scholarly journals Biosynthesis, Characterization and Antibacterial Application of Novel Silver Nanoparticles against Drug Resistant Pathogenic Klebsiella pneumoniae and Salmonella Enteritidis

Molecules ◽  
2021 ◽  
Vol 26 (19) ◽  
pp. 5996
Author(s):  
Md. Amdadul Huq ◽  
Shahina Akter

The present study highlights the biosynthesis of silver nanoparticles (AgNPs) using culture supernatant of Massilia sp. MAHUQ-52 as well as the antimicrobial application of synthesized AgNPs against multi-drug resistant pathogenic Klebsiella pneumoniae and Salmonella Enteritidis. Well-defined AgNPs formation occurred from the reaction mixture of cell-free supernatant and silver nitrate (AgNO3) solution within 48 h of incubation. UV-visible spectroscopy analysis showed a strong peak at 435 nm, which corresponds to the surface plasmon resonance of AgNPs. The synthesized AgNPs were characterized by FE-TEM, EDX, XRD, DLS and FT-IR. From FE-TEM analysis, it was found that most of the particles were spherical shape, and the size of synthesized nanoparticles (NPs) was 15–55 nm. EDX spectrum revealed a strong silver signal at 3 keV. XRD analysis determined the crystalline, pure, face-centered cubic AgNPs. FT-IR analysis identified various functional molecules that may be involved with the synthesis and stabilization of AgNPs. The antimicrobial activity of Massilia sp. MAHUQ-52 mediated synthesized AgNPs was determined using the disk diffusion method against K. pneumoniae and S. Enteritidis. Biosynthesized AgNPs showed strong antimicrobial activity against both K. pneumoniae and S. Enteritidis. The MICs of synthesized AgNPs against K. pneumoniae and S. Enteritidis were 12.5 and 25.0 μg/mL, respectively. The MBC of biosynthesized AgNPs against both pathogens was 50.0 μg/mL. From FE-SEM analysis, it was found that the AgNPs-treated cells showed morphological changes with irregular and damaged cell walls that culminated in cell death.

Author(s):  
VISHNU KIRAN MANAM ◽  
MURUGESAN SUBBAIAH

Objective: The current study illustrates the biosynthesis of economically scalable and energy efficient colloidal silver nanoparticles (AgNPs) from marine red seaweed Halymenia porphyroides Boergesen (Crypton) collected from Southeast coast of Tamil Nadu, India, and their antifungal efficacy against dermatophytic and non-dermatophytic fungi was evaluated. Methods: The biosynthesis of silver nanoparticles from marine macroscopic red seaweed H. porphyroides Boergesen were synthesized by green synthesis method and characterized by UV–Vis spectroscopy, Fourier transform infrared (FT-IR) spectroscopy, X-ray diffraction, thermogravimetric analysis (TGA), scanning electron microscope (SEM), and transmission electron microscopy (TEM). The efficacy of silver nanoparticles against dermatophytic and non-dermatophytic fungi was performed by disk diffusion method. Results: The presence of silver nanoparticles with an average size between 34.3 and 80 nm and exhibiting face-centered cubic structure was confirmed. SEM revealed the morphology of the nanoparticles as spherical and TEM exhibited the nanoparticle distribution. The FT-IR spectra confirmed the presence of potential biomolecules in the seaweed crude extract which is responsible for reducing and capping the bioreduced silver nanoparticles. The UV absorption spectra at 430.5 nm revealed the characteristic spectra of the silver nanoparticles. The purity and the thermal stability of silver nanoparticles were revealed by TGA. Silver nanoparticles showed significant efficacy against dermatophytes and Rhizopus microsporus among non-dermatophytes. Conclusion: Intermediate efficacy was observed against dermatophytes and among non-dermatophytic fungi R. microsporus exhibited better efficacy, whereas Aspergillus flavus were resistant to the biosynthesized silver nanoparticle.


Animals ◽  
2021 ◽  
Vol 11 (12) ◽  
pp. 3554
Author(s):  
Rasha M. M. Abou Elez ◽  
Ibrahim Elsohaby ◽  
Nashwa El-Gazzar ◽  
Hala M. N. Tolba ◽  
Eman N. Abdelfatah ◽  
...  

