scholarly journals Synergistic Efficacy of Antibiotics and Silver Nanoparticles Synthesized from Eichhornia crassipes

2016 ◽  
Vol 6 ◽  
Author(s):  
S Basker
Keyword(s):  
Silver Nanoparticles ◽  
Eichhornia Crassipes ◽  
Bacterial Resistance ◽  
Synergistic Effects ◽  
Public Health Issue ◽  
Metallic Silver ◽  
Gram Positive ◽  
Zone Formation ◽  
Gram Negative ◽  
E Coli

<p><strong>The increasing prevalence of bacterial resistance has made an important public health issue in the present scenario.  Thus it is urging to develop alternate and more effective therapeutic strategies to treat both Gram-negative and Gram-positive microbes.</strong>  <strong>Now a days silver nanoparticles (AgNPs) synthesized biologically gaining much importance with different applications as they are nontoxic and eco-friendliness.</strong> <strong>The antimicrobial activity of biosynthesized silver nanoparticles synthesized from aqueous extracts of</strong><strong><em> Eichhornia crassipes</em></strong><strong> was evaluated with the panel of antibiotics </strong><strong>like vancomycin, penicillin, streptomycin and tetracycline</strong><strong> and microorganisms </strong><strong>in the category of either gram positive or gram negative type.</strong><strong> <em>E. coli</em> and <em>S. aureus </em>proved to be effective with highest zone formation. In addition, possible synergistic effects of antibiotics were loaded with standard concentration of 20</strong> <strong>μl</strong><strong> of AgNPs and the effect of inhibition was highest in the antibiotic Tetracycline followed by Streptomycin, Vancomycin and Penicillin with different tested microbes. </strong><strong>The synergistic association of antibiotics with biosynthesized metallic silver nanoparticles proved to be effective against the tested microbes than control. The antibiotics showed higher zone of inhibition when added to AgNPs.</strong></p>

scholarly journals Synthesis of Plant-Mediated Silver Nanoparticles UsingDioscorea batatasRhizome Extract and Evaluation of Their Antimicrobial Activities

2011 ◽  
Vol 2011 ◽  
pp. 1-7 ◽  
Author(s):  
P. C. Nagajyothi ◽  
K. D. Lee
Keyword(s):  
Antimicrobial Activity ◽  
Silver Nanoparticles ◽  
Room Temperature ◽  
Antimicrobial Activities ◽  
Gram Positive ◽  
Gram Negative ◽  
Synthesis Of Nanoparticles ◽  
E Coli ◽  
Synthesize Silver Nanoparticles ◽  
Dioscorea Batatas

The eco-friendly synthesis of nanoparticles through various biological means helps to explore various plants for their ability to synthesize silver nanoparticles (AgNPs). Here we have synthesized AgNPs by using rhizome extract ofDioscorea batatasat as well as room temperature (). AgNPs were characterized under UV-vis spectrophotometer, SEM, FTIR, XRD, and EDX. The antimicrobial activity of AgNPs was evaluated on gram positive (B. substilisandS. aureus), gram negative (E. coli), and fungi (S. cerivisaeandC. albicans). At room temperature,S. cerivisaeandC. albicanswere found to be more susceptible to AgNPs than at .

scholarly journals PSIX-20 Antibacterial activity of an essential oil combination against several common enteropathogens in swine production

2020 ◽  
Vol 98 (Supplement_3) ◽  
pp. 184-184
Author(s):  
Bernat Canal ◽  
Luis Mesas ◽  
Cinta Sol ◽  
Monica Puyalto ◽  
Ana Carvajal ◽  
...  
Keyword(s):  
Antibacterial Activity ◽  
Synergistic Effects ◽  
Bacterial Species ◽  
Active Principle ◽  
Swine Production ◽  
Gram Positive ◽  
Minimum Concentration ◽  
Gram Negative ◽  
E Coli ◽  
Broth Microdilution Method

