scholarly journals Alternative “Green” Antimicrobial Agents Obtained by Selective Sorption from Lactobacillus plantarum Culture

2020 ◽  
Vol 24 (1) ◽  
pp. 740-754
Author(s):  
Georgii Riabinin ◽  
A. M. Abd El-Aty ◽  
Dagnija Blumberga ◽  
Denis Baranenko

Abstract According to the world health organization report from September 2016, the development of pathogenic bacteria resistance to antimicrobial drugs is one of the most important problems of the modern medicine. In this regard, the urgent task is the search for alternative antibiotics for the treatment of bacterial infections. One approach to solving this problem is obtaining antimicrobial compounds synthesized by probiotic lactic acid bacteria. The probiotic strain of Lactobacillus plantarum 8P-A3, was chosen to study its antimicrobial action. This strain produces at least two bacteriocins – plantaricin EF and plantaricin NC8. The chromatographic isolation of peptide fractions from the supernatant was carried out using a polymer sorbent based on methacrylic acid and ethyleneglycol dimethacrylate. Optimal parameters for chromatographic process were determined. It is shown that all the target biologically active substances were bound with the sorbent in sorption at acidic pH values. Elution was performed in isocratic mode. The antimicrobial activity of the obtained peptide fractions against indicator culture was determined by turbidimetric method. During incubation process, the turbidity of the microbial suspension was determined by measuring the optical density at λ = 600 nm. It is revealed that the fraction obtained at rinse by eluent with pH 8 has the maximum inhibitory ability. Сhromatomass-spectrometry analysis of the peptide fraction was carried out using Shimadzu LCMS-8040.The antimicrobial activity of the fraction is comparable to the action of ampicillin against gram-negative bacteria Escherichia coli. To confirm the peptide nature of the antimicrobial activity of the fraction, an indicator culture was incubated with the fraction treated with proteolytic enzymes (trypsin). It is determined the fraction can be stored at −18 °C and saves antimicrobial properties after defrosting.

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.


2021 ◽  
Vol 22 (4) ◽  
pp. 2050
Author(s):  
Lukas Hofmann ◽  
Melanie Hirsch ◽  
Sharon Ruthstein

Thirty-five thousand people die as a result of more than 2.8 million antibiotic-resistant infections in the United States of America per year. Pseudomonas aeruginosa (P. aeruginosa) is classified a serious threat, the second-highest threat category of the U.S. Department of Health and Human Services. Among others, the World Health Organization (WHO) encourages the discovery and development of novel antibiotic classes with new targets and mechanisms of action without cross-resistance to existing classes. To find potential new target sites in pathogenic bacteria, such as P. aeruginosa, it is inevitable to fully understand the molecular mechanism of homeostasis, metabolism, regulation, growth, and resistances thereof. P. aeruginosa maintains a sophisticated copper defense cascade comprising three stages, resembling those of public safety organizations. These stages include copper scavenging, first responder, and second responder. Similar mechanisms are found in numerous pathogens. Here we compare the copper-dependent transcription regulators cueR and copRS of Escherichia coli (E. coli) and P. aeruginosa. Further, phylogenetic analysis and structural modelling of mexPQ-opmE reveal that this efflux pump is unlikely to be involved in the copper export of P. aeruginosa. Altogether, we present current understandings of the copper homeostasis in P. aeruginosa and potential new target sites for antimicrobial agents or a combinatorial drug regimen in the fight against multidrug resistant pathogens.


2011 ◽  
Vol 36 (1) ◽  
pp. 55-64 ◽  
Author(s):  
Y Ramakrishna ◽  
H Goda ◽  
MS Baliga ◽  
AK Munshi

The association between the oral microbiota and oral diseases is well established. Various antimicrobial agents including antibiotics are commercially available against oral pathogenic bacteria. For the reasons of antibiotic resistance, their adverse effects and financial considerations in the developing countries, there is a need for alternate preventive and curative treatment options that are also safe, effective and economical. Traditional medicines have been used since ancient times for the treatment of oral diseases including dental caries, periodontal diseases that affect the majority of the population and can affect a person's overall health. Natural phytochemicals are certain organic components isolated from plants and some of these extracts are considered to be beneficial to health. They serve as antioxidants, enhance immune response,provide protection against oral cancer and other diseases and also repair DNA damage caused by smoking and other toxic exposure, and detoxify carcinogens. The natural products derived from medicinal plants have proven to be an abundant source of biologically active compounds, many of which have been the basis for the development of new lead chemicals for pharmaceuticals.They are considered to be good alternatives to synthetic chemicals. This article presents a review of natural alternatives derived from plants and plant products that can serve as a prevention and treatment option against cariogenic bacteria.


2017 ◽  
Vol 61 (11) ◽  
Author(s):  
Marc B. Habash ◽  
Mara C. Goodyear ◽  
Amber J. Park ◽  
Matthew D. Surette ◽  
Emily C. Vis ◽  
...  

