scholarly journals Synergistic Effects of Anionic/Cationic Dendrimers and Levofloxacin on Antibacterial Activities

Molecules ◽  
2019 ◽  
Vol 24 (16) ◽  
pp. 2894 ◽  
Author(s):  
Natalia Wrońska ◽  
Jean Pierre Majoral ◽  
Dietmar Appelhans ◽  
Maria Bryszewska ◽  
Katarzyna Lisowska
Keyword(s):  
Antibacterial Activity ◽  
Biomedical Applications ◽  
Synergistic Effects ◽  
Antibacterial Activities ◽  
Drug Dosage ◽  
General Interest ◽  
Gram Negative Bacteria ◽  
Gram Negative ◽  
Fluoroquinolone Antibiotics ◽  
Proteus Hauseri

Despite the numerous studies on dendrimers for biomedical applications, the antibacterial activity of anionic phosphorus dendrimers has not been explored. In our research, we evaluated the antibacterial activity of modified polycationic and polyanionic dendrimers in combination with levofloxacin (LVFX) against Gram-negative (Escherichia coli ATCC 25922, Proteus hauseri ATCC 15442) and Gram-positive (Staphylococcus aureus ATCC 6538) bacteria. In the case of Gram-negative bacteria, we concluded that a combination of dendrimers and antibiotic gave satisfactory results due to a synergistic effect. The use of fluoroquinolone antibiotics, such as LVFX, not only caused resistance in disease-causing microorganisms but also increased environmental pollution. Therefore, reduction of drug dosage is of general interest.

scholarly journals Antibacterial and Cytotoxic Activities of the Sesquiterpene Lactones Cnicin and Onopordopicrin

2011 ◽  
Vol 6 (2) ◽  
pp. 1934578X1100600 ◽  
Author(s):  
Sandra M. Bach ◽  
Mario A. Fortuna ◽  
Rodgoun Attarian ◽  
Juliana T. de Trimarco ◽  
César A. N. Catalán ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Antibacterial Activity ◽  
Methicillin Resistant Staphylococcus Aureus ◽  
Sesquiterpene Lactones ◽  
Antibacterial Activities ◽  
Chloroform Extract ◽  
Cytotoxic Activities ◽  
Gram Negative Bacteria ◽  
Gram Negative ◽  
High Cytotoxicity

The antimicrobial and cytotoxic activities of chloroform extracts from the weeds Centaurea tweediei and C. diffusa, and the main sesquiterpene lactones isolated from these species, onopordopicrin and cnicin, respectively, were assayed. Results show that the chloroform extracts from both Centaurea species possess antibacterial activities against a panel of Gram-positive and Gram-negative bacteria. Remarkable antibacterial activity against methicillin-resistant Staphylococcus aureus was also measured. Both the extracts and the purified sesquiterpene lactones show high cytotoxicity against human-derived macrophages. Despite this cytotoxicity, C. diffusa chloroform extract and cnicin are attractive candidates for evaluation as antibiotics in topical preparations against skin-associated pathogens.

Antibacterial Activity and Chemical Composition of the Essential Oil of Grammosciadium platycarpum Boiss. from Iran

2005 ◽  
Vol 60 (1-2) ◽  
pp. 30-34 ◽  
Author(s):  
Ali Sonboli ◽  
Fereshteh Eftekhar ◽  
Morteza Yousefzadi ◽  
Mohammad Reza Kanani
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Antibacterial Activity ◽  
Chemical Composition ◽  
Essential Oil ◽  
Essential Oils ◽  
Antibacterial Activities ◽  
Gram Negative Bacteria ◽  
Gram Negative ◽  
Two Samples

The chemical composition of the essential oils obtained from two samples (GP1 and GP2) of Grammosciadium platycarpum Boiss. was analyzed by GC and GC-MS. The analysis of the oils resulted in the identification of twenty-two constituents. Linalool (79.0% - GP1, 81.8% - GP2) and limonene (10.0%, 5.8%) were found to be the major components, respectively. The in vitro antibacterial activities of these oils and their main compounds against seven Gram-positive and Gram-negative bacteria were investigated. The results exhibited that the total oils and their major components possess strong to moderate activities against all the tested bacteria except for Pseudomonas aeruginosa.

scholarly journals 5-Bromo-1-(4-chlorobenzyl)-1H-indole-2-carboxamides as new potent antibacterial agents

