scholarly journals Dimerization of cell-penetrating buforin II enhances antimicrobial properties

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Hyunhee Lee ◽  
Sungtae Yang
Keyword(s):  
Cytotoxic Activity ◽  
Lipid Bilayers ◽  
Pathogenic Bacteria ◽  
Antimicrobial Properties ◽  
Substantial Impact ◽  
Bacterial Membranes ◽  
Intracellular Targeting ◽  
Cell Penetrating ◽  
Magainin Ii ◽  
Conventional Antibiotics

AbstractAntimicrobial peptides (AMPs) that selectively permeabilize bacterial membranes are promising alternatives to conventional antibiotics. Dimerization of AMP is considered an attractive strategy to enhance antimicrobial and membrane-lytic activity, but it also increases undesired hemolytic and cytotoxic activity. Here, we prepared Lys-linked homodimers of membrane-permeabilizing magainin II and cell-penetrating buforin II. Dimerization did not significantly alter conformational behavior, but it had a substantial impact on antimicrobial properties. We found that while the magainin II dimer showed increased antimicrobial and cytotoxic effects, the buforin II dimer conferred much greater antibacterial potency without exhibiting cytotoxic activity. Interestingly, the buforin II dimer was highly effective against several antibiotic-resistant bacterial isolates. Membrane permeabilization experiments indicated that the magainin II dimer rapidly disrupted both anionic and zwitterionic membranes, whereas the buforin II dimer selectively disrupted anionic membranes. Like the monomeric form, the buforin II dimer was efficiently translocated across lipid bilayers. Therefore, our results suggest that the dimerization of cell-penetrating buforin II not only disrupts the bacterial membrane, but also translocates it across the membrane to target intracellular components, resulting in effective antimicrobial activity. We propose that dimerization of intracellular targeting AMPs may present a superior strategy for therapeutic control of pathogenic bacteria.

scholarly journals Chemical Profiling and Antimicrobial Properties of Honey Bee (Apis mellifera L.) Venom

Molecules ◽  
2021 ◽  
Vol 26 (10) ◽  
pp. 3049
Author(s):  
Irina Tanuwidjaja ◽  
Lidija Svečnjak ◽  
Domenika Gugić ◽  
Marko Levanić ◽  
Slaven Jurić ◽  
...  
Keyword(s):  
Apis Mellifera ◽  
Honey Bee ◽  
Pathogenic Bacteria ◽  
Therapeutic Potential ◽  
Antimicrobial Properties ◽  
Gram Negative Bacteria ◽  
Absorption Bands ◽  
Chemical Profiling ◽  
Atr Spectroscopy ◽  
Conventional Antibiotics

The incidence of antibiotic resistance in pathogenic bacteria has become an alarming clinical and social problem. Therefore, the demand for alternative antimicrobial compounds has increased. In this study, a chemical profile of honey bee (Apis mellifera L.) venom (HBV) has been determined by HPLC and FTIR-ATR spectroscopy, and tested for antibacterial activity, as well as efficiency with regard to conventional antibiotics. The investigated HBV was of high quality with melittin and total protein contents of 70.10 ± 7.01%, and 84.44 ± 3.12 g/100 g, respectively. The purity of HBV was confirmed by FTIR-ATR spectral profiling, which revealed a unique pattern of absorption bands that are characteristic of its major fractions. In addition, HBV showed a broad spectrum of activity against all three tested biomasses of potentially pathogenic Gram-positive and Gram-negative bacteria with MIC values ranging between 12.5 and 200 µg/mL, and MBC between 12.5 and 400 µg/mL. When compared to conventional antibiotics, HBV (400 µg) showed up to 27.8% efficiency of tetracycline (30 µg), 52.2% erythromycin (15 µg), 21.2% ciprofloxacin (5 µg), and 34.6% of ampicillin-sulbactam (20 µg). The overall results demonstrate the therapeutic potential of the analyzed HBV.