ABSTRACT Increasing antibiotic resistance among pathogenic bacterial species is a serious public health problem and has prompted research examining the antibacterial effects of alternative compounds and novel treatment strategies. Compounding this problem is the ability of many pathogenic bacteria to form biofilms during chronic infections. Importantly, these communities are often recalcitrant to antibiotic treatments that show effectiveness against acute infection. The antimicrobial properties of silver have been known for decades, but recently silver and silver-containing compounds have seen renewed interest as antimicrobial agents for treating bacterial infections. The goal of this study was to assess the ability of citrate-capped silver nanoparticles (AgNPs) of various sizes, alone and in combination with the aminoglycoside antibiotic tobramycin, to inhibit established Pseudomonas aeruginosa biofilms. Our results demonstrate that smaller 10-nm and 20-nm AgNPs were more effective at synergistically potentiating the activity of tobramycin. Visualization of biofilms treated with combinations of 10-nm AgNPs and tobramycin reveals that the synergistic bactericidal effect may be caused by disrupting cellular membranes. Minimum biofilm eradication concentration (MBEC) assays using clinical P. aeruginosa isolates shows that small AgNPs are more effective than larger AgNPs at inhibiting biofilms, but that the synergy effect is likely a strain-dependent phenomenon. These data suggest that small AgNPs synergistically potentiate the activity of tobramycin against P. aeruginosa in vitro and may reveal a potential role for AgNP/antibiotic combinations in treating patients with chronic infections in a strain-specific manner.


2002 ◽  
Vol 15 (2) ◽  
pp. 333-371 ◽  
Author(s):  
John R Pluske ◽  
David W Pethick ◽  
Deborah E Hopwood ◽  
David J Hampson

AbstractThere are several enteric bacterial diseases and conditions of pigs that require control to prevent overt disease, to reduce morbidity and mortality, and to improve the efficiency of production. Traditionally, veterinarians, feed manufacturers and producers have relied upon antibiotics and minerals (for example, ZnO, CuSO4) in diets for a large part of this control. However, recent trends, particularly in Europe, are to reduce antimicrobial use and seek alternative or replacement strategies for controlling enteric bacterial diseases. The majority of these strategies rely on ‘nutrition’, taken in its broadest sense, to reduce the susceptibility of pigs to these diseases. Evidence to date suggests that specific dietary interventions, for example feeding very highly-digestible diets based on cooked white rice, can reduce the proliferation of a number of specific enteric bacterial infections, such as post-weaning colibacillosis. No simple and universal way to reduce susceptibility to pathogens in the gastrointestinal tract has been identified, and the underlying basis for many of the reported positive effects of ‘nutrition’ on controlling enteric infections lacks robust, scientific understanding. This makes it difficult to recommend dietary guidelines to prevent or reduce enteric bacterial diseases. Furthermore, some diseases, such as porcine intestinal spirochaetosis caused byBrachyspira pilosicoli, are sometimes associated with other pathogens (co-infections). In such cases, each pathogen might have different nutrient requirements, ecological niches and patterns of metabolism for which a variety of dietary interventions are needed to ameliorate the disease. Greater understanding of how ‘nutrition’ influences gut epithelial biology and immunobiology, and their interactions with both commensal and pathogenic bacteria, holds promise as a means of tackling enteric disease without antimicrobial agents. In addition, it is important to consider the overall system (i.e. management, housing, welfare) of pig production in the context of controlling enteric bacterial diseases.


2013 ◽  
Vol 2013 ◽  
pp. 1-10 ◽  
Author(s):  
Carmen Steluta Ciobanu ◽  
Simona Liliana Iconaru ◽  
Mariana Carmen Chifiriuc ◽  
Adrian Costescu ◽  
Philippe Le Coustumer ◽  
...  

The synthesis of nanosized particles of Ag-doped hydroxyapatite with antibacterial properties is of great interest for the development of new biomedical applications. The aim of this study was the evaluation ofCa10−xAgx(PO4)6(OH)2nanoparticles (Ag:HAp-NPs) for their antibacterial and antifungal activity. Resistance to antimicrobial agents by pathogenic bacteria has emerged in the recent years and became a major health problem. Here, we report a method for synthesizing Ag doped nanocrystalline hydroxyapatite. A silver-doped nanocrystalline hydroxyapatite was synthesized at 100°C in deionised water. Also, in this paper Ag:HAp-NPs are evaluated for their antimicrobial activity against Gram-positive and Gram-negative bacteria and fungal strains. The specific antimicrobial activity revealed by the qualitative assay is demonstrating that our compounds are interacting differently with the microbial targets, probably due to the differences in the microbial wall structures.


