Determination of Synergistic effects of antibiotics and Zno NPs against isolated E. coli and A. baumannii bacterial strains from clinical samples

This study aimed to determine phytochemical contents, antibacterial properties, and antibiotic modulating potential of Punica granatum leaf extracts: hexane, chloroform, ethyl acetate, ethanol, and aqueous extracts as well as an extract enriched with total oligomer flavonoids (TOFs). The TOF extract contained the highest value of phenols and flavonoids. Rutin, luteolin, gallic acid, and ellagic acid were determined by HPLC analysis of this extract. The antibacterial activity was assayed by the disc diffusion method and microdilution method against Staphylococcus aureus and Escherichia coli standard ATCC strains and clinical isolates resistant strains. The TOF extract was the most active against all tested strains. The checkerboard method was used for the determination of synergy between two antibiotics (amoxicillin and cefotaxime) and P. granatum leaf extracts. The best synergistic interaction was found with TOF extract combined with amoxicillin for penicillin-resistant E. coli and penicillin-resistant S. aureus. These results can be assigned to tannins, flavonoids, and phenolic acids found in P. granatum leaf extracts. Pomegranate leaf extracts or active compounds isolated from these extracts could be used to fight the emergence and spread of resistant bacterial strains.

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Antimicrobial Peptides Display Strong Synergy with Vancomycin Against Vancomycin-Resistant E. faecium, S. aureus, and Wild-Type E. coli

International Journal of Molecular Sciences ◽

10.3390/ijms21134578 ◽

2020 ◽

Vol 21 (13) ◽

pp. 4578 ◽

Cited By ~ 3

Author(s):

Chih-Lung Wu ◽

Ju-Yun Hsueh ◽

Bak-Sau Yip ◽

Ya-Han Chih ◽

Kuang-Li Peng ◽

...

Keyword(s):

Antimicrobial Peptides ◽

Synergistic Effects ◽

Synergistic Activity ◽

Wild Type ◽

Bacterial Strains ◽

Antibiotic Resistant ◽

Minimal Inhibitory Concentrations ◽

E Coli ◽

Large Size ◽

Vancomycin Resistant

There is an urgent and imminent need to develop new antimicrobials to fight against antibiotic-resistant bacterial and fungal strains. In this study, a checkerboard method was used to evaluate the synergistic effects of the antimicrobial peptide P-113 and its bulky non-nature amino acid substituted derivatives with vancomycin against vancomycin-resistant Enterococcus faecium, Staphylococcus aureus, and wild-type Escherichia coli. Boron-dipyrro-methene (BODIPY) labeled vancomycin was used to characterize the interactions between the peptides, vancomycin, and bacterial strains. Moreover, neutralization of antibiotic-induced releasing of lipopolysaccharide (LPS) from E. coli by the peptides was obtained. Among these peptides, Bip-P-113 demonstrated the best minimal inhibitory concentrations (MICs), antibiotics synergism, bacterial membrane permeabilization, and supernatant LPS neutralizing activities against the bacteria studied. These results could help in developing antimicrobial peptides that have synergistic activity with large size glycopeptides such as vancomycin in therapeutic applications.

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Epilobi Hirsuti Herba Extracts Influence the In Vitro Activity of Common Antibiotics on Standard Bacteria

Open Chemistry ◽

10.1515/chem-2016-0004 ◽

2016 ◽

Vol 14 (1) ◽

pp. 65-75 ◽

Cited By ~ 1

Author(s):

Lucia Pirvu ◽

Isabela Nicorescu ◽

Cristina Hlevca ◽

Bujor Albu ◽

Valentin Nicorescu

Keyword(s):

