scholarly journals Antibacterial Activity of Copper Nanoparticles (CuNPs) against a Resistant Calcium Hydroxide Multispecies Endodontic Biofilm

Nanomaterials ◽  
2021 ◽  
Vol 11 (9) ◽  
pp. 2254
Author(s):  
Beatriz Rojas ◽  
Nicole Soto ◽  
Marcela Villalba ◽  
Helia Bello-Toledo ◽  
Manuel Meléndrez-Castro ◽  
...  
Keyword(s):  
Antibacterial Activity ◽  
Calcium Hydroxide ◽  
Copper Nanoparticles ◽  
Antimicrobial Agents ◽  
Ex Vivo ◽  
Multispecies Biofilm ◽  
Irrigation Solution ◽  
Potential Alternative ◽  
Resistant Strains ◽  
Plaque Count

Endodontic treatment reduces the amount of bacteria by using antimicrobial agents to favor healing. However, disinfecting all of the canal system is difficult due to its anatomical complexity and may result in endodontic failure. Copper nanoparticles have antimicrobial activity against diverse microorganisms, especially to resistant strains, and offer a potential alternative for disinfection during endodontic therapy. This study evaluated the antibacterial action of copper nanoparticles (CuNPs) on an ex vivo multispecies biofilm using plaque count compared to the antibacterial activity of calcium hydroxide Ca(OH)2. There were significant differences between the Ca(OH)2 and CuNPs groups as an intracanal dressing compared with the CuNPs groups as an irrigation solution (p < 0.0001). An increase in the count of the group exposed to 7 days of Ca(OH)2 was observed compared to the group exposed to Ca(OH)2 for 1 day. These findings differ from what was observed with CuNPs in the same period of time. Antibacterial activity of CuNPs was observed on a multispecies biofilm, detecting an immediate action and over-time effect, gradually reaching their highest efficacy on day 7 after application. The latter raises the possibility of the emergence of Ca(OH)2-resistant strains and supports the use of CuNPs as alternative intracanal medication.

scholarly journals In VitroAntibacterial Activity of the Ceftazidime-Avibactam Combination against Enterobacteriaceae, Including Strains with Well-Characterized β-Lactamases

2015 ◽  
Vol 59 (4) ◽  
pp. 1931-1934 ◽  
Author(s):  
Premavathy Levasseur ◽  
Anne-Marie Girard ◽  
Christine Miossec ◽  
John Pace ◽  
Ken Coleman
Keyword(s):  
Antibacterial Activity ◽  
Antimicrobial Agents ◽  
The Novel ◽  
Content Type ◽  
Class A ◽  
Fixed Weight ◽  
Class D ◽  
Resistant Strains ◽  
Esbl Producers

ABSTRACTThe novel β-lactamase inhibitor avibactam is a potent inhibitor of class A, class C, and some class D enzymes. Thein vitroantibacterial activity of the ceftazidime-avibactam combination was determined for a collection ofEnterobacteriaceaeclinical isolates; this collection was enriched for resistant strains, including strains with characterized serine β-lactamases. The inhibitor was added either at fixed weight ratios to ceftazidime or at fixed concentrations, with the latter type of combination consistently resulting in greater potentiation of antibacterial activity. In the presence of 4 μg/ml of avibactam, the ceftazidime MIC50and MIC90(0.25 and 2 μg/ml, respectively) were both below the CLSI breakpoint for ceftazidime. Further comparisons with reference antimicrobial agents were performed using this fixed inhibitor concentration. Against most ceftazidime-susceptible and -nonsusceptible isolates, the addition of avibactam resulted in a significant increase in ceftazidime activity, with MICs generally reduced 256-fold for extended-spectrum β-lactamase (ESBL) producers, 8- to 32-fold for CTX-M producers, and >128-fold for KPC producers. Overall, MICs of a ceftazidime-avibactam combination were significantly lower than those of the comparators piperacillin-tazobactam, cefotaxime, ceftriaxone, and cefepime and similar or superior to those of imipenem.

scholarly journals Antibacterial activity of intracanal medications based on calcium hydroxide and zinc oxide micro- or nanoparticles: an ex vivo study

