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

scholarly journals Synergistic Effect of Propidium Iodide and Small Molecule Antibiotics with the Antimicrobial Peptide Dendrimer G3KL against Gram-Negative Bacteria

Molecules ◽  
2020 ◽  
Vol 25 (23) ◽  
pp. 5643
Author(s):  
Bee-Ha Gan ◽  
Xingguang Cai ◽  
Sacha Javor ◽  
Thilo Köhler ◽  
Jean-Louis Reymond
Keyword(s):  
Synergistic Effect ◽  
Propidium Iodide ◽  
Synergistic Effects ◽  
Multidrug Resistant ◽  
Resistant Bacteria ◽  
Gram Negative Bacteria ◽  
Bacterial Killing ◽  
Gram Negative ◽  
Outer Membranes ◽  
New Antibiotics

There is an urgent need to develop new antibiotics against multidrug-resistant bacteria. Many antimicrobial peptides (AMPs) are active against such bacteria and often act by destabilizing membranes, a mechanism that can also be used to permeabilize bacteria to other antibiotics, resulting in synergistic effects. We recently showed that G3KL, an AMP with a multibranched dendritic topology of the peptide chain, permeabilizes the inner and outer membranes of Gram-negative bacteria including multidrug-resistant strains, leading to efficient bacterial killing. Here, we show that permeabilization of the outer and inner membranes of Pseudomonas aeruginosa by G3KL, initially detected using the DNA-binding fluorogenic dye propidium iodide (PI), also leads to a synergistic effect between G3KL and PI in this bacterium. We also identify a synergistic effect between G3KL and six different antibiotics against the Gram-negative Klebsiella pneumoniae, against which G3KL is inactive.

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 The Antibacterial Activity of Catunaregam tomentosa Against Selected Gram-Positive and Gram-Negative Bacteria

2021 ◽  
Vol 5 (S1) ◽  
pp. 34-38
Author(s):  
Nor Aleesa Ali ◽  
Wan Amalina Wan Mamat ◽  
Syed Ahmad Tajudin Tuan Johari ◽  
Muhammad Yusran Abdul Aziz ◽  
Ahmad Syibli Othman
Keyword(s):  
Antibacterial Activity ◽  
Plant Extracts ◽  
Bacterial Infections ◽  
Scientific Basis ◽  
Diffusion Method ◽  
Antibacterial Drug ◽  
Gram Negative Bacteria ◽  
Gram Positive ◽  
Gram Negative ◽  
Value Evaluation

Catunaregam tomentosa is a plant from Rubiaceae family that is used in traditional medicine for the treatment of stomatitis and ulcers due to bacterial infections. Besides, it also helps in the treatment of oliguria and dysuria. Indiscriminate use of commercial antibacterial medicines had led to the search for novel antibacterial drugs. Since for ages medicinal plants have been used to treat bacterial infection, so they can be excellent sources of the novel antibacterial drug. To evaluate the scientific basis of the use of plant, antibacterial activity leaves extract of C.tomentosa was investigated against selected Gram-positive and Gram-negative bacteria. The study also investigated the effect of pH on its antibacterial activity. Antibacterial activity of the plant extracts was evaluated against Staphylococcus aureus, Escherichia coli, Klebsiella pneumoniae, and Pseudomonas aeruginosa by using the disc diffusion method at 100mg/mL concentration. Extracts of C. tomentosa inhibit the activity of S. aureus but do not inhibit the activity of Gram-negative bacteria. Minimum inhibitory concentration (MIC) was also determined against S. aureus at concentration 100, 50, 25, 12.5, 6, 3, 1.5, 0.75 and 0.395mg/mL and 3mg/mL were the MIC value. Evaluation on the effect of different pH on antibacterial activity of plant extracts shows that the activity of the plant extracts does not affect when treated with acidic pH but increased at alkaline pH. Based on the present finding, C. tomentosa leaves extract have the potential to be a viable candidate in the discovery of a natural antibacterial agent against S. aureus infections. This study provides scientific knowledge to further determine the antibacterial values of C. tomentosa extracts.

scholarly journals Biological activity of manganese(i) tricarbonyl complexes on multidrug-resistant Gram-negative bacteria: From functional studies to in vivo activity in Galleria mellonella

