scholarly journals A Pilot Study of the Synergy between Two Antimicrobial Peptides and Two Common Antibiotics

Antibiotics ◽  
2019 ◽  
Vol 8 (2) ◽  
pp. 60 ◽  
Author(s):  
Franziska Kampshoff ◽  
Mark D. P. Willcox ◽  
Debarun Dutta
Keyword(s):  
Staphylococcus Aureus ◽  
Antibacterial Agents ◽  
Inhibitory Concentration ◽  
Synergistic Activity ◽  
Fractional Inhibitory Concentration ◽  
First Line ◽  
Checkerboard Assay ◽  
Resistant Strains ◽  
And Staphylococcus Aureus ◽  
Broth Dilution

Background: Frequent and unrestricted use of antibiotics has been associated with the development of antibiotic resistance by microorganisms. Thus, there is a need to find novel antibacterial agents or a combination of agents as the first line of treatment for various infections. This study aimed to investigate the synergy between antimicrobial peptide (AMP) combinations or between AMP-antibiotics combinations using two common pathogens, Pseudomonas aeruginosa and Staphylococcus aureus. Methods: The AMPs melimine, Mel4 and protamine, and antibiotics cefepime and ciprofloxacin were used in this study. The minimum inhibitory concentration (MIC) of each were evaluated against P. aeruginosa and S. aureus strains by a microtiter broth dilution. Based on the MIC of each antimicrobial agent, a checkerboard assay was performed to investigate the synergy between them, which was expressed as the fractional inhibitory concentration (FIC). Results: The combination of melimine and ciprofloxacin showed synergistic activity against antibiotic sensitive or resistant strains of P. aeruginosa and with FIC values ≤0.5. Conclusion: Combinations of AMPs and the fluoroquinolone ciprofloxacin is a promising method for reducing resistance to the fluoroquinolone of P. aeruginosa.

scholarly journals The Synergy and Mode of Action of Cyperus rotundus L. Extract Plus Ampicillin against Ampicillin-Resistant Staphylococcus aureus

2018 ◽  
Vol 2018 ◽  
pp. 1-11 ◽  
Author(s):  
Prairadda Cheypratub ◽  
Wilairat Leeanansaksiri ◽  
Griangsak Eumkeb
Keyword(s):  
Staphylococcus Aureus ◽  
Concentration Index ◽  
Inhibitory Concentration ◽  
Cytoplasmic Membrane ◽  
Chemical Compounds ◽  
Cyperus Rotundus ◽  
Synergistic Activity ◽  
Electron Microscopic ◽  
Average Cell ◽  
Checkerboard Assay

Cyperus rotundus L. has been used for pharmaceutical applications including antibacterial infections. Nevertheless, there is still no data regarding the mode of actions. This study aimed to determine the antibacterial activity and mode of actions of Cyperus rotundus extract (CRE) against ampicillin-resistant Staphylococcus aureus (ARSA) which poses a serious problem for hospitalized patients. The majority of chemical compounds of CRE were flavonoids and alkaloids. The minimum inhibitory concentrations (MICs) for ampicillin and CRE against all ARSA strains were 64 μg/ml and 0.5 mg/ml, respectively. Checkerboard assay revealed synergistic activity in the combination of ampicillin and CRE at the lowest fractional inhibitory concentration index (FICI) at 0.27. The killing curve assay had confirmed the synergistic and bactericidal activity of the combination against ARSA. Electron microscopic results showed that these ARSA cells treated with this combination caused peptidoglycan and cytoplasmic membrane (CM) damage and average cell areas significantly smaller than control. Also, this combination caused an increase in CM permeability of ARSA. CRE revealed the inhibitory activity against β-lactamase. It is normally known that some drugs are derived from flavonoids or alkaloids. So, this CRE proposes the potential to develop a novel adjunct phytopharmaceutical to ampicillin for the remedy of ARSA.

scholarly journals In VitroAntistaphylococcal Effects ofEmbelia schimperiExtracts and Their Component Embelin with Oxacillin and Tetracycline

2015 ◽  
Vol 2015 ◽  
pp. 1-7 ◽  
Author(s):  
Johana Rondevaldova ◽  
Olga Leuner ◽  
Alemtshay Teka ◽  
Ermias Lulekal ◽  
Jaroslav Havlik ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Medicinal Plants ◽  
Bacterial Infections ◽  
Inhibitory Concentration ◽  
Developed Countries ◽  
Positive Interactions ◽  
Fractional Inhibitory Concentration ◽  
Broth Microdilution ◽  
Microdilution Method ◽  
Broth Microdilution Method