2017 ◽  
Vol 46 (3) ◽  
pp. 153-157
Author(s):  
Juliane Maria GUERREIRO-TANOMARU ◽  
Alana Priscila SOUZA AGUIAR ◽  
Gisselle Moraima CHÁVEZ-ANDRADE ◽  
Maria Inês Basso BERNARDI ◽  
Mário TANOMARU-FILHO
Keyword(s):  
Antimicrobial Activity ◽  
Zinc Oxide ◽  
Antibacterial Activity ◽  
Calcium Hydroxide ◽  
Ex Vivo ◽  
Bacterial Reduction ◽  
Human Teeth ◽  
Root Canals ◽  
Ph Increase ◽  
Ex Vivo Study

Abstract Introduction Nanoparticles and associations to calcium hydroxide can be used to increase antimicrobial activity. Objective To evaluate antibacterial activity against Enterococcus faecalis and pH of intracanal medications (IM) based on calcium hydroxide (CH) and zinc oxide (ZnO) micro- or nanoparticles, and their association with 0.4% chlorhexidine (CHX). Material and method Root canals from single-rooted human teeth were inoculated and incubated for 21 days. After sample (S1), the root canals were filled with the medications for 7 days and samples were collected immediately after medication (S2) and 7 days later (S3). Counting of CFU mL-1 was performed. Polyethylene tubes filled with the medications were used for the pH evaluation after 3, 7, 14 and 28 days. Data were submitted to ANOVA and Tukey tests (p<0.05). Result All IM promoted elimination of E. faecalis immediately after medication (S2). All the pastes promoted a similar pH increase. Conclusion CH/ZnO micro- or nanoparticles associated with CHX promoted greater bacterial reduction in the root canals and similar pH.

scholarly journals New Hybrid Copper Nanoparticles/Conjugated Polyelectrolyte Composite with Antibacterial Activity

Polymers ◽  
2021 ◽  
Vol 13 (3) ◽  
pp. 401
Author(s):  
Ignacio A. Jessop ◽  
Yasmín P. Pérez ◽  
Andrea Jachura ◽  
Hipólito Nuñez ◽  
Cesar Saldías ◽  
...  
Keyword(s):  
Antibacterial Activity ◽  
Copper Nanoparticles ◽  
Salmonella Enteritidis ◽  
Theoretical Calculations ◽  
Chemical Reduction ◽  
Metallic Copper ◽  
Resistant Bacteria ◽  
Small Contribution ◽  
Antibiotic Resistant ◽  
Conjugated Polyelectrolyte

In the search for new materials to fight against antibiotic-resistant bacteria, a hybrid composite from metallic copper nanoparticles (CuNPs) and a novel cationic π-conjugated polyelectrolyte (CPE) were designed, synthesized, and characterized. The CuNPs were prepared by chemical reduction in the presence of CPE, which acts as a stabilizing agent. Spectroscopic analysis and electron microscopy showed the distinctive band of the metallic CuNP surface plasmon and their random distribution on the CPE laminar surface, respectively. Theoretical calculations on CuNP/CPE deposits suggest that the interaction between both materials occurs through polyelectrolyte side chains, with a small contribution of its backbone electron density. The CuNP/CPE composite showed antibacterial activity against Gram-positive (Staphylococcus aureus and Enterococcus faecalis) and Gram-negative (Escherichia coli and Salmonella enteritidis) bacteria, mainly attributed to the CuNPs’ effect and, to a lesser extent, to the cationic CPE.

scholarly journals Synthesis, Characterization and Bactericidal Activity of a 4-Ammoniumbuthylstyrene-Based Random Copolymer

Polymers ◽  
2021 ◽  
Vol 13 (7) ◽  
pp. 1140
Author(s):  
Silvana Alfei ◽  
Gabriella Piatti ◽  
Debora Caviglia ◽  
Anna Maria Schito
Keyword(s):  
Antibacterial Activity ◽  
Bactericidal Activity ◽  
Antimicrobial Agents ◽  
Water Solubility ◽  
Physicochemical Characterization ◽  
Random Copolymer ◽  
Water Soluble ◽  
Cationic Polymers ◽  
Severe Infections

