scholarly journals Preparation and Characterization of Chitosan Nanoparticles-Doped Cellulose Films with Antimicrobial Property

2014 ◽  
Vol 2014 ◽  
pp. 1-10 ◽  
Author(s):  
Ain Nadirah Binti Romainor ◽  
Suk Fun Chin ◽  
Suh Cem Pang ◽  
Lesley Maurice Bilung
Keyword(s):  
Antimicrobial Activity ◽  
Citric Acid ◽  
Antimicrobial Agents ◽  
Antimicrobial Property ◽  
Chitosan Nanoparticles ◽  
Assay Method ◽  
E Coli ◽  
Cellulose Films ◽  
Diffusion Assay

Cellulose films with antimicrobial property were prepared by incorporation of chitosan nanoparticles as antimicrobial agents into the cellulose films. The antimicrobial property of these chitosan nanoparticles-doped cellulose films againstEscherichia coli(E. coli) was evaluated via diffusion assay method, minimum inhibitory concentration (MIC) method, and minimum bactericidal concentration (MBC) method. The effects of antimicrobial agent amount, size-related property (nanoparticles and bulk chitosan), and crosslinking by citric acid on antimicrobial activity of cellulose films were studied. It was observed that the antimicrobial activity was enhanced when chitosan nanoparticles were used as compared to when bulk chitosan was used. A maximumE. coliinhibition of 85% was achieved with only 5% (v/v) doping of chitosan nanoparticles into the cellulose films. Crosslinking of the cellulose films with citric acid was observed to have resulted in 50% reduction of water absorbency and a slight increase ofE. coliinhibition by 3% for chitosan nanoparticles-doped cellulose films.

scholarly journals Characterization and Antimicrobial Activities of a Metabolite from a New Streptomyces Species from Bangladeshi Soil

2009 ◽  
Vol 2 (1) ◽  
pp. 178-185
Author(s):  
M. Akhand ◽  
M. A. A. Al-Bari ◽  
M. A. Islam ◽  
Proma Khondkar
Keyword(s):  
Antimicrobial Activity ◽  
Antimicrobial Activities ◽  
Assay Method ◽  
Streptomyces Species ◽  
Isolation And Characterization ◽  
Test Organisms ◽  
Actinomycete Strain ◽  
Diffusion Assay ◽  
Strong Antimicrobial Activity

A new actinomycete strain was isolated from Western part of Bangladesh and identified as a new Streptomyces species on the basis of its morphological, biochemical, cultural characteristics and 16S rRNA data. The present paper describes the isolation and characterization of compound 1 from this new Streptomyces species with the help of various chemical and spectroscopic methods. Antimicrobial activity of compound 1 was tested by disc diffusion assay method and compared with that of standard antibiotics (Kanamycin for antibacterial activity and Nystatin for antifungal activity). The compound has been found to exhibit moderate to strong antimicrobial activity against the test organisms. Cytotoxicity of the compound 1 and the pet. ether extract of Czapek Dox (alkaline) broth of Streptomyces species was evaluated in brine shrimp bioassay with LC50 values of 23.85 µg/ml (ppm) and 19.95 µg/ml (ppm), respectively. Keywords: Streptomyces; Antimicrobial activity; Cytotoxicity. © 2010 JSR Publications. ISSN: 2070-0237 (Print); 2070-0245 (Online). All rights reserved. DOI: 10.3329/jsr.v2i1.3079                  J. Sci. Res. 2 (1), 178-185 (2010)  

SYNTHESIS, CHARACTERIZATION AND BIOLOGICAL EVALUATION OF 3-FORMYL INDOLE BASED SCHIFF BASES

2018 ◽  
Vol 7 (6) ◽  
Author(s):  
Singh Gurvinder ◽  
Singh Prabhsimran ◽  
Dhawan R. K.
Keyword(s):  
Antimicrobial Activity ◽  
Spectral Analysis ◽  
Schiff Bases ◽  
Antimicrobial Agents ◽  
Biological Evaluation ◽  
Fungal Strain ◽  
Bacterial Strains ◽  
Standard Drug ◽  
Gram Negative ◽  
E Coli

In order to develop new antimicrobial agents, a series of 3-formyl indole based Schiff bases were synthesized by reacting 3-formyl indole(indole-3-carboxaldehyde) with substituted aniline taking ethanol as solvent. The reaction was carried in the presence of small amount of p-toluene sulphonic acid as catalyst.All the synthesized compounds were characterized by IR, 1H-NMR spectral analysis. All the synthesized compounds were evaluated for antimicrobial activity against two gram positive bacterial strains (B. subtilisand S. aureus) and two gram negative bacterial strains (P. aeruginosaand E. coli) and one fungal strain (C. albicans). All the synthesized compounds were found to have moderate to good antimicrobial activity. The  standard drug amoxicillin, fluconazole were used for antimicrobial activity. Among the synthesized compounds, the maximum antimicrobial activity was shown by compounds GS04, GS07, GS08 and GS10.