Bacterial infections are in less-developed countries traditionally treated by remedies prepared from medicinal plants.Embelia schimperi(Vatke) is a plant used as a taenicide or disinfectant in Ethiopia, very often taken mixed with another plant species. In the present study, we examined two extracts prepared from seeds and twigs with leaves ofE. schimperiand its main present secondary metabolite embelin for their antibacterial combinatory effect with oxacillin and tetracycline against sensitive and resistantStaphylococcus aureusstrains. Minimum inhibitory concentrations were determined through the broth microdilution method, whereas the combinatory effect was evaluated through fractional inhibitory concentration sum (ΣFIC) indices. Results show many positive interactions and synergy occurring in embelin and oxacillin combinations against 4 out of 9 strains (ΣFIC 0.203–0.477) and for embelin and tetracycline combination against 3 out of 9 strains (ΣFIC 0.400–0.496). Moreover, the resistance to oxacillin has been overcome in 2 strains and to tetracycline in 3 strains. According to our knowledge, this is the first study showing antimicrobial combinatory effect ofE. schimperias well as of embelin. These findings can be used for the further research targeted on the development of new antistaphylococcal agents.

scholarly journals Effect the combination of antibiotics on clinical isolates of Staphylococcus aureus

2009 ◽  
Vol 6 (4) ◽  
pp. 683-692
Author(s):  
Baghdad Science Journal
Keyword(s):  
Staphylococcus Aureus ◽  
Concentration Index ◽  
Inhibitory Concentration ◽  
Morphological Characterization ◽  
Penicillin G ◽  
Clinical Samples ◽  
Fractional Inhibitory Concentration ◽  
Fractional Inhibitory Concentration Index ◽  
Lactam Antibiotic ◽  
Susceptibility Tests

Atotal of 75 different clinical samples were collected from different hospitals in Baghdad Biochemical and morphological characterization tests showed that forty isolates were identified as Staphylococcus aureus Antibiotic susceptibility tests of all isolates towards ten antibiotics were carried out and results showed that many isolates (97.5 %) were resistant to ?-lactam antibiotic , 70 % were resistant to Tetracyclinee , 62.5% were resistant to co-trimoxazole , 60 % were resistant to ciprofloxacin , 55% were resistant both of chloramphenicol and erythromycin , 52.5% were resistant to gentamicin , 35% were resistant to rifampicin , 10% were resistant to vancomycin . According to the above results the S.aureus I1 which is isolated from patients with osteomyelitis showed resistant to all ten antibiotics therefore was used in the followed experiments. The minimum inhibitory concentration (MIC) of S.aureus I1 vancomycin, cefotaxim , penicillin G, amoxicillin , ciprofloxacin , co-trimoxazole ,gentamicin, rifampicin was checked.The results showed that isolates had MIC between (390-12500) ?g/ml. The combination of different antibiotics with vancomycin showed synergistic effect based on the Fractional inhibitory concentration index (FIC).

scholarly journals Antipneumococcal activities of cefpirome and cefotaxime, alone and in combination with vancomycin and teicoplanin, determined by checkerboard and time-kill methods.

1996 ◽  
Vol 40 (9) ◽  
pp. 1973-1976 ◽  
Author(s):  
S Bajaksouzian ◽  
M A Visalli ◽  
M R Jacobs ◽  
P C Appelbaum
Keyword(s):  
Inhibitory Concentration ◽  
Fractional Inhibitory Concentration ◽  
Beta Lactams ◽  
Pneumococcal Infections ◽  
Titration Method ◽  
Resistant Strains ◽  
Time Kill ◽  
Checkerboard Titration