Metallomics ◽  
2019 ◽  
Vol 11 (12) ◽  
pp. 2033-2042 ◽  
Author(s):  
Paul Güntzel ◽  
Christoph Nagel ◽  
Jeanette Weigelt ◽  
Jono W. Betts ◽  
Calum A. Pattrick ◽  
...  
Keyword(s):  
Antibacterial Activity ◽  
Biological Activity ◽  
Galleria Mellonella ◽  
Atp Release ◽  
Multidrug Resistant ◽  
Gram Negative Bacteria ◽  
Bacterial Clearance ◽  
Gram Negative ◽  
Functional Studies

Antibacterial activity of four Mn(CO)3 complexes on multidrug-resistant clinical isolates of A. baumannii and P. aeruginosa correlated with lipophilicity and increase in ATP release. Absence of host toxicity in G. mellonella was combined with effective bacterial clearance.

scholarly journals Antibacterial activity in the leaves of seven bitter medicinal plants of Bangladesh

1970 ◽  
Vol 18 ◽  
pp. 128-133 ◽  
Author(s):  
MTH Molla ◽  
MS Ahsan ◽  
MT Alam ◽  
ME Haque
Keyword(s):  
Antibacterial Activity ◽  
Bacillus Subtilis ◽  
Medicinal Plants ◽  
Plant Extracts ◽  
Salmonella Typhi ◽  
Antimicrobial Activities ◽  
Gram Negative Bacteria ◽  
Gram Positive ◽  
Gram Negative ◽  
Ethanolic Extracts

Context: Development of resistance in human pathogens against conventional antibiotic necessitates searching indigenous medicinal plants having antibacterial property. Seven medicinal plants used actively in folklore, ayurvedic and traditional system of medicine were selected for the evaluation of their antimicrobial activity for this study.   Objectives: Evaluation of the effectiveness of some medicinal plant extracts against four Gram-positive and five Gram-negative bacteria.  Materials and Methods: The antibacterial activity of the crude ethanolic extracts obtained from the leaves of seven medicinal plants; viz., Andrographis paniculata, Catharanthus roseus, Adhatoda vasica, Vitex vegundo, Aloe vera, Flacortia ramontchi and Nyctanthes arbortristis were tested against nine bacteria at concentrations of 300-, 400- and 500 μg/ml. Standard antibiotic disc kanamycin (30μg/ml) was used for comparison. The minimum inhibitory concentration (MIC) of ethanolic extracts of the leaves of these medicinal plants were determined by testing the extracts on four Gram-positive and five Gram-negative bacteria by serial tube dilution method.   Results: All the extracts have notable antimicrobial activities against the test organisms. The ethanolic extracts of the leaves showed the highest antimicrobial activities against Bacillus megaterium and Shigella dysenteriae for An. paniculata, Ad. vasica and Al. vera; Bacillus subtilis and Salmonella typhi for C. roseus and N. arbortristis; Staphylociccus aureus and Salmonella typhi for V. vegundo; and Bacillus subtilis and Shigella sonnei for F. ramontchi respectively. The extract of the plants had MIC values ranging from 32 to 128 mg/ml. All plant extracts showed no MIC against Shigella shiga and against Sarcina lutea only C. roseus showed MIC 128 mg/ml.   Conclusion: The results revealed that the ethanolic extracts of the plants under present investigation have notable antimicrobial activities.   Keywords: medicinal plants; antimicrobial screening; MIC; bacteria. DOI: http://dx.doi.org/10.3329/jbs.v18i0.8788 JBS 2010; 18(0): 128-133

scholarly journals Chitosan-Stabilized Ag Nanoparticles with Superior Biocompatibility and Their Synergistic Antibacterial Effect in Mixtures with Essential Oils

Nanomaterials ◽  
2018 ◽  
Vol 8 (10) ◽  
pp. 826 ◽  
Author(s):  
Ludmila Cinteza ◽  
Cristina Scomoroscenco ◽  
Sorina Voicu ◽  
Cristina Nistor ◽  
Sabina Nitu ◽  
...  
Keyword(s):  
Antibacterial Activity ◽  
Essential Oils ◽  
Metallic Nanoparticles ◽  
Synergistic Effects ◽  
Medical Application ◽  
Colloidal Dispersion ◽  
Multidrug Resistant ◽  
Antimicrobial Activities ◽  
Promising Alternative

