SILVER NANOPARTICLES-DISK DIFFUSION TEST AGAINST Escherichia coli ISOLATES

Cunha, Francisco Afrânio; Maia, Kamila Rocha; Mallman, Eduardo José Jucá; Cunha, Maria da Conceição dos Santos Oliveira; Maciel, Antonio Auberson Martins; Souza, Ieda Pereira de; Menezes, Everardo Albuquerque; Fechine, Pierre Basílio Almeida

doi:10.1590/s1678-9946201658073

Cited by 17 publications

(11 citation statements)

References 18 publications

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“…A regression line was drawn through the points. The antilogarithm of the intercept on the logarithm of concentration axis gave the MIC value [23,24].…”

Section: Introductionmentioning

confidence: 99%

Antimicrobial Activity of Silver-Treated Bacteria against other Multi-Drug Resistant Pathogens in Their Environment

et al. 2020

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Silver is a potent antimicrobial agent against a variety of microorganisms and once the element has entered the bacterial cell, it accumulates as silver nanoparticles with large surface area causing cell death. At the same time, the bacterial cell becomes a reservoir for silver. This study aims to test the microcidal effect of silver-killed E. coli O104: H4 and its supernatant against fresh viable cells of the same bacterium and some other species, including E. coli O157: H7, Multidrug Resistant (MDR) Pseudomonas aeruginosa and Methicillin Resistant Staphylococcus aureus (MRSA). Silver-killed bacteria were examined by Transmission Electron Microscopy (TEM). Agar well diffusion assay was used to test the antimicrobial efficacy and durability of both pellet suspension and supernatant of silver-killed E. coli O104:H4 against other bacteria. Both silver-killed bacteria and supernatant showed prolonged antimicrobial activity against the tested strains that extended to 40 days. The presence of adsorbed silver nanoparticles on the bacterial cell and inside the cells was verified by TEM. Silver-killed bacteria serve as an efficient sustained release reservoir for exporting the lethal silver cations. This promotes its use as a powerful disinfectant for polluted water and as an effective antibacterial which can be included in wound and burn dressings to overcome the problem of wound contamination.

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“…A regression line was drawn through the points. The antilogarithm of the intercept on the logarithm of concentration axis gave the MIC value [23,24].…”

Section: Introductionmentioning

confidence: 99%

Antimicrobial Activity of Silver-Treated Bacteria against other Multi-Drug Resistant Pathogens in Their Environment

et al. 2020

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“…Then two sterile paper disk (5 mm) saturated with 30 µL of CT-Fe 3 O 4 and another with JC-Fe 3 O 4 NPs (200 ppm) were placed in the culture medium. The plates were sealed by parafilm and incubated at 37 • C for 24 h, and the diameter of the resulting inhibition zone in every plate was measured [45,46]. All the experiments were performed in duplicates, and the results were expressed as mean values.…”

Section: Disk Diffusion Testmentioning

confidence: 99%

Green Synthesis, Characterization and Application of Natural Product Coated Magnetite Nanoparticles for Wastewater Treatment

et al. 2020

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Adsorption of organic pollutants, toxic metal ions, and removal of harmful bacteria can give us clean and pure drinkable water from wastewater resources. Respective magnetite nanoparticles (MNPs) were synthesized using a cheaper and greener way in an open-air environment with the use of crude latex of Jatropha curcas (JC) and leaf extract of Cinnamomum tamala (CT). Characterization of MNPs had been performed by dynamic light scattering (DLS), Ultraviolet-visible (UV-vis) spectroscopy, Fourier-transform infrared (FTIR) spectroscopy, powdered X-ray diffraction (XRD), and field emission scanning electron microscope (FE-SEM). The size ranges of the synthesized MNPs were observed in between 20–42 nm for JC-Fe3O4 and within 26–35 nm for CT-Fe3O4 by FE-SEM images. The effect of synthesized magnetic nanoparticles in wastewater treatment (bacterial portion), dye adsorption, toxic metal removal as well as antibacterial, antioxidant, and cytotoxic activities were studied. This purification will lead to an increase in the resources of pure drinking water in the future.

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“…It was indicated that K. pneumoniae was affected by Lactobacillus acidophilus-synthesized AgNPs antibacterial activity (Rajesh et al, 2014). AgNPs antibacterial activity against E. coli was reported (Cunha et al, 2016;Li et al, 2010). Mode of action of AgNPs as antimicrobial may be attributed to free radicals generation, also after penetration of AgNPs into the cells, oxidative stress was reported (Hussain et al, 2006).…”

Section: Isolate No Resistance Patternmentioning

confidence: 99%

Molecular characterization of silver resistant E. coli strains isolated from patients suffering from diarrhea

Mohamed¹,

Ahmed²,

El-Baky³

2019

Afr. J. Microbiol. Res.

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Silver nanoparticles (AgNPs) are considered a good alternative for antibiotics due to emerging Multidrug Resistance (MDR) crisis. Resistance to AgNPs is approximately limited among Gram-positive and Gram-negative pathogens. Low toxicity to human cells permits its safe use as a new antimicrobial with broad spectrum. Bacterial cells are used as a factory for AgNPs synthesis supplying a powerful antimicrobial with eco-friendly way. In this study, MDR Escherichia coli strains were recovered from patients attending Minia University hospital. Biogenic synthesis of AgNPs was performed using E. coli cells. Transmission Electron Microscopy (TEM) was used to characterize AgNPs size and shape. Antibacterial activity of AgNPs was tested against the MDR E. coli isolates. Screening for Sil and Omp genes was done using polymerase chain reaction (PCR). A total of 13 MDR E. coli bacterial culture supernatant isolates were recovered from patients under study. Biosynthesis of AgNPs was observed after addition of supernatant to AgNO 3 by color change from yellow to brown. TEM characterization indicated the presence of silver nanoparticles with 15-75 nm particle size range. Eleven of MDR E. coli isolates were sensitive to biogenic AgNPs under study. SilB and SilE genes were encoded by the two AgNPs-resistant E. coli isolates which were negative for OmpF and OmpC genes, respectively demonstrating the role of Sil efflux pump genes and porin deficiency in AgNPs resistance. As indicated, the emergence of silver resistance due to the wide spread of biocides including silver has become a great challenge for the treatment of different infections.

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SILVER NANOPARTICLES-DISK DIFFUSION TEST AGAINST Escherichia coli ISOLATES

Cited by 17 publications

References 18 publications

Antimicrobial Activity of Silver-Treated Bacteria against other Multi-Drug Resistant Pathogens in Their Environment

Antimicrobial Activity of Silver-Treated Bacteria against other Multi-Drug Resistant Pathogens in Their Environment

Green Synthesis, Characterization and Application of Natural Product Coated Magnetite Nanoparticles for Wastewater Treatment

Molecular characterization of silver resistant E. coli strains isolated from patients suffering from diarrhea

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