scholarly journals Antibacterial properties of poly ( N , N -dimethylaminoethyl methacrylate) obtained at different initiator concentrations in solution polymerization

2022 ◽  
Vol 9 (1) ◽  
Author(s):  
Dawid Stawski ◽  
Karolina Rolińska ◽  
Dorota Zielińska ◽  
Priyanka Sahariah ◽  
Martha Á. Hjálmarsdóttir ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Radical Polymerization ◽  
Antibacterial Properties ◽  
Clear Relationship ◽  
Gram Negative Bacteria ◽  
Solution Polymerization ◽  
Gram Positive ◽  
Gram Negative ◽  
Dimethylaminoethyl Methacrylate ◽  
Polymerization Conditions

The samples of poly( N , N -dimethylaminoethyl methacrylate) were synthesized by radical polymerization. The amount of monomer and solvent was constant as opposed to an amount of initiator which was changing. No clear relationship between polymerization conditions and the molecular weight of the polymer was found, probably due to the branched configuration of produced polymer. Bactericidal interactions in all samples against Gram-positive and Gram-negative bacteria have been demonstrated. However, the observed effect has various intensities, depending on the type of bacteria and the type of sample.

scholarly journals Antimicrobial effect of essential oils of some Fijian medicinal plant leaves on pathogenic bacteria

2016 ◽  
Vol 34 (2) ◽  
pp. 35
Author(s):  
Prayna P. P. Maharaj ◽  
Riteshma Devi ◽  
Surendra Prasad
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Antimicrobial Agent ◽  
Essential Oils ◽  
Pathogenic Bacteria ◽  
Antibacterial Properties ◽  
Antimicrobial Activities ◽  
Diffusion Method ◽  
Gram Negative Bacteria ◽  
Gram Positive ◽  
Gram Negative

Fiji is highly populated with plants containing essential oils (EO). The essential oils extracted from the leaves of the selected Fijian leafy plants were screened against two Gram-negative bacteria (Salmonella typhimurium, Pseudomonas aeruginosa) and three Gram-positive bacteria (Staphylococcus aureus, Enterococcus faecalis and Bacillus subtilis). The agar diffusion method was used to examine the antimicrobial activities of the extracted EO. All the EO tested showed antibacterial properties against one or more strains while none of the EO was active against Pseudomonas aeruginosa. Viburnum lantana (Wayfaring tree), Annona muricata (Soursop), Coleus amboinicus (Spanish thyme) and Cinnamomum zeylancium (Cinnamon) showed good inhibition against both Gram-positive and Gram-negative bacteria and proved as worthy source of antimicrobial agent. These findings will help the Pacific population to use the studied plants leaves as antimicrobial agent.

scholarly journals Physicochemical and Antibacterial Properties of Chitosan Extracted from Waste Shrimp Shells

2016 ◽  
Vol 2016 ◽  
pp. 1-7 ◽  
Author(s):  
José Carlos Vilar Junior ◽  
Daylin Rubio Ribeaux ◽  
Carlos Alberto Alves da Silva ◽  
Galba Maria De Campos-Takaki
Keyword(s):  
Antibacterial Activity ◽  
Antibacterial Properties ◽  
Gram Negative Bacteria ◽  
Gram Positive ◽  
Gram Negative ◽  
Degree Of Deacetylation ◽  
Shrimp Shells ◽  
Shrimp Shell ◽  
Ft Ir ◽  
High Degree

This research aims to study the production of chitosan from shrimp shell (Litopenaeus vannamei) of waste origin using two chemical methodologies involving demineralization, deproteinization, and the degree of deacetylation. The evaluation of the quality of chitosan from waste shrimp shells includes parameters for the yield, physical chemistry characteristics by infrared spectroscopy (FT-IR), the degree of deacetylation, and antibacterial activity. The results showed (by Method 1) extraction yields for chitin of 33% and for chitosan of 49% and a 76% degree of deacetylation. Chitosan obtained by Method 2 was more efficient: chitin (36%) and chitosan (63%), with a high degree of deacetylation (81.7%). The antibacterial activity was tested against Gram-negative bacteria (Stenotrophomonas maltophiliaandEnterobacter cloacae) and Gram-positiveBacillus subtilisand the Minimum Inhibitory Concentrations (MIC) and the Minimum Bactericidal Concentration (MBC) were determined. Method 2 showed that extracted chitosan has good antimicrobial potential against Gram-positive and Gram-negative bacteria and that the process is viable.

