scholarly journals Extracellular probiotic lipase capped silver nanoparticles as highly efficient broad spectrum antimicrobial agents

RSC Advances ◽  
2018 ◽  
Vol 8 (55) ◽  
pp. 31358-31365 ◽  
Author(s):  
Imran Khan ◽  
Nivetha Sivasankaran ◽  
Ravikiran Nagarjuna ◽  
Ramakrishnan Ganesan ◽  
Jayati Ray Dutta

A series of Ag NPs capped with different concentrations of probiotic lipase have been synthesized. The obtained Ag NPs exhibited efficient broad spectrum antimicrobial activity at concentrations much lower than the LC50values of zebrafish.

Author(s):  
Ahmad Jafari ◽  
Ramin Mazaheri Nezhad Fard ◽  
Sima Shahabi ◽  
Farid Abbasi ◽  
Golshid Javdani Shahedin ◽  
...  

Background and Objectives: Silver nanoparticles (Ag-NPs) are potent antimicrobial agents, which have recently been used in dentistry. The aim of the current study was to optimize antimicrobial activity of Ag-NPs used in preparing irre- versible hydrocolloid impressions against three microorganisms of Escherichia coli, Streptococcus mutans and Candida albicans. Materials and Methods: After assessing antimicrobial activity of the compound using disk diffusion method, three parame- ters of concentration of Ag-NPs (250-1000 ppm), ratio of hydrocolloid impression material powder to water (0.30-0.50) and time of mixing (20.0-60.0 s), affecting antimicrobial activity of irreversible hydrocolloid impression materials against the three microorganisms, were optimized. This combined process was successfully modeled and optimized using Box-Behnken design with response surface methodology (RSM). Decreases in colony number of E. coli, S. mutans and C. albicans were proposed as responses. Results: Qualitative antimicrobial assessments respectively showed average zone of inhibition (ZOI) of 3.7 mm for E. coli, 3.5 mm for S. mutans and 4 mm for C. albicans. For all responses, when the mixing duration and powder-to-water ratio increased, the circumstances (mixing duration of 59.38 s, powder-to-water ratio of 0.4 and Ag-NP concentration of 992 response) increased. Results showed that in optimum ppm, the proportion of decreases in colony numbers was maximum (89.03% for E. coli, 87.08% for S. mutans and 74.54% for C. albicans). Regression analysis illustrated a good fit of the ex- perimental data to the predicted model as high correlation coefficients validated that the predicted model was well fitted with data. Values of R2Adj with R2Pred were associated to the accuracy of this model in all responses. Conclusion: Disinfection efficiency dramatically increased with increasing of Ag-NP concentration, powder-to-water ratio and mixing time.


RSC Advances ◽  
2019 ◽  
Vol 9 (5) ◽  
pp. 2673-2702 ◽  
Author(s):  
Anupam Roy ◽  
Onur Bulut ◽  
Sudip Some ◽  
Amit Kumar Mandal ◽  
M. Deniz Yilmaz

In this review, we discuss the recent advances in green synthesis of silver nanoparticles, their application as antimicrobial agents and mechanism of antimicrobial mode of action.


2019 ◽  
Vol 70 (7) ◽  
pp. 2571-2573
Author(s):  
Alina Andreea Tischer (Tucuina) ◽  
Delia Berceanu Vaduva ◽  
Nicolae Balica ◽  
Alina Heghes ◽  
Adelina Cheveresan ◽  
...  

In recent years, bacterial infections in hospitals have grown particularly due to the development of antibiotic resistance. Recent research targets the discovery of new antibiotics that exhibit broad spectrum of action without adverse effects or minimizing adverse effects. In this study, the activity of biosynthesized silver nanoparticles against three bacteria commonly found in infectious diseases in the ORL sphere was evaluated. The recorded data revealed an activity comparable to that of the standard antibiotics used in these types of infections, with the observation that the activity of the nanoparticles could also be observed in the particular cases of antibiotic resistance.


2020 ◽  
Vol 8 (32) ◽  
pp. 7197-7212 ◽  
Author(s):  
Zhiyong Qian ◽  
Yating Bai ◽  
Jin Zhou ◽  
Linhao Li ◽  
Jing Na ◽  
...  

The CTS-SF/SA/Ag-Exo dressing possessed multifunctional properties including broad-spectrum antimicrobial activity, promoting wound healing, retaining moisture and maintaining electrolyte balance.


2016 ◽  
Vol 2016 ◽  
pp. 1-7 ◽  
Author(s):  
Melisa A. Quinteros ◽  
Ivana M. Aiassa Martínez ◽  
Pablo R. Dalmasso ◽  
Paulina L. Páez

