scholarly journals Tethering (Arene)Ru(II) Acylpyrazolones Decorated with Long Aliphatic Chains to Polystyrene Surfaces Provides Potent Antibacterial Plastics

Materials ◽  
2020 ◽  
Vol 13 (3) ◽  
pp. 526 ◽  
Author(s):  
Corrado Di Nicola ◽  
Fabio Marchetti ◽  
Riccardo Pettinari ◽  
Alessia Tombesi ◽  
Claudio Pettinari ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Self Assembly ◽  
Simple Procedure ◽  
13C Nmr Spectroscopy ◽  
Aliphatic Chain ◽  
1H And 13C Nmr ◽  
E Coli ◽  
Micellar Aggregates ◽  
Elemental Analyses ◽  
And Staphylococcus Aureus

The acylpyrazolone proligands HQR (HQR in general, in detail: HQCy = 1-phenyl-3-methyl-4-carbonylcyclohexyl-5-pyrazolone, 4-C(O)-phenyl, HQPh = 1-phenyl-3-methyl-4-benzoyl-5-pyrazolone, HQC17 = 1-phenyl-3-methyl-4-stearoyl-5-pyrazolone, HQC17,Ph = 1-phenyl-3-stearyl-4-benzoyl-5-pyrazolone) were synthesized and reacted with (arene)Ru(II) acceptors affording complexes [(arene)Ru(QR)Cl] (arene = cymene (cym) or hexamethylbenzene (hmb)). The complexes were characterized by elemental analyses, thermogravimetric analysis-Differntial Thermal Analysis (TGA-DTA), IR spectroscopy, ESI-MS and 1H, and 13C NMR spectroscopy. Complexes [(arene)Ru(QR)Cl] where QR = QC17 and QC17,Ph, due to the long aliphatic chain in the ligand, afford nanometric dispersions in methanol via self-assembly into micellar aggregates of dimensions 50–200 nm. The antibacterial activity of the complexes was established against Escherichia coli and Staphylococcus aureus, those containing the ligands with a long aliphatic chain being the most effective. The complexes were immobilized on polystyrene by a simple procedure, and the resulting composite materials showed to be very effective against E. coli and S. aureus.

scholarly journals Synthesis and Antibacterial Study of Aspirin-Chalcone Derivatives

1970 ◽  
Vol 3 (1) ◽  
pp. 52-57
Author(s):  
Zainab Ngaini ◽  
Doris Ho Ai Hui ◽  
Hasnain Hussain ◽  
Wan Sharifatun Handayani Wan Zulkiplee ◽  
Meng Guan Tay ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Antibacterial Activity ◽  
Nmr Spectroscopy ◽  
13C Nmr ◽  
13C Nmr Spectroscopy ◽  
Antibacterial Activities ◽  
1H And 13C Nmr ◽  
Antibacterial Study ◽  
E Coli ◽  
Chalcone Derivatives

The chemistry of aspirin and chalcone derivatives has been extensively studied and developed as one of thepharmaceutically important molecules. In this study, new aspirin-chalcone derivatives have been successfullysynthesized and characterized via FTIR, 1H and 13C NMR spectroscopy. The antibacterial activities ofsynthesized compounds were investigated towards Escherichia coli ATCC 8739 via turbidimetric kineticmethod. The newly synthesized aspirin-chalcone derivatives, however showed poor antibacterial activityagainst E. coli ATCC 8739 at the concentration of 50, 80 and 100 ppm. The effect of the molecular structureof the synthesized compounds on the antibacterial activity is discussed.

