scholarly journals Activity of Engineered Nano-Semiconductor Oxides against Gram Positive and Gram Negative Bacteria

2019 ◽  
Vol 8 (4S2) ◽  
pp. 645-650
Keyword(s):  
Wide Spectrum ◽  
Antibacterial Activities ◽  
Engineered Nanoparticles ◽  
Diffusion Method ◽  
Gram Negative Bacteria ◽  
Gram Positive ◽  
Bacillus Brevis ◽  
Gram Negative ◽  
E Coli ◽  
Semiconductor Oxides

Antibacterial activities of semiconductor oxides such as ZnO and TiO2 have induced research on the design of engineered nanoparticles (ENPs) for the last few decades. We had synthesized modified ZnO and TiO2 using rare earth salts and analyzed their antibacterial activities against Bacillus brevis. (Gram positive) and E. coli (Gram negative) by modified well diffusion method. Among the seventeen nanoparticles studied, Ag-TiO2 showed highest antibacterial activity against Gram positive and Gram negative bacteria. Antibacterial activities of Ni-Ag-TiO2, ZnO, Eu2O3-ZnO, DyMoO4-ZnO, GdMoO4-ZnO, DyVO4-ZnO, GdVO4-ZnO and HoVO4-ZnO were found to be significant. From the microbial plating experiments it was shown that the synthesized nano materials show a wide spectrum of antibacterial activities performed against Bacillus brevis, and E. coli. In this study we help to understand the influence of the engineered nanoparticles (ENPs) against microbes, as these ENPs finds wide applications in medicine, water treatment, in food industry as anti-coating agents.

Study of the chemical composition, antimicrobial activity of the essen- al oil of Cistus salviifolius from Tissemsilt National Park (Algeria) and influence of the drying period in the shade on the yield of this oil

2020 ◽  
Vol 9 (6) ◽  
pp. 238-244
Author(s):  
Meharrar Nadjet ◽  
Bekada Ahmed Mohamed Ali ◽  
Dris Ibrahim ◽  
Jacques Dommes ◽  
Arabi Abed ◽  
...  
Keyword(s):  
Antimicrobial Activity ◽  
Chemical Composition ◽  
Wide Spectrum ◽  
Diffusion Method ◽  
Bacterial Suspension ◽  
Gram Negative Bacteria ◽  
Gram Positive ◽  
Gram Negative ◽  
Antibiotic Susceptibility Test ◽  
Cistus Salviifolius

The genera Cistus present groups of about twenty species of shrubs belon- ging to the Cistaceae family are very common throughout the Mediterranean region. Cistus salviifolius, known as Melliya is a species of this genus that occurs in the forest region of Mount Ouarsenis (northwest Algeria), exactly in Thniet El Had Na onal Park in the Wilaya of Tissemsilt. This study was un- dertaken to evaluate the an bacterial effects of C. salviifolius and its chemical composition in addition the effect of shade drying me on essen al oil yield in order to op mize this parameter which is most o en not controlled for producers. The op mal yield recorded is about 0.07± 0.02%. Its characte- riza on by gas chromatography coupled with mass spectrometry shows a dominance of hydrocarbon compounds. The minimum inhibitory concentration (MIC) is established using 6 strains of Gram-positive and negative bacteria. The antibiotic susceptibility test is performed using the giliose- environment diffusion method, a bacterial suspension is prepared and subsequently well homogenized. Opacity must be adjusted to 0.5 McF (McFarland), from a young exponen al culture (18 to 24 hours). The an mi- crobial ac vity of C. salviifolius EO was tested against three Gram-posi ve and three Gram-nega ve bacteria. In fact, a strong inhibitory and bactericidal effect has been demonstrated against all Gram-positive and Gram- negative bacteria tested. It appears from this study that the EO of C. salviifo- lius has a very high antimicrobial activity, it shows a wide spectrum covering Gram positive and Gram negative bacteria. Taking into account the results of this study, new an bacterial agents could be developed and the use of C.salviifolius should be encouraged in the pharmaceutical and perfumery industries.

