scholarly journals Amine-Coated Carbon Dots (NH2-FCDs) as Novel Antimicrobial Agent for Gram-Negative Bacteria

2021 ◽  
Vol 3 ◽  
Author(s):  
Asmita Devkota ◽  
Anju Pandey ◽  
Zeinab Yadegari ◽  
Korsi Dumenyo ◽  
Ali Taheri

Multidrug resistance (MDR) is a major concern in battling infectious bacterial diseases. The overuse of antibiotics contributes to the emergence of resistance by eradicating the drug-sensitive strains, leaving behind the resistant strains that multiply without any competition. Nanoparticles are becoming popular as novel antimicrobial agents that follow a different mode of action from standard antibiotics and are therefore desirable against MDR bacteria. In this study, we synthesized carbon dots from different precursors including glucosamine HCL (GlcNH2·HCl) and 4,7,10-trioxa-1,13-tridecanediamine (TTDDA, and studied their antimicrobial effects in a diverse list of Gram-negative bacteria including Escherichia coli, Pseudomonas syringae, Salmonella enterica subsp. enterica serovar Typhimurium, Pectobacterium carotovorum, Agrobacterium tumefaciens, and Agrobacterium rhizogenes. We demonstrated the antimicrobial properties of these carbon dots against these bacteria and provided the optimum concentration and incubation times for each bacterial species. Our findings indicated that not all carbon dots carry antimicrobial properties, and there is also a variation between different bacterial species in their resistance against these carbon dots.

Author(s):  
Bianca PizzornoBackx ◽  
Mayara Santana dos Santos ◽  
Otávio Augusto Leitão dos Santos ◽  
Sérgio Antunes Filho

: Nanotechnology is an area of science able to develop new materials. The relation between nanotechnology and microbiology is essential for the development of new drugs and vaccines. The main advantage of blend in both areas is to associate the latest technology to obtain new ways to solve problems related to microorganisms. This review seeks to investigate nanoparticle formation's antimicrobial properties, primarily when connected to the green synthesis of silver nanoparticles. The development of new sustainable methods for nanoparticle production has been instrumental in designing alternative, non-toxic, energy-friendly, and environmentally friendly routes. In this sense, it is necessary to study silver nanoparticles' green synthesis concerning their antimicrobial properties. Antimicrobial mechanisms of silver nanoparticles demonstrate efficiency to gram-positive bacteria, gram-negative bacteria, fungi, viruses, and parasites. However, attention is needed with the emergence of resistance to these antimicrobials. This article seeks to relate the parameters of green silver-based nanosystems with the efficiency of antimicrobial activity.


Nanomaterials ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 2012
Author(s):  
Anju Pandey ◽  
Asmita Devkota ◽  
Zeinab Yadegari ◽  
Korsi Dumenyo ◽  
Ali Taheri

While multi-drug resistance in bacteria is an emerging concern in public health, using carbon dots (CDs) as a new source of antimicrobial activity is gaining popularity due to their antimicrobial and non-toxic properties. Here we prepared carbon dots from citric acid and β-alanine and demonstrated their ability to inhibit the growth of diverse groups of Gram-negative bacteria, including E. coli, Salmonella, Pseudomonas, Agrobacterium, and Pectobacterium species. Carbon dots were prepared using a one-pot, three-minute synthesis process in a commercial microwave oven (700 W). The antibacterial activity of these CDs was studied using the well-diffusion method, and their minimal inhibitory concentration was determined by exposing bacterial cells for 20 h to different concentrations of CDs ranging from 0.5 to 10 mg/mL. Our finding indicates that these CDs can be an effective alternative to commercially available antibiotics. We also demonstrated the minimum incubation time required for complete inhibition of bacterial growth, which varied depending on bacterial species. With 15-min incubation time, A. tumefaciens and P. aeruginosa were the most sensitive strains, whereas E. coli and S. enterica were the most resistant bacterial strains requiring over 20 h incubation with CDs.


Molecules ◽  
2021 ◽  
Vol 26 (13) ◽  
pp. 4007
Author(s):  
Magdalena Ratajczak ◽  
Dorota Kaminska ◽  
Eliza Matuszewska ◽  
Elżbieta Hołderna-Kedzia ◽  
Jarosław Rogacki ◽  
...  

Bee products have been known for centuries for their versatile healing properties. In recent decades they have become the subject of documented scientific research. This review aims to present and compare the impact of bee products and their components as antimicrobial agents. Honey, propolis, royal jelly and bee venom are bee products that have antibacterial properties. Sensitivity of bacteria to these products varies considerably between products and varieties of the same product depending on their origin. According to the type of bee product, different degrees of activity were observed against Gram-positive and Gram-negative bacteria, yeasts, molds and dermatophytes, as well as biofilm-forming microorganisms. Pseudomonas aeruginosa turned out to be the most resistant to bee products. An analysis of average minimum inhibitory concentration values for bee products showed that bee venom has the strongest bacterial effectiveness, while royal jelly showed the weakest antibacterial activity. The most challenging problems associated with using bee products for medical purposes are dosage and safety. The complexity and variability in composition of these products raise the need for their standardization before safe and predictable clinical uses can be achieved.