Comparison of the Effects of Silver in Nanostructured and Ultrahigh Diluted Form on Growth and Volatile Compounds Produced by Escherichia coli and Staphylococcus aureus

2020 ◽  
Vol 10 (3) ◽  
pp. 316-329
Author(s):  
Fateme Mirzajani ◽  
Amin Hamidi
Keyword(s):  
Escherichia Coli ◽  
Staphylococcus Aureus ◽  
Life Cycles ◽  
Gas Chromatography Mass Spectrometry ◽  
Untreated Sample ◽  
E Coli ◽  
Volatile Metabolites ◽  
Octyl Acetate ◽  
Volatile Organic ◽  
And Staphylococcus Aureus

Introduction: In this project, the growth and volatile metabolites profiles of Escherichia coli (E. coli ) and Staphylococcus aureus were monitored under the influence of silver base chemical, nanoparticle and ultra-highly diluted compounds. Materials & Methods: The treatments were done for 12000 life cycles using silver nanoparticles (AgNPs) as well as ultra-highly diluted Argentum nitricum (Arg-n). Volatile organic metabolites analysis was performed using gas chromatography mass spectrometry (GC-MS). The results indicated that AgNPs treatment made the bacteria resistant and adapted to growth in the nanoparticle condition. The use of ultra-highly diluted Arg-n initially increased growth but it decreased later. Also, with the continuous usage of these materials, no more bacterial growth was observed. Results: The most important compounds produced by E. coli are Acetophenone, Octyl acetate, Styrene, 1,8-cineole, 4-t-butyl-2-(1-methyl-2-nitroethyl)cyclohexane, hexadecane and 2-Undecanol. The main compounds derived from S. aureus are Acetophenone,1,8-cineole, Benzaldehyde, 2-Hexan-1-ol, Tridecanol, Dimethyl Octenal and tetradecane. Acetophenone and 1,8-cineole were common and produced by both organisms. Conclusion: Based on the origin of the produced volatiles, main volatiles percentage of untreated sample is hydrocarbon (>50%), while bacteria treatments convert the ratio in to aldehydes, ketones and alcohols in the case of AgNPs, (>80%) and aldehydes, ketones and terpenes in the case of Arg-n (>70%).

Antimicrobial Properties of Mono- and Di-fac-rhenium Tricarbonyl 2-Pyridyl-1,2,3-triazole Complexes

2016 ◽  
Vol 69 (5) ◽  
pp. 489 ◽  
Author(s):  
Sreedhar V. Kumar ◽  
Warrick K. C. Lo ◽  
Heather J. L. Brooks ◽  
Lyall R. Hanton ◽  
James D. Crowley
Keyword(s):  
Staphylococcus Aureus ◽  
Antimicrobial Properties ◽  
13C Nmr Spectroscopy ◽  
1H And 13C Nmr ◽  
X Ray Crystallography ◽  
The Family ◽  
Elemental Analyses ◽  
Solid State Structures ◽  
Rhenium Tricarbonyl

A family of mono- and di-fac-rhenium tricarbonyl 2-pyridyl-1,2,3-triazole complexes with different aliphatic and aromatic substituents was synthesized in good-to-excellent yields (46–99 %). The complexes were characterized by 1H and 13C NMR spectroscopy, infrared spectroscopy, electronic (UV-visible) spectroscopy, high-resolution electrospray mass spectrometry, and elemental analyses. In four examples, the solid-state structures of the rhenium(i) complexes were confirmed by X-ray crystallography. The family of the mono- and di-rhenium(i) complexes and the corresponding 2-pyridyl-1,2,3-triazole was tested for antimicrobial activity in vitro against both Gram-positive (Staphylococcus aureus) and Gram-negative (Escherichia coli) microorganisms. Agar-based disk diffusion assays indicated that most of the rhenium(i) complexes were active against Staphylococcus aureus and that the cationic rhenium(i) complexes were more active than the related neutral systems. However, in all cases, the minimum inhibitory concentrations for all the complexes were modest (i.e. 16–1024 µg mL–1).

