scholarly journals The Antibacterial Assay of Tectorigenin with Detergents or ATPase Inhibitors against Methicillin-ResistantStaphylococcus aureus

2014 ◽  
Vol 2014 ◽  
pp. 1-7 ◽  
Author(s):  
Dae-Ki Joung ◽  
Su-Hyun Mun ◽  
Kuang-Shim Lee ◽  
Ok-Hwa Kang ◽  
Jang-Gi Choi ◽  
...  
Keyword(s):  
Antibacterial Activity ◽  
Biological Activities ◽  
Wide Spectrum ◽  
Multidrug Resistant ◽  
Transmission Electron ◽  
Antibacterial Assay ◽  
Atpase Inhibitors ◽  
Resistant Strains ◽  
Activity Mechanism ◽  
Triton X

Tectorigenin (TTR) is an O-methylated isoflavone derived from the rhizome ofBelamacanda chinensis(L.) DC. It is known to perform a wide spectrum of biological activities such as antioxidant, anti-inflammatory, anti-tumor. The aim of this study is to examine the mechanism of antibacterial activity of TTR against methicillin-resistantStaphylococcus aureus(MRSA). The anti-MRSA activity of TTR was analyzed in combination assays with detergent, ATPase inhibitors, and peptidoglycan (PGN) derived fromS. aureus. Transmission electron microscopy (TEM) was used to monitor survival characteristics and changes inS. aureusmorphology. The MIC values of TTR against all the tested strains were 125 μg/mL. The OD(600) of each suspension treated with a combination of Triton X-100, DCCD, and NaN3with TTR (1/10 × MIC) had been reduced from 68% to 80%, compared to the TTR alone. At a concentration of 125 μg/mL, PGN blocked antibacterial activity of TTR. This study indicates that anti-MRSA action of TTR is closely related to cytoplasmic membrane permeability and ABC transporter, and PGN at 125 μg/mL directly bind to and inhibit TTR at 62.5 μg/mL. These results can be important indication in study on antimicrobial activity mechanism against multidrug resistant strains.

scholarly journals The Mechanism Underlying the Antibacterial Activity of Shikonin against Methicillin-ResistantStaphylococcus aureus

2015 ◽  
Vol 2015 ◽  
pp. 1-9 ◽  
Author(s):  
Young-Seob Lee ◽  
Dae-Young Lee ◽  
Yeon Bok Kim ◽  
Sang-Won Lee ◽  
Seon-Woo Cha ◽  
...  
Keyword(s):  
Antibacterial Activity ◽  
Low Dose ◽  
Cytoplasmic Membrane ◽  
Antitumor Effects ◽  
Microdilution Method ◽  
Transmission Electron ◽  
Broth Microdilution Method ◽  
Atpase Inhibitors ◽  
Triton X ◽  
Time Kill

Shikonin (SKN), a highly liposoluble naphthoquinone pigment isolated from the roots ofLithospermum erythrorhizon, is known to exert antibacterial, wound-healing, anti-inflammatory, antithrombotic, and antitumor effects. The aim of this study was to examine SKN antibacterial activity against methicillin-resistantStaphylococcus aureus(MRSA). The SKN was analyzed in combination with membrane-permeabilizing agents Tris and Triton X-100, ATPase inhibitors sodium azide andN,N′-dicyclohexylcarbodiimide, andS. aureus-derived peptidoglycan; the effects on MRSA viability were evaluated by the broth microdilution method, time-kill test, and transmission electron microscopy. Addition of membrane-permeabilizing agents or ATPase inhibitors together with a low dose of SKN potentiated SKN anti-MRSA activity, as evidenced by the reduction of MRSA cell density by 75% compared to that observed when SKN was used alone; in contrast, addition of peptidoglycan blocked the antibacterial activity of SKN. The results indicate that the anti-MRSA effect of SKN is associated with its affinity to peptidoglycan, the permeability of the cytoplasmic membrane, and the activity of ATP-binding cassette (ABC) transporters. This study revealed the potential of SKN as an effective natural antibiotic and of its possible use to substantially reduce the use of existing antibiotic may also be important for understanding the mechanism underlying the antibacterial activity of natural compounds.