Efficacy of Silver Nanoparticles Synthesized from Hymenocallis species (Spider Lilly) Leaf Extract as Antimicrobial Agents

2019 ◽  
Vol 12 (5) ◽  
pp. 4644-4647
Author(s):  
K.K. Gupta ◽  
Neha Kumari ◽  
Neha Sinha ◽  
Akruti Gupta
Keyword(s):  
Silver Nanoparticles ◽  
Leaf Extract ◽  
Antimicrobial Agents ◽  
Color Change ◽  
Bacterial Species ◽  
Antimicrobial Property ◽  
Biogenic Synthesis ◽  
E Coli ◽  
Light Yellow ◽  
Antibiotic Property

Biogenic synthesis of silver nanoparticles synthesized from Hymenocallis species (Spider Lilly) leaf extract was subjected for investigation of its antimicrobial property against four bacterial species (E. coli, Salmonella sp., Streptococcus sp. & Staphylococcus sp.). The results revealed that synthesized nanoparticles solution very much justify the color change property from initial light yellow to final reddish brown during the synthesis producing a characteristics absorption peak in the range of 434-466 nm. As antimicrobial agents, their efficacy was evaluated by analysis of variance in between the species and among the different concentration of AgNPs solution, which clearly showed that there was significant variation in the antibiotic property between the four different concentrations of AgNPs solution and also among four different species of bacteria taken under studies. However, silver nanoparticles solution of 1: 9 and 1:4 were proved comparatively more efficient as antimicrobial agents against four species of bacteria.

scholarly journals Conditions to Prolonged Release of Microencapsulated Carvacrol on Alginate Films as Affected by Emulsifier Type and PH

2015 ◽  
Vol 2015 ◽  
pp. 1-12 ◽  
Author(s):  
Silvia Matiacevich ◽  
Natalia Riquelme ◽  
María Lidia Herrera
Keyword(s):  
Storage Time ◽  
Antimicrobial Agents ◽  
Antimicrobial Properties ◽  
Edible Film ◽  
Initial Time ◽  
Tween 20 ◽  
Prolonged Release ◽  
E Coli ◽  
Fresh Foods

Alginate from algal biomass is used as edible film and the incorporation of antimicrobial agents improves its performance to increase the shelf-life of fresh foods. However, environmental conditions and intrinsic properties of films influence their release. The aim of this study was to investigate the effect of the concentration and type of encapsulating agent and pH of emulsions on the physical and antimicrobial properties of alginate-carvacrol films. Films containing alginate, carvacrol as antimicrobial agent, and Tween 20 or trehalose (0.25 and 0.75% w/w) as encapsulating agents were obtained from suspensions at pH 4 and pH 8. Physical characterization of emulsions and films and antimicrobial properties (E. coliandB. cinerea) was evaluated. Results showed that droplets size depended on trehalose concentration, but emulsion stability depended on pH and type of encapsulating agent, being more stable samples with trehalose at pH 4. Although films with Tween 20 presented the highest opacity, they showed the best antimicrobial properties at initial time; however, during storage time, they lost their activity before samples with trehalose and relative humidity (RH) was the principal factor to influence their release. Therefore, sample formulated with 0.25% trehalose at pH 4 and stored at 75% RH had the best potential as edible film for fresh fruits.

scholarly journals Characterization of bacteriocin and chitinase producing bacterial isolates with broad-spectrum antimicrobial activities

2021 ◽  
Vol 3 (8) ◽  
Author(s):  
Muhammad Yasir ◽  
Basit Zeshan ◽  
Nur Hardy A. Daud ◽  
Izzah Shahid ◽  
Hafza Khalid
Keyword(s):  
Antimicrobial Activity ◽  
Inhibitory Activity ◽  
Antifungal Drugs ◽  
Proteinase K ◽  
Diffusion Method ◽  
List Type ◽  
Bacterial Isolates ◽  
E Coli ◽  
Inhibitory Potential