Food Poisoning Potential of Artificially Contaminated Vacuum Packaged Sliced Ham in Sandwiches1

1981 ◽  
Vol 44 (6) ◽  
pp. 430-434 ◽  
Author(s):  
JAMES E. STEELE ◽  
MICHAEL E. STILES
Keyword(s):  
Escherichia Coli ◽  
Staphylococcus Aureus ◽  
Storage Temperature ◽  
Food Poisoning ◽  
Microbial Competition ◽  
Growth And Survival ◽  
E Coli ◽  
Enteropathogenic Bacteria ◽  
Test Conditions ◽  
And Staphylococcus Aureus

Ham sandwiches inoculated with a mixture of five enteropathogenic bacteria, Bacillus cereus, Clostridium perfringens. Escherichia coli, Salmonella typhimurium and Staphylococcus aureus, were held at 30, 21 and 4 C for up to 24 h. Food poisoning potential was judged by the growth and survival of the inoculated pathogens. Major differences were observed between new and old (30 days of storage at 4 C) ham samples. On new ham, all enteropathogens were able to grow except C. perfringens, whereas on old ham, with high microbial competition. the pathogens survived but did not grow. Severe storage temperature abuse was necessary to develop a food poisoning potential in new ham samples. The safety of old ham was attributed to the competitive microflora that grew in the ham during storage at 4 C for 30 days. Infective pathogens, E. coli and S. typhimurium, either survived or increased in numbers under all test conditions. The safety of vacuum packaged sliced ham for use in sandwiches, in its present market form, was indicated by these studies.

scholarly journals Ex vivo antibacterial properties of rufloxacin compared with those of norfloxacin in a study with healthy volunteers.

1996 ◽  
Vol 40 (1) ◽  
pp. 17-21 ◽  
Author(s):  
L Aguilar ◽  
I P Balcabao ◽  
P Salvá ◽  
M Martín ◽  
J Costa ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Clinical Trial ◽  
Ex Vivo ◽  
Antibacterial Properties ◽  
Adult Males ◽  
E Coli ◽  
Crossover Phase ◽  
Uncomplicated Cystitis ◽  
And Staphylococcus Aureus ◽  
Early Sample

Twelve adult males participated in a randomized crossover phase I clinical trial comparing serum bactericidal titers (SBTs), urine bactericidal titers (UBTs), and urine killing rates (UKRs) against Escherichia coli ATCC 25922 and Staphylococcus aureus ATCC 29213, after the administration of single 400-mg doses of rufloxacin and norfloxacin at different times up to 72 h postdose. SBTs were significantly higher (P < 0.05) against E. coli from 8 to 48 h and against S. aureus from 4 to 24 h with rufloxacin. UBTs for E. coli were higher (P < 0.05) for norfloxacin at early sample times (0 to 8 h) but higher for rufloxacin (P < 0.05) at sample times from 16 h on for both E. coli and S. aureus. Similar UKRs were obtained for both quinolones for 0 to 2 h and 8 to 12 h, but the UKR was maintained for 72 h with rufloxacin. The high and sustained mean levels of rufloxacin in urine (> 35 micrograms/ml), median UBTs (> 32 for E. coli and 16 for S. aureus) and UKRs for E. coli suggest prolonged urine antibacterial activity (for at least 72 h) and its use as a single 400-mg dose in the treatment of uncomplicated cystitis.

Fate of Pathogens Inoculated onto Vacuum-Packaged Sliced Hams to Simulate Contamination During Packaging1

1979 ◽  
Vol 42 (6) ◽  
pp. 464-469 ◽  
Author(s):  
M. E. STILES ◽  
L.-K. NG
Keyword(s):  
Escherichia Coli ◽  
Staphylococcus Aureus ◽  
Salmonella Typhimurium ◽  
Bacillus Cereus ◽  
Clostridium Perfringens ◽  
Subsequent Treatment ◽  
Vacuum Packaging ◽  
E Coli ◽  
Survival And Growth ◽  
And Staphylococcus Aureus

Ham and chopped ham from two manufacturers were contaminated with five enteropathogens: Bacillus cereus, Clostridium perfringens, Escherichia coli, Salmonella typhimurium and Staphylococcus aureus, at time of slicing and vacuum-packaging, to simulate contamination by manufacturer. Subsequent treatment of the samples, representing sound and undesirable retail handling and consumer use conditions, indicated marked differences in the fate of the pathogens between these products and within product type between the two manufacturers. Greatest differences were observed between the chopped ham products. All pathogens, except C. perfringens, grew actively in fresh ham and chopped ham with abusive holding at 30 and 21 C. After storage at 4 or 10 C for 30 days, B. cereus and C. perfringens were no longer detected, even after subsequent holding at 30 or 21 C for 24 h. E. coli survival and growth was variable, S. typhimurium survived well and grew under some conditions and S. aureus was generally inhibited at high levels of competition.