scholarly journals A Novel Cecropin D-Derived Short Cationic Antimicrobial Peptide Exhibits Antibacterial Activity Against Wild-Type and Multidrug-Resistant Strains of Klebsiella pneumoniae and Pseudomonas aeruginosa

2020 ◽  
Vol 16 ◽  
pp. 117693432093626
Author(s):  
Iván Darío Ocampo-Ibáñez ◽  
Yamil Liscano ◽  
Sandra Patricia Rivera-Sánchez ◽  
José Oñate-Garzón ◽  
Ashley Dayan Lugo-Guevara ◽  
...  
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Antibacterial Activity ◽  
Klebsiella Pneumoniae ◽  
Multidrug Resistant ◽  
Clinical Isolates ◽  
Health Concern ◽  
Wild Type ◽  
Cationic Antimicrobial Peptide ◽  
Promising Alternative ◽  
Resistant Strains

Infections caused by multidrug-resistant (MDR) Pseudomonas aeruginosa and Klebsiella pneumoniae are a serious worldwide public health concern due to the ineffectiveness of empirical antibiotic therapy. Therefore, research and the development of new antibiotic alternatives are urgently needed to control these bacteria. The use of cationic antimicrobial peptides (CAMPs) is a promising candidate alternative therapeutic strategy to antibiotics because they exhibit antibacterial activity against both antibiotic susceptible and MDR strains. In this study, we aimed to investigate the in vitro antibacterial effect of a short synthetic CAMP derived from the ΔM2 analog of Cec D-like (CAMP-CecD) against clinical isolates of K pneumoniae (n = 30) and P aeruginosa (n = 30), as well as its hemolytic activity. Minimal inhibitory concentrations (MICs) and minimal bactericidal concentrations (MBCs) of CAMP-CecD against wild-type and MDR strains were determined by the broth microdilution test. In addition, an in silico molecular dynamic simulation was performed to predict the interaction between CAMP-CecD and membrane models of K pneumoniae and P aeruginosa. The results revealed a bactericidal effect of CAMP-CecD against both wild-type and resistant strains, but MDR P aeruginosa showed higher susceptibility to this peptide with MIC values between 32 and >256 μg/mL. CAMP-CecD showed higher stability in the P aeruginosa membrane model compared with the K pneumoniae model due to the greater number of noncovalent interactions with phospholipid 1-Palmitoyl-2-oleyl-sn-glycero-3-(phospho-rac-(1-glycerol)) (POPG). This may be related to the boosted effectiveness of the peptide against P aeruginosa clinical isolates. Given the antibacterial activity of CAMP-CecD against wild-type and MDR clinical isolates of P aeruginosa and K pneumoniae and its nonhemolytic effects on human erythrocytes, CAMP-CecD may be a promising alternative to conventional antibiotics.

Synthesis of Fluorinated Piperazinyl Substituted Quinazolines as Potential Antibacterial Agents

2020 ◽  
Vol 5 (3) ◽  
pp. 227-233
Author(s):  
Amit B. Patel ◽  
Purvesh Patel ◽  
Kajal Patel ◽  
Krupa Prajapati
Keyword(s):  
Antibacterial Activity ◽  
13C Nmr ◽  
Antibacterial Agents ◽  
Multidrug Resistant ◽  
Biological Species ◽  
Piperazine Ring ◽  
Minimum Inhibitory Concentrations ◽  
Ft Ir ◽  
Resistant Strains ◽  
Quinazoline Derivatives

In present study, fluorinated piperazine and benzonitrile/nicotinonitrile fused quinazoline derivatives have synthesized, characterized using FT-IR, 1H & 13C NMR, 19F NMR and MS analysis and evaluated as potential antibacterial agents. They were also tested against the multidrug resistant strains. The antibacterial activity results revealed that the majority of synthesized compounds exhibited potential antibacterial with the extraordinary level of minimum inhibitory concentrations comparable to the control drugs. Moreover, the influence of presence or absence of fluoro and trifluoromethyl functional groups on the piperazine ring systems towards different biological species is elaborated. The synthesized compounds were also found non-toxic on the human cervical (HeLa) cells at their minimum inhibitory concentrations.