Gram-Negative and Gram-Positive Antibacterial Properties of the Whole Plant Extract of Willow Herb (Epilobium angustifolium)

2011 ◽  
Vol 14 (1) ◽  
pp. 85-89 ◽  
Author(s):  
Wally J. Bartfay ◽  
Emma Bartfay ◽  
Julia Green Johnson
Keyword(s):  
Plant Extract ◽  
Micrococcus Luteus ◽  
Antibacterial Properties ◽  
Health Concern ◽  
Gram Negative Bacteria ◽  
Gram Positive ◽  
Gram Negative ◽  
Whole Plant ◽  
Epilobium Angustifolium ◽  
Herb Extract

The emergence of new pathogens and the increase in the number of multidrug-resistant strains in well-established pathogens during the past decade represent a growing public health concern globally. With the current lack of research and development of new antibiotics by large pharmaceutical companies due to poor financial returns, new alternatives need to be explored including natural herbal or plant-based extracts with reported antibacterial properties. Willow herb ( Epilobium angustifolium) preparations have been used in traditional aboriginal and folk medicine preparations externally as an antiphlogistic to treat prostate and gastrointestinal disorders and as an antiseptic to treat infected wounds. The authors hypothesized that a whole plant extract of willow herb would exhibit antimicrobial properties on a variety of both Gram-positive and gram-negative bacteria in culture. The authors found that, in comparison to growth controls, willow herb extract significantly inhibited the growth of Micrococcus luteus ( p < .01), Staphylococcus aureus ( p < .05), Escherichia coli ( p < .001), and Pseudomonas aeruginosa ( p < .001). They also found that willow herb extract inhibited the growth of bacteria in culture more effectively than vancomycin ( p < .05) or tetracycline ( p < .004). These results provide preliminary support for the traditional folkloric claim that the plant willow herb possesses antibacterial properties against a variety of gram-positive and gram-negative bacteria. Given that whole plant extract was utilized for this study, further investigations are warranted to determine which specific part of the plant (i.e., leaves, stem, roots, and flowers) possess the antibacterial properties.

scholarly journals Development of a novel selective medium for culture of Gram-negative bacteria

2021 ◽  
Vol 14 (1) ◽  
Author(s):  
Shooq Yousef Al-blooshi ◽  
Mustafa Amir Abdul Latif ◽  
Nour K. Sabaneh ◽  
Michael Mgaogao ◽  
Ashfaque Hossain
Keyword(s):  
New Media ◽  
Culture Media ◽  
Bacterial Pathogens ◽  
Antibacterial Properties ◽  
Water Extract ◽  
Selective Medium ◽  
Gram Negative Bacteria ◽  
Gram Positive ◽  
Gram Negative ◽  
Selective Media

Abstract Objective Although many bacterial culture media are available commercially, there is a continuous effort to develop better selective media for bacteria, which cannot be grown on existing media. While exploring antibacterial properties of clove, we observed that it has the potential to selectively inhibit growth of certain types of bacteria. This led us to do the experiments, which resulted in developing a new media which selectively allowed the growth of only Gram-negative bacteria, while inhibiting the Gram-positive bacteria. Results Mueller Hinton Agar (MHA) was used as the base media and was modified to develop MHA-C15 (MHA containing 15% volume/volume water extract of clove). Gram-negative bacterial pathogens Escherichia coli, Klebsiella pneumoniae, Salmonella typhimurium and Pseudomonas aeruginosa grew on MHA-C15. However, none of the major Gram-positive bacterial pathogens such as Staphylococcus aureus, Streptococcus pneumoniae, Streptococcus pyogenes, Streptococcus mutans, Bacillus spp. and Enterococcus spp. grew on it. Taken together, these findings show that MHA-C15 is a newly developed selective media for culture of Gram-negative bacteria.

scholarly journals The Antibacterial Activities of NiO Nanoparticles Against Some Gram-Positive and Gram-Negative Bacterial Strains

2019 ◽  
Vol 4 (2) ◽  
pp. 69-74
Author(s):  
Ghazaleh Ilbeigi ◽  
Ashraf Kariminik ◽  
Mohammad Hasan Moshafi
Keyword(s):  
Antibiotic Resistance ◽  
Antibacterial Properties ◽  
Diffusion Method ◽  
Resistance Pattern ◽  
Resistant Bacteria ◽  
Gram Negative Bacteria ◽  
Nio Nanoparticles ◽  
Bacterial Strains ◽  
Gram Positive ◽  
Gram Negative