Synergistic Effects ◽

Herbal Medicines ◽

Antimicrobial Properties ◽

Inhibition Zone ◽

In Vitro Activity ◽

Bacterial Strains ◽

Gram Negative ◽

E Coli ◽

Effective Source

AbstractEpilobium genus has been confirmed as an effective source of natural antimicrobials. However, the influence of Epilobi hirsuti herba derived products on usual antibiotics activity has not been studied. In this study, several standardized Epilobi hirsuti herba extracts (EHE) were evaluated in order to asses their potential effects on usual antibiotics tested on standard Gram-positive and Gram-negative bacterial strains in vitro. The results emphasized that the bacterial strains ranged from sensitive (MIC values between 50–200 μg GAE mL-1) (S. epidermidis ATCC 12228) to very resistant (E. coli strains), E. faecalis ATCC 29212 being practically immune to EHE. In terms of synergistic interaction, Tetracycline and Ampicillin combinations lead to the most important stimulatory effects, the diameters of the inhibition zone being even 60% bigger compared to the antibiotic alone. Synergistic effects between myricetin(galloyl) derivates and Tetracycline were also revealed on P. aeruginosa and E. coli strains. Together, it clearly demonstrated not only EHE’s own antimicrobial properties, but also their capacity to influence the antimicrobial potency of some common antibiotics. These results could be useful for the area of herbal medicines and as potential candidates in managing microbial resistance, but also for physicians and pharmacists using combined antibacterial therapy.

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Chemical Composition and Antibacterial Activity of Berries Essential Oil of Algerian Juniperus thurifera (Var. aurasiaca)

Pharmaceutical Sciences ◽

10.15171/ps.2018.35 ◽

2018 ◽

Vol 24 (3) ◽

pp. 240-245

Author(s):

Lamia Boudjedjou ◽

Messaoud Ramdani ◽

Azzeddine Zeraib ◽

Tarek Benmeddour ◽

Azzedine Fercha

Keyword(s):

Antibacterial Activity ◽

Chemical Composition ◽

Essential Oil ◽

Synergistic Effects ◽

Diffusion Method ◽

Bacterial Strains ◽

Juniperus Thurifera ◽

E Coli ◽

Conventional Antibiotics ◽

Promising Source

Background: Over the past decade, most antibiotic research programs have focused on finding new compounds with antimicrobial activity. This study aims to investigate the chemical composition and antibacterial activity of the essential oil (EO) extracted from ripe berries of Algerian Juniperus thurifera var. aurasiaca. Methods: The chemical composition of J. thurifera EO extracted by hydrodistillation was analyzed by using the GC-MS technique. Antibacterial activity of EO alone and in combination with three conventional antibiotics was assessed by using disc diffusion method against four bacterial strains. Results: Thirty-five components were identified, representing ~87 % of the oil. The main components were m-mentha-6,8-diene (15.43 %), β-pinene (10.59 %), elemol (8.31 %) and terpinene-4-ol (7.44 %). The essential oil showed strong antibacterial activity against S. aureus and E. coli, but no activity against P. aeruginosa and B. subtilis. Synergistic effects were observed because of the combined application of EO with gentamicin against all strains tested, and with amoxicillin against B. subtilis. Furthermore, the combination of EO/cefazolin demonstrated an additive effect against B. subtilis. In contrast, the combination of EO with amoxicillin and céfazoline revealed antagonistic effects against S. aureus, E. coli, and P. aeruginosa. Conclusion: This is the first report on the chemical composition and antibacterial activity of Algerian juniper berries’ essential oil. The results indicate that the studied EO may be a promising source of antibacterial compounds that could be useful for pharmaceutical applications especially in combination with conventional antibiotics.

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Antibacterial Activity of cLFchimera and its Synergistic Potential with Antibiotics against Some Foodborne Pathogens Bacteria

10.21203/rs.3.rs-31015/v1 ◽

2020 ◽

Author(s):

Sahar Roshanak ◽

Zana Pirkhezranian ◽

Fakhri Shahidi ◽

Mohammad hadi Sekhavati

Keyword(s):