Salmonella enterica is one of the most common causes of foodborne illness worldwide. Contaminated poultry products, especially meat and eggs are the main sources of human salmonellosis. Thus, the aim of the present study was to determine prevalence, antimicrobial resistance profiles, virulence, and resistance genes of Salmonella Enteritidis (S. enteritidis) and Salmonella Typhimurium (S. Typhimurium) isolated from laying hens, table eggs, and humans, in Sharkia Governorate, Egypt. The antimicrobial activity of Biosynthesized Silver Nanoparticles (AgNPs) was also evaluated. Salmonella spp. were found in 19.3% of tested samples with laying hens having the highest isolation rate (33.1%). S. Enteritidis) (5.8%), and S. Typhimurium (2.8%) were the dominant serotypes. All isolates were ampicillin resistant (100%); however, none of the isolates were meropenem resistant. Multidrug-resistant (MDR) was detected in 83.8% of the isolates with a multiple antibiotic resistance index of 0.21 to 0.57. Most isolates (81.1%) had at least three virulence genes (sopB, stn, and hilA) and none of the isolates harbored the pefA gene; four resistance genes (blaTEM, tetA, nfsA, and nfsB) were detected in 56.8% of the examined isolates. The AgNPs biosynthesized by Aspergillus niveus exhibit an absorption peak at 420 nm with an average size of 27 nm. AgNPs had a minimum inhibitory concentration of 5 µg/mL against S. enteritidis and S. typhimurium isolates and a minimum bactericidal concentration of 6 and 8 µg/mL against S. enteritidis and S. typhimurium isolates, respectively. The bacterial growth and gene expression of S. enteritidis and S. typhimurium isolates treated with AgNPs were gradually decreased as storage time was increased. In conclusion, this study indicates that S. enteritidis and S. typhimurium isolated from laying hens, table eggs, and humans exhibits resistance to multiple antimicrobial classes. The biosynthesized AgNPs showed potential antimicrobial activity against MDR S. enteritidis and S. typhimurium isolates. However, studies to assess the antimicrobial effectiveness of the biosynthesized AgNPs in laying hen farms are warranted.


2021 ◽  
Vol 14 (1) ◽  
pp. 38-44
Author(s):  
F.Z. Idris ◽  
U.A. Habibu

The present study was conducted to investigate antimicrobial activity of ethanol, dichloromethane and n-hexane extracts of Cinnamomum verum stem bark against Multi-drug resistant clinical isolates. C. verum bark powder was extracted with ethanol, dichloromethane and hexane respectively using Soxhlet extractor for 6 hrs. at temperature not exceeding the boiling point of the respective solvents. The extracts were further subjected to phytochemical screening as well as antimicrobial tests against clinical isolates of confirmed multi-drug resistant Staphylococcus aureus, Klebsiella pneumoniae and Pseudomonas aeruginosa using agar well diffusion method. Minimum inhibitory concentrations (MICs) and Minimum bactericidal concentrations (MBCs) were also determined. The extracts yield 11.8g, 10.2g and 9.0g for ethanol, dichloromethane and hexane respectively. The results of phytochemical screening indicated the presence of alkaloids, reducing sugars, saponins, steroids, cardiac glycoside, flavonoid, anthraquinones and tannins in the extracts. The ethanolic extracts showed the highest antimicrobial activity of 12.3±0.5mm against P. aeruginosa and 15.3±1.3mm against K. pneumoniae at 100mg/ml and antibacterial activities of 11.3±0.5mm against K. pneumoniae followed by 9.0±0.4mm against Pseudomonas aeruginosa and the least 8.0±0.0mm against Staphylococcus aureus at 20mg/ml concentration. While hexane extract of the plant has the highest activity of 9.0±0.0mm against Staphylococcus aureus isolates but less active against the remaining isolates at 20mg/ml concentration. Dichloromethane extract was less active against all the MDR isolates. The results showed that the MICs of C. verum ranged from 5-20 mg/ml while the MBCs ranged from 10-40 mg/ml. Thus C. verum could be used as potential source of antibacterial agents against MDR microbes.