scholarly journals Evernimicin Binds Exclusively to the 50S Ribosomal Subunit and Inhibits Translation in Cell-Free Systems Derived from both Gram-Positive and Gram-Negative Bacteria

2000 ◽  
Vol 44 (5) ◽  
pp. 1121-1126 ◽  
Author(s):  
Paul M. McNicholas ◽  
David J. Najarian ◽  
Paul A. Mann ◽  
David Hesk ◽  
Roberta S. Hare ◽  
...  
Keyword(s):  
Protein Synthesis ◽  
Dissociation Constants ◽  
Wide Spectrum ◽  
Ribosomal Subunit ◽  
Gram Negative Bacteria ◽  
Metabolic Labeling ◽  
Gram Positive ◽  
Gram Negative ◽  
E Coli ◽  
Free Translation

ABSTRACT Evernimicin (SCH 27899) is a new antibiotic with activity against a wide spectrum of gram-positive bacteria and activity against some gram-negative bacteria. Previous metabolic labeling studies indicated that evernimicin specifically inhibited protein synthesis inStaphylococcus aureus. Using a susceptibleEscherichia coli strain, we demonstrated that evernimicin also inhibited protein synthesis in E. coli. In cell-free translation assays with extracts from either E. coli orS. aureus, evernimicin had a 50% inhibitory concentration of approximately 125 nM. In contrast, cell-free systems derived from wheat germ and rabbit reticulocytes were inhibited only by very high levels of evernimicin. Evernimicin did not promote transcript misreading. [14C]evernimicin specifically bound to the 50S subunit from E. coli. Nonlinear regression analysis of binding data generated with 70S ribosomes from E. coli andS. aureus and 50S subunits from E. colireturned dissociation constants of 84, 86, and 160 nM, respectively. In binding experiments, performed in the presence of excess quantities of a selection of antibiotics known to bind to the 50S subunit, only the structurally similar drug avilamycin blocked binding of [14C]evernimicin to ribosomes.

Bacterial Pattern of Community acquired Urinary Tract Infections: A Challenge for Antimicrobial Resistance

2021 ◽  
Vol 30 (3) ◽  
pp. 153-162
Author(s):  
Nader A. Nemr ◽  
Rania M. Kishk ◽  
Mohammed Abdou ◽  
Hassnaa Nassar ◽  
Noha M Abu bakr Elsaid ◽  
...  
Keyword(s):  
Urinary Tract ◽  
Antimicrobial Resistance ◽  
Bacterial Infections ◽  
Diffusion Method ◽  
Gram Negative Bacteria ◽  
Isolation And Identification ◽  
Gram Positive ◽  
Gram Negative ◽  
E Coli ◽  
Tract Infections

Background: Urinary tract infection (UTI) is considered one of the most common bacterial infections seen in health care. To our knowledge, there is no available antimicrobial resistance surveillance system for monitoring of community-acquired UTIs (CA- UTIs) in our country. Objectives: we aimed to discuss the bacterial pattern and resistance profile of CA-UTIs in Ismailia, Egypt. Methods: This cross-sectional study included 400 patients suffering from symptoms of acute UTIs. Urine specimens were collected by clean-catch mid-stream method, examined microscopically and inoculated immediately on blood agar and MacConkey's agar plates. Colony counting, isolation and identification of the urinary pathogens were performed by the conventional biochemical tests according to the isolated organism. Antibiotic susceptibility testing was performed by Kirby Bauer disk diffusion method. Interpretation was performed according to Clinical Laboratory Standard Institute (CLSI) guidelines. Results: out of 400 specimens, 136 of them revealed no bacterial growth or insignificant bacteriuria. Most of participants with UTI were females (81.8%) (p=0.008) and 54.5% of them were married (P=0.1). Gram negative bacteria were more common than Gram positive representing 66 % and 34% respectively. E. coli was the most common isolated organism (39%) followed by S. aureus (32%), K. Pneumoniae and Pseudomonas (10.5% for each), Proteus (6%) and Enterococci (2%). E. coli isolates showed the highest susceptibility to imipenem, meropenem, amikacin, nitrofurantoin, levofloxacin and ciprofloxacin. Most of our patients were diabetics (64.8%) (p=0.004). The mean ± SD of HbA1c was 6.4±2.0 with 4 to 12.6 range, S.E was 0.1 and 95% C.I was 6.2- 6.7. The highest mean ± SD of HbA1c was in S. aureus infections. Conclusion: Gram negative bacteria were most common than Gram positive with predominance of E. coli with significant relation to the presence of diabetes.