scholarly journals Antibacterial Activity of Essential Oil of <i>Aeollanthus pubescens</i> on Multidrug Resistant Strains of <i>Salmonella</i> and <i>Escherichia coli</i> Isolated from Laying Hens Farming in Benin

2019 ◽  
Vol 09 (09) ◽  
pp. 804-823
Author(s):  
Aguidissou Oscar Nestor ◽  
Boko Kadoeito Cyrille ◽  
Sessou Philippe ◽  
Yovo Mahudro ◽  
Komagbe S. Gwladys ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Antibacterial Activity ◽  
Essential Oil ◽  
Laying Hens ◽  
Multidrug Resistant ◽  
Resistant Strains

scholarly journals Phenylpropanoids and Furanocoumarins as Antibacterial and Antimalarial Constituents of the Bhutanese Medicinal Plant Pleurospermum amabile

2014 ◽  
Vol 9 (7) ◽  
pp. 1934578X1400900
Author(s):  
Phurpa Wangchuk ◽  
Stephen G. Pyne ◽  
Paul A. Keller ◽  
Malai Taweechotipatr ◽  
Sumalee Kamchonwongpaisan
Keyword(s):  
Antibacterial Activity ◽  
Plasmodium Falciparum ◽  
Bacillus Subtilis ◽  
Medicinal Plant ◽  
Antimalarial Activity ◽  
Biological Activities ◽  
Multidrug Resistant ◽  
Scientific Data ◽  
Methyl Eugenol ◽  
Weak Antibacterial Activity

With the objective of determining safety and verifying the traditional uses of the Bhutanese medicinal plant, Pleurospermum amabile Craib & W. W. Smith, we investigated its crude extracts and the isolated phytochemicals for their biological activities. Four phenylpropanoids [( E)-isomyristicin (1), ( E)-isoapiol (2), methyl eugenol (3) and ( E)-isoelemicin (4)] and six furanocoumarins [psoralen (5), bergapten (6), isoimperatorin (7), isopimpinellin (8), oxypeucedanin hydrate (9) and oxypeucedanin methanolate (10)] were isolated from this plant. Among the test samples, compound 10 showed weak antibacterial activity against Bacillus subtilis and best antimalarial activity against the Plasmodium falciparum strains, TM4/8.2 (chloroquine and antifolate sensitive) and K1CB1 (multidrug resistant). None of the test samples showed cytotoxicity. This study generated scientific data that support the traditional medical uses of the plant.

scholarly journals In Vitro Antibacterial Potency and Spectrum of ABT-492, a New Fluoroquinolone

2003 ◽  
Vol 47 (10) ◽  
pp. 3260-3269 ◽  
Author(s):  
Angela M. Nilius ◽  
Linus L. Shen ◽  
Dena Hensey-Rudloff ◽  
Laurel S. Almer ◽  
Jill M. Beyer ◽  
...  
Keyword(s):  
Antibacterial Activity ◽  
Respiratory Tract Infections ◽  
Rank Order ◽  
Multidrug Resistant ◽  
Topoisomerase Iv ◽  
The Family ◽  
Resistant Strains ◽  
Lung Infections ◽  
Tract Infections