The checkerboard titration method was used to test the synergy of cefpirome and cefotaxime with teicoplanin or vancomycin against 35 penicillin-susceptible, 34 penicillin-intermediate, and 31 penicillin-resistant pneumococci. The MICs at which 50 and 90% of isolates are inhibited (MIC50s and MIC90s, respectively) of both cefpirome and cefotaxime were 0.016 and 0.06 microgram/ml, respectively, for penicillin-susceptible strains and 0.125 and 0.5 microgram/ml, respectively, for penicillin-intermediate strains. The MIC50s and MIC90s of cefotaxime for penicillin-resistant strains were 1.0 and 2.0 micrograms/ml, respectively, and those of cefpirome were 0.5 and 1.0 microgram/ml, respectively. All pneumococci were inhibited by cefpirome at MICs of < or = 1.0 microgram/ml. The MIC50s and MIC90s of vancomycin and teicoplanin (0.25 and 0.25 microgram/ml and 0.03 and 0.03 microgram/ml, respectively) did not differ for the three groups. Checkerboard synergy studies showed that cefpirome and vancomycin showed synergy for 31 strains (fractional inhibitory concentration [FIC] indices, < or = 0.5) cefpirome and teicoplanin showed synergy for 18 strains, cefotaxime and vancomycin showed synergy for 51 strains, and cefotaxime and teicoplanin showed synergy for 27 strains. Cefpirome and vancomycin had FIC indices indicating indifference (2.0) for two strains, and cefotaxime and vancomycin had FIC indices indicating indifference for one strain. All other FIC indices indicating indifference or additivity were > 0.5 to 1.0. No FIC indices indicating antagonism (> 4.0) were found. Synergy between beta-lactams and glycopeptides for three susceptible, three intermediate, and three resistant strains were tested by the time-kill assay, and all combinations were synergistic by this method. Synergy between cephalosporins and glycopeptides can be demonstrated and may be useful for the treatment of pneumococcal infections, especially meningitis.

scholarly journals Antibacterial Activity of Geraniol in Combination with Standard Antibiotics against Staphylococcus aureus, Escherichia coli and Helicobacter pylori

2018 ◽  
Vol 13 (7) ◽  
pp. 1934578X1801300 ◽  
Author(s):  
Subrat Kumar Bhattamisra ◽  
Chew Hui Kuean ◽  
Lee Boon Chieh ◽  
Vivian Lee Yean Yan ◽  
Chin Koh Lee ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Staphylococcus Aureus ◽  
Helicobacter Pylori ◽  
Antibacterial Activity ◽  
Synergistic Effect ◽  
Inhibitory Concentration ◽  
Therapeutic Potential ◽  
E Coli ◽  
Checkerboard Assay ◽  
H Pylori

The antibacterial activity of geraniol and its effect in combination with ampicillin, amoxicillin and clarithromycin against Staphylococcus aureus, Escherichia coli and Helicobacter pylori was tested. The minimum inhibitory concentrations (MICs) and combinatory effects of geraniol against the bacteria were assessed by using the modified broth microdilution and checkerboard assay, respectively. The combinatory effect is expressed as fractional inhibitory concentration index (FICI). The MIC of geraniol against S. aureus, E. coli and H. pylori was found to be 11200, 5600, and 7325 μg/mL, respectively. A significant synergistic effect was observed with geraniol and ampicillin against S. aureus with FICI in the range 0.19 to 0.32. Geraniol and ampicillin exhibited a partial synergistic effect against E. coli. A similar effect was observed with geraniol and clarithromycin against S. aureus. A partial synergistic effect was observed with clarithromycin and geraniol against H. pylori with the FICI value in the range 0.86 to 0.89. An additive effect was observed with geraniol and amoxicillin combination against H. pylori. However, the amoxicillin and clarithromycin dose was reduced by thirty-two fold when combined with geraniol against H. pylori. The anti- H. pylori effect of geraniol with clarithromycin and amoxicillin could be of potential interest in the treatment of H. pylori infection and associated ulcers in humans. Further, geraniol, in combination with other antibiotics, has substantial therapeutic potential against S. aureus and E.coli infection.

scholarly journals Antibacterial Activity of 2-(3’,5'-Dibromo-2'-methoxyphenoxy)-3,5-dibromophenol Isolated from Phyllospongia papyracea

2017 ◽  
Vol 12 (4) ◽  
pp. 1934578X1701200 ◽  
Author(s):  
Shi Sun ◽  
Corene Canning ◽  
Kuiwu Wang ◽  
Wenjun Zhu ◽  
Fei Yang ◽  
...  
Keyword(s):  
Antibacterial Agents ◽  
Inhibitory Concentration ◽  
Methanol Extract ◽  
Minimal Bactericidal Concentration ◽  
Antimicrobial Compound ◽  
Highly Active ◽  
Microdilution Method ◽  
Broth Microdilution Method ◽  
Bioassay Guided Fractionation ◽  
And Staphylococcus Aureus