Introduction: Given the increasing rate of antibiotic resistance among bacterial strains, many researchers have been working to produce new and efficient and inexpensive antibacterial agents. It has been reported that some nanoparticles may be used as novel antimicrobial agents.Here, we evaluated antibacterial properties of nickel oxide (NiO) nanoparticles. Methods: NiO nanoparticles were synthesized using microwave method. In order to control the quality and morphology of nanoparticles, XRD (X-ray diffraction) and SEM (scanning electronmicroscope) were utilized. The antibacterial properties of the nanoparticles were assessed against eight common bacterial strains using agar well diffusion assay. The minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) were measured. Antibiotic resistance pattern of the bacteria to nine antibiotics was obtained by Kirby-Bauer disk diffusion method. Results: The crystalline size and diameter (Dc) of NiO nanoparticles were obtained 40-60 nm. The nanoparticles were found to inhibit the growth of both gram-positive and gram-negative bacteria with higher activity against gram-positive organisms. Among bacterial strains, maximum sensitivity was observed in Staphylococcus epidermidis with MIC and MBC of 0.39 and 0.78 mg/mL, respectively. The bacteria had high resistance to cefazolin, erythromycin, rifampicin,ampicillin, penicillin and streptomycin.Conclusion: NiO nanoparticles exhibited remarkable antibacterial properties against gram positive and gram-negative bacteria and can be a new treatment for human pathogenic and antibiotic-resistant bacteria.

scholarly journals Physiochemical synthesis of Silver/Kaolinite nanocomposites and study their antibacterial properties

2021 ◽  
Vol 1 (1) ◽  
pp. 1-11
Author(s):  
Salmah Moosa ◽  
Anis Nadia Mohd Faisol Mahadeven ◽  
Kamyar Shameli
Keyword(s):  
Gamma Irradiation ◽  
Ambient Pressure ◽  
Synthesis Method ◽  
Antibacterial Properties ◽  
Gram Negative Bacteria ◽  
Zone Of Inhibition ◽  
Gram Positive ◽  
Gram Negative ◽  
Physical Synthesis ◽  
Ag Ncs

Silver nanocomposites (Ag NCs) were prepared by two methods, chemical and physical synthesis using sodium borohydride and gamma irradiation as a reducing tool. A one-step silver/kaolinite nanocomposite (Ag/Kln NCs) synthesis method has been developed successfully by irradiation technique at room temperature and under ambient pressure. The Ag/Kln NCs produced by the ?-irradiation technique is pure without chemical residues, has a good distribution with enhanced antibacterial properties, and environmentally friendly. The effects of various experimental parameters on the formation of NCs, such as the concentration of Ag+ and the irradiation dose, have been investigated. A study on antimicrobial susceptibility was undertaken to determine the antibacterial properties of Ag NCs in the presence of gram-positive and gram-negative bacteria. The susceptibility of the microorganisms to varying concentrations of Ag NCs synthesized via physical synthesis using gamma irradiation was compared to those synthesized chemically. Concentrations of Ag NCs used were 0.5, 1.0, 2.0, 5.0, and 10 % for chemical synthesis and irradiation doses used for physical synthesis were 7, 13, 20, 30, 40, 50, 65 and 80 kGy. Observation on well diffusion variant showed a significantly large zone of inhibition for physically synthesized NCs, (63 to 107% relative to control) which indicates high antimicrobial activity. Chemically synthesized NCs using the same experimental set up however showed a significantly smaller zone of inhibition. The Ag/Kln NCs in 20kGy showed higher antibacterial activity against Enterococcus faecalis and Escherichia coli as gram-positive and gram-negative bacteria. These suggest that Ag/Kln NCs can be employed as an effective bacteria inhibitor and can be applied in the medical field.

Development of a Novel Selective Medium for Culture of Gram-negative Bacteria

2021 ◽  
Author(s):  
Shooq Yousef Al-blooshi ◽  
Mustafa Amir Abdul Latif ◽  
Nour K. Sabaneh ◽  
Michael Mgaogao ◽  
Ashfaque Hossain
Keyword(s):  
Culture Media ◽  
Bacterial Pathogens ◽  
Antibacterial Properties ◽  
Water Extract ◽  
Selective Medium ◽  
Gram Negative Bacteria ◽  
Gram Positive ◽  
Gram Negative ◽  
Selective Media ◽  
Bacillus Spp

Abstract Objective: Although many bacterial culture media are commercially available, there is a continuous effort to develop better selective media for bacteria, which cannot be grown on existing media. While exploring antibacterial properties of clove, we observed that it has the potential to selectively inhibit growth of certain types of bacteria. This led us to do the experiments which resulted in developing the media which selectively allowed the growth of only Gram-negative bacteria, while inhibiting the Gram-positive bacteria. Results: Mueller Hinton Agar (MHA) was used as the base media and was modified to develop MHA-C15 (MHA containing 15 % volume / volume water extract of clove). Different Gram-negative bacterial pathogens including Escherichia coli, Klebsiella pneumoniae, Salmonella typhimurium and Pseudomonas aeruginosa grew on MHA-C15. However, none of the major Gram-positive bacterial pathogens such as Staphylococcus aureus, Streptococcus pneumoniae, Streptococcus pyogenes, Streptococcus mutans, Bacillus spp. and Enterococcus spp. grew on it. Taken together, these findings show that MHA-C15 is a newly developed selective media for culture of Gram-negative bacteria.