scholarly journals Antibiogram of single, double and triple chain Aroyl hydrazine against some gram positive and gram negative bacteria

1970 ◽  
Vol 1 (1) ◽  
pp. 17-21
Author(s):  
R Parvin ◽  
MN Absar ◽  
M Ershaduzzaman ◽  
ATM Mahbub-E-Elahi ◽  
A Shil
Keyword(s):  
Inhibition Zone ◽  
Antibacterial Activities ◽  
Diffusion Method ◽  
Gram Negative Bacteria ◽  
Significant Activity ◽  
Single Chain ◽  
Double Chain ◽  
Gram Positive ◽  
Gram Negative ◽  
Bacterial Cell Membrane

The antibacterial sensitivity of some single, double and triple chain aroylhydrazine against gram positive and gram negative bacteria were performed by disc diffusion method. Most of the compounds showed appreciable antibacterial activity against different gram positive and gram negative bacteria. The single chain hydrazines are more active then double chain and triple chain hydrazine. Among the single chain aroylhydrazines studied only 4-n-hexyloxy benzoyl hydrazine is the most active. The significant activity of 4-n-hexyloxybenzoyl hydrazine and heptyloxybenzoyl hydrazine against gram positive and gram negative bacteria may be (formation of inhibition zone 8 to 22 mm with most of the test bacteria) due to their liophilicity of the bacterial cell membrane. Anti-microbial activity decreases as the number of carbon of single chain hydrazine increases (C6 > C7 > C8 > C9 > C10 single chain hydrazine). Double chain hydrazines (3, 5 or 3, 4) are more active than triple chain hydrazines (3, 5 > 3, 4 > 3, 4, 5 hydrazine). The antibacterial activities of hydrazines are being decreased as their increasing number of side chain.Keyword: Antibacterial sensitivity; Aroyl hydrazine.DOI: http://dx.doi.org/10.3329/ijns.v1i1.8610 International Journal of Natural Sciences (2011), 1(1):17-21 

scholarly journals Antibacterial Activity of Borassus flabellifer Vinegar-Graphene Quantum Dots Against Gram-Positive and Gram-Negative Bacteria

2021 ◽  
Vol 33 (11) ◽  
pp. 2662-2666
Author(s):  
Amnuay Noypha ◽  
Paweena Porrawatkul ◽  
Nongyao Teppaya ◽  
Parintip Rattanaburi ◽  
Saksit Chanthai ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Staphylococcus Aureus ◽  
Quantum Dots ◽  
Antibacterial Activity ◽  
Graphene Quantum Dots ◽  
Diffusion Method ◽  
Gram Negative Bacteria ◽  
Gram Positive ◽  
Gram Negative ◽  
E Coli

Borassus flabellifer vinegar–graphene quantum dots (BFV-GQDs) were successfully synthesized using a pyrolysis method with Borassus flabellifer vinegar (BFV) as the precursor. All the samples were characterized using ultraviolet-visible spectrophotometry (UV-Vis), scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy (EDX). The antibacterial activities of BFV-GQDs against strains of Gram-negative bacteria (Escherichia coli) and Gram-positive bacteria (Staphylococcus aureus) were determined using the agar well diffusion method for preliminary screening, while minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) were determined using the broth macro-dilution method. The zones of inhibition were compared with those of citric acid–graphene quantum dots (CA-GQDs). It was observed that the synthesized BFV-GQDs demonstrated excellent antibacterial activity against Staphylococcus aureus (82.3%) and good antibacterial activity against Escherichia coli (73.3%). The MIC of BFV-GQDs against E. coli was 6.25 mg/mL and S. aureus was 12.5 mg/mL, whereas the MBC of BFV-GQDs against E. coli was 12.5 mg/mL and S. aureus was 25.0 mg/mL.