2018 ◽  
Vol 24 (6) ◽  
pp. 327-332 ◽  
Author(s):  
Yogesh D. Mane ◽  
Smita S. Patil ◽  
Dhanraj O. Biradar ◽  
Bhimrao C. Khade
Keyword(s):  
Escherichia Coli ◽  
Antibacterial Activity ◽  
Antibacterial Agents ◽  
Inhibitory Concentration ◽  
Antibacterial Activities ◽  
Gram Negative Bacteria ◽  
Internal Standards ◽  
Gram Negative ◽  
E Coli ◽  
High Antibacterial Activity

Abstract Ten 5-bromoindole-2-carboxamides were synthesized, characterized and evaluated for antibacterial activity against pathogenic Gram-negative bacteria Klebsiella pneumoniae, Escherichia coli, Pseudomonas aeruginosa and Salmonella Typhi using gentamicin and ciprofloxacin as internal standards. Compounds 7a–c, 7g and 7h exhibit high antibacterial activity with a minimum inhibitory concentration (MIC) of 0.35–1.25 μg/mL. Compounds 7a–c exhibit antibacterial activities that are higher than those of the standards against E. coli and P. aeruginosa.

The Effects of Natural Dopant Acids on Morphologies and Antibacterial Activity of Polyaniline

2013 ◽  
Vol 650 ◽  
pp. 249-252 ◽  
Author(s):  
Jia Li Mu ◽  
Wen Jun Fan ◽  
Shao Yun Shan ◽  
Ting Wei Hu ◽  
Ya Ming Wang ◽  
...  
Keyword(s):  
Antibacterial Activity ◽  
Salicylic Acid ◽  
Citric Acid ◽  
Rosin Acid ◽  
Antibacterial Activities ◽  
Gram Negative Bacteria ◽  
Gram Positive ◽  
Gram Negative ◽  
Gram Positive Bacteria ◽  
Bacillus Coli

Polyaniline(PANI) doped by natural acid(citric acid, salicylic acid or rosin acid)solutions was synthesized using aniline as monomer and ammonium peroxydisulfate ((NH4)2S2O8) as oxidant. The antibacterial activities of the PANI against Gram positive bacteria(Bacillus megatherium, Bacillus subtilis, Bacillus cereus and Staphylo-coccus aureus) and Gram negative bacteria(Bacillus coli) were investigated. It was shown that PANI doped by citric acid possessed the better antibacterial activity against the selected species of Gram positive bacteria and Gram negative bacteria than PANI doped by rosin acid. PANI doped by salicylic acid exhibited ascendant antibacterial activities against Gram positive bacteria, but it has little antibacterial activity against the Gram negative bacteria.

scholarly journals Antibacterial Activities of Actinomycete Isolates Collected from Soils of Rajshahi, Bangladesh

2011 ◽  
Vol 2011 ◽  
pp. 1-6 ◽  
Author(s):  
Md. Ajijur Rahman ◽  
Mohammad Zahidul Islam ◽  
Md. Anwar Ul Islam
Keyword(s):  
Antibacterial Activity ◽  
Secondary Metabolites ◽  
Inhibitory Activity ◽  
Pure Culture ◽  
Agar Medium ◽  
Antibacterial Activities ◽  
Soil Samples ◽  
Indicator Bacteria ◽  
Gram Negative Bacteria ◽  
Gram Negative

This study was performed to isolate actinomycete colonies having antibacterial activity from soil samples collected from different places around Rajshahi, Bangladesh. Thirty actinomycete colonies were isolated in pure culture from five soil samples using Starch-casein-nitrate-agar medium. The isolates were grouped in five color series based on their aerial mycelia color and screened for their antibacterial activity against a range of test bacteria. Sixteen isolates (53.3%) were found to have moderate to high activity against four gram-positive and four gram-negative bacteria. Since many isolates showed inhibitory activity against indicator bacteria, it is suggestive that Bangladeshi soil could be an interesting source to explore for antibacterial secondary metabolites.

Antibacterial activity of a microemulsion loaded with cephalosporin

Biologia ◽  
2016 ◽  
Vol 71 (7) ◽  
Author(s):  
Mayson H. Alkhatib ◽  
Magda M. Aly ◽  
Ohud A. Saleh ◽  
Hana M. Gashlan
Keyword(s):  
Antibacterial Activity ◽  
Antibacterial Activities ◽  
Distilled Water ◽  
Gram Negative Bacteria ◽  
Food Technology ◽  
Cremophor El ◽  
Gram Negative ◽  
Transmission Electron ◽  
Pharmaceutical Industries ◽  
Ethyl Decanoate