Biology ◽  
2021 ◽  
Vol 10 (6) ◽  
pp. 473
Author(s):  
Prabu Kumar Seetharaman ◽  
Rajkuberan Chandrasekaran ◽  
Rajiv Periakaruppan ◽  
Sathishkumar Gnanasekar ◽  
Sivaramakrishnan Sivaperumal ◽  
...  

To develop a benign nanomaterial from biogenic sources, we have attempted to formulate and fabricate silver nanoparticles synthesized from the culture filtrate of an endophytic fungus Penicillium oxalicum strain LA-1 (PoAgNPs). The synthesized PoAgNPs were exclusively characterized through UV–vis absorption spectroscopy, Fourier Transform Infra-Red spectroscopy (FT-IR), X-ray powder diffraction (XRD), and Transmission Electron Microscopy (TEM) with energy dispersive X-ray spectroscopy (EDX). The synthesized nanoparticles showed strong absorbance around 430 nm with surface plasmon resonance (SPR) and exhibited a face-centered cubic crystalline nature in XRD analysis. Proteins presented in the culture filtrate acted as reducing, capping, and stabilization agents to form PoAgNPs. TEM analysis revealed the generation of polydispersed spherical PoAgNPs with an average size of 52.26 nm. The PoAgNPs showed excellent antibacterial activity against bacterial pathogens. The PoAgNPs induced a dose-dependent cytotoxic activity against human adenocarcinoma breast cancer cell lines (MDA-MB-231), and apoptotic morphological changes were observed by dual staining. Additionally, PoAgNPs demonstrated better larvicidal activity against the larvae of Culex quinquefasciatus. Moreover, the hemolytic test indicated that the as-synthesized PoAgNPs are a safe and biocompatible nanomaterial with versatile bio-applications.


Author(s):  
Aseel Alsarahni ◽  
Zuhair Muhi Eldeen ◽  
Elham Al-kaissi ◽  
Ibrahim Al- Adham ◽  
Najah Al-muhtaseb

<p><strong>Objective: </strong>To design and synthesize amino acetylenic and thiocarbonate of 2-mercapto-1,3-benthiazoles as potential antimicrobial agents.</p><p><strong>Methods: </strong>A new series of 2-{[4-(t-amino-1-yl) but-2-yn-1-yl] sulfanyl}-1,3-benzothiazole derivatives (AZ1-AZ6), and S-1,3-benzothiazol-2-yl-O-alkyl carbonothioate derivatives were synthesised, with the aim that the target compounds show new and potential antimicrobial activity. The elemental analysis was indicated by the EuroEA elemental analyzer, and biological characterization was via IR, <sup>1</sup>H-NMR, [13]C-NMR, DSC were determined with the aid of Bruker FT-IR and Varian 300 MHz spectrometer using DMSO-d<sub>6</sub> as a solvent.<em> </em><em>In vitro </em>antimicrobial activity, evaluation was done for the synthesised compounds, by agar diffusion method and broth dilution test. The minimum inhibitory concentration (MIC) and the minimum bactericidal concentration (MBC) were determined. <em></em></p><p><strong>Results: </strong>The IR, <sup>1</sup>H-NMR, <sup>13</sup>C-NMR, DSC and elemental analysis were consistent with the assigned structures. Compound of 2-{[4-(4-methylpiperazin-1-yl)but-2-yn-1-yl] sulfanyl}-1,3-benzothiazole (AZ1), 2-{[4-(2-methylpiperidin-1-yl)but-2-yn-1-yl]sulfanyl}-1,3-benzothiazole (AZ2), 2-{[4-(piperidin-1-yl) but-2-yn-1-yl]sulfanyl}-1, 3-benzothiazole (AZ6), S-1,3-benzothiazol-2-yl-O-ethyl carbonothioate (AZ7), and S-1,3-benzothiazol-2-yl-O-(2-methylpropyl) carbonothioate (AZ9) showed the highest antimicrobial activity against <em>Pseudomonas aeruginosa </em>(<em>P. aeruginosa</em>), AZ-9 demonstrated the highest antifungal activity against <em>Candida albicans </em>(<em>C. albicans</em>), with MIC of 31.25 µg/ml.</p><p><strong>Conclusion: </strong>These promising results promoted our interest to investigate other structural analogues for their antimicrobial activity further.</p>