Abstract Essential oils (EOs) have different mechanisms, most of them targeting the bacterial wall. This fact can explain differences in the effectivity of EOs between Gram-positive and Gram-negative bacteria. Therefore, combining certain EOs can broaden their individual spectrum of efficacy due to potential synergistic effects. This trial aimed to test the in vitro antibacterial activity of an EO combination (oregano and clove oils) against a collection of relevant bacterial pathogens in swine production. The Gram-negative bacterial species chosen were Salmonella enterica ssp. enterica, Escherichia coli and Brachyspira hyodysenteriae and the Gram-positive bacterial species were Clostridium perfringens and Streptococcus suis. In addition, Lactobacillus fermentum was included to compare the susceptibility between this beneficial intestinal bacteria and the pathogens tested. The broth microdilution method at pH 6 and the subculturing from wells without bacterial growth were used to determine the minimum concentration of active principle necessary to inhibit (MIC) or kill (MBC) the 50% and 90% (MIC50/90/MBC50/90) of the population of every bacteria. The results showed that the lowest MIC50/90 were obtained for B. hyodysenteriae (37.5/75 ppm) while for S. enterica ssp. enterica (150/300 ppm), C. perfringens (150/150 ppm), E. coli (300/300 ppm) and S. suis (150/300 ppm) results were similar. Regarding the MBC50/90; B. hyodysenteriae (18.8/75 ppm) was the most susceptible pathogen, again, compared to S. enterica ssp. enterica (300/300 ppm), C. perfringens (150/150 ppm), E. coli (300/300 ppm) and S. suis (150/300 ppm). In contrast, the highest bacteriostatic/bactericidal concentrations were obtained against L. fermentum (MIC50/90 600/1,200 ppm and MBC50/90 600/2,400 ppm). These results suggest that the bacterial category (Gram-positive or Gram-negative) did not have an influence on the MIC and MBC. It can also be concluded that B. hyodysenteriae is the most susceptible enteropathogen to this EO blend. However, the in vivo effect of this combination of EOs must be further studied.

scholarly journals The Combined Use of Gentamicin and Silver Nitrate in Bone Cement for a Synergistic and Extended Antibiotic Action against Gram-Positive and Gram-Negative Bacteria

Materials ◽  
2021 ◽  
Vol 14 (12) ◽  
pp. 3413
Author(s):  
John Jackson ◽  
Joey Lo ◽  
Eric Hsu ◽  
Helen M. Burt ◽  
Ali Shademani ◽  
...  
Keyword(s):  
Silver Nitrate ◽  
Bone Cement ◽  
Bacterial Resistance ◽  
Synergistic Effects ◽  
Gram Negative Bacteria ◽  
Antibacterial Effects ◽  
Release Rates ◽  
Gram Positive ◽  
Gram Negative ◽  
Combined Use

Using bone cement as a carrier, gentamicin was for years the default drug to locally treat orthopedic infections but has lost favor due to increasing bacterial resistance to this drug. The objective of this study was to investigate the effect of combining gentamicin with silver nitrate in bone cement against S. aureus and P. aeruginosa. Antibacterial effects (CFU counts) of gentamicin and silver were initially studied followed by studies using subtherapeutic concentrations of each in combination. The release rates from cement were measured over 10 days and day 7 release samples were saved and analyzed for antibiotic activity. A strong synergistic effect of combining silver with gentamicin was found using both dissolved drugs and using day 7 bone cement release media for both Gram-positive and Gram-negative bacteria. The cement studies were extended to vancomycin and tobramycin, which are also used in bone cement, and similar synergistic effects were found for day 7 release media with P. aeruginosa but not S. aureus. These studies conclude that the combined use of low loadings of gentamicin and silver nitrate in bone cement may offer an economical and much improved synergistic method of providing anti-infective orthopedic treatments in the clinic.

scholarly journals Effective Small Molecule Antibacterials from a Novel Anti-Protein Secretion Screen

2021 ◽  
Vol 9 (3) ◽  
pp. 592
Author(s):  
Mohamed Belal Hamed ◽  
Ewa Burchacka ◽  
Liselotte Angus ◽  
Arnaud Marchand ◽  
Jozefien De Geyter ◽  
...  
Keyword(s):  
Protein Secretion ◽  
Small Molecule ◽  
Bacterial Resistance ◽  
Bacterial Species ◽  
Attractive Potential ◽  
Gram Positive ◽  
Gram Negative ◽  
E Coli ◽  
Gram Positive Bacteria