Abstract There is a need for more efficient and eco-friendly approaches to overcome increasing microbial infections. Bacteriocins and chitinases from Bacillus spp. can be powerful alternatives to conventional antibiotics and antifungal drugs, respectively. The purpose of this study was to assess the inhibitory potential of bacteriocins and chitinase enzymes against multiple resistant bacterial and fungal pathogens. Bacterial isolates were selected by growth on minimal salts medium and after that were morphologically and biochemically characterized. The physiochemical characterization of bacteriocins was carried out. The inhibitory potential of bacteriocins towards six pathogenic bacteria was determined by the well diffusion assay while chitinase activity towards three fungal strains was determined by the dual plate culture assay. Two bacterial strains (WW2P1 and WRE4P2), out of nine showed inhibition of K. pneumonia, P. aeruginosa, E. coli and MRSA while WW4P2 was positive against S. typhimurium and E. coli and WRE10P2 against P. aeruginosa, S. pneumoniae. Two bacterial isolates (WW3P1 and WRE10P2) were chosen for further study on the basis of their antifungal activities. Of these, WW3P1 isolate was more effective against A. fumigatus as well as A. niger. The proteinaceous nature of the bacteriocins was confirmed by treatment of the crude extract with proteinase K. It was found that the inhibitory activity of strain WW3P1 against E. coli was highest at 20 °C, and against S. pneumoniae it was at 20 °C and pH 10 after treatment with EDTA. Inhibition by strain the WRE10P2 against P. aeruginosa was highest at 20 °C and pH 14. It was found that EDTA increased the inhibitory activity of strain WW2P1 against P. aeruginosa, K. pneumoniae and E. coli by 2 ± 0.235, 3.5 ± 0.288, 2.5 ± 1.040 times, respectively, of strain WRE4P2 against P. aeruginosa and E. coli by 2.5 ± 0.763, 2.7 ± 0.5 times, respectively, and of strain WRE10P2 against S. pneumoniae by 3 ± 0.6236 times. The isolates have promising inhibitory activity, which should be further analyzed for the commercial production of antimicrobials. Article highlights The current study aimed to isolate the microbiome from wheat plant (Triticum aestivum L.), to screen for bacteriocin production and to assess its antimicrobial activity against human pathogens. Forty-one phenotypically different bacterial colonies were subjected to bacteriocin purification from which 25 colonies showed positive reactions. These 25 bacterial isolates were screened against six different human bacterial pathogens using the well diffusion method to check the antimicrobial activity. Out of nine bacterial isolates, WW3P1 and WRE10P2 were able to degrade the chitin and utilize it as their sole energy source. Strain WRE4P2 exhibited partial inactivation in its activity against MRSA after treatment with proteinase K.

scholarly journals Antimicrobial activity of honeys from two stingless honeybee species and Apis mellifera (Hymenoptera: Apidae) against pathogenic microorganisms

2014 ◽  
Vol 44 (2) ◽  
pp. 287-290 ◽  
Author(s):  
Carolinie Batista Nobre da Cruz ◽  
Fabio Alessandro Pieri ◽  
Gislene Almeida Carvalho-Zilse ◽  
Patrícia Puccinelli Orlandi ◽  
Carlos Gustavo Nunes-Silva ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Antimicrobial Activity ◽  
Apis Mellifera ◽  
Antimicrobial Agents ◽  
Dilution Method ◽  
Agar Dilution Method ◽  
Therapeutic Approaches ◽  
E Coli ◽  
Agar Dilution ◽  
Amazonas State

Honeys are described possessing different properties including antimicrobial. Many studies have presented this activity of honeys produced by Apis mellifera bees, however studies including activities of stingless bees honeys are scarce. The aim of this study was to compare the antimicrobial activity of honeys collected in the Amazonas State from Melipona compressipes, Melipona seminigra and Apis mellifera against Staphylococcus aureus, Enterococcus faecalis, Escherichia coli, Chromobacterium violaceum, and Candida albicans. Minimum inhibitory concentrations were determined using the agar dilution method with Müller-Hinton agar (for bacteria) or Saboraud agar (for yeast). Staphylococcus aureus and E. faecalis were inhibited by all honeys at concentrations below 12%, while E. coli and C. violaceum were inhibited by stingless bee honeys at concentrations between 10 and 20%. A. mellifera honey inhibited E. coli at a concentration of 7% and Candida violaceum at 0.7%. C. albicans were inhibited only with honey concentrations between 30 and 40%. All examined honey had antimicrobial activity against the tested pathogens, thus serving as potential antimicrobial agents for several therapeutic approaches.

scholarly journals Synthesis, Molecular Docking and Antimicrobial Evaluation of Some Benzothiazoles