ABSTRACT ABT-492 demonstrated potent antibacterial activity against most quinolone-susceptible pathogens. The rank order of potency was ABT-492 > trovafloxacin > levofloxacin > ciprofloxacin against quinolone-susceptible staphylococci, streptococci, and enterococci. ABT-492 had activity comparable to those of trovafloxacin, levofloxacin, and ciprofloxacin against seven species of quinolone-susceptible members of the family Enterobacteriaceae, although it was less active than the comparators against Citrobacter freundii and Serratia marcescens. The activity of ABT-492 was greater than those of the comparators against fastidious gram-negative species, including Haemophilus influenzae, Moraxella catarrhalis, Neisseria gonorrhoeae, and Legionella spp. and against Pseudomonas aeruginosa and Helicobacter pylori. ABT-492 was as active as trovafloxacin against Chlamydia trachomatis, indicating good intracellular penetration and antibacterial activity. In particular, ABT-492 was more active than trovafloxacin and levofloxacin against multidrug-resistant Streptococcus pneumoniae, including strains resistant to penicillin and macrolides, and H. influenzae, including β-lactam-resistant strains. It retained greater in vitro activity than the comparators against S. pneumoniae and H. influenzae strains resistant to other quinolones due to amino acid alterations in the quinolone resistance-determining regions of the target topoisomerases. ABT-492 was a potent inhibitor of bacterial topoisomerases, and unlike the comparators, DNA gyrase and topoisomerase IV from either Staphylococcus aureus or Escherichia coli were almost equally sensitive to ABT-492. The profile of ABT-492 suggested that it may be a useful agent for the treatment of community-acquired respiratory tract infections, as well as infections of the urinary tract, bloodstream, and skin and skin structure and nosocomial lung infections.

scholarly journals Antibacterial and Zebrafish-based Screening for Wnt Signal Inhibitory Activities of Syzygium polycephaloides (C.B. Robb. Merr.) Bark Extracts

2021 ◽  
Vol 15 ◽  
pp. 1-6
Author(s):  
Rolly Garnace Fuentes ◽  
Gio Martin A. Ocfemia ◽  
Galileo Gregory Abrasaldo
Keyword(s):  
Antibacterial Activity ◽  
Inhibitory Activity ◽  
Wide Spectrum ◽  
Methanolic Extracts ◽  
Antibacterial Assay ◽  
Disk Diffusion Assay ◽  
Activity Screening ◽  
Inhibitory Potential ◽  
Diffusion Assay ◽  
Wnt Signal

Syzygium polycephaloides, a plant native to Southeast Asia, is used to cure common illnesses. In this study, the methanolic bark extracts of S. polycephaloides was evaluated for their antibacterial activity and screened for their Wnt signal inhibitory activity using zebrafish-based assay. In the antibacterial assay, the extracts were tested against Staphylococcus aureus, Bacillus subtilis, Pseudomonas aeroginosa, and Escherichia coli using disk diffusion assay. On the other hand, zebrafish-based screening was used to determine the inhibitory potential of S. polycephaloides against the Wnt signal. Zebrafish embryos were treated with LiCl to upregulate the Wnt signal which produces eyeless phenotype. The methanolic extracts had antibacterial activity against the test microorganisms except P. aeruginosa. After fractionation, ethyl acetate (EtOAc) and aqueous fractions exhibited wide-spectrum antibacterial activity. For the Wnt signal inhibitory activity screening, the LiCl-treated embryos were rescued to their normal eye development after treatment with the S. polycephaloides bark extracts (100 g/mL). The results suggest that the extracts may have inhibited the Wnt signal. This study shows that the S. polycephaloides is a potent source of antibacterial compounds and Wnt inhibitors.

Design, Synthesis, Evaluation of Antimicrobial Activity and Docking Studies of New Thiazole-based Chalcones

2019 ◽  
Vol 19 (5) ◽  
pp. 356-375 ◽  
Author(s):  
Christophe Tratrat ◽  
Michelyne Haroun ◽  
Iakovos Xenikakis ◽  
Konstantinos Liaras ◽  
Evangelia Tsolaki ◽  
...  
Keyword(s):  
Antimicrobial Activity ◽  
Antibacterial Activity ◽  
Antimicrobial Agents ◽  
Biological Activities ◽  
Wide Spectrum ◽  
Bacterial Species ◽  
Antibacterial Properties ◽  
Docking Studies ◽  
In Vivo Evaluation ◽  
Better Than