The growing resistance of bacteria to current chemotherapy is a global concern that urgently requires new and effective antimicrobial agents, aimed at curing untreatable infection, reducing unacceptable healthcare costs and human mortality. Cationic polymers, that mimic antimicrobial cationic peptides, represent promising broad-spectrum agents, being less susceptible to develop resistance than low molecular weight antibiotics. We, thus, designed, and herein report, the synthesis and physicochemical characterization of a water-soluble cationic copolymer (P5), obtained by copolymerizing the laboratory-made monomer 4-ammoniumbuthylstyrene hydrochloride with di-methyl-acrylamide as uncharged diluent. The antibacterial activity of P5 was assessed against several multi-drug-resistant clinical isolates of both Gram-positive and Gram-negative species. Except for strains characterized by modifications of the membrane charge, most of the tested isolates were sensible to the new molecule. P5 showed remarkable antibacterial activity against several isolates of genera Enterococcus, Staphylococcus, Pseudomonas, Klebsiella, and against Escherichia coli, Acinetobacter baumannii and Stenotrophomonas maltophilia, displaying a minimum MIC value of 3.15 µM. In time-killing and turbidimetric studies, P5 displayed a rapid non-lytic bactericidal activity. Due to its water-solubility and wide bactericidal spectrum, P5 could represent a promising novel agent capable of overcoming severe infections sustained by bacteria resistant the presently available antibiotics.

scholarly journals An In Vitro Study on the Antimicrobial Properties of Essential Oil Modified Resin Composite against Oral Pathogens

Materials ◽  
2020 ◽  
Vol 13 (19) ◽  
pp. 4383
Author(s):  
Barbara Lapinska ◽  
Aleksandra Szram ◽  
Beata Zarzycka ◽  
Janina Grzegorczyk ◽  
Louis Hardan ◽  
...  
Keyword(s):  
Antimicrobial Activity ◽  
Antibacterial Activity ◽  
Antifungal Activity ◽  
Antimicrobial Agents ◽  
Resin Composite ◽  
Antimicrobial Properties ◽  
In Vitro Study ◽  
Diffusion Method ◽  
Oral Pathogens

Modifying the composition of dental restorative materials with antimicrobial agents might induce their antibacterial potential against cariogenic bacteria, e.g., S.mutans and L.acidophilus, as well as antifungal effect on C.albicans that are major oral pathogens. Essential oils (EOs) are widely known for antimicrobial activity and are successfully used in dental industry. The study aimed at evaluating antibacterial and antifungal activity of EOs and composite resin material (CR) modified with EO against oral pathogens. Ten EOs (i.e., anise, cinnamon, citronella, clove, geranium, lavender, limette, mint, rosemary thyme) were tested using agar diffusion method. Cinnamon and thyme EOs showed significantly highest antibacterial activity against S.mutans and L.acidophilus among all tested EOs. Anise and limette EOs showed no antibacterial activity against S.mutans. All tested EOs exhibited antifungal activity against C.albicans, whereas cinnamon EO showed significantly highest and limette EO significantly lowest activity. Next, 1, 2 or 5 µL of cinnamon EO was introduced into 2 g of CR and microbiologically tested. The modified CR showed higher antimicrobial activity in comparison to unmodified one. CR containing 2 µL of EO showed the best antimicrobial properties against S.mutans and C.albicans, while CR modified with 1 µL of EO showed the best antimicrobial properties against L.acidophilus.

scholarly journals Arginine Is a Critical Substrate for the Pathogenesis of Pseudomonas aeruginosa in Burn Wound Infections

mBio ◽  
2017 ◽  
Vol 8 (2) ◽  
Author(s):  
Jake Everett ◽  
Keith Turner ◽  
Qiuxian Cai ◽  
Vernita Gordon ◽  
Marvin Whiteley ◽  
...  
Keyword(s):  
Antimicrobial Agents ◽  
Hospital Setting ◽  
Multidrug Resistant ◽  
Burn Patients ◽  
Burn Wound ◽  
Burn Wounds ◽  
Resistant Strains ◽  
High Doses ◽  
Ubiquitous Presence