2021 ◽  
Author(s):  
Smita J. Pawar ◽  
Amol Kale ◽  
Priya Zori ◽  
Rahul Dorugade
Keyword(s):  
Antimicrobial Activity ◽  
Antimicrobial Property ◽  
Docking Study ◽  
Gram Negative Bacteria ◽  
Zone Of Inhibition ◽  
E Coli ◽  
Good Antibacterial Activity ◽  
Comparable Activity ◽  
Antimicrobial Evaluation ◽  
Bacteria And Fungi

Abstract Abstract The new series of 2-(substituted amino)-N-(6- substituted-1,3-benzothiazol-2yl) acetamide BTC(a-t) has been synthesized by appropriate synthetic route from substituted 2-amino benzothiazole. The synthesized compounds were screened experimentally for its antimicrobial property against gram positive, gram negative bacteria and fungi. Zone of inhibition and minimum inhibitory concentration of compounds was determined against selected bacterial and fungal strains. Compound BTC-j N-(6-methoxy-1,3-benzothiazol-2-yl)-2-(pyridine-3-yl amino) acetamide and compound BTC-r N-(6-nitro-1,3-benzothiazol-2-yl)-2-(pyridine-3-yl amino) acetamide found to have good antimicrobial potential. The compound BTC-j has shown good antibacterial activity against S. aureus at MIC of 12.5 µg/ml, B. subtilis at MIC of 6.25µg/ml, E. coli at MIC of 3.125µg/ml and P. aeruginosa at MIC of 6.25µg/ml. No statistical difference in antimicrobial activity of standard and test compounds was found indicating test compounds have comparable activity. Further docking study was carried out to check the probable interactions with the selected protein using V-life MDS 3.5 software. (DNA gyrase, PDB: 3G75). The dock score of compounds and antimicrobial activity found to be consistent.

Novel Quantitative Assays for Estimating the Antimicrobial Activity of Fresh Garlic Juice†,‡

2001 ◽  
Vol 64 (2) ◽  
pp. 189-194 ◽  
Author(s):  
R. UNAL ◽  
H. P. FLEMING ◽  
R. F. McFEETERS ◽  
R. L. THOMPSON ◽  
F. BREIDT ◽  
...  
Keyword(s):  
Antimicrobial Activity ◽  
Dose Response ◽  
Ratio Method ◽  
E Coli ◽  
Agar Diffusion ◽  
Dilution Assay ◽  
Agar Diffusion Assay ◽  
Slope Ratio Method ◽  
Diffusion Assay ◽  
Broth Dilution

Novel agar diffusion and broth dilution assays were developed for quantitatively estimating the antimicrobial activity of fresh garlic juice. Bacteria found to be inhibited by garlic juice in agar diffusion assay included two gram-positive and five gram-negative species. Leuconostoc mesenteroides was not inhibited. Escherichia coli B-103 (HB101, with pJH101, ampicillin resistant, 100 μg ml−1) was inhibited and chosen as the standard culture for quantitative assays. The agar diffusion assay was based on the slope ratio method, where the slope of dose response for garlic juice was divided by the slope of dose response for methylmethane thiosulfonate (MMTSO2). Juice from fresh garlic varied in activity between 1.76 and 2.31 μg of MMTSO2 per mg of garlic juice. The activity of juice decreased during 11 months of storage of garlic cloves at 5°C from 2.31 to less than 0.1 μg of MMTSO2 per mg of juice. The broth dilution assay also used the E. coli B-103 culture, which permitted selective enumeration of this bacterium when 100 μg ml−1 of ampicillin was incorporated into the enumerating agar. Selective enumeration was essential since the garlic juice was not sterile and, thus, contained natural flora. Growth of E. coli was unaffected by 0.1%, delayed by 0.25%, and completely inhibited at 0.5 and 2% garlic juice in broth during 24 h of incubation at 37°C. The minimum inhibition concentration of garlic juice by broth dilution assay was, thus, estimated to be 0.5%, which is equivalent to 3.46 μg of MMTSO2 per mg of garlic juice by the agar diffusion assay.

scholarly journals 3-Amino-5-(indol-3-yl)methylene-4-oxo-2-thioxothiazolidine Derivatives as Antimicrobial Agents: Synthesis, Computational and Biological Evaluation