The increasing problem of bacterial resistance to antibiotics underscores the urgent need for new antibacterials. Protein export pathways are attractive potential targets. The Sec pathway is essential for bacterial viability and includes components that are absent from eukaryotes. Here, we used a new high-throughput in vivo screen based on the secretion and activity of alkaline phosphatase (PhoA), a Sec-dependent secreted enzyme that becomes active in the periplasm. The assay was optimized for a luminescence-based substrate and was used to screen a ~240K small molecule compound library. After hit confirmation and analoging, 14 HTS secretion inhibitors (HSI), belonging to eight structural classes, were identified with IC50 < 60 µM. The inhibitors were evaluated as antibacterials against 19 Gram-negative and Gram-positive bacterial species (including those from the WHO’s top pathogens list). Seven of them—HSI#6, 9; HSI#1, 5, 10; and HSI#12, 14—representing three structural families, were bacteriocidal. HSI#6 was the most potent hit against 13 species of both Gram-negative and Gram-positive bacteria with IC50 of 0.4 to 8.7 μM. HSI#1, 5, 9 and 10 inhibited the viability of Gram-positive bacteria with IC50 ~6.9–77.8 μM. HSI#9, 12, and 14 inhibited the viability of E. coli strains with IC50 < 65 μM. Moreover, HSI#1, 5 and 10 inhibited the viability of an E. coli strain missing TolC to improve permeability with IC50 4 to 14 μM, indicating their inability to penetrate the outer membrane. The antimicrobial activity was not related to the inhibition of the SecA component of the translocase in vitro, and hence, HSI molecules may target new unknown components that directly or indirectly affect protein secretion. The results provided proof of the principle that the new broad HTS approach can yield attractive nanomolar inhibitors that have potential as new starting compounds for optimization to derive potential antibiotics.

scholarly journals Dose-Dependent Antimicrobial Activity of Silver Nanoparticles on Polycaprolactone Fibers against Gram-Positive and Gram-Negative Bacteria

2017 ◽  
Vol 2017 ◽  
pp. 1-9 ◽  
Author(s):  
Erick Pazos-Ortiz ◽  
Jose Hafid Roque-Ruiz ◽  
Efrén Amador Hinojos-Márquez ◽  
Juan López-Esparza ◽  
Alejandro Donohué-Cornejo ◽  
...  
Keyword(s):  
Antimicrobial Activity ◽  
Silver Nanoparticles ◽  
Metallic Nanoparticles ◽  
Antibacterial Properties ◽  
Electrospinning Process ◽  
Drug Resistant ◽  
Gram Positive ◽  
Gram Negative ◽  
E Coli ◽  
Dose Dependent

The adhesion ability and adaptability of bacteria, coupled with constant use of the same bactericides, have made the increase in the diversity of treatments against infections necessary. Nanotechnology has played an important role in the search for new ways to prevent and treat infections, including the use of metallic nanoparticles with antibacterial properties. In this study, we worked on the design of a composite of silver nanoparticles (AgNPS) embedded in poly-epsilon-caprolactone nanofibers and evaluated its antimicrobial properties against various Gram-positive and Gram-negative microorganisms associated with drug-resistant infections. Polycaprolactone-silver composites (PCL-AgNPs) were prepared in two steps. The first step consisted in the reduction in situ of Ag+ions using N,N-dimethylformamide (DMF) in tetrahydrofuran (THF) solution, and the second step involved the simple addition of polycaprolactone before electrospinning process. Antibacterial activity of PCL-AgNPs nanofibers againstE. coli,S. mutans,K. pneumoniae,S. aureus,P. aeruginosa, andB. subtiliswas evaluated. Results showed sensibility ofE. coli,K. pneumoniae,S. aureus, andP. aeruginosa, but not forB. subtilisandS. mutans. This antimicrobial activity of PCL-AgNPs showed significant positive correlations associated with the dose-dependent effect. The antibacterial property of the PCL/Ag nanofibers might have high potential medical applications in drug-resistant infections.

