabilization of these tested AgNPs. The AgNPs showed a good stability of −23.9 ± 1.02 mV. Good antimicrobial activity (6.0–18.0 mm) was seen on all tested bacteria at a minimum inhibitory concentration (MIC) ranging from 5 to 16 μg/ml, with the highest activity seen against Gram-negative Escherichia coli (18 ± 0.5 mm), and the lowest activity was seen against Gram-positive Listeria monocytogenes (6.0 ± 0.4 mm) after treatment with the AgNPs. These NPs showed a concentration-dependent and cell-specific cytotoxicity with low IC50 values (41.7, 56.3, and 63.8 μg/ml). The NPs were well tolerated by tested cells as indicated by a more than 50% cell viability at the high dose tested and low apoptotic indices (<0.2). These findings indicated that these biosynthesized AgNPs showed great potential as effective antibacterial agents and anticancer drug delivery modalities.

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