ABSTRACT Environmental conditions affect bacterial behavior and can greatly influence the course of an infection. However, the environmental cues that elicit bacterial responses in specific infection sites are relatively unknown. Pseudomonas aeruginosa is ubiquitous in nature and typically innocuous. However, it is also one of the most prevalent causes of fatal sepsis in burn wound patients. The aim of this study was to determine the impact of environmental factors, specifically the availability of arginine, on the pathogenesis of P. aeruginosa in burn wound infections. Comparison of burned versus noninjured tissue revealed that l-arginine (l-Arg) was significantly depleted in burn wounds as a consequence of elevated arginase produced by myeloid-derived suppressor cells. We also observed that l-Arg was a potent chemoattractant for P. aeruginosa, and while low concentrations of l-Arg increased P. aeruginosa’s swimming motility, high concentrations resulted in diminished swimming. Based on these observations, we tested whether the administration of exogenous l-Arg into the burn wound could attenuate the virulence of P. aeruginosa in thermally injured mice. Administration of l-Arg resulted in decreased P. aeruginosa spread and sepsis and increased animal survival. Taken together, these data demonstrate that the availability of environmental arginine greatly influences the virulence of P. aeruginosa in vivo and may represent a promising phenotype-modulating tool for future therapeutic avenues. IMPORTANCE Despite our growing understanding of the pathophysiology of burn wounds and the evolution of techniques and practices to manage infections, sepsis remains a significant medical concern for burn patients. P. aeruginosa continues to be a leader among all causes of bacteremic infections due to its tendency to cause complications in immunocompromised patients and its ubiquitous presence in the hospital setting. With the unforgiving emergence of multidrug-resistant strains, it is critical that alternative strategies to control or prevent septic infections in burn patients be developed in parallel with novel antimicrobial agents. In this study, we observed that administration of l-Arg significantly reduced bacterial spread and sepsis in burned mice infected with P. aeruginosa. Given the safety of l-Arg in high doses and its potential wound-healing benefits, this conditionally essential amino acid may represent a useful tool to modulate bacterial behavior in vivo and prevent sepsis in burn patients. IMPORTANCE Despite our growing understanding of the pathophysiology of burn wounds and the evolution of techniques and practices to manage infections, sepsis remains a significant medical concern for burn patients. P. aeruginosa continues to be a leader among all causes of bacteremic infections due to its tendency to cause complications in immunocompromised patients and its ubiquitous presence in the hospital setting. With the unforgiving emergence of multidrug-resistant strains, it is critical that alternative strategies to control or prevent septic infections in burn patients be developed in parallel with novel antimicrobial agents. In this study, we observed that administration of l-Arg significantly reduced bacterial spread and sepsis in burned mice infected with P. aeruginosa. Given the safety of l-Arg in high doses and its potential wound-healing benefits, this conditionally essential amino acid may represent a useful tool to modulate bacterial behavior in vivo and prevent sepsis in burn patients.

UJI AKTIVITAS ANTIBAKTERI EKSTRAK ETANOL DAUN MEKAI (Pycnarrhena cauliflora DIELS.) TERHADAP Staphylococcus aureus

2020 ◽  
Vol 6 (2) ◽  
pp. 246
Author(s):  
Yayuk Bulam Sarifati ◽  
Sjarif Ismail ◽  
Khemasili Kosala
Keyword(s):  
Staphylococcus Aureus ◽  
Antibacterial Activity ◽  
Antimicrobial Agents ◽  
Statistical Tests ◽  
Ethanol Extract ◽  
Inhibition Zone ◽  
Positive Control ◽  
Negative Control ◽  
Control Measurement ◽  
Eye Pain

Mekai leaves (Pycnarrhena cauliflora Diels.) (P. cauliflora). Are known to contain flavonoid compounds, tannins and phenolics that act as antibacterial agents and are used in the treatment of eye pain. Staphylococcus aureus (S. aureus) is one of the examples of bacterial diseases of eye pain and also a major cause of many infections in communities and health facilities with cases of resistance to various antimicrobial agents. The purpose of this study was to prove the antibacterial activity of mekai leaves ethanol extract against S. aureus bacteria. This research is an experimental research. The stages of this research began by extracting mekai leaves using maceration method with 96% ethanol solvent. Antibacterial activity was tested by the disc method (Kirby-Bauer) using ethanol extract concentrations of mekai leaves (EPC) 20%, 30%, 40%, 50%, 60%, 70%, and 80%, positive control using 25 μg amoxicillin and negative control using DMSO 10%. The measurement results of inhibition zones of mekai leaf ethanol extract 20%, 30%, 40%, 50%, 60%, 70% and 80% respectively were 8.32 mm, 8.32 mm, 8.32 mm, 8.67 mm, 9.00 mm, 8.67 mm, and 8.33 mm. While the positive control measurement of 25 μg amoxicillin against S. aureus is 28.67 mm and the measurement of 10% negative DMSO control does not produce inhibitory zones, so it can be concluded that the ethanol extract of mekai leaves has antibacterial activity, but the area of ​​inhibition zone produced is smaller than amoxicillin 25 µg. The results of statistical tests using Mann Whitney between negative controls with all EPC concentrations obtained significant differences with p values ​​<0.05, it can be concluded that there is antibacterial activity produced at all EPC concentrations.