Antimicrobial properties of actively purified secondary metabolites isolated from different marine organisms

2020 ◽  
Vol 21 ◽  
Author(s):  
Nilushi Indika Bamunu Arachchige ◽  
Fazlurrahman Khan ◽  
Young-Mog Kim
Keyword(s):  
Secondary Metabolites ◽  
Pathogenic Bacteria ◽  
Antimicrobial Agents ◽  
Bacterial Species ◽  
Antimicrobial Properties ◽  
Antimicrobial Effect ◽  
Cost Effective ◽  
Resistance Mechanisms ◽  
Marine Organisms ◽  
Antimicrobial Compounds

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.

A Review on Quantum Dots: Synthesis to In- silico Analysis as Next Generation Antibacterial Agents

2019 ◽  
Vol 20 (3) ◽  
pp. 255-262 ◽  
Author(s):  
Sounik Manna ◽  
Munmun Ghosh ◽  
Ranadhir Chakraborty ◽  
Sudipto Ghosh ◽  
Santi M. Mandal
Keyword(s):  
Quantum Dots ◽  
Pathogenic Bacteria ◽  
Antibacterial Agents ◽  
Antimicrobial Properties ◽  
Binding Potential ◽  
Antibacterial Drug ◽  
Next Generation ◽  
Mechanism Of Reaction ◽  
High Level ◽  
Membrane Components

Succumbing to Multi-Drug Resistant (MDR) bacteria is a great distress to the recent health care system. Out of the several attempts that have been made to kill MDR pathogens, a few gained short-lived success. The failures, of the discovered or innovated antimicrobials, were mostly due to their high level of toxicity to hosts and the phenomenal rate of developing resistance by the pathogens against the new arsenal. Recently, a few quantum dots were tested against the pathogenic bacteria and therefore, justified for potential stockpiling of next-generation antibacterial agents. The key players for antimicrobial properties of quantum dots are considered to be Reactive Oxygen Species (ROS). The mechanism of reaction between bacteria and quantum dots needs to be better understood. They are generally targeted towards the cell wall and membrane components as lipoteichoic acid and phosphatidyl glycerol of bacteria have been documented here. In this paper, we have attempted to simulate ZnS quantum dots and have analysed their mechanism of reaction as well as binding potential to the above bacterial membrane components using CDOCKER. Results have shown a high level of antibacterial activity towards several pathogenic bacteria which specify their potentiality for future generation antibacterial drug development.

scholarly journals The Potential of Human Peptide LL-37 as an Antimicrobial and Anti-Biofilm Agent

Antibiotics ◽  
2021 ◽  
Vol 10 (6) ◽  
pp. 650
Author(s):  
Kylen E. Ridyard ◽  
Joerg Overhage
Keyword(s):  
Bacterial Infections ◽  
Antimicrobial Properties ◽  
Cross Resistance ◽  
Resistant Bacteria ◽  
Peptide Antibiotic ◽  
Adaptive Responses ◽  
Antibiotic Resistant ◽  
Structural Modifications ◽  
Immobilization Techniques ◽  
Conventional Antibiotics

The rise in antimicrobial resistant bacteria threatens the current methods utilized to treat bacterial infections. The development of novel therapeutic agents is crucial in avoiding a post-antibiotic era and the associated deaths from antibiotic resistant pathogens. The human antimicrobial peptide LL-37 has been considered as a potential alternative to conventional antibiotics as it displays broad spectrum antibacterial and anti-biofilm activities as well as immunomodulatory functions. While LL-37 has shown promising results, it has yet to receive regulatory approval as a peptide antibiotic. Despite the strong antimicrobial properties, LL-37 has several limitations including high cost, lower activity in physiological environments, susceptibility to proteolytic degradation, and high toxicity to human cells. This review will discuss the challenges associated with making LL-37 into a viable antibiotic treatment option, with a focus on antimicrobial resistance and cross-resistance as well as adaptive responses to sub-inhibitory concentrations of the peptide. The possible methods to overcome these challenges, including immobilization techniques, LL-37 delivery systems, the development of LL-37 derivatives, and synergistic combinations will also be considered. Herein, we describe how combination therapy and structural modifications to the sequence, helicity, hydrophobicity, charge, and configuration of LL-37 could optimize the antimicrobial and anti-biofilm activities of LL-37 for future clinical use.