In-vitro Antioxidant and Antibacterial Activity of Methanolic Extract of Shorea robusta Gaertn. F. Resin

2016 ◽  
Vol 6 (4) ◽  
pp. 68
Author(s):  
Sushma Vashisht ◽  
Manish Pal Singh ◽  
Viney Chawla
Keyword(s):  
Antibacterial Activity ◽  
Methanolic Extract ◽  
Diffusion Method ◽  
Gram Negative Bacteria ◽  
Disc Diffusion ◽  
Gram Positive ◽  
Gram Negative ◽  
Shorea Robusta ◽  
Dose Dependent ◽  
Resin Extract

The methanolic extract of the resin of Shorea robusta was subjected to investigate its antioxidant and antibacterial properties its utility in free radical mediated diseases including diabetic, cardiovascular, cancer etc. The methanol extract of the resin was tested for antioxidant activity using scavenging activity of DPPH (1,1-diphenyl-2-picrylhydrazil) radical method, reducing power by FeCl3 and antibacterial activity against gram positive and gram negative bacteria using disc diffusion method. The phytochemical screening considered the presence of triterpenoids, tannins and flavoniods. Overall, the plant extract is a source of natural antioxidants which might be helpful in preventing the progress of various oxidative stress mediated diseases including aging. The half inhibition concentration (IC50) of resin extract of Shorea robusta and ascorbic acid were 35.60 µg/ml and 31.91 µg/ml respectively. The resin extract exhibit a significant dose dependent inhibition of DPPH activity. Antibacterial activity was observed against gram positive and gram negative bacteria in dose dependent manner.Key Words: Shorea robusta, antioxidant, antibacterial, Disc-diffusion, DPPH.

Antibacterial activity of magnesium oxide nanoparticles prepared by Calcination method

2019 ◽  
Vol 10 (03) ◽  
Author(s):  
Elaf Ayad Kadhem ◽  
Miaad Hamzah Zghair ◽  
Sarah , Hussam H. Tizkam, Shoeb Alahmad Salih Mahdi ◽  
Hussam H. Tizkam ◽  
Shoeb Alahmad
Keyword(s):  
Antibacterial Activity ◽  
Magnesium Oxide ◽  
Diffusion Method ◽  
Oxide Nanoparticles ◽  
Gram Negative Bacteria ◽  
Gram Positive ◽  
Gram Negative ◽  
Gram Positive Bacteria ◽  
Magnesium Oxide Nanoparticles ◽  
Agar Disc

magnesium oxide nanoparticles (MgO NPs) were prepared by simple wet chemical method using different calcination temperatures. The prepared NPs were characterized by Electrostatic Discharge (ESD), Scanning Electron Microscope (SEM) and X-ray Diffraction (XRD). It demonstrates sharp intensive peak with the increase of crystallinty and increase of the size with varying morphologies with respect to increase of calcination temperature. Antibacterial studies were done on gram negative bacteria (E.coli) and gram positive bacteria (S.aureus) by agar disc diffusion method. The zones of inhibitions were found larger for gram positive bacteria than gram negative bacteria, this mean, antibacterial MgO NPs activity more active on gram positive bacteria than gram negative bacteria because of the structural differences. It was found that antibacterial activity of MgO NPs was found it has directly proportional with their concentration.

