scholarly journals Antifungal Mechanism of Vip3Aa, a Vegetative Insecticidal Protein, against Pathogenic Fungal Strains

Antibiotics ◽  
2021 ◽  
Vol 10 (12) ◽  
pp. 1558
Author(s):  
Seong-Cheol Park ◽  
Jin-Young Kim ◽  
Jong-Kook Lee ◽  
Hye Song Lim ◽  
Hyosuk Son ◽  
...  
Keyword(s):  
Antimicrobial Agents ◽  
Antifungal Agents ◽  
Protein A ◽  
Insecticidal Protein ◽  
Inhibition Mechanism ◽  
Oxygen Species ◽  
Antimicrobial Proteins ◽  
Vegetative Insecticidal Protein ◽  
Action Mechanisms ◽  
Potential Applications

Discovering new antifungal agents is difficult, since, unlike bacteria, mammalian and fungal cells are both eukaryotes. An efficient strategy is to consider new antimicrobial proteins that have variety of action mechanisms. In this study, a cDNA encoding Bacillus thuringiensis Vip3Aa protein, a vegetative insecticidal protein, was obtained at the vegetative growth stage; its antifungal activity and mechanism were evaluated using a bacterially expressed recombinant Vip3Aa protein. The Vip3Aa protein demonstrated various concentration- and time-dependent antifungal activities, with inhibitory concentrations against yeast and filamentous fungi ranging from 62.5 to 125 µg/mL and 250 to 500 µg/mL, respectively. The uptake of propidium iodide and cellular distributions of rhodamine-labeled Vip3Aa into fungal cells indicate that its growth inhibition mechanism involves its penetration within cells and subsequent intracellular damage. Furthermore, we discovered that the death of Candida albicans cells was caused by the induction of apoptosis via the generation of mitochondrial reactive oxygen species and binding to nucleic acids. The presence of significantly enlarged Vip3Aa-treated fungal cells indicates that this protein causes intracellular damage. Our findings suggest that Vip3Aa protein has potential applications in the development of natural antimicrobial agents.

Design and synthesis of new antifungals based on N- un-substituted azoles as 14α demethylase inhibitor

2020 ◽  
Vol 16 ◽  
Author(s):  
Asghar Davood ◽  
Aneseh Rahimi ◽  
Maryam Iman ◽  
Parisa Azerang ◽  
Soroush Sardari ◽  
...  
Keyword(s):  
Antimicrobial Agents ◽  
Antifungal Agents ◽  
Molecular Design ◽  
Pathogenic Fungi ◽  
Antimicrobial Activities ◽  
Docking Studies ◽  
Receptor Interaction ◽  
Main Role ◽  
Design And Synthesis ◽  
Antifungal Antibiotics

Objective(s): Azole antifungal agents, which are widely used as antifungal antibiotics, inhibit cytochrome P450 sterol 14α-demethylase (CYP51). Nearly all azole antifungal agents are N-substituted azoles. In addition, an azolylphenalkyl pharmacophore is uniquely shared by all azole antifungals. Due to importance of nitrogen atom of azoles (N-3 of imidazole and N-4 of triazole) in coordination with heme in the binding site of the enzyme, here a group of N- un-substituted azoles in which both of nitrogen is un-substituted was reported. Materials and Methods: Designed compounds were synthesized by reaction of imidazole-4-carboxaldehyde with appropriate arylamines and subsequently reduced to desired amine derivatives. Antifungal activity against Candida albicans and Saccharomyces cervisiae were done using a broth micro-dilution assay. Docking studies were done using AutoDock. Results: Antimicrobial evaluation revealed that some of these compounds exhibited moderate antimicrobial activities against tested pathogenic fungi, wherein compound 3, 7 and 8 were potent. Docking studies propose that all of the prepared azoles interacted with 14α-DM, wherein azole-heme coordination play main role in drug-receptor interaction. Conclusion: Our results offer some useful references in order to molecular design performance or modification of this series of compounds as a lead compound to discover new and potent antimicrobial agents.

scholarly journals Evaluation of Toxicity and Antioxidant Property of Cassia fistula Stem Bark Extracts in Zebrafish

2020 ◽  
Vol 10 (03) ◽  
pp. 109-115
Author(s):  
Shreya Udaya ◽  
Nishith Babu ◽  
Dechamma Pandyanda Nanjappa ◽  
Krithika Kalladka ◽  
Gunimala Chakraborty ◽  
...  
Keyword(s):  
Aqueous Extract ◽  
Antioxidant Properties ◽  
Ethanol Extract ◽  
Antioxidant Property ◽  
Stem Bark ◽  
Oxygen Species ◽  
Cassia Fistula ◽  
Potential Applications ◽  
Ethanol Extracts ◽  
Stress Models

Abstract Objective This study was aimed at evaluating the toxicity and the antioxidant property of Cassia fistula stem bark extracts in zebrafish. Materials and Methods Crude aqueous and ethanol extracts of C. fistula stem bark were obtained following a standard solvent-based extraction method. The toxicity of these extracts on zebrafish embryonic development was determined and the LC50 values were calculated. Finally, the antioxidant property of C. fistula stem bark extracts was determined in arsenic-induced oxidative stress models of zebrafish. Results The aqueous extract of C. fistula stem bark showed a slightly larger LC50 value (213.6 ppm) compared with the ethanol extract (LC50 = 63.5 ppm), suggesting a lower toxicity of the aqueous extract. A significant reduction of reactive oxygen species (ROS) signal was observed in arsenic-exposed embryos treated with the aqueous extract, but not the ethanol extract, indicating that the antioxidant activity is present only in the aqueous extract of C. fistula stem bark. Conclusion Identification of antioxidants from natural sources is desirable because of increasing safety concerns associated with synthetic antioxidants. This study demonstrated that aqueous extract from C. fistula stem bark possesses antioxidant properties, which can be further characterized for mechanism of action and potential applications.

scholarly journals Green synthesis of silver nanoparticles using plant extracts and their antimicrobial activities: a review of recent literature

RSC Advances ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 2804-2837
Author(s):  
Chhangte Vanlalveni ◽  
Samuel Lallianrawna ◽  
Ayushi Biswas ◽  
Manickam Selvaraj ◽  
Bishwajit Changmai ◽  
...  
Keyword(s):  
Silver Nanoparticles ◽  
Green Synthesis ◽  
Plant Extracts ◽  
Antimicrobial Agents ◽  
Recent Literature ◽  
Antimicrobial Activities ◽  
New Findings ◽  
Potential Applications ◽  
Research Domain

Herein, we have reviewed new findings in the research domain of the green synthesis of silver nanoparticles using different plant extracts and their potential applications as antimicrobial agents covering the literature since 2015.

scholarly journals Identification of a promoter for the vegetative insecticidal protein-encoding genevip3LBfromBacillus thuringiensis

2005 ◽  
Vol 247 (1) ◽  
pp. 101-104 ◽  
Author(s):  
Lobna Abdelkefi Mesrati ◽  
Slim Tounsi ◽  
Fakher Kamoun ◽  
Samir Jaoua
Keyword(s):  
Insecticidal Protein ◽  
Vegetative Insecticidal