scholarly journals Sorting out the Superbugs: Potential of Sortase A Inhibitors among Other Antimicrobial Strategies to Tackle the Problem of Antibiotic Resistance

Antibiotics ◽  
2021 ◽  
Vol 10 (2) ◽  
pp. 164 ◽  
Author(s):  
Nikita Zrelovs ◽  
Viktorija Kurbatska ◽  
Zhanna Rudevica ◽  
Ainars Leonchiks ◽  
Davids Fridmanis
Keyword(s):  
Cell Wall ◽  
Antibiotic Resistance ◽  
Pathogenic Bacteria ◽  
Resistance Mechanisms ◽  
Surface Proteins ◽  
Sortase A ◽  
Inhibitory Compounds ◽  
Alternative Means ◽  
Alternative Approaches ◽  
Conventional Antibiotics

Rapid spread of antibiotic resistance throughout the kingdom bacteria is inevitably bringing humanity towards the “post-antibiotic” era. The emergence of so-called “superbugs”—pathogen strains that develop resistance to multiple conventional antibiotics—is urging researchers around the globe to work on the development or perfecting of alternative means of tackling the pathogenic bacteria infections. Although various conceptually different approaches are being considered, each comes with its advantages and drawbacks. While drug-resistant pathogens are undoubtedly represented by both Gram(+) and Gram(−) bacteria, possible target spectrum across the proposed alternative approaches of tackling them is variable. Numerous anti-virulence strategies aimed at reducing the pathogenicity of target bacteria rather than eliminating them are being considered among such alternative approaches. Sortase A (SrtA) is a membrane-associated cysteine protease that catalyzes a cell wall sorting reaction by which surface proteins, including virulence factors, are anchored to the bacterial cell wall of Gram(+) bacteria. Although SrtA inhibition seems perspective among the Gram-positive pathogen-targeted antivirulence strategies, it still remains less popular than other alternatives. A decrease in virulence due to inactivation of SrtA activity has been extensively studied in Staphylococcus aureus, but it has also been demonstrated in other Gram(+) species. In this manuscript, results of past studies on the discovery of novel SrtA inhibitory compounds and evaluation of their potency were summarized and commented on. Here, we discussed the rationale behind the inhibition of SrtA, raised some concerns on the comparability of the results from different studies, and touched upon the possible resistance mechanisms as a response to implementation of such therapy in practice. The goal of this article is to encourage further studies of SrtA inhibitory compounds.

scholarly journals Photorhabdus sp. ETL Antimicrobial Properties and Characterization of Its Secondary Metabolites by Gas Chromatography–Mass Spectrometry

Life ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 787
Author(s):  
Tshikala Eddie Lulamba ◽  
Ezekiel Green ◽  
Mahloro Hope Serepa-Dlamini
Keyword(s):  
Mass Spectrometry ◽  
Gas Chromatography ◽  
Secondary Metabolites ◽  
Pathogenic Bacteria ◽  
Insect Pests ◽  
Antimicrobial Properties ◽  
Antimicrobial Activities ◽  
Gas Chromatography Mass Spectrometry ◽  
Toxigenic Fungi ◽  
Properties And Characterization

Entomopathogenic nematodes (EPNs) are known to be highly pathogenic to insect pests, due to their associated symbiotic bacteria, which produce virulence factors, exo-enzymes and other harmful secondary metabolites to conquer, kill, and degrade their insect hosts. However, these properties are not fully characterized. This study reports on the antimicrobial activities of Photorhabdus sp. strain ETL, symbiotically associated to an insect pathogenic nematode, Heterorhabditis zealandica, against human pathogenic bacteria and toxigenic fungi, as well as the non-targeted profiling of its secondary metabolites (SMs) using gas chromatography coupled to high-resolution time-of-flight mass spectrometry. Fatty acids including 3-eicosene, (E)-; 5-eicosene, (E)-; eicosene; 9-octadecenamide; undecanoic acid with shown antimicrobial activities were detected. This provided more insight on the composition and bioactivities of SMs produced by the Photorhabdus sp.