1983 ◽  
Vol 46 (4) ◽  
pp. 325-329 ◽  
Author(s):  
J. M. JAY ◽  
G. M. RIVERS ◽  
W. E. BOISVERT

By surface plating on plate count agar, 0.005 M (430 ppm) of the α-dicarbonyl compound, diacetyl, inhibited 28 of 40 organisms with the medium at pH 6 but only 11 at pH 8. Diacetyl was more effective against gram-negative bacteria and yeasts than non-lactic gram-positive bacteria and least effective against lactic acid bacteria. Acetoin, butanedioldiacetate and five butanediol isomers were considerably less effective than diacetyl, although all were more effective at pH 6 than 8. Diacetylmonoxime and diacetyldioxime were more effective than the diols and were less affected by pH of medium than diacetyl. Phenylglyoxal (PG) and 1,2-cyclohexanedione (CHD) ranked closest to diacetyl but, unlike the latter, they were more effective against gram-positive bacteria and less so against fungi and gram-negative bacteria. All 12 compounds were more effective against selected organisms by pour plating and in broth culture than by surface plating. Like diacetyl, CHD and PG are α, α-dicarbonyls and are widely used as arginine reactive agents resulting in the blockage of enzyme-substrate reactions. Although their antimicrobial activity may be due to this property, they apparently affect different enzymes than diacetyl because their antimicrobial spectra were different. The possibility of a class of food-use antimicrobial agents bearing α-dicarbonyl groups is suggested by the findings of this study.


2019 ◽  
Vol 10 ◽  
pp. 1864-1872
Author(s):  
Prof. Teodora P. Popova

The effect of ionized aqueous solutions (anolytes and catholyte) in the processing of fruits (cherries, morellos, and strawberries) for decontamination has been tested. Freshly prepared analytes and catholyte without the addition of salts were used, as well as stored for 7 months anolytes, prepared with 0.5% NaCl and a combination of 0.5% NaCl and 0.5% Na2CO3. The anolyte prepared with a combination of 0.5% NaCl and 0.5% Na2CO3, as well as the anolyte obtained with 0.5% NaCl, exhibit high antimicrobial activity against the surface microflora of strawberries, cherries, and sour cherries. They inactivate E. coli for 15 minutes. The other species of the fam. Enterobacteriaceae were also affected to the maximum extent, as is the total number of microorganisms, especially in cherries and sour cherries. Even stored for 7 months, they largely retain their antimicrobial properties. Anolyte and catholyte, obtained without the addition of salts, showed a lower effect on the total number of microorganisms, but had a significant effect on Gram-negative bacteria, and especially with regard to the sanitary indicative E. coli.


Author(s):  
Nilushi Indika Bamunu Arachchige ◽  
Fazlurrahman Khan ◽  
Young-Mog Kim

Background: The treatment of infection caused by pathogenic bacteria becomes one of the serious concerns globally. The failure in the treatment was found due to the exhibition of multiple resistance mechanisms against the antimicrobial agents. Emergence of resistant bacterial species has also been observed due to prolong treatment using conventional antibiotics. To combat these problems, several alternative strategies have been employed using biological and chemically synthesized compounds as antibacterial agents. Marine organisms considered as one of the potential sources for the isolation of bioactive compounds due to the easily available, cost-effective, and eco-friendly. Methods: The online search methodology was adapted for the collection of information related to the antimicrobial properties of marine-derived compounds. These compound has been isolated and purified by different purification techniques, and their structure also characterized. Furthermore, the antibacterial activities have been reported by using broth microdilution as well as disc diffusion assays. Results: The present review paper describes the antimicrobial effect of diverse secondary metabolites which are isolated and purified from the different marine organisms. The structural elucidation of each secondary metabolite has also been done in the present paper, which will help for the in silico designing of the novel and potent antimicrobial compounds. Conclusion: A thorough literature search has been made and summarizes the list of antimicrobial compounds that are isolated from both prokaryotic and eukaryotic marine organisms. The information obtained from the present paper will be helpful for the application of marine compounds as antimicrobial agents against different antibiotic-resistant human pathogenic bacteria.


2020 ◽  
Vol 20 (3) ◽  
pp. 192-208 ◽  
Author(s):  
Talita Odriane Custodio Leite ◽  
Juliana Silva Novais ◽  
Beatriz Lima Cosenza de Carvalho ◽  
Vitor Francisco Ferreira ◽  
Leonardo Alves Miceli ◽  
...  