2020 ◽  
Vol 13 (9) ◽  
pp. 229
Author(s):  
Volodymyr Horishny ◽  
Victor Kartsev ◽  
Vasyl Matiychuk ◽  
Athina Geronikaki ◽  
Petrou Anthi ◽  
...  
Keyword(s):  
Antimicrobial Activity ◽  
Antibacterial Activity ◽  
Antifungal Activity ◽  
Antimicrobial Agents ◽  
Biological Evaluation ◽  
Minimal Bactericidal Concentration ◽  
Active Compounds ◽  
Hek 293 ◽  
E Coli ◽  
Thiazolyl Blue Tetrazolium Bromide

Herein we report the design, synthesis, computational, and experimental evaluation of the antimicrobial activity of fourteen new 3-amino-5-(indol-3-yl) methylene-4-oxo-2-thioxothiazolidine derivatives. The structures were designed, and their antimicrobial activity and toxicity were predicted in silico. All synthesized compounds exhibited antibacterial activity against eight Gram-positive and Gram-negative bacteria. Their activity exceeded those of ampicillin and (for the majority of compounds) streptomycin. The most sensitive bacterium was S. aureus (American Type Culture Collection ATCC 6538), while L. monocytogenes (NCTC 7973) was the most resistant. The best antibacterial activity was observed for compound 5d (Z)-N-(5-((1H-indol-3-yl)methylene)-4-oxo-2-thioxothiazolidin-3-yl)-4-hydroxybenzamide (Minimal inhibitory concentration, MIC at 37.9–113.8 μM, and Minimal bactericidal concentration MBC at 57.8–118.3 μM). Three most active compounds 5d, 5g, and 5k being evaluated against three resistant strains, Methicillin resistant Staphilococcus aureus (MRSA), P. aeruginosa, and E. coli, were more potent against MRSA than ampicillin (MIC at 248–372 μM, MBC at 372–1240 μM). At the same time, streptomycin (MIC at 43–172 μM, MBC at 86–344 μM) did not show bactericidal activity at all. The compound 5d was also more active than ampicillin towards resistant P. aeruginosa strain. Antifungal activity of all compounds exceeded those of the reference antifungal agents bifonazole (MIC at 480–640 μM, and MFC at 640–800 μM) and ketoconazole (MIC 285–475 μM and MFC 380–950 μM). The best activity was exhibited by compound 5g. The most sensitive fungal was T. viride (IAM 5061), while A. fumigatus (human isolate) was the most resistant. Low cytotoxicity against HEK-293 human embryonic kidney cell line and reasonable selectivity indices were shown for the most active compounds 5d, 5g, 5k, 7c using thiazolyl blue tetrazolium bromide MTT assay. The docking studies indicated a probable involvement of E. coli Mur B inhibition in the antibacterial action, while CYP51 inhibition is likely responsible for the antifungal activity of the tested compounds.

Characterization of the genetic environment of blaKPC in Escherichia coli isolates from hospitals in China

2020 ◽  
Vol 367 (11) ◽  
Author(s):  
Xuejing Yang ◽  
Yan Qi ◽  
Guoping Li ◽  
Yuying Wang ◽  
Zhengqing Lou ◽  
...  
Keyword(s):  
Antimicrobial Agents ◽  
Carbapenem Resistance ◽  
Pcr Analysis ◽  
Genetic Environment ◽  
E Coli ◽  
Carbapenem Resistant ◽  
Infection Treatment ◽  
Hospital Infection Control ◽  
Klebsiella Pneumoniae Carbapenemases

ABSTRACT Carbapenem resistance in Enterobacteriaceae members has become a major challenge, and the genetic environment of blaKPC, encoding Klebsiella pneumoniae carbapenemases, has not been fully clarified in China. In this study, we aimed to explore the genetic environment of blaKPC in 25 carbapenem-resistant E. coli isolates from hospitals in Hangzhou Province, China. Antimicrobial susceptibility against 22 common antimicrobial agents was tested. Polymerase chain reaction (PCR) analysis was performed for screening of the resistent genes, such as blaKPC, blaCTX-M, blaTEM, blaSHV, blaNDM, qnrA, qnrB, qnrS, aac(6’)-Ib, armA and rmtB. The genetic environment of blaKPC were determinedin one isolate. blaKPC was detected by PCR in all the clinical E. coli isolates. There were no strains carrying blaNDM, qnrA and armA. The genetic environment of blaKPC showed that blaKPC dissemination is plasmid mediated and that it is located in the Tn3–Tn4401 transposon complex. Encoding of blaKPC-2 was responsible for carbapenem resistance in the 25 E. coli isolates. The genetic environment of blaKPC was characterized by the Tn3–Tn4401 complex. Our findings may provide a theoretical basis for clinical drug-resistance monitoring, anti-infection treatment and hospital infection control.

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