Author(s):  
Shobha Kl ◽  
Amita Shobha Rao ◽  
Pai Ksr ◽  
Sujatha Bhat

Objective: The objective of this study was to evaluate the antimicrobial activity of leaves of Anacardium occidentale (A. occidentale) against microorganisms including multidrug-resistant (MDR) bacteria. Methods: Agar well diffusion method was employed to demonstrate the antimicrobial activity of leaves A. occidentale. Ethanol and aqueous extracts of the leaves were used against microorganisms, which included American type culture collection strains of Staphylococcus aureus, Escherichia coli, Klebsiella pneumoniae, Enterococcus faecalis, and Pseudomonas aeruginosa and the clinical isolates of Streptococcus pneumoniae, Candida albicans, MDR Escherichia coli, and MDR Klebsiella pneumoniae. Results: The ethanolic extract of leaves of A. occidentale showed significant antimicrobial activity. Aqueous extract had mild antifungal activity. Conclusion: Ethanolic extract of leaves of A. occidentale could be a good source for the antibacterials to combat MDR bacterial infections. Further studies are necessary for these potent plant extracts to evaluate the in vivo efficacy and toxicity.


2021 ◽  
Vol 2021 ◽  
pp. 1-13
Author(s):  
Shiara Ramdath ◽  
John Mellem ◽  
Londiwe Simphiwe Mbatha

Health issues involving inadequate treatment of diseases such as cancer and microbial infections continue to be the subject of much ongoing recent research. Biosynthesized silver nanoparticles (AgNPs) were characterized using Transmission Electron Microscopy (TEM), Zeta Sizer, Ultraviolet (UV), and Fourier Transform Infrared (FTIR) spectroscopy. Their antimicrobial activity was evaluated on selected Gram-positive and Gram-negative bacterial strains, using the disc diffusion and broth dilution assays. Cell viability profiles were evaluated using MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) and apoptosis studies on selected human noncancer and cancer cells. The biosynthesized AgNPs were evaluated to be spherical clusters, with sizes between 40 and 70 nm. The absorption peak at 423 nm and the presence of polyphenols confirmed the synthesis and stabilization of these tested AgNPs. The AgNPs showed a good stability of −23.9 ± 1.02 mV. Good antimicrobial activity (6.0–18.0 mm) was seen on all tested bacteria at a minimum inhibitory concentration (MIC) ranging from 5 to 16 μg/ml, with the highest activity seen against Gram-negative Escherichia coli (18 ± 0.5 mm), and the lowest activity was seen against Gram-positive Listeria monocytogenes (6.0 ± 0.4 mm) after treatment with the AgNPs. These NPs showed a concentration-dependent and cell-specific cytotoxicity with low IC50 values (41.7, 56.3, and 63.8 μg/ml). The NPs were well tolerated by tested cells as indicated by a more than 50% cell viability at the high dose tested and low apoptotic indices (<0.2). These findings indicated that these biosynthesized AgNPs showed great potential as effective antibacterial agents and anticancer drug delivery modalities.