Foodborne Pathogens ◽

Synergistic Effects ◽

Salmonella Typhi ◽

Synergistic Activity ◽

Bacterial Cells ◽

Bacterial Strains ◽

E Coli ◽

Viable Cells ◽

Electron Microscopy Analysis ◽

Microscopy Analysis

Abstract Background: Frequent and unlimited use of antibiotics caused the development of antibiotic resistance by microorganisms. Therefore, there is an argent need to discover novel antibacterial agents or a combination of agents as a safe treatment strategy for various infections. The aim of the present study was to evaluate the synergistic effects of cLFchimera, an antimicrobial peptides (AMPs), and antibiotics on several foodborne bacterial strains. Methods: A checkerboard method was used to determine the synergistic effects of cLFchimera and several antibiotics (Gentamicin, Cefazolin and Ceftazidime) on bacterial strains (Escherichia coli, Pseudomonas aeruginosa and Salmonella typhi). Results: The combination of cLFchimera and antibiotics generated a total and partial synergistic interaction for all foodborne bacterial strain used in the present study (FIC= 0.25 to 0.77). In most cases, the effect of peptide and antibiotic synergist on release of cellular content was not different compared to antibiotics when they used alone, but the count of viable cells significantly decreased in combination peptide and antibiotics treatments. Generally, antibacterial dynamics of the combination of peptide and antibiotics showed an increase and stable trend after reaching the peak point for E. coli, P. aeruginosa and S. typhi, respectively. Scanning electron microscopy analysis showed that bacterial cells treated with the combination Gentamycin and cLFchimera were markedly damaged, and most of the outermost layer of the bacterial cells disappeared. Conclusion: Overall, our results may suggest that cLFchimera mediated its synergistic activity independent to antibiotics mode of action by disrupting the cell membrane and intramolecular mechanisms.

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Comparison between Phenolic Content, Antioxidant and Antibacterial ac-tivity of Algerian and Turkish Propolis

Combinatorial Chemistry & High Throughput Screening ◽

10.2174/1386207323999201111193040 ◽

2020 ◽

Vol 23 ◽

Author(s):

Narimane Segueni ◽

Merve Keskin ◽

Şaban Keskin ◽

Benlabed Kadour ◽

Sevgi Kolaylı ◽

...

Keyword(s):

Phenolic Content ◽

Antibacterial Activities ◽

Total Phenolic ◽

Bacterial Strains ◽

Frap Assay ◽

Antioxidant Power ◽

E Coli ◽

Ferric Reducing Antioxidant Power ◽

Pharmaceutical Industries

Background:: Propolis is a natural resinous material produced by honeybees. Propolis biological activity and its phenolic profile were largely studied all over the world. However, only few investigations have been carried out on Algerian and Turkish propolis. The aim of the present study is to compare the phenolic content, antioxidant and antibacterial activity of propolis samples collected from different localities of Algeria and Turkey. Methods:: Propolis extracts were performed using maceration in ethanol 80%. Total phenolic and flavonoid contents were determined. Antioxidant and antibacterial activities were evaluated using FRAP assay and the determination of MIC against four bacterial strains (S. aureus ATCC 25923, E. coli ATCC 25922, P. aeruginosa ATCC 27853 and K. pneumonia). Results:: TP varied from 19.51 ± 0.86 to 219.66 ± 1.23 mg GAE/g. Whereas, TF varied from 5.27± 0.07 to 74.57 ± 1.03 QE/g. All samples showed good ferric reducing antioxidant power ranging from 267.30 ± 4.77 to 2387.30 ± 44.15 μmol Trolox eq./g. All Algerian propolis samples displayed a more pronounced activity against S. aureus ATCC 25923 with MIC values ranging from 0,04 ± 0.00 mg/mL to 0.30±0.06 mg/mL with an activity 30 times more powerful than Anatolian propo-lis. While, Anatolian propolis samples were most active against P. aeruginosa ATCC 27853 with MIC values ranging from 0.20±0.00 mg/mL to 0.60±0.00 mg/mL with an activity 5 to 10 times more powerful than Algerian propolis. Conclusion:: Algerian and Anatolian propolis possessed considerable phenolic and flavonoids contents. In addition, they ex-hibited an interesting antioxidant and antibacterial activities. Our finding suggest that both propolis could be useful in food and pharmaceutical industries.

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Fabrication of green ZnO nanoparticles using walnut leaf extract to develop an antibacterial film based on polyethylene–starch–ZnO NPs

Green Processing and Synthesis ◽

10.1515/gps-2021-0011 ◽

2021 ◽

Vol 10 (1) ◽

pp. 112-124

Author(s):

Rouhina Saemi ◽

Elham Taghavi ◽

Hoda Jafarizadeh-Malmiri ◽

Navideh Anarjan

Keyword(s):