Structure-Activity Relationship and Antimicrobial Evaluation of N-Phenylpyrazole Curcumin Derivatives

2020 ◽  
Vol 16 (4) ◽  
pp. 481-488
Author(s):  
Heli Sanghvi ◽  
Satyendra Mishra
Keyword(s):  
Antibacterial Activity ◽  
Gram Negative Bacteria ◽  
Pyrazole Derivatives ◽  
Gram Positive ◽  
Gram Negative ◽  
E Coli ◽  
Curcumin Derivatives ◽  
Structure Activity ◽  
Electron Donating Groups ◽  
Derivatives Of

Background: Curcumin, one of the most important pharmacologically significant natural products, has gained significant consideration among scientists for decades since its multipharmacological activities. 1, 3-Dicarbonyl moiety of curcumin was found to be accountable for the rapid degradation of curcumin molecule. The aim of present work is to replace 1, 3-dicarbonyl moiety of curcumin by pyrazole and phenylpyrazole derivatives with a view to improving its stability and to investigate the role of substitution in N-phenylpyrazole curcumin on its antibacterial activity against both Gram-positive as well as Gram-negative bacteria. Methods: Pyrazole derivatives of curcumin were prepared by heating curcumin with phenyhydrazine/ substituted phenyhydrazine derivatives in AcOH. The residue was purified by silica gel column chromatography. Structures of purified compounds were confirmed by 1H NMR and Mass spectroscopy. The synthesized compounds were evaluated for their antibacterial activity by the microdilution broth susceptibility test method against gram positive (S. aureus) and gram negative (E. coli). Results: Effects of substitution in N-phenylpyrazole curcumin derivatives against S. aureus and E. coli were studied. The most active N-(3-Nitrophenylpyrazole) curcumin (12) exhibits twenty-fold more potency against S. aureus (MIC: 10μg/mL)) and N-(2-Fluoroophenylpyrazole) curcumin (5) fivefold more potency against E. coli (MIC; 50 μg/mL) than N-phenylpyrazole curcumin (4). Whereas, a remarkable decline in anti-bacterial activity against S. aureus and E. coli was observed when electron donating groups were incorporated in N-phenylpyrazole curcumin (4). Comparative studies of synthesized compounds suggest the effects of electron withdrawing and electron donating groups on unsubstituted phenylpyrazole curcumin (4). Conclusion: The structure-activity relationship (SAR) results indicated that the electron withdrawing and electron donating at N-phenylpyrazole curcumin played key roles for their bacterial inhibitory effects. The results of the antibacterial evaluation showed that the synthesized pyrazole derivatives of curcumin displayed moderate to very high activity in S. aureus. In conclusion, the series of novel curcumin derivatives were designed, synthesized and tested for their antibacterial activities against S. aureus and E. coli. Among them, N-(3-Nitrophenylpyrazole curcumin; 12) was most active against S. aureus (Gram-positive) and N-(2-Fluoroophenylpyrazole) curcumin (5) against E. coli (Gram-negative) bacteria.

Green synthesised silver nanoparticles incorporated electrospun poly(methyl methacrylate) nanofibers with different architectures for ophthalmologic alternatives

2021 ◽  
Vol 36 (2) ◽  
pp. 93-110
Author(s):  
Princy Philip ◽  
Tomlal Jose ◽  
Sarath KS ◽  
Sunny Kuriakose
Keyword(s):  
Silver Nanoparticles ◽  
Methyl Methacrylate ◽  
Antibacterial Properties ◽  
Analytical Techniques ◽  
Morphological Properties ◽  
Gram Positive ◽  
Gram Negative ◽  
Poly Methyl Methacrylate ◽  
Antimicrobial Studies ◽  
Eye Problems

Silver nanoparticles with 5–10 nm diameters are synthesised using Couroupita guianensis flower extract. The synthesised silver nanoparticles found to show good antimicrobial activity against gram negative and gram positive bacteria. Poly(methyl methacrylate) nanofibers with pristine, surface roughened and coaxial hollow forms are prepared by electrospinning. The structural and morphological properties of these pure and structurally modified poly(methyl methacrylate) nanofibers are evidenced by various analytical techniques. The antimicrobial studies of poly(methyl methacrylate) nanofibers having different architectures incorporated with silver nanoparticles are carried out. It is found that, all the three forms of poly(methyl methacrylate) nanofibers incorporated with silver nanoparticles show antibacterial properties against both gram positive and gram negative bacteria. Among these, surface roughened poly(methyl methacrylate) nanofibers incorporated with silver nanoparticles show highest antibacterial activity than the other two structural forms. The present study offers an alternative to the existing optical lenses. People especially those who suffer from eye problems can protect their eyes in a better way from infectious agents by wearing optical lens made from C. guianensis stabilised silver nanoparticles incorporated poly(methyl methacrylate) nanofibers than that made from pure poly(methyl methacrylate) nanofibers or films.