2021 ◽  
Vol 11 (6) ◽  
pp. 88-96
Author(s):  
Chhajed Shweta ◽  
Arora Asha

Diabetic Foot Ulcer (DFU) is one of the major complications of Diabetes. Patients with Diabetic Foot ulcers have a high susceptibility to microbial infections and are the leading cause of hospitalization and amputation of lower limbs. In the era of increased prevalence of bacterial resistance and outbreak of resistant infectious diseases, it is very essential to develop effective therapeutic strategies towards multi-drug resistant pathogens. The antimicrobial properties of silver nanoparticles have been well studied, therefore their use in biomedicine and pharmacology is a trend. Herein we present the use of Phyto-mediated synthesized AgNPs for the treatment of diabetic foot ulcers by topical administration. The nanoparticles were synthesized by reducing silver nitrate using Terminalia chebula fruit extract. The nanoparticles were analyzed and characterized using UV-Visible Spectrophotometer, FTIR, XRD, SEM with EDAX, TEM, and DLS. The synthesized silver nanoparticles were assayed for antimicrobial activity against five Diabetic Foot Ulcer bacterial isolates i.e. Escherichia coli, Klebsiella Pneumoniae, Pseudomonas aeruginosa, Streptococcus aureus, and Bacillus subtilis. The bactericidal property of synthesized nanoparticles was analyzed by the Agar well diffusion method, which revealed the remarkable antimicrobial effects against all the selective pathogenic bacterial isolates of Diabetic foot ulcers in the present study. These results constituted the basis for further studies on the use of plant-based silver nanoparticles for the treatment of Diabetic Foot ulcers from different origins


Author(s):  
B. Anandh ◽  
A. Muthuvel ◽  
M. Emayavaramban

The present investigation demonstrates the formation of silver nanoparticles by the reduction of the aqueous silver metal ions during exposure to the Lagenaria siceraria leaf extract. The synthesized AgNPs have characterized by UV-visible spectroscopy, X-ray diffraction (XRD) and Fourier transform infrared spectroscopy (FT-IR) techniques. AgNPs formation has screened by UV-visible spectroscopy through colour conversion due to surface plasma resonance band at 427 nm. X-ray diffraction (XRD) confirmed that the resulting AgNPs are highly crystalline and the structure is face centered cubic (fcc). FT-IR spectrum indicates the presence of different functional groups present in the biomolecules capping the nanoparticles. Further, inhibitory activity of AgNPs and leaf extract were tested against human pathogens like gram-pastive (Staphylococcus aureus, Bacillus subtilis), gram-negative (Escherichia coli and Pseudomonas aeruginosa). The results indicated that the AgNPs showed moderate inhibitory actions against human pathogens than Lagenaria siceraria leaf extract, demonstrating its antimicrobial value against pathogenic diseases


Author(s):  
Sara Davoudabadi ◽  
Hossein Goudarzi ◽  
Mehdi Goudarzi ◽  
Abdollah Ardebili ◽  
Ebrahim Faghihloo ◽  
...  

Abstract In this study, we focused on the emergence of extensively drug-resistant (XDR), pandrug-resistant (PDR), and hypervirulent Klebsiella pneumoniae (hvKP) in Iran. During 2018 to 2020 a total of 52 K. pneumoniae isolates were collected from different clinical specimens. The hvKP isolates were identified by PCR amplification of virulence and capsular serotype-specific genes. Hypermucoviscous K. pneumoniae (hmKP) were identified by string test. Carbapenem-resistant hvKP (CR-hvKP), multidrug-resistant hvKP (MDR-hvKP), extensively drug-resistant hvKP (XDR-hvKP), and pandrug-resistant hvKP (PDR-hvKP) were determined by disc diffusion method, Carba-NP test and PCR method. XDR-hvKP isolates were typed by multilocus sequence typing (MLST). Among all K. pneumoniae isolates 14 (26.9%) were identified as hvKP and 78.6% (11/14) of them were hmKP however, none of the classic K. pneumoniae (cKP) isolates were hmKP. The predominant capsular serotype of hvKP was K2 (42.85%) followed by K1 (35.71%). The prevalence of MDR-hvKP, XDR-hvKP and PDR-hvKP isolates were 6 (42.9%), 5 (35.7%) and 1 (7.1%), respectively. ESBL production was found in 85.7% of hvKP isolates and most of them carried bla TEM gene (78.6%) and 6 isolates (42.9%) were CR-hvKP. Among hvKP isolates, 1 (7.1%), 2 (14.3%), 3 (21.4%), 8 (28.6%), and 11 (78.6%) carried bla NDM-6, bla OXA-48, bla CTX-M, bla SHV, and bla TEM genes, respectively. According to MLST analysis, 2, 1, 1, and 1 XDR-hvKP isolates belonged to ST15, ST377, ST442, and ST147, respectively. The occurrence of such isolates is deeply concerning due to the combination of hypervirulence and extensively drug-resistance or pandrug-resistance.


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