Reaction Time ◽

Leaf Extract ◽

Spherical Shape ◽

Thermoplastic Starch ◽

Bacterial Strains ◽

X Ray Diffraction ◽

Zno Nps ◽

E Coli ◽

Optimal Processing ◽

Microscopy Image

Abstract Zinc oxide nanoparticles (ZnO NPs) were synthesized utilizing prepared walnut leaf extract by various amounts of its leaves (5–25 g) via a heater and stirrer adjusted at 60°C and reaction time ranging from 30 to 90 min. Fourier transform infrared spectroscopy and gas chromatography indicated the six main functional groups and 29 bioactive compounds in the provided walnut leaf extract. Antioxidant and antibacterial inhibitory activities of the fabricated ZnO NPs, in powder form, were modeled as a function of two synthesized parameters using response surface methodology, and the fabrication process was optimized. The results indicated that the ZnO NPs synthesized using walnut leaf extract, with 15.51 g of its dried powder and reaction time of 60 min, had maximum antioxidant activity and antibacterial effects against Escherichia coli. X-ray diffraction analysis and scanning electron microscopy image indicated that the synthesized ZnO NPs using optimal processing conditions had crystals in triangular nanoprisms to nearly spherical shape with the particle size ranging from 15 to 40 nm. Finally, prepared biodegradable film composed of thermoplastic starch (5% w/w), polyethylene (93% w/w), and ZnO NPs (2% w/w) indicated high bactericidal inhibitory activity against both Gram-positive (Staphylococcus aureus) and Gram-negative (E. coli) bacterial strains.

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Carbapenemase production in hospital isolates of multidrug-resistant Klebsiella pneumoniae and Escherichia coli in Serbia

Vojnosanitetski pregled ◽

10.2298/vsp150917260t ◽

2017 ◽

Vol 74 (8) ◽

pp. 715-721 ◽

Cited By ~ 2

Author(s):

Anika Trudic ◽

Zora Jelesic ◽

Mira Mihajlovic-Ukropina ◽

Deana Medic ◽

Branka Zivlak ◽

...

Keyword(s):

Escherichia Coli ◽

Klebsiella Pneumoniae ◽

Carbapenem Resistance ◽

Multidrug Resistant ◽

Clinical Samples ◽

Reference Laboratory ◽

Bacterial Strains ◽

Beta Lactamases ◽

E Coli ◽

Novi Sad

Background/Aim. Carbapenem resistance has escalated in medically important enterobacteria such as Klebsiella pneumoniae and Escherichia coli worldwide. Multidrug-resistant strains represent an important source of concern as effective therapeutic options of infections they cause are limited or none. There were no comprehensive studies considering the presence of carbapenemase production in enterobacteria in Serbia so far. The aim of the study was to determine carbapenemase production in hospital isolates of multidrug-resistant K. pneumoniae and E. coli in Serbia. Methods. Strains of K. pneumoniae and E. coli resistant to at least one carbapenem (imipenem, meropenem, ertapenem) were collected from November 2013 to May 2014. Isolates were obtained from clinical samples of patients treated in 14 hospitals in Serbia. Carbapenem resistance was confirmed using phenotypic tests and polymerase chain reaction (PCR) in National Reference Laboratory for Registration and Surveillance of Antimicrobial Resistance of Bacterial Strains in Novi Sad. Results. Of 129 collected strains, 121 (93.8%) were K. pneumoniae and 8 (6.2%) were E. coli. Seventy (54.3%) strains were obtained from urine, 26 (20.2%) from blood, 19 (14.7%) from wound secretions and 14 (10.9%) from lower respiratory tract secretions. Carbapenemase genes were detected in 58 (45%) isolates. The gene bla New Delhimetallo-beta-lactamases (blaNDM) was found in 33 (27.3%) K. pneumoniae, bla oxacillinases-48 (blaOXA-48) in 10 (8.3%), bla K. pneumonia carbapenemase (blaKPC) in 1 (0.8%), and 7 (5.4%) strains harbored both blaOXA-48 and blaNDM. Seven E.coli harbored blaNDM gene. Conclusions. In Serbia, the most common type of carbapenemase in both multidrug-resistant K. pneumoniae and E. coli is NDM. Co-production of OXA-48 and NDM was found in K. pneumoniae. To our knowledge, KPC production was detected for the first time in Serbia.