scholarly journals Dermaseptins fromPhyllomedusa oreadesandPhyllomedusa distincta

2002 ◽  
Vol 277 (51) ◽  
pp. 49332-49340 ◽  
Author(s):  
Guilherme D. Brand ◽  
José Roberto S. A. Leite ◽  
Luciano P. Silva ◽  
Sérgio Albuquerque ◽  
Maura V. Prates ◽  
...  
Keyword(s):  
Molecular Mass ◽  
Biological Activities ◽  
White Blood Cells ◽  
Antibacterial Properties ◽  
Biologically Active ◽  
Gram Negative Bacteria ◽  
Amphibian Skin ◽  
Gram Positive ◽  
Amphibian Species ◽  
Gram Negative

Amphibian skin secretions are known as a rich source of biologically active molecules, most of which are alkaloids, biogenic amines, and peptides. Dermaseptins are a class of antimicrobial peptides present in tree frogs of thePhyllomedusagenus. They are cationic molecules of 28–34 residues that permeabilize the membrane of Gram-positive and Gram-negative bacteria, yeasts, and filamentous fungi, showing little or no hemolytic activity. This work reports the isolation, molecular mass analysis, primary structure determination, biological activities, and potential therapeutic applications of an antimicrobial peptide found in the skin secretion ofPhyllomedusa oreades,which is a newly described amphibian species endemic of the Brazilian savanna. DS 01 is a 29-residue-long peptide with a molecular mass of 2793.39 Da showing antibacterial properties against Gram-positive and Gram-negative bacteria in the range of 3–25 μm. Anti-protozoan activity was investigated usingT. cruziin its trypomatigote and epimastigote forms cultivated in both cell culture and blood media. Within 2 h after incubation with DS 01 at a final concentration of ∼6 μm, no protozoan cells were detected. Two synthetic dermaseptins, described previously by our group and named dermadistinctins K and L (DD K and DD L), also had their anti-Trypanosoma cruziactivity investigated and demonstrated similar properties. Toxicity of DS 01 to mouse erythrocytes and white blood cells was evaluated by means of atomic force microscopy and flow cytometry. No morphological alterations were observed at a lytic concentration of DS 01, suggesting its therapeutic value especially as an anti-T. cruziagent to prevent infections during blood transfusion.

Evaluation of the Antibacterial Activity of Ag- and Au-Nanoparticles Loaded TiO2 Nanotubes

2020 ◽  
Vol 16 (9) ◽  
pp. 1416-1425
Author(s):  
Katarzyna Arkusz ◽  
Ewa Paradowska ◽  
Marta Nycz ◽  
Justyna Mazurek-Popczyk ◽  
Katarzyna Baldy-Chudzik
Keyword(s):  
Gold Nanoparticles ◽  
Antibacterial Activity ◽  
Staphylococcus Epidermidis ◽  
Metallic Nanoparticles ◽  
Antibacterial Properties ◽  
Gram Negative Bacteria ◽  
Gram Positive ◽  
Gram Negative ◽  
Gram Positive Bacteria ◽  
Live Bacteria

Current research on the antibacterial properties of implant surfaces has focused on using titanium nanotubes (TNTs) with diameters of 100 and 200 nm, which simultaneously show the best antibacterial properties, poor osseointegration, and ability to immobilize proteins. Therefore, the research aimed to develop an implantable material based on titanium dioxide nanotubes with a diameter of 50 nm doped with silver (AgNPs) and gold nanoparticles (AuNPs), indicating good absorption and antibacterial properties. Moreover, metallic nanoparticles deposited by varying methods should maintain sphericity and lack of agglomeration. For this purpose, the surface charge, wettability, stability of nanoparticles, and antibacterial properties against Gram-positive and Gram-negative bacteria, i. e., Staphylococcus epidermidis, Streptococcus mutans, and Pseudomonas aeruginosa , were performed. Obtained results indicate a greater resistance to leaching of silver nanoparticles compared to gold nanoparticles. These results are reflected in microbiological studies, both into the time and the effectiveness of the implantable material's antibacterial activity. A greater antibacterial effect of AgNPs than AuNPs has been confirmed. Also, AgNPs inhibit the multiplication of Gram-negative bacteria to a greater extent than Gram-positive bacteria. It has been proven that the TNT platforms deposited with metal nanoparticles via the voltammetric method are more effective in deactivating microorganisms. Besides, the results have proven that smaller TNTs effectively reduce live bacteria as nanotubes with a diameter of 100 and 200 nm.

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