Background: According to the World Health Organization, antimicrobial resistance is one of the most important public health threats of the 21st century. Therefore, there is an urgent need for the development of antimicrobial agents with new mechanism of action, especially those capable of evading known resistance mechanisms. Objective: We described the synthesis, in vitro antimicrobial evaluation, and in silico analysis of a series of 1H-indole-4,7-dione derivatives. Methods: The new series of 1H-indole-4,7-diones was prepared with good yield by using a copper(II)- mediated reaction between bromoquinone and β-enamino ketones bearing alkyl or phenyl groups attached to the nitrogen atom. The antimicrobial potential of indole derivatives was assessed. Molecular docking studies were also performed using AutoDock 4.2 for Windows. Characterization of all compounds was confirmed by one- and two-dimensional NMR techniques 1H and 13C NMR spectra [1H, 13C – APT, 1H x 1H – COSY, HSQC and HMBC], IR and mass spectrometry analysis. Results: Several indolequinone compounds showed effective antimicrobial profile against Grampositive (MIC = 16 µg.mL-1) and Gram-negative bacteria (MIC = 8 µg.mL-1) similar to antimicrobials current on the market. The 3-acetyl-1-(2,5-dimethylphenyl)-1H-indole-4,7-dione derivative exhibited an important effect against different biofilm stages formed by a serious hospital life-threatening resistant strain of Methicillin-Resistant Staphylococcus aureus (MRSA). A hemocompatibility profile analysis based on in vitro hemolysis assays revealed the low toxicity effects of this new series. Indeed, in silico studies showed a good pharmacokinetics and toxicological profiles for all indolequinone derivatives, reinforcing their feasibility to display a promising oral bioavailability. An elucidation of the promising indolequinone derivatives binding mode was achieved, showing interactions with important sites to biological activity of S. aureus DNA gyrase. These results highlighted 3-acetyl-1-(2-hydroxyethyl)-1Hindole- 4,7-dione derivative as broad-spectrum antimicrobial prototype to be further explored for treating bacterial infections. Conclusion: The highly substituted indolequinones were obtained in moderate to good yields. The pharmacological study indicated that these compounds should be exploited in the search for a leading substance in a project aimed at obtaining new antimicrobials effective against Gram-negative bacteria.


Antibiotics ◽  
2021 ◽  
Vol 10 (6) ◽  
pp. 695
Author(s):  
Estelle J. Ramchuran ◽  
Isabel Pérez-Guillén ◽  
Linda A. Bester ◽  
René Khan ◽  
Fernando Albericio ◽  
...  

Microbial infections are a major public health concern. Antimicrobial peptides (AMPs) have been demonstrated to be a plausible alternative to the current arsenal of drugs that has become inefficient due to multidrug resistance. Herein we describe a new AMP family, namely the super-cationic peptide dendrimers (SCPDs). Although all members of the series exert some antibacterial activity, we propose that special attention should be given to (KLK)2KLLKLL-NH2 (G1KLK-L2KL2), which shows selectivity for Gram-negative bacteria and virtually no cytotoxicity in HepG2 and HEK293. These results reinforce the validity of the SCPD family as a valuable class of AMP and support G1KLK-L2KL2 as a strong lead candidate for the future development of an antibacterial agent against Gram-negative bacteria.


1990 ◽  
Vol 10 (2) ◽  
pp. 127-133 ◽  
Author(s):  
Paul Nikolaidis

Newer fluoroquinolones such as ciprofloxacin, pefloxacin, ofloxacin, enoxacin, and fleroxacin are potent antimicrobial agents against many gram-negative bacteria, including Pseudomonas aeruginosa species and staphylococci-sensitive or resistant to methicillin. They are almost completely absorbed when given orally, reaching therapeutic plasma and dialysate concentrations, and their long half lives permit infrequent dosing intervals. Clinical studies on fluoroquinolones efficacy in continuous ambulatory peritoneal dialysis (CAPD) infections, although not extensive, demonstrate good results. They are well tolerated and the adverse reactions, consisting mainly of gastrointestinal disturbance, were uncommon, mild, and reversible. The fluoroquinolones offer a promising alternative to standard parenteral treatments in CAPD patients, while their good oral bioavailability makes them attractive and convenient for both patients and hospital staff. However, they must be used with caution until we have more information and gain further experience.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Shira Mandel ◽  
Janna Michaeli ◽  
Noa Nur ◽  
Isabelle Erbetti ◽  
Jonathan Zazoun ◽  
...  

AbstractNew antimicrobial agents are urgently needed, especially to eliminate multidrug resistant Gram-negative bacteria that stand for most antibiotic-resistant threats. In the following study, we present superior properties of an engineered antimicrobial peptide, OMN6, a 40-amino acid cyclic peptide based on Cecropin A, that presents high efficacy against Gram-negative bacteria with a bactericidal mechanism of action. The target of OMN6 is assumed to be the bacterial membrane in contrast to small molecule-based agents which bind to a specific enzyme or bacterial site. Moreover, OMN6 mechanism of action is effective on Acinetobacter baumannii laboratory strains and clinical isolates, regardless of the bacteria genotype or resistance-phenotype, thus, is by orders-of-magnitude, less likely for mutation-driven development of resistance, recrudescence, or tolerance. OMN6 displays an increase in stability and a significant decrease in proteolytic degradation with full safety margin on erythrocytes and HEK293T cells. Taken together, these results strongly suggest that OMN6 is an efficient, stable, and non-toxic novel antimicrobial agent with the potential to become a therapy for humans.


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