A principal active antimicrobial compound, 2-(3’,5'-dibromo-2'-methoxyphenoxy)-3,5-dibromophenol, was isolated from the methanol extract of Phyllospongia papyracea via bioassay-guided fractionation and isolation. The crude extract and the purified compound were assayed to determine the minimal inhibitory concentration and minimal bactericidal concentration (MBC) using the broth microdilution method. The purified compound was found to be highly active against Bacillus subtilis and Staphylococcus aureus at MIC=1 μg/mL, Campylobacter jejuni at MIC=2 μg/mL, Pseudomonas aeruginosa at MIC=4 μg/mL, and Streptococcus pneumoniae and Listeria monocytogenes at MIC = 8 μg/mL. The activity of this compound was found to be comparable with antibiotics commonly used to control these species of bacteria. The results establish 2-(3’,5'-dibromo-2'-methoxyphenoxy)-3,5-dibromophenol as a potential lead molecule for the development of antibacterial agents.

scholarly journals Combinations of Lysostaphin with β-Lactams Are Synergistic against Oxacillin-Resistant Staphylococcus epidermidis

2002 ◽  
Vol 46 (6) ◽  
pp. 2017-2020 ◽  
Author(s):  
Nandini Kiri ◽  
Gordon Archer ◽  
Michael W. Climo
Keyword(s):  
Staphylococcus Aureus ◽  
Aortic Valve ◽  
Staphylococcus Epidermidis ◽  
Concentration Index ◽  
Inhibitory Concentration ◽  
Rabbit Model ◽  
Fractional Inhibitory Concentration ◽  
Fractional Inhibitory Concentration Index ◽  
Synergy Testing ◽  
Better Than

ABSTRACT Oxacillin-resistant Staphylococcus aureus is rapidly killed by the endopeptidase lysostaphin, and the addition of β-lactam antibiotics provides synergistic killing. We investigated the possibility that β-lactams given in combination with lysostaphin would improve the activity of lysostaphin against oxacillin-resistant Staphylococcus epidermidis (ORSE), which is normally less susceptible to lysostaphin. Checkerboard synergy testing was performed for lysostaphin given in combination with oxacillin against 10 ORSE isolates for which the lysostaphin MICs were ≥ 8 μg/ml. The fractional inhibitory concentration index ranged from 0.0234 to 0.2656, indicating synergy, which was confirmed in growth curve experiments. In the rabbit model of experimental aortic valve endocarditis using an ORSE strain, the combination of lysostaphin and nafcillin was as effective as vancomycin alone and significantly better than lysostaphin or nafcillin alone. We conclude that β-lactam antibiotics given in combination with lysostaphin are synergistic against many strains of ORSE.

scholarly journals The Search for New Antibacterial Agents among 1,2,3-Triazole Functionalized Ciprofloxacin and Norfloxacin Hybrids: Synthesis, Docking Studies, and Biological Activity Evaluation

2021 ◽  
Vol 90 (1) ◽  
pp. 2
Author(s):  
Halyna Hryhoriv ◽  
Illia Mariutsa ◽  
Sergiy M. Kovalenko ◽  
Victoriya Georgiyants ◽  
Lina Perekhoda ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Staphylococcus Aureus ◽  
Biological Activity ◽  
Antibacterial Agents ◽  
Docking Studies ◽  
Synthetic Method ◽  
Bacillus Subtilis Atcc ◽  
Resistant Strains ◽  
Derivatives Of

Among all modern antibiotics, fluoroquinolones are well known for their broad spectrums of activity and efficiency toward microorganisms and viruses. However, antibiotic resistance is still a problem, which has encouraged medicinal chemists to modify the initial structures in order to combat resistant strains. Our current work is aimed at synthesizing novel hybrid derivatives of ciprofloxacin and norfloxacin and applying docking studies and biological activity evaluations in order to find active promising molecules. We succeeded in the development of a synthetic method towards 1,2,3-triazole-substituted ciprofloxacin and norfloxacin derivatives. The structure and purity of the obtained compounds were confirmed by 1H NMR, 13C NMR, 19F NMR, LC/MS, UV-, IR- spectroscopy. Docking studies, together with in vitro research against Staphylococcus aureus ATCC 25923, Escherichia coli ATCC 25922, Bacillus subtilis ATCC 6633, Pseudomonas aeruginosa ATCC 27853, Candida albicans NCTC 885-653 revealed compounds in which activity exceeded the initial molecules.

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