scholarly journals Antimicrobial activity of the volatile phase of essential oils and their constituents on Legionella pneumophila

2020 ◽  
Vol 14 (1) ◽  
pp. 54-61
Author(s):  
Lucia Bićanić ◽  
Silvestar Mežnarić ◽  
Ivana Gobin
Keyword(s):  
Essential Oil ◽  
Essential Oils ◽  
Legionella Pneumophila ◽  
Pathogenic Bacteria ◽  
Antimicrobial Properties ◽  
Model Organism ◽  
Public Health Problem ◽  
Volatile Components ◽  
Atypical Pneumonia ◽  
Pontiac Fever

Abstract Pathogenic bacteria of the genus Legionella cause atypical pneumonia known as Legionnaires’ disease and flu – like disease known as Pontiac fever. As pathogens of the respiratory system, these bacteria represent a public health problem and there is a need for examine new alternative ways to inactivate them. These bacteria live naturally in water and are transmitted by infectious aerosols. To purify the air, essential oils that show antimicrobial properties are widely used. The anti-Legionella activity of five exotic essential oils and five Mediterranean essential oils characteristic for coastal Croatia was examined. Model organism used in experiments was L. pneumophila (strain 130b). This experiment was conducting with modified version of sealed plate method using a BCYE medium. The exotic essential oil with highest anti-Legionella activity was Niaouli essential oil, and the best anti-Legionella activity among Mediterranean essential oils showed Immortelle essential oil. Anti- Legionella activity of four main chemical compounds was examined and compound that show significant highest anti-Legionella activity was α – pinene. Volatile components of essential oils have a great potential as anti-Legionella agents and further research are needed.

scholarly journals Study of Antimicrobial, Antioxidant and Cytotoxicity Properties of Selected Plant Extracts for Food Preservative Applications

2021 ◽  
pp. 95-111
Author(s):  
Tania Islam ◽  
Md Nazrul Islam ◽  
Wahidu Zzaman ◽  
Md Morsaline Billah
Keyword(s):  
Pathogenic Bacteria ◽  
Radical Scavenging Activity ◽  
Radical Scavenging ◽  
Antimicrobial Properties ◽  
In Vivo Studies ◽  
Diffusion Method ◽  
Plant Materials ◽  
Food Preservative

An attempt has been made to evaluate antimicrobial, antioxidant and cytotoxicity properties of extracts from onion (Allium cepa L.), garlic (Allium sativum), leaves of guava (Psidium guajava), papaya (Carica papaya), tea (Camellia sinensis), baen (Avicennia alba) and keora (Sonneratia apetala), respectively to apply as natural preservatives for tomatoes. The air-dried plant materials of the respective plant species were subjected to ethanol-methanol extraction, concentrated and stored at 4 °C before use. The extracts were dissolved in 95% ethanol for analysis of antioxidant and antimicrobial properties. Of the extracts tested, tea extracts showed the highest zone of inhibition against several pathogenic bacteria (E. coli 35.0±3.2 mm; P. aeruginosa 29.3±2.6 mm; S. typhi 28.4±2.1 mm and S. pyogenes 27.7±3.7 mm) using the disc diffusion method. In regard to DPPH free radical scavenging assay, keora and guava extracts showed the highest percentage of radical scavenging activity with the values of 89.64± 0.18 and 89.39± 0.88, respectively, which were in agreement with higher total antioxidant capacity (TAC) of these extracts obtained by the phosphomolybdenum method. Brine shrimp lethality bioassay for cytotoxicity assessment showed LC50 of 132.54 ± 18.99 µg/mL for the leaf extract of keora which was found to be most toxic among all studied extracts. The initial results indicated that the extracts could be used for food preservative applications based on the antimicrobial, antioxidant and cytotoxicity properties of the tested extracts. However, efficacy, stability and safety issues need to be addressed with both in vitro and in vivo studies.

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