2013 ◽  
Vol 785-786 ◽  
pp. 660-665 ◽  
Author(s):  
Zhi Ying Huang ◽  
Qiao Lei ◽  
Jian Qiang Bao ◽  
Qian Nan Xun

Antimicrobial effect of functional protein films incorporating garlic oil (GO), potassium sorbate (PS) and nisin (N) at various concentrations were discussed. This activity was tested against food pathogenic bacteria namely Escherichia coli (E.coli) and Staphylococcus aureus (S.aureus).Mechanical and physical properties were characterized. In the range of antimicrobial agents concentration studied, tensile strength (TS) and elongation at break (E) of functional protein films were changed by incorporating GO,PS and N. And the WVP value of functional protein films decreased as antimicrobial agents added. GO incorporated into protein films had no effect on E.coli, but incorporation of GO at 300μl had antimicrobial activity against S.aureus. Protein films incorporated with PS showed antimicrobial activity against S.aureus, but there was no effect on E.coli. Incorporation of N at the lowest level of 25,000 IU had antimicrobial activity against both E.coli and S.aureus.


2019 ◽  
Vol 8 (1) ◽  
pp. 3484
Author(s):  
Gopalakrishnaiah B. ◽  
Aniel Kumar O.

India is found to be a country with rich biodiversity and enormous treasure of herbal plants and consequently called as medicinal garden of the world. Plants are the richest source of natural antimicrobial agents. In recent years drug resistance to human pathogenic bacteria has been commonly reported from all over the world. Therefore, there is a need to develop alternative antimicrobial drugs for the treatment of infectious diseases; one approach is to screen local medicinal plants for possible antimicrobial properties. The present study was designed to evaluate the antimicrobial efficacy of hexane, chloroform and methanol crude extracts of the leaves of three important medicinal plants viz., Biophytum sensitivum (L.) DC, Bougainvillea spectabilis L. and Caesalpinia bonducella (L.) Fleming, collected from in and around Visakhapatnam District. The antimicrobial activity of the crude extracts was tested against three Gram Positive bacteria (Bacillus subtilis MTCC 441, Enterococcus faecalis MTCC 439, Staphylococcus aureus MTCC 737), Three Gram Negative bacteria (Escherichia coli MTCC 443, Proteus vulgaris MTCC 426 and Pseudomonas aeruginosa MTCC 1688) and three Fungal strains (Candida albicans MTCC 227, Epidermophyton floccosum MTCC 613 and Trichophyton mentagrophytes MTCC 7687) using agar well diffusion assay. Our results demonstrated that methanol extracts of these plants leaves have concentration dependent antibacterial activity against some of the tested organisms. Further studies should be undertaken to elucidate the exact mechanism of action of antimicrobial effect to identify the active ingredients which can be used for drug development program.


2020 ◽  
Vol 2 (1) ◽  
pp. 79-82
Author(s):  
Nadia Afifah

Probiotics are defined as living microorganisms which, when consumed in sufficient quantities, can provide health benefits. Lactobacillus Plantarum and Lactobacillus acidophilus include probiotics. Probiotics can protect the digestive tract from adhesion to pathogenic bacteria. Diarrhea is a disease characterized by increasing the frequency of bowel movements more than 3-4 days. The cause of diarrhea can be in the form of infections (bacteria, viruses, parasites), food poisoning, drug use, and others. Diarrhea can also occur due to physiological changes such as: (1) increased intraluminal osmolarity, (2) increased fluid and electrolyte secretion, (3) presence of infectious agents in the intestinal wall. The management of the World Health Organization (WHO) is rehydration (ORS fluids), diet, zinc, selective antibiotics, and education to parents of patients. But lately, probiotics have been proven to accelerate the healing process of diarrhea patients. There are emat mechanisms in the immune system process for patients with first diarrhea, preventing adhesion of pathogenic bacteria to the intestinal epithelium, both improving the function of the intestinal epithelium, the therapeutic effect of L. Plantarum will prevent bacteria from passing through the parasellular and transepithelial (transcellular) pathways to tissues outside the intestine, third inhibits pro-inflammatory cytokines, fourth induces immunoglobulin A (IgA)


2020 ◽  
Vol 16 (2) ◽  
pp. 207-212
Author(s):  
Wissam Zam ◽  
Ali Ali ◽  
Walaa Ibrahim

Background and Objective: With the significant increase in the prevalence of infectious diseases and the development of drug resistance by human pathogenic bacteria, there is a continuous need to discover new antimicrobial compounds from plants. Methods: Four extracts of wild Myrtus communis L. berries (myrtle berries) were prepared with the addition of Cinnamomum verum and Eugenia caryophyllata. The extracts were screened in vitro for their antimicrobial activities using agar-well diffusion method against Escherichia coli, Staphylococcus aureus, Enterobacter cloacae, Listeria monocytogenes, Pseudomonas aeruginosa and Proteus mirabilis cultures. Results: The inhibition zones ranged from 12 to 22 mm. The MICs values of extracts lies between the ranges of 30 to 100 mg/ml. Of the extracts studied, the most active ones were those obtained from the myrtle berries:cloves, myrtle berries:cinnamon:cloves with the highest inhibition zones 22 mm and 17mm against S. aureus and L. monocytogenes at 50 mg/ml and 80 mg/ml, respectively. None of the extracts was active against E. coli and P. mirabilis. Conclusion: The present investigations have exposed that the myrtle berries:cloves, myrtle berries: cinnamon:cloves extracts could be used in traditional medicine as natural antimicrobial agents in treatment the bacterial infections.


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