AbstractMicroemulsions (MEs), isotropic mixture of water, oil, surfactant and most frequently cosurfactant, have gained great interest in the pharmaceutical industries and food technology due to their great potential to act as antimicrobials as well as nanocarriers for antibiotics. In this study, the antibacterial activities of a ME, composed of 23.5% Cremophor EL, 12.5% transcutol, 30% ethyl decanoate and 34% distilled water, against Gram-positive and Gram-negative bacteria and its potential as a nanocarrier for cephalosporine (CEPH/ME) were assessed. The morphological structures of the ME and CEPH/ME, revealed by transmission electron microscopy, were spherical and their droplet diameters were 15.55 ± 3.17 nm and 10.56 ± 2.32 nm, respectively. ME was found to have great antibacterial activity against

scholarly journals Antibacterial activity of cobalt(II) complexes with some benzimidazole derivatives

2008 ◽  
Vol 73 (12) ◽  
pp. 1153-1160 ◽  
Author(s):  
S.O. Podunavac-Kuzmanovic ◽  
V.M. Leovac ◽  
D.D. Cvetkovic
Keyword(s):  
Antibacterial Activity ◽  
Chemical Structure ◽  
Antibacterial Activities ◽  
Benzimidazole Derivatives ◽  
Wall Structure ◽  
Gram Negative Bacteria ◽  
Bacterial Strains ◽  
Gram Positive ◽  
Gram Negative

The antibacterial activities of cobalt(II) complexes with two series of benzimidazoles were evaluated in vitro against three Gram-positive bacterial strains (Bacillus cereus, Staphylococcus aureus, and Sarcina lutea) and one Gram-negative isolate (Pseudomonas aeruginosa). The minimum inhibitory concentration was determined for all the complexes. The majority of the investtigated complexes displayed in vitro inhibitory activity against very persistent bacteria. They were found to be more active against Gram-positive than Gram-negative bacteria. It may be concluded that the antibacterial activity of the compounds is related to the cell wall structure of the tested bacteria. Comparing the inhibitory activities of the tested complexes, it was found that the 1-substituted- -2-aminobenzimidazole derivatives were more active than complexes of 1-substituted- 2-amino-5,6-dimethylbenzimidazoles. The effect of chemical structure on the antibacterial activity is discussed.

scholarly journals Syzygium jambosDisplayed Antibacterial and Antibiotic-Modulating Activities against Resistant Phenotypes

2018 ◽  
Vol 2018 ◽  
pp. 1-12
Author(s):  
Brice E. N. Wamba ◽  
Paul Nayim ◽  
Armelle T. Mbaveng ◽  
Igor K. Voukeng ◽  
Joachim K. Dzotam ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Synergistic Effects ◽  
Enterobacter Aerogenes ◽  
Antibacterial Activities ◽  
Bark Extract ◽  
Gram Negative Bacteria ◽  
Gram Negative ◽  
Syzygium Jambos ◽  
Broth Microdilution Method ◽  
Mic Value

The present study was designed to evaluate the antibacterial activities of methanol extracts of bark and leaves ofSyzygium jambos, as well as their synergistic effects with selected antibiotics against drug-resistant Gram-positive and Gram-negative bacteria. The crude extracts were subjected to qualitative phytochemical screening; broth microdilution method was used for antibacterial assays. Phytochemical studies indicate that leaves and bark extracts contained polyphenols, anthraquinones, tannins, and steroids. Extract of the leaves was active against all the 26 strains ofStaphylococcus aureusand all the 21 strains of Gram-negative bacteria tested, within the minimum inhibitory concentration (MIC) range of 32–512 μg/mL. The lowest MIC value of 32 μg/mL was obtained with extract of the leaves againstStaphylococcus aureusMRSA9 strain. In Gram-negative bacteria, the lowest MIC value of 64 μg/mL was also obtained againstEnterobacter aerogenesEA294 andKlebsiella pneumoniaeK24 strains. AgainstS. aureusstrains, antibiotic-modulating activity of extracts at MIC/2 towards more than 70% of the tested strains was obtained when leaves and bark extracts were tested in association with chloramphenicol (CHL). This was also the case when leaves extract was combined with CHL, kanamycin (KAN), tetracycline (TET), and erythromycin (ERY) and when bark extract was combined with ciprofloxacin (CIP), TET, and ERY against Gram-negative bacteria. In conclusion, this study demonstrated thatSyzygium jamboshas antibacterial and antibiotic-modulating activities.

scholarly journals A Comparative Study of Antibacterial Activity of CuO/Ag and ZnO/Ag Nanocomposites

2020 ◽  
Vol 2020 ◽  
pp. 1-18
Author(s):  
R. B. Asamoah ◽  
E. Annan ◽  
B. Mensah ◽  
P. Nbelayim ◽  
V. Apalangya ◽  
...  
Keyword(s):  
Antibacterial Activity ◽  
Transition Metal ◽  
Synergistic Effects ◽  
Bacterial Species ◽  
Antibacterial Activities ◽  
Disc Diffusion ◽  
Gram Positive ◽  
Gram Negative ◽  
Antibacterial Performance ◽  
Depth Analysis