scholarly journals Asymptomatic Bacteriuria among Pregnant Women Attending Tertiary Care Hospital in Lucknow, India

2021 ◽  
pp. 1-8
Author(s):  
Naimshree Sonkar ◽  
Malay Banerjee ◽  
Suman Gupta ◽  
Absar Ahmad
Keyword(s):  
Haemoglobin Level ◽  
Pregnant Women ◽  
Antimicrobial Susceptibility ◽  
Tertiary Care Hospital ◽  
Tertiary Care ◽  
Asymptomatic Bacteriuria ◽  
Care Hospital ◽  
Gram Positive ◽  
Gram Negative ◽  
E Coli

Introduction: Asymptomatic bacteriuria (ASB) is the presence of actively multiplying bacteria within the urinary tract with absence of any symptoms, resulting in adverse pregnancy outcomes. This research study was done in order to review prevalence, antimicrobial susceptibility profile, and factors associated with ASB occurring in female patients who are pregnant and being treated at a tertiary care hospital in Lucknow, India. Method and Materials: This is a cross-sectional study done among 216 pregnant women attending a hospital for antenatal check-ups. Clean catch midstream urine samples were collected and examined microscopically, and semi-quantitative culture was done on blood agar and MacConkey agar. Isolates were identified by colony morphology and biochemical tests, and antimicrobial susceptibility testing was done by using the Kirby-Bauer method. Results: Of the 216 pregnant women, 36 (16.7%) tested positive for ASB. The female gestational period, haemoglobin level, and BMI were significantly associated with ASB. Logistic regression also showed that higher haemoglobin level was less likely to ASB (AOR = 0.42, 95% confidence interval: 0.202–0.88, p = 0.021). The predominant and usual isolates were E. coli (n = 22, 61.1%), followed by Cons (n = 6, 16.7%), and S. aureus (3, 8.3%). All Gram-negative isolates were mostly sensitive to most of the drugs like piperacillin-tazobactam, cefepime, nitrofurantoin, and meropenem but were 100% resistant to ampicillin. Similarly, Gram-positive isolates were sensitive to ampicillin, vancomycin, linezolid, and nitrofurantoin but 100% resistant to co-trimoxazole. Conclusion: The present study shows the existence of ASB was 16.7% among women who are pregnant. Pregnancy duration, haemoglobin level, and BMI were significantly associated with ASB. The isolates identified more frequently were E. coli (61.16%), Cons (16.7%), and S. aureus (8.3%). All isolates which were Gram-negative were mostly sensitive to most of the drugs but were 100% resistant to ampicillin. Similarly, Gram-positive isolates were sensitive to most of the drugs but 100% resistant to co-trimoxazole.

Effectiveness of ZnO Nano Particles against the Foodborne Microbial Pathogens E. coli and S. aureus

2020 ◽  
Vol 15 (2) ◽  
pp. 87-94
Keyword(s):  
Antimicrobial Agents ◽  
Inhibitory Concentration ◽  
Antimicrobial Effect ◽  
Nano Particles ◽  
Microbial Pathogens ◽  
Gram Positive ◽  
Gram Negative ◽  
E Coli ◽  
Antimicrobial Susceptibility Tests ◽  
Susceptibility Tests

In this work, various concentrations of ZnO nano particles, prepared by the coprecipitation method with a size range of 47-68 nm, have been investigated as antimicrobial agents. Dilution antimicrobial susceptibility tests were carried out on two kinds of microbes (Gram-positive Staphylococcus aureus and Gram-negative Escherichia coli) according to the standard method recommended by Clinical and Laboratory Standards Institute, CLSI-2015-M07-A10. The results showed that the antimicrobial effect is larger, the higher the concentration of ZnO nano particles in solution. It was also found that Gram-positive microbes are more sensitive to ZnO nano particles when compared with the Gram-negative ones. The minimum inhibitory concentration (MIC) for E. coli was found to be 50 mg/mL while that for S. aureus was 25 mg/mL. The minimum bactericidal concentration (MBC) was 1600 mg/mL for E. coli and 800 mg/mL for S. aureus.

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