Structure-Activity Relationship and Antimicrobial Evaluation of N-Phenylpyrazole Curcumin Derivatives

2020 ◽  
Vol 16 (4) ◽  
pp. 481-488
Author(s):  
Heli Sanghvi ◽  
Satyendra Mishra
Keyword(s):  
Antibacterial Activity ◽  
Gram Negative Bacteria ◽  
Pyrazole Derivatives ◽  
Gram Positive ◽  
Gram Negative ◽  
E Coli ◽  
Curcumin Derivatives ◽  
Structure Activity ◽  
Electron Donating Groups ◽  
Derivatives Of

Background: Curcumin, one of the most important pharmacologically significant natural products, has gained significant consideration among scientists for decades since its multipharmacological activities. 1, 3-Dicarbonyl moiety of curcumin was found to be accountable for the rapid degradation of curcumin molecule. The aim of present work is to replace 1, 3-dicarbonyl moiety of curcumin by pyrazole and phenylpyrazole derivatives with a view to improving its stability and to investigate the role of substitution in N-phenylpyrazole curcumin on its antibacterial activity against both Gram-positive as well as Gram-negative bacteria. Methods: Pyrazole derivatives of curcumin were prepared by heating curcumin with phenyhydrazine/ substituted phenyhydrazine derivatives in AcOH. The residue was purified by silica gel column chromatography. Structures of purified compounds were confirmed by 1H NMR and Mass spectroscopy. The synthesized compounds were evaluated for their antibacterial activity by the microdilution broth susceptibility test method against gram positive (S. aureus) and gram negative (E. coli). Results: Effects of substitution in N-phenylpyrazole curcumin derivatives against S. aureus and E. coli were studied. The most active N-(3-Nitrophenylpyrazole) curcumin (12) exhibits twenty-fold more potency against S. aureus (MIC: 10μg/mL)) and N-(2-Fluoroophenylpyrazole) curcumin (5) fivefold more potency against E. coli (MIC; 50 μg/mL) than N-phenylpyrazole curcumin (4). Whereas, a remarkable decline in anti-bacterial activity against S. aureus and E. coli was observed when electron donating groups were incorporated in N-phenylpyrazole curcumin (4). Comparative studies of synthesized compounds suggest the effects of electron withdrawing and electron donating groups on unsubstituted phenylpyrazole curcumin (4). Conclusion: The structure-activity relationship (SAR) results indicated that the electron withdrawing and electron donating at N-phenylpyrazole curcumin played key roles for their bacterial inhibitory effects. The results of the antibacterial evaluation showed that the synthesized pyrazole derivatives of curcumin displayed moderate to very high activity in S. aureus. In conclusion, the series of novel curcumin derivatives were designed, synthesized and tested for their antibacterial activities against S. aureus and E. coli. Among them, N-(3-Nitrophenylpyrazole curcumin; 12) was most active against S. aureus (Gram-positive) and N-(2-Fluoroophenylpyrazole) curcumin (5) against E. coli (Gram-negative) bacteria.

scholarly journals Antibacterial, Antioxidant and Cytotoxic Properties of Crinum asiaticum Bulb Extract

2012 ◽  
Vol 28 (1) ◽  
pp. 1-5 ◽  
Author(s):  
Md Atiar Rahman ◽  
Rumana Sharmin ◽  
Md Nazim Uddin ◽  
Md Sohel Rana ◽  
Nazim Uddin Ahmed
Keyword(s):  
Radical Scavenging ◽  
Diffusion Method ◽  
Gram Negative Bacteria ◽  
Gram Positive ◽  
Gram Negative ◽  
Scavenging Effect ◽  
Ic50 Value ◽  
Radical Scavenging Effect ◽  
Dpph Scavenging ◽  
Crinum Asiaticum