scholarly journals SYNTHESIS AND ANTIMICROBIAL EVALUATION OF QUINAZOLINONE PEPTIDE DERIVATIVES

2017 ◽  
Vol 10 (16) ◽  
pp. 7 ◽  
Author(s):  
Bhupinder Kapoor ◽  
Arshid Nabi ◽  
Reena Gupta ◽  
Mukta Gupta
Keyword(s):  
Antibacterial Activity ◽  
Amino Acid ◽  
Antimicrobial Agents ◽  
Methyl Esters ◽  
Standard Drug ◽  
Amino Acid Peptide ◽  
Chemical Structures ◽  
1H Nuclear Magnetic Resonance ◽  
Peptide Derivatives ◽  
Derivatives Of

  Objective: The increased microbial resistance against commercially available drugs initiated the development of novel and safe antimicrobial agents in last few decades. In this view, a series of amino acid/dipeptide derivatives of quinazolin-3(4H)-one was synthesized and was evaluated for their antimicrobial potential.Method: Synthesis of amino acid/peptide derivatives were carried out by coupling 5-(2-(2-chlorophenyl)-4-oxoquinazolin-3(4H)-yl)-2-hydroxy benzoic acid with amino acid/dipeptide methyl esters in the presence of dicyclohexylcarbodiimide and N-methylmorpholine. The chemical structures of synthesized compounds were characterized by 1H nuclear magnetic resonance and infrared spectroscopy and were screened for antibacterial activity by disc diffusion method.Results: All the synthesized derivatives exhibited moderate to significant antibacterial activity against both Gram-positive and Gram-negative bacteria. The potency of compound 5d was comparable to standard drug ciprofloxacin in all the strains of bacteria used. The compound 5a was found to be more active against Streptococcus pyogenes and Staphylococcus aureus while compound 5c against Pseudomonas aeruginosa and Escherichia coli. Conclusion: Peptide derivatives of quinazolinone are promising antimicrobial agent and can be used for the synthesis of other novel compounds.

scholarly journals INVESTIGATION OF THE SYNERGISTIC ANTIBACTERIAL ACTION OF COPPER NANOPARTICLES ON CERTAIN ANTIBIOTICS AGAINST HUMAN PATHOGENS

2018 ◽  
Vol 10 (10) ◽  
pp. 83
Author(s):  
Selvarani Murugan
Keyword(s):  
Antibacterial Activity ◽  
Copper Nanoparticles ◽  
Pathogenic Bacteria ◽  
Color Change ◽  
Quantitative Information ◽  
Inorganic Nanoparticles ◽  
Diffusion Method ◽  
Human Pathogens ◽  
Bacterial Strains ◽  
Agar Disc

Objective: Resistance to antibacterial agents by pathogenic bacteria has emerged in recent years and is a major challenge for the healthcare industry. Copper nanoparticles (CuNPs) are known to be one of the multifunctional inorganic nanoparticles with effective antibacterial activity. Hence the present investigation has been focused on synthesizing and evaluating the bactericidal effect of copper nanoparticles.Methods: CuNPs were synthesized by reducing the aqueous solution of copper sulfate with sodium borohydride. The synthesized particles were characterized by x-ray diffractogram (XRD), scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS) techniques to analyze size, morphology and quantitative information respectively. The antibacterial activity of CuNPs was examined by agar well diffusion method. Synergistic effect of CuNPs with broad-spectrum antibiotics was determined by the agar disc diffusion method.Results: Color change of reaction mixture from blue to dark brown indicated the formation of CuNPs. SEM image clearly demonstrated that the synthesized particles were spherical in shape and its size was found to be 17.85 nm. EDS report confirmed the presence of elemental copper in the resultant nanoparticles and its accounts for major proportion (96%) of the mass of nanoparticles. Bacterial effect of CuNPs revealed that Pseudomonas aeruginosa showed the highest antibacterial sensitivity (16.00±1.63 mm), whereas least susceptibility (9.67±0.47 mm) was noticed against Staphylococcus aureus. An enhanced antibacterial activity of commercial antibiotics was also noticed when it combined with CuNPS. A minimum zone of inhibition was increased from 0.67±0.47 mm to 10.66±0.24 mm when the nanoparticles and antibiotics were given together.Conclusion: It was observed that copper nanoparticles exhibited profound activity against all the tested bacterial strains which shows that CuNPs may serve as a better option for use in medicine in the future.

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