Sensitivity analysis of Escherichia coli and Staphylococcus aureus of mixed salad vegetables during washing step at packing house

2020 ◽  
Author(s):  
Sukhuntha Osiriphun ◽  
Phichaya Poonlarp ◽  
Danai Boonyakiat ◽  
Patcharin Raviyan
Keyword(s):  
Escherichia Coli ◽  
Staphylococcus Aureus ◽  
Sensitivity Analysis ◽  
Assessment Model ◽  
Health Food ◽  
E Coli ◽  
Global Trend ◽  
Washing Process ◽  
Fresh Cut ◽  
And Staphylococcus Aureus

Fresh cut vegetables are a source of minerals, vitamins, and phytonutrients that are convenient foods for consumers which are following the global trend of inclination toward health food. In terms of food safety, contamination of vegetables with microorganisms can occur at multiple points along the supply chain. This study was conducted to investigate the risk factors of Escherichia coli and Staphylococcus aureus which contaminate freshly cut vegetables during production (receiving, washing, centrifuging, and packing areas) by using a statistical method for sensitivity analysis and an exposure assessment model complying with the @RiskTM software program. At washing step, the numbers of S. aureus found in the vegetables and water were 0.79 ±1.76 Log cfu/g and 0.68±1.52 Log cfu, respectively. For the equipment, the hand, and the table swabbing samples, the numbers of S. aureus were 0.48±1.07 Log cfu/25 cm2, 1.81±1.69 Log cfu/25 cm2 , and 0.54±1.21 Log cfu/25 cm2 , respectively. An amount of E. coli of 0.48±1.07 Log cfu/25 cm2 was found in the table swabbing samples at the packing area. E.coli and S. aureus were not found in any of the mixed fresh-cut salad samples; therefore, the product samples could be considered safe for consumers. The result of the sensitivity analysis showed that the temperature and pH of water samples were the important factors in the washing process. The suggested interventions included monitoring and maintaining the water temperature at 5°C; also, maintaining the pH of water between 6.5 and 7.5 could help to reduce pathogen contamination of freshly cut vegetables.

scholarly journals Mutant analysis of glyceraldehyde 3-phosphate dehydrogenase in Escherichia coli

1979 ◽  
Vol 179 (1) ◽  
pp. 99-107 ◽  
Author(s):  
Jeffrey D. Hillman
Keyword(s):  
Escherichia Coli ◽  
Simple Procedure ◽  
Rabbit Antiserum ◽  
Double Diffusion ◽  
Wild Type ◽  
Wild Type Enzyme ◽  
Glycolytic Intermediate ◽  
E Coli ◽  
Catalytic Function ◽  
Mutant Strains

NAD+-specific glyceraldehyde 3-phosphate dehydrogenase (EC 1.2.1.12) from Escherichia coli was purified to homogeneity by a relatively simple procedure involving affinity chromatography on agarose–hexane–NAD+ and repeated crystallization. Rabbit antiserum directed against this protein produced one precipitin line in double-diffusion studies against the pure enzyme, and two lines against crude extracts of wild-type E. coli strains. Both precipitin lines represent the interaction of antibody with determinants specific for glyceraldehyde 3-phosphate dehydrogenase. Nine independent mutants of E. coli lacking glyceraldehyde 3-phosphate dehydrogenase activity all possessed some antigenic cross-reacting material to the wild-type enzyme. The mutants could be divided into three groups on the basis of the types and amounts of precipitin lines observed in double-diffusion experiments; one group formed little cross-reacting material. The cross-reacting material in crude cell-free extracts of several of the mutant strains were also tested for alterations in their affinity for NAD+ and their phosphorylative activity. The cumulative data indicate that the protein in several of the mutant strains is severely altered, and thus that glyceraldehyde 3-phosphate dehydrogenase is unlikely to have an essential, non-catalytic function such as buffering nicotinamide nucleotide or glycolytic-intermediate concentrations. Others of the mutants tested have cross-reacting material which behaved like the wild-type enzyme for the several parameters studied; the proteins from these strains, once purified, might serve as useful analogues of the wild-type enzyme.