Antibacterial effect of Crinum asiaticum bulb extract (1mg/disc) was tested on four Gram- positive and six Gram-negative bacteria by disc diffusion method using kanamycin (30 ìg/disc) as standard antibiotic disc. The bulb extract (250-1000mg/disc) showed significant zone of inhibition against all Gram-positive and Gram-negative bacteria ranging from 12-14 mm in diameter. Antioxidant potential of the same extract was evaluated by 2,2-diphenyl-1-picrylhydrazyl (DPPH) scavenging method. The extract showed remarkable free radical scavenging effect (95.96%) providing the IC50 value of 5.62 for the bulb extract and 5.46 for ascorbic acid (standard antioxidant) at the concentration of 1000 ìg/ml. The bulb extract was found to be (LC50 value 94.06 ?g/ml) in Brine-Shrimp lethality test. DOI: http://dx.doi.org/10.3329/bjm.v28i1.11801 Bangladesh J Microbiol, Volume 28, Number 1, June 2011, pp 1-5

scholarly journals 660. Evaluation of Qvella’s FAST-Prep™ Liquid Colony™ for Early Antimicrobial Sensitivity Testing of Positive Blood Culture by Disk Diffusion Method

2020 ◽  
Vol 7 (Supplement_1) ◽  
pp. S386-S386
Author(s):  
Susan M Novak-Weekley ◽  
Aye Aye Khine ◽  
Tino Alavie ◽  
Namidha Fernandez ◽  
Laxman Pandey ◽  
...  
Keyword(s):  
Direct Method ◽  
Viable Cell ◽  
Turnaround Time ◽  
Disk Diffusion ◽  
Diffusion Method ◽  
Gram Negative Bacteria ◽  
Sensitivity Testing ◽  
Gram Positive ◽  
Disk Diffusion Method ◽  
Gram Negative

Abstract Background Conventional antimicrobial susceptibility testing (AST) of microorganisms from positive blood cultures (PBC) can take ≥ 2 days. In order to improve the turnaround time for AST on a PBC, CLSI and EUCAST have made efforts to standardize procedures for disk diffusion (DD) direct from a PBC. Qvella Corporation (Richmond Hill, ON, Canada) has recently developed FAST-Prep, an automated centrifugal sample preparation system that rapidly delivers a Liquid Colony consisting of a purified, concentrated, viable cell suspension directly from a PBC. This study was performed to investigate the feasibility of DD AST off of a PBC using a FAST-Prep Liquid Colony. Methods Contrived PBC samples were prepared by spiking 6 species of Gram-positive and 4 species of Gram-negative bacteria (3-5 strains per species) into FA® Plus bottles and incubating in the BACT/ALERT® VIRTUO® System (bioMerieux, Durham, NC). After positivity, 3 mL of PBC was added to the FAST-Prep cartridge. After 20 minutes of processing in the FAST-Prep instrument, the Liquid Colony was removed from the cartridge and a 0.5 McFarland sample was prepared for DD AST. In parallel, the DD AST from a PBC was performed using 4 drops of PBC (CLSI direct method). Both methods were compared to conventional colony-based DD AST. After 16-18 hours of incubation zone diameters and S/I/R interpretations were determined. Categorical agreement (CA) and errors for both DD AST methods were calculated. In addition, colony plate counting was performed on 0.5 McFarland suspensions of Liquid Colony and the plate colony to determine biomass recovery and sample purity. Results CA for a FAST-Prep DD AST for Gram-positive and Gram-negative bacteria was 95.6% and 98.6%, respectively, compared to CA for CLSI DD AST of 77.2% and 81.9%, respectively. Biomass in the Liquid Colony was 7.2x108 and 1.2x109 CFU for Gram-positive and Gram-negative bacteria, respectively. Cell concentration in the 0.5 McFarland suspension of the Liquid Colony was 3.7x107 and 5.9x107 CFU/mL for Gram-positive and Gram-negative bacteria, respectively, which was similar to the concentration for the reference colony suspension. Conclusion The results support the potential role of FAST-Prep in providing a Liquid Colony for use in rapid AST. Disclosures Susan M. Novak-Weekley, PhD, D(ABMM), Qvella (Employee, Shareholder) Aye Aye Khine, PhD, Qvella (Employee, Shareholder) Tino Alavie, PhD, Qvella (Employee) Namidha Fernandez, MS, Qvella (Employee) Laxman Pandey, MS, Qvella (Employee) Abdossamad Talebpour, PhD, Qvella (Employee, Shareholder)

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