Silver nanoparticles (AgNPs) are considered a promising alternative to the use of antibiotics in fighting multidrug-resistant pathogens. However, their use in medical application is hindered by the public concern regarding the toxicity of metallic nanoparticles. In this study, rationally designed AgNP were produced, in order to balance the antibacterial activity and toxicity. A facile, environmentally friendly synthesis was used for the electrochemical fabrication of AgNPs. Chitosan was employed as the capping agent, both for the stabilization and to improve the biocompatibility. Size, morphology, composition, capping layer, and stability of the synthesized nanoparticles were characterized. The in vitro biocompatibility and antimicrobial activities of AgNPs against common Gram-negative and Gram-positive bacteria were evaluated. The results revealed that chitosan-stabilized AgNPs were nontoxic to normal fibroblasts, even at high concentrations, compared to bare nanoparticles, while significant antibacterial activity was recorded. The silver colloidal dispersion was further mixed with essential oils (EO) to increase the biological activity. Synergistic effects at some AgNP–EO ratios were observed, as demonstrated by the fractionary inhibitory concentration values. Our results reveal that the synergistic action of both polymer-stabilized AgNPs and essential oils could provide a significant efficiency against a large variety of microorganisms, with minimal side effects.

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 Efficacy of Humanized Exposures of Cefiderocol (S-649266) against a Diverse Population of Gram-Negative Bacteria in a Murine Thigh Infection Model

2017 ◽  
Vol 61 (11) ◽  
Author(s):  
Marguerite L. Monogue ◽  
Masakatsu Tsuji ◽  
Yoshinori Yamano ◽  
Roger Echols ◽  
David P. Nicolau
Keyword(s):  
Antibacterial Activity ◽  
Multidrug Resistant ◽  
Infection Model ◽  
Gram Negative Bacteria ◽  
Diverse Population ◽  
Gram Negative ◽  
Content Type ◽  
Log Reduction

ABSTRACT Cefiderocol (S-649266) is a novel siderophore cephalosporin with potent in vitro activity against clinically encountered multidrug-resistant (MDR) Gram-negative isolates; however, its spectrum of antibacterial activity against these difficult-to-treat isolates remains to be fully explored in vivo. Here, we evaluated the efficacy of cefiderocol humanized exposures in a neutropenic murine thigh model to support a suitable MIC breakpoint. Furthermore, we compared cefiderocol's efficacy with humanized exposures of meropenem and cefepime against a subset of these phenotypically diverse isolates. Ninety-five Gram-negative isolates were studied. Efficacy was determined as the change in log10 CFU at 24 h compared with 0-h controls. Bacterial stasis or ≥1 log reduction in 67 isolates with MICs of ≤4 μg/ml was noted in 77, 88, and 85% of Enterobacteriaceae, Acinetobacter baumannii, and Pseudomonas aeruginosa, respectively. For isolates with MICs of ≥8 μg/ml, bacterial stasis or ≥1 log10 reduction was observed in only 2 of 28 (8 Enterobacteriaceae, 19 A. baumannii, and 1 P. aeruginosa) strains. Against highly resistant meropenem and cefepime organisms, cefiderocol maintained its in vivo efficacy. Overall, humanized exposures of cefiderocol produced similar reductions in bacterial density for organisms with MICs of ≤4 μg/ml, whereas isolates with MICs of ≥8 μg/ml generally displayed bacterial growth in the presence of the compound. Data derived in the current study will assist with the delineation of MIC susceptibility breakpoints for cefiderocol against these important nosocomial Gram-negative pathogens; however, additional clinical data are required to substantiate these observations.

In vitro and in silico evaluation of some plant extracts and phytocompounds against multidrug-resistant Gram-negative bacteria

2021 ◽  
Author(s):  
Eda Aydemir ◽  
Emrah Sarıyer ◽  
Esma Akyıldız ◽  
Azer Özad Düzgün ◽  
Yasemin Camadan ◽  
...  
Keyword(s):  
Plant Extracts ◽  
In Silico ◽  
Multidrug Resistant ◽  
Gram Negative Bacteria ◽  
Gram Negative
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