scholarly journals Steroid Derivatives as Potential Antimicrobial Agents against Staphylococcus aureus Planktonic Cells

2020 ◽  
Vol 8 (4) ◽  
pp. 468 ◽  
Author(s):  
Adriana Vollaro ◽  
Anna Esposito ◽  
Eleni Antonaki ◽  
Vita Dora Iula ◽  
Daniele D’Alonzo ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Antibacterial Activity ◽  
Protein C ◽  
Antimicrobial Agents ◽  
Antimicrobial Effect ◽  
Staphylococcal Enterotoxin A ◽  
Planktonic Cells ◽  
Enterococcus Spp ◽  
Fibronectin Binding Protein ◽  
Dose Dependent

In this work, the antibacterial activity of deflazacort and several of its synthetic precursors was tested against a panel of bacterial pathogens responsible for most drug-resistant infections including Staphylococcus aureus, Enterococcus spp., Acinetobacter baumannii, Pseudomonas aeruginosa, Klebsiella pneumoniae, Escherichia coli, and Enterobacter spp. The derivative of deflazacort, PYED-1 (pregnadiene-11-hydroxy-16α,17α-epoxy-3,20-dione-1) showed the best antibacterial activity in a dose-dependent way. We focused on the action of PYED-1 against S. aureus cells. PYED-1 exhibited an additive antimicrobial effect with gentamicin and oxacillin against the methicillin-resistant S. aureus isolate 00717. In addition to its antimicrobial effect, PYED-1 was found to repress the expression of several virulence factors of S. aureus, including toxins encoded by the hla (alpha-haemolysin), hlb (beta-haemolysin), lukE-D (leucotoxins E-D), and sea (staphylococcal enterotoxin A) genes, and cell surface factors (fnbB (fibronectin-binding protein B) and capC (capsule biosynthesis protein C)). The expression levels of autolysin isaA (immunodominant staphylococcal antigen) were also increased.

UJI AKTIVITAS ANTIBAKTERI EKSTRAK ETANOL DAUN MEKAI (Pycnarrhena cauliflora DIELS.) TERHADAP Staphylococcus aureus

2020 ◽  
Vol 6 (2) ◽  
pp. 246
Author(s):  
Yayuk Bulam Sarifati ◽  
Sjarif Ismail ◽  
Khemasili Kosala
Keyword(s):  
Staphylococcus Aureus ◽  
Antibacterial Activity ◽  
Antimicrobial Agents ◽  
Statistical Tests ◽  
Ethanol Extract ◽  
Inhibition Zone ◽  
Positive Control ◽  
Negative Control ◽  
Control Measurement ◽  
Eye Pain

Mekai leaves (Pycnarrhena cauliflora Diels.) (P. cauliflora). Are known to contain flavonoid compounds, tannins and phenolics that act as antibacterial agents and are used in the treatment of eye pain. Staphylococcus aureus (S. aureus) is one of the examples of bacterial diseases of eye pain and also a major cause of many infections in communities and health facilities with cases of resistance to various antimicrobial agents. The purpose of this study was to prove the antibacterial activity of mekai leaves ethanol extract against S. aureus bacteria. This research is an experimental research. The stages of this research began by extracting mekai leaves using maceration method with 96% ethanol solvent. Antibacterial activity was tested by the disc method (Kirby-Bauer) using ethanol extract concentrations of mekai leaves (EPC) 20%, 30%, 40%, 50%, 60%, 70%, and 80%, positive control using 25 μg amoxicillin and negative control using DMSO 10%. The measurement results of inhibition zones of mekai leaf ethanol extract 20%, 30%, 40%, 50%, 60%, 70% and 80% respectively were 8.32 mm, 8.32 mm, 8.32 mm, 8.67 mm, 9.00 mm, 8.67 mm, and 8.33 mm. While the positive control measurement of 25 μg amoxicillin against S. aureus is 28.67 mm and the measurement of 10% negative DMSO control does not produce inhibitory zones, so it can be concluded that the ethanol extract of mekai leaves has antibacterial activity, but the area of ​​inhibition zone produced is smaller than amoxicillin 25 µg. The results of statistical tests using Mann Whitney between negative controls with all EPC concentrations obtained significant differences with p values ​​<0.05, it can be concluded that there is antibacterial activity produced at all EPC concentrations.

scholarly journals Isolation of Enterococcus Species from Food Sources and Its Antibacterial Activity against Staphylococcus Aureus

2020 ◽  
pp. 3164-3171
Author(s):  
Andalus S. Atiyah ◽  
Marwa H. Alkhafaji
Keyword(s):  
Staphylococcus Aureus ◽  
Antibacterial Activity ◽  
Dairy Products ◽  
Food Samples ◽  
Food Sources ◽  
Enterococcus Spp ◽  
Microbial Defense ◽  
Prevalent Species ◽  
Different Sources ◽  
By Products

The microbial production of substances that have the ability to inhibit the growth of other microorganisms is possibly the most common defense strategy developed in nature. Microorganisms produce a variable collection of microbial defense systems, which include antibiotics, metabolic by-products, lytic agents, bacteriocins and others. The aim of the present study was to isolate and identify Enterococcus spp. and  its most prevalent species from food samples and determine its antibacterial activity against Staphylococcus aureus isolates. A total of 50 food samples from different sources (dairy products (20 samples) and vegetables and fish (15 samples each)) were collected from different local markets in Baghdad and cultured. Enterococcus spp were isolated from only 32 food samples. E. faecium was the most predominant species which was recovered from 20 samples (62.5 %), 10 dairies, 7 vegetables, and 2 fish. E. faecalis was found in 8 samples (25 %), 5 vegetables and 3 fish.  E. avium was recovered 6.25% as well as E. gallinarium (2 samples for each) Enterococcus avium were all isolated from dairy products but Enterococcus gallinarium one sample isolated from dairies and the other from fish. This study indicates the presence of Enterococcus spp. in the food samples and the ability of these bacteria to produce antibacterial substances which are active against closely related clinical isolates.

scholarly journals Analysis of aristolochlic acids and evaluation of antibacterial activity of Aristolochia clematitis L.

2019 ◽  
Vol 70 (4) ◽  
pp. 323-329 ◽  
Author(s):  
Gergely Sámuel Bartha ◽  
Gergő Tóth ◽  
Péter Horváth ◽  
Eszter Kiss ◽  
Nóra Papp ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Antimicrobial Activity ◽  
Antibacterial Activity ◽  
High Performance Liquid Chromatography ◽  
High Performance ◽  
Antimicrobial Effect ◽  
Aristolochic Acids ◽  
Microdilution Method ◽  
Stem Leaf ◽  
Ethyl Acetate Extracts

Introduction Several Aristolochia species were used as medicinal herb across Europe and in recent years, their antimicrobial activity has also been investigated. Materials and methods In this study, A. clematitis was selected to evaluate the aristolochic acids I and II (AA I and AA II) concentrations and the antimicrobial activity of methanol, hexane, butanol, and ethyl acetate extracts of the root, stem, leaf, root, and fruit. AA I and AA II contents were measured by a validated high-performance liquid chromatography–ultraviolet method. Results Each fraction of the plant contained AA I and AA II and the root was found to have the highest contents of AA I (1.09%) and AA II (0.7454%). The minimum inhibitory concentrations of all extracts were determined by standard microdilution method. The fruit’s extracts showed the most efficient antimicrobial effect against both methicillin sensitive and resistant Staphylococcus aureus strains. Conclusion Correlation between the AA I and AA II concentrations and the antimicrobial effect was not found.

scholarly journals Inhibition of Penicillinase by Epigallocatechin Gallate Resulting in Restoration of Antibacterial Activity of Penicillin against Penicillinase-Producing Staphylococcus aureus

2002 ◽  
Vol 46 (7) ◽  
pp. 2266-2268 ◽  
Author(s):  
Wei-Hua Zhao ◽  
Zhi-Qing Hu ◽  
Yukihiko Hara ◽  
Tadakatsu Shimamura
Keyword(s):  
Staphylococcus Aureus ◽  
Antibacterial Activity ◽  
Inhibitory Concentration ◽  
Epigallocatechin Gallate ◽  
Clinical Isolates ◽  
Main Constituent ◽  
Tea Catechins ◽  
Dose Dependent Fashion ◽  
Dose Dependent

ABSTRACT The combination of epigallocatechin gallate (EGCg, a main constituent of tea catechins) with penicillin showed synergism against 21 clinical isolates of penicillinase-producing Staphylococcus aureus. Besides binding directly to peptidoglycan, the inhibition of penicillinase activity by EGCg is responsible for the synergism. EGCg inhibited the penicillinase activity in a dose-dependent fashion, with a 50% inhibitory concentration of 10 μg/ml.

Note. Pollen Analysis and Antibacterial Activity of Spanish Honeys

2001 ◽  
Vol 7 (2) ◽  
pp. 155-158 ◽  
Author(s):  
M. Garcia ◽  
C. Perez-Arquillue ◽  
T. Juan ◽  
M. I. Juan ◽  
A. Herrera
Keyword(s):  
Staphylococcus Aureus ◽  
Antibacterial Activity ◽  
Pollen Analysis ◽  
Inhibitory Activity ◽  
Antimicrobial Agents ◽  
Botanical Origin ◽  
Free Acidity ◽  
Normal Range ◽  
Resistant Microorganism ◽  
Inhibition Ability

Antibacterial activity of twenty-five samples of honey from different botanical origin was evaluated. Staphylococcus aureus ATCC 25923 was used as the resistant microorganism. Pollen analysis revealed different botanical origins: Labiatae, rosemary, eucalyptus, heather and multifloral. The pH and acidity values were in the normal range, except for four samples that showed acidity values over 40 meq/kg, but none exhibited a state of fermentation. We have not found correlation between antibacterial activity and free acidity in the samples. Labiatae and rosemary honeys have exhibited the largest inhibition against Staphylococcus aureus ATCC, conversely to heather honeys, which showed lowest inhibition ability against this microorganism. Our results may indicate the presence of antimicrobial agents in Labiatae and rosemary honeys that have inhibited the growth of Staphylococcus aureus ATCC. Likewise, the free acids of heather honeys have not shown inhibitory activity over this microorganism.

scholarly journals In VitroAntibacterial and Antifungal Activity of Salicylanilide Benzoates

2012 ◽  
Vol 2012 ◽  
pp. 1-7 ◽  
Author(s):  
Martin Krátký ◽  
Jarmila Vinšová ◽  
Vladimír Buchta
Keyword(s):  
Staphylococcus Aureus ◽  
Antibacterial Activity ◽  
Antifungal Activity ◽  
Benzoic Acid ◽  
Antimicrobial Agents ◽  
Bacterial Species ◽  
Phenyl Benzoate ◽  
Methicillin Resistant ◽  
Micromolar Range

The resistance to antimicrobial agents brings a need of novel antimicrobial agents. We have synthesized and found thein vitroantibacterial activity of salicylanilide esters with benzoic acid (2-(phenylcarbamoyl)phenyl benzoates) in micromolar range. They were evaluatedin vitrofor the activity against eight fungal and eight bacterial species. All derivatives showed a significant antibacterial activity against Gram-positive strains with minimum inhibitory concentrations ≥0.98 μmol/L including methicillin-resistantStaphylococcus aureusstrain. The most active compounds were 5-chloro-2-(3,4-dichlorophenylcarbamoyl)phenyl benzoate and 4-chloro-2-(4-(trifluoromethyl)phenylcarbamoyl)phenyl benzoate. The antifungal activity is significantly lower.

Comparative Study of the Antimicrobial Effect of Different Antibiotics Mixed with CuO, MgO and ZnO Nanoparticles in Staphylococcus aureus, Pseudomonas aeruginosa and Escherichia coli cultures

2014 ◽  
Vol 1675 ◽  
pp. 59-64
Author(s):  
Raúl Alenó ◽  
Anthony López Collazo ◽  
Eulalia Medina ◽  
Lourdes Díaz Figueroa ◽  
José I. Ramírez ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Staphylococcus Aureus ◽  
Pseudomonas Aeruginosa ◽  
Cell Death ◽  
Optical Properties ◽  
Antibacterial Agents ◽  
Antimicrobial Agents ◽  
Antimicrobial Effect ◽  
Antibacterial Effects ◽  
New Methods

ABSTRACTDue to the rapid advance of the emergence of resistant microorganisms to different antibiotics, there is a need to create new antimicrobial agents. It is possible that Nanotechnology has a great impact in this area since the nanoparticles can improve the antimicrobial effect of the antibiotics. In this study we used three different metal oxides nanoparticles, the MgO, ZnO and CuO. These nanoparticles were selected because their interactions leading to cell death and their optical properties. The aim of this study is to develop new methods that are more effective against resistance bacteria, developing antibacterial agents using different nanoparticles against Escherichia coli (ATCC 10536), Pseudomonas aeruginosa (ATCC 10145), and Staphylococcus aureus (ATCC BAA-1026). This study was conducted to evaluate the antibacterial effects of a combination of nanoparticles together with different concentrations of three antibiotics, Gentamicin, Cephalexin and Co-Trimoxazole. The results showed that some nanoparticles are effective to inhibit growth in these microorganisms by increasing the effectiveness of the antibiotic. Therefore, the present study indicates that the combination of the nanoparticles with antibiotics may be applicable as a new antimicrobial agent.

Synthesis Ruthenium complexes Functionalized with Benzothiophene and their Antibacterial activity against Staphylococcus aureus

2021 ◽  
Author(s):  
Xiangwen Liao ◽  
lianghong liu ◽  
yanhui Tan ◽  
guijuan jiang ◽  
haihong fang ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Antibacterial Activity ◽  
Mode Of Action ◽  
Antimicrobial Agents ◽  
Ruthenium Complexes ◽  
Resistant Bacteria ◽  
Drug Resistant ◽  
Drug Resistant Bacteria

New effective antimicrobial agents with novel mode of action are urgently need due to the continued emergence of drug-resistant bacteria. Here, three ruthenium complexes functionalized with benzothiophene: [Ru(phen)2(BTPIP)](ClO4)2 (Ru(II)-1), [Ru(dmp)2(BTPIP)](ClO4)2...

scholarly journals Assessment of Antimicrobial Effect of Alcohol and Aqueous Extracts of Garcinia kola on Staphylococcus aureus, Bacillus cereus, Escherichia coli and Klebsiella pneumonia

2020 ◽  
Vol 24 (9) ◽  
pp. 1519-1522
Author(s):  
A. Banso ◽  
B.F. Banso ◽  
A.A. Koleola
Keyword(s):  
Escherichia Coli ◽  
Staphylococcus Aureus ◽  
Bacillus Cereus ◽  
Plant Extracts ◽  
Antimicrobial Agents ◽  
Antimicrobial Effect ◽  
Inhibitory Effect ◽  
Klebsiella Pneumonia ◽  
Garcinia Kola ◽  
Development Of Resistance

As a result of the development of resistance of microorganisms to older antimicrobial agents there is need for a search for new agents, which are effective for the treatment of infections. The crude aqueous and alcoholic extr acts of Garcinia kola fruits were assayed against Staphylococcus aureus, Bacillus cereus, Escherichia coli and Klebsiella pneumoniae. The results revealed that the plant extracts possess inhibitory effect against the microorganisms tested. The minimum inhibitory concentration of the plant extracts ranged between 20mg/ml and 45mg/ml. There was a change in the antibacterial activity of the test extracts on variation of temperature. The results obtained may suggest that the plant extract is thermal stable and could serve as a source of industrial drugs useful in chemotherapy of some microbial infections. Keywords: Garcinia kola, microorganisms, inhibitory, chemotherapy, drug

scholarly journals Antibacterial activities of extracts from twelve Centaurea species from Turkey

2011 ◽  
Vol 63 (3) ◽  
pp. 685-690 ◽  
Author(s):  
Yener Tekeli ◽  
Gokhan Zengin ◽  
Abdurrahman Aktumsek ◽  
Mehmet Sezgin ◽  
Emrah Torlak
Keyword(s):  
Escherichia Coli ◽  
Staphylococcus Aureus ◽  
Antibacterial Activity ◽  
Bacillus Cereus ◽  
Salmonella Enteritidis ◽  
Antimicrobial Effect ◽  
Antibacterial Activities ◽  
Methanol Extracts ◽  
Microdilution Method ◽  
Based Medicine

Members of the genus Centaurea (Asteraceae) have been used in traditional plant-based medicine. The methanol extracts of twelve Centaurea species, of which five are endemic to Turkey flora, were screened for antibacterial activity against four bacteria (Escherichia coli, Bacillus cereus, Salmonella enteritidis, Staphylococcus aureus). The antibacterial activity was evaluated by the microdilution method and the minimum inhibition concentrations (MIC) of the extracts were determined. C. cariensis subsp. microlepis exhibited an antimicrobial effect on all tested microorganisms. The extracts from eight Centaurea species (C. balsamita, C. calolepis, C. cariensis subsp. maculiceps, C. cariensis subsp. microlepis, C. kotschyi var. kotschyi, C. solstitialis subsp. solstitialis, C. urvillei subsp. urvillei and C. virgata) possessed antibacterial activity against several of the tested microorganisms.

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