The synergistic effects of transition metal based nanocomposites are known to possess enhanced antibacterial activities. However, in-depth analysis of the relative antibacterial performance of some of the prominent nanocomposites remains unavailable. This study compares the antibacterial activity of two separate nanocomposites, which are copper oxide with silver (CuO/Ag) and zinc oxide with silver (ZnO/Ag). The individual CuO/Ag and ZnO/Ag nanocomposites were synthesised by a mixed wet-chemical method. The resulting particles were analysed by XRD, XRF, TEM, UV-Vis spectrophotometer, BET, and FTIR. The antibacterial activity of the nanoparticles were tested on Gram-negative and Gram-positive bacteria, Escherichia coli (ATCC25922) and Staphylococcus aureus (ATCC25923), respectively, using the Kirby–Bauer disc diffusion and the microdilution methods. The Kirby–Bauer disc diffusion test results had the same minimum inhibition concentration (MIC) value for both CuO/Ag and ZnO/Ag against E. coli and S. aureus, which was 0.25 mg/ml. The applied nanocomposites using microdilution showed that CuO/Ag had approximately 98.8% and 98.7% efficiency on the respective Gram-positive and Gram-negative bacterial species, while ZnO/Ag achieved 91.7% and 89.3% efficiency, respectively, against the Gram-positive and Gram-negative bacterial species. This study presents a novel approach for relative analysis of the performance efficiency of transition metal based nanocomposites.

scholarly journals Antibacterial Effect of Some Palestinian Plant Extracts against Clinical Multidrug-Resistant Gram- Negative Bacteria: A possible synergism with antibiotics

2020 ◽  
Vol 19 (3) ◽  
pp. 509-519
Author(s):  
Emad Abou Elkhair ◽  
Tarek A El Bashiti ◽  
Atef A Masad ◽  
Wesam S Abu Draz
Keyword(s):  
Antibacterial Activity ◽  
Synergistic Effect ◽  
Essential Oils ◽  
Plant Extracts ◽  
Synergistic Effects ◽  
Medical Science ◽  
Average Diameter ◽  
Multidrug Resistant ◽  
Gram Negative Bacteria ◽  
Gram Negative

Objectives: The present study was designed to screen the antibacterial and synergistic effects of Allium sativum, Ecballiumelaterium, Pelargoniumgraveolens, Rosmarinusofficinalis, Phagnalonrupestre and Rutagraveolens plant extracts and essential oils against the followingclinical multidrug-resistant(MDR) Gram negative pathogenic isolates: Escherichia coli, Klebsiella pneumoniae and Pseudomonas aeruginosa. Methods: All extracts and essential oils were screened for their antibacterial activity and synergistic effect in combination with known antibiotics.The minimum inhibitory concentrations (MICs) and the minimum bactericidal concentrations (MBCs) of the plant extracts were assessed. Results: Our results revealed that, the average diameter of inhibition zones ranged from: 7-14 mm, 7-17 mm, 8-17 mm and 7-13 mm for water, ethanol, methanol and EOs extracts, respectively. The MICs and MBCs were determined for extracts which showed antibacterial activity. The average MICs values ranged from 1.6-100 mg/ml, 1.6-50 mg/ml, 0.39 -50 mg/ml and 3.13-100 μl/ml for water, ethanol, methanol and EOs extracts, respectively. While MBCs values ranged from 25->200 mg/ml, 25- 200 mg/ml and 50->200 μl/ml for water, ethanol, methanol and EOs extracts, respectively. The antibacterial activity of the afore mentioned plant extracts combined with Ciprofloxacin (CIP), Ampicillin (AM), Cefotaxime (CTX), Nalidixic acid (NA), Norofloxacin (NOR), Cefuroxime (CXM), Cefaclor (CF), Ofloxacin (OFX), Cefalexin (CL), Tetracycline (TE), Rifampicin (RIF), Amoxyclav (AMC) and Amikacin (AK) had different degrees of synergism against the selectedbacteria.Essential oils (Eos) of screened plants had the best synergism with antibiotics than the plant extracts against the tested bacteria. The best synergism was noticed in the Eos of A. sativum, P. graveolens and R. officinalis. Conclusion: It was concluded that the synergistic effect of antibiotics and plant extracts is promising approach fortreating infectious diseases caused byMDR Gram negative bacteria. Bangladesh Journal of Medical Science Vol.19(3) 2020 p.509-519

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