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Modifying Plaque assay and Clearance test as tools in determination of phage typing for E. Coli bacterial interspecies

Baghdad Science Journal ◽

10.21123/bsj.10.1.161-167 ◽

2013 ◽

Vol 10 (1) ◽

pp. 161-167

Author(s):

Baghdad Science Journal

Keyword(s):

Plaque Assay ◽

High Specificity ◽

Inhibition Zone ◽

Phage Typing ◽

Sewage Sample ◽

Bacterial Strains ◽

E Coli ◽

Phage Strain ◽

Clearance Test

Bacteriophage of E. Coli interspecies from sewage samples were isolated , the phage particles were isolated from two different sewage samples . The first sample was collected from sewage sample of Baghdad university and the second sample was isolated from domestic sewage sample , first sample showed phages specialized for three E. Coli interspecies bacteria (first plate ) and two E. Coli interspecies bacteria (second plate ) , meanwhile second sample showed phage specialized for two E. Coli. interspeciesThe study of appearance of E coli phages from first sample showed three types of E. coli phages with different size of inhibition zone ( 1 , 0.7,0.5 )Cm respectively ( first plate ) , meanwhile E. Coli interspecies bacteria showed phages related with two interspecies with size of inhibition zone ( 0.5 ,0.4) Cm respectively ( second plate ), on other hand , the second sample showed also two interspecies E. coli with inhibition zone (1,0.8)Cm . experimental method has been designed which showed the modifying method of phage assay to determine phage typing assay . phage has been tested particles with different bacterial strains ( E. coli , shagilla and Serratia ) from different sources and the control was the host of each bacteriophages by taking the O.D for all the tests and controls , to setup new criteria for phage typing .:and this test is called ( Clearance Test ) The result showed that O.D for Test 1 , 2 , 3, was ( 1.6 , 1.2 . 1.7) for ( E. coli , shagilla and Serratia ) bacterial strains , meanwhile the control tests was ( 0.3 , 0.2, 0.4 ) for strains isolated from first sample (first and second plate ) and second samples with different interspecies respectively . This result can predict high specificity of phage strain and this method can be used to determine interspecies strains .So from this experiment we can identify only Clearance Test by measuring only O.D. of bacterial strain with different phages instead of going through plaque assay .

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Antibacterial activity of human defensins against Staphylococcus aureus and Escherichia coli

PeerJ ◽

10.7717/peerj.10455 ◽

2020 ◽

Vol 8 ◽

pp. e10455

Author(s):

Albert Bolatchiev

Keyword(s):

Escherichia Coli ◽

Staphylococcus Aureus ◽

Antibiotic Resistance ◽

Synergistic Effects ◽

Bacterial Strains ◽

E Coli ◽

Checkerboard Assay ◽

Conventional Antibiotics ◽

Human Defensins ◽

Methods Of Treatment

Background The global problem of antibiotic resistance requires the search for and development of new methods of treatment. One of the promising strategies is the use of low doses of antimicrobial peptides, in particular, human defensins HNP-1, hBD-1, and hBD-3, in combination with antibacterial drugs already used in clinical practice. This approach may be used to increase the effectiveness of conventional antibiotics. However, this requires thorough study of the effectiveness of defensins in combination with antibiotics against a large number of bacterial strains with known phenotypes of antibiotic resistance. The aim of this work was to study the antibacterial effect of HNP-1, hBD-1 and hBD-3 in combination with rifampicin or amikacin against clinical isolates of Staphylococcus aureus (n = 27) and Escherichia coli (n = 24) collected from hospitalized patients. Methods The standard checkerboard assay was used to determine minimum inhibitory concentrations (MICs) of antimicrobials. The combined microbicidal effects of two substances (defensin + conventional antibiotic) were assessed by the fractional inhibitory concentration index (FICI). Results The highest anti-staphylococcal activity (including methicillin-resistant strains) among defensins was demonstrated by hBD-3 that had MIC of 1 (0.5–4) mg/L (hereinafter, MIC values are presented as median and interquartile range). The MIC of HNP-1 against S. aureus was 4 (2–8) mg/L; the MIC of hBD-1 was 8 (4–8) mg/L. Against E. coli, the most effective was also found to be hBD-3 that had MIC of 4 (4–8) mg/L; the MIC of HNP-1 was 12 (4–32) mg/L. The combinations of HNP-1 + rifampicin and hBD-3 + rifampicin demonstrated synergistic effects against S. aureus. Against E. coli, combinations of HNP-1 + amikacin and hBD-3 + amikacin also showed synergy of action.

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