Background:Thiazole derivates as well as chalcones, are very important scaffold for medicinal chemistry. Literature survey revealed that they possess wide spectrum of biological activities among which are anti-inflammatory and antimicrobial.Objectives:The current studies describe the synthesis and evaluation of antimicrobial activity of twenty eight novel thiazole-based chalcones.Methods:The designed compounds were synthesized using classical methods of organic synthesis. The in vivo evaluation of antimicrobial activity was performed by microdilution method.Results:All compounds have shown antibacterial properties better than that of ampicillin and in many cases better than streptomycin. As far as the antifungal activity is concerned, all compounds possess much higher activity than reference drugs bifonazole and ketoconazole. The most sensitive bacterial species was B. cereus (MIC 6.5-28.4 µmol × 10-2/mL and MBC 14.2-105.0 µmol × 10-2/mL) while the most resistant ones were L. monocytogenes (MIC 21.4-113.6 µmol × 10-2/mL) and E. coli (MIC 10.7- 113.6 µmol × 10-2/mL) and MBC at 42.7-358.6 µmol × 10-2/mL and 21.4-247.2 µmol × 10-2/mL, respectively. All the compounds exhibited antibacterial activity against the three resistant strains, MRSA, P. aeruginosa and E.coli. with MIC and MBC in the range of 0.65-11.00 µmol/mL × 10-2 and 1.30-16.50 µmol/mL × 10-2. Docking studies were performed.Conclusion:Twenty-eight novel thiazole-based chalcones were designed, synthesized and evaluated for antimicrobial activity. The results showed that these derivatives could be lead compounds in search of new potent antimicrobial agents. Docking studies indicated that DNA gyrase, GyrB and MurA inhibition may explain the antibacterial activity.

Enhanced antibacterial activity of the gentamicin against multidrug-resistant strains when complexed with Canavalia ensiformis lectin

2020 ◽  
pp. 104639
Author(s):  
Valdenice F. Santos ◽  
Ana C.J. Araújo ◽  
Priscilla R. Freitas ◽  
Ana L.P. Silva ◽  
Ana L.E. Santos ◽  
...  
Keyword(s):  
Antibacterial Activity ◽  
Multidrug Resistant ◽  
Canavalia Ensiformis ◽  
Resistant Strains

scholarly journals Chemical Composition and Antibacterial Activity of Essential Oils from the Algerian Endemic Origanum glandulosum Desf. against Multidrug-Resistant Uropathogenic E. coli Isolates

Antibiotics ◽  
2020 ◽  
Vol 9 (1) ◽  
pp. 29 ◽  
Author(s):  
Larbi Zakaria Nabti ◽  
Farida Sahli ◽  
Hocine Laouar ◽  
Ahmed Olowo-okere ◽  
Joice Guileine Nkuimi Wandjou ◽  
...  
Keyword(s):  
Antibacterial Activity ◽  
Chemical Composition ◽  
Essential Oils ◽  
Multidrug Resistant ◽  
Diffusion Method ◽  
Resistant Bacteria ◽  
E Coli ◽  
Broth Microdilution Method ◽  
Resistant Strains ◽  
Tract Infections

Antibiotics are becoming ineffective against resistant bacteria. The use of essential oils (EOs) may constitute an alternative solution to fight against multidrug-resistant bacteria. This study aims to determine the chemical composition of EOs from five populations of the endemic Algerian Origanum glandulosum Desf. and to investigate their potential antibacterial activity against multidrug-resistant uropathogenic E. coli strains. The EOs were obtained by hydrodistillation and their composition was investigated by gas chromatography/mass spectrometry (GC/MS). The antibacterial activity was evaluated by the disc diffusion method against eight E. coli strains (six uropathogenic resistant and two referenced susceptible strains). Minimum inhibitory and bactericidal concentrations (MIC/MBC) were obtained by the broth microdilution method. The main EO components were thymol (15.2–56.4%), carvacrol (2.8–59.6%), γ-terpinene (9.9–21.8%) and p-cymene (8.5–13.9%). The antibacterial tests showed that all the EOs were active against all the strains, including the multidrug-resistant strains. The EO from the Bordj location, which contained the highest amount of carvacrol (59.6%), showed the highest antibacterial activity (inhibition diameters from 12 to 24.5 mm at a dilution of 1/10). To our knowledge, this is the first description of the activity of O. glandulosum EOs against resistant uropathogenic strains. Our study suggests that O. glandulosum EO could be used in some clinical situations to treat or prevent infections (e.g., urinary tract infections) with multidrug-resistant strains.

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