Currently, the biosynthesis of silver-based nanomaterials attracts enormous attention owing to the documented antimicrobial properties of these ones. This study reports the extracellular biosynthesis of silver nanoparticles (Ag-NPs) using aPseudomonas aeruginosastrain from a reference culture collection. A greenish culture supernatant ofP. aeruginosaincubated at 37°C with a silver nitrate solution for 24 h changed to a yellowish brown color, indicating the formation of Ag-NPs, which was confirmed by UV-vis spectroscopy, transmission electron microscopy, and X-ray diffraction. TEM analysis showed spherical and pseudospherical nanoparticles with a distributed size mainly between 25 and 45 nm, and the XRD pattern revealed the crystalline nature of Ag-NPs. Also it provides an evaluation of the antimicrobial activity of the biosynthesized Ag-NPs against human pathogenic and opportunistic microorganisms, namely,Staphylococcus aureus,Staphylococcus epidermidis,Enterococcus faecalis,Proteus mirabilis,Acinetobacter baumannii,Escherichia coli,P. aeruginosa, andKlebsiella pneumonia. Ag-NPs were found to be bioactive at picomolar concentration levels showing bactericidal effects against both Gram-positive and Gram-negative bacterial strains. This work demonstrates the first helpful use of biosynthesized Ag-NPs as broad spectrum bactericidal agents for clinical strains of pathogenic multidrug-resistant bacteria such as methicillin-resistantS. aureus,A. baumannii, andE. coli. In addition, these Ag-NPs showed negligible cytotoxic effect in human neutrophils suggesting low toxicity to the host.


2017 ◽  
Vol 10 (5) ◽  
pp. 1322
Author(s):  
S. Krishnakumar ◽  
R. Divya ◽  
N.R. Kanchana Devi ◽  
G. Keerthana ◽  
A. Ancy Judi

2021 ◽  
Vol 6 (1) ◽  
pp. 68-78
Author(s):  
Senthilkumar Palanisamy ◽  
Kalaivani Subramanian ◽  
Lerince Godrina Bennet ◽  
Janani Ambrose ◽  
Aganiya Gopalakrishnan ◽  
...  

Abstract The pregnant cow urine (PCU) is an active source of antimicrobial agents that is used for fabricating chitosan coated Ag/AgCl nanoparticles (NPs) in the present study. These PCU@C-Ag/AgCl NPs were physicochemically characterized and evaluated for antimicrobial activity against selected respiratory tract infection (RTI) pathogens. The absorption band around 420 nm in UV-Visible spectrum indicated the presence of Ag NPs. The spherical shape of NPs was observed using TEM. Also, the crystalline structure was confirmed using the XRD pattern. The PCU@C-Ag/AgCl NPs showed strong antimicrobial activity against all tested RTI pathogens. In addition, FESEM analysis showed morphological changes in RTI bacterial pathogens. Thereby, PCU@C-Ag/AgCl NPs may be used as an antimicrobial material to treat RTIs in near future at clinical level.


Antibiotics ◽  
2020 ◽  
Vol 9 (10) ◽  
pp. 718 ◽  
Author(s):  
Gervonne Barran ◽  
Jolanta Kolodziejek ◽  
Laurent Coquet ◽  
Jérôme Leprince ◽  
Thierry Jouenne ◽  
...  

Ocellatins are peptides produced in the skins of frogs belonging to the genus Leptodactylus that generally display weak antimicrobial activity against Gram-negative bacteria only. Peptidomic analysis of norepinephrine-stimulated skin secretions from Leptodactylus insularum Barbour 1906 and Leptodactylus nesiotus Heyer 1994, collected in the Icacos Peninsula, Trinidad, led to the purification and structural characterization of five ocellatin-related peptides from L. insularum (ocellatin-1I together with its (1–16) fragment, ocellatin-2I and its (1–16) fragment, and ocellatin-3I) and four ocellatins from L. nesiotus (ocellatin-1N, -2N, -3N, and -4N). While ocellatins-1I, -2I, and -1N showed a typically low antimicrobial potency against Gram-negative bacteria, ocellatin-3N (GIFDVLKNLAKGVITSLAS.NH2) was active against an antibiotic-resistant strain of Klebsiella pneumoniae and reference strains of Escherichia coli, K. pneumoniae, Pseudomonas aeruginosa, and Salmonella typhimurium (minimum inhibitory concentrations (MICs) in the range 31.25–62.5 μM), and was the only peptide active against Gram-positive Staphylococcus aureus (MIC = 31.25 μM) and Enterococcus faecium (MIC = 62.5 μM). The therapeutic potential of ocellatin-3N is limited by its moderate hemolytic activity (LC50 = 98 μM) against mouse erythrocytes. The peptide represents a template for the design of long-acting, non-toxic, and broad-spectrum antimicrobial agents for targeting multidrug-resistant pathogens.


RSC Advances ◽  
2016 ◽  
Vol 6 (38) ◽  
pp. 31871-31875 ◽  
Author(s):  
Lini Yang ◽  
Lina Xing ◽  
Cunxia Cheng ◽  
Lixin Xia ◽  
Hongyang Liu

The Ag NPs with sizes ranging form 5–6 nm confined into SBA-15 show a very good activity and robust recycle ability for hydrogenation of chloronitrobenzenes to the corresponding chloroanilines by H2, comparing with that of the traditional SiO2 supported Ag catalysts.


RSC Advances ◽  
2016 ◽  
Vol 6 (24) ◽  
pp. 20392-20398 ◽  
Author(s):  
Rui Ding ◽  
Xinjun Yu ◽  
Peng Wang ◽  
Jinnan Zhang ◽  
Yan Zhou ◽  
...  

We report the development of a type of novel hybrid photosensitizers for photodynamic inactivation of broad-spectrum bacteria.


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