scholarly journals Sensitivity of antibiotic resistant and antibiotic susceptible Escherichia coli, Enterococcus and Staphylococcus strains against ozone

2015 ◽  
Vol 13 (4) ◽  
pp. 1020-1028 ◽  
Author(s):  
Stefanie Heß ◽  
Claudia Gallert
Keyword(s):  
Escherichia Coli ◽  
Biofilm Formation ◽  
Resistance Pattern ◽  
Resistant Bacteria ◽  
Antibiotic Resistant ◽  
E Coli ◽  
Enterococcus Casseliflavus ◽  
Subsurface Layers ◽  
Wastewater Samples ◽  
And Staphylococcus Aureus

Tolerance of antibiotic susceptible and antibiotic resistant Escherichia coli, Enterococcus and Staphylococcus strains from clinical and wastewater samples against ozone was tested to investigate if ozone, a strong oxidant applied for advanced wastewater treatment, will affect the release of antibiotic resistant bacteria into the aquatic environment. For this purpose, the resistance pattern against antibiotics of the mentioned isolates and their survival after exposure to 4 mg/L ozone was determined. Antibiotic resistance (AR) of the isolates was not correlating with higher tolerance against ozone. Except for ampicillin resistant E. coli strains, which showed a trend towards increased resistance, E. coli strains that were also resistant against cotrimoxazol, ciprofloxacin or a combination of the three antibiotics were similarly or less resistant against ozone than antibiotic sensitive strains. Pigment-producing Enterococcus casseliflavus and Staphylococcus aureus seemed to be more resistant against ozone than non-pigmented species of these genera. Furthermore, aggregation or biofilm formation apparently protected bacteria in subsurface layers from inactivation by ozone. The relatively large variance of tolerance against ozone may indicate that resistance to ozone inactivation most probably depends on several factors, where AR, if at all, does not play a major role.

Study on Propolis Quality from China and Uruguay

2000 ◽  
Vol 55 (9-10) ◽  
pp. 778-784 ◽  
Author(s):  
Josep Serra Bonvehí ◽  
Francesc Ventura Coll
Keyword(s):  
Escherichia Coli ◽  
Staphylococcus Aureus ◽  
Bacillus Subtilis ◽  
Biological Activities ◽  
The State ◽  
Active Components ◽  
E Coli ◽  
Geographic Origins ◽  
Potential Activity ◽  
And Staphylococcus Aureus

Abstract The composition, bacteriostatic and ROO• -scavenging potential activities of fifteen propolis samples from various botanic and geographic origins were determined to obtain objective information related to propolis quality. Variance analysis showed significant differences (p ≤ 0.05) in the contents of polyphenols, flavonoids and active components between fresh and aged propolis. The state of the product (fresh or aged) could be differentiate by using flavonoid pattern and biological activities. A minimum propolis concentration of 80 μg/ml was required inhibit Bacillus subtilis and Staphylococcus aureus while 800 μg/ml was required to inhibit Escherichia coli using fresh propolis. Aged propolis inhibit B. subtilis and S. aureus at concentration of 100 μg/ml and E. coli at 1000 μg/ml. A minimum flavonoids percentage of 18 g/100 g and a maximum ROO• -scavenging potential activity of 4.3 μg/ml were determined in fresh propolis. Flavonoids levels in aged propolis were approximately 20% lower than in fresh propolis. A maximum flavonoids percentage of 19.8 g/100 g and a ROO•-scavenging potential activity between 5.7 to 6.4 μg/ml in aged propolis were quantified. Another objective was to assess the use of ROO•-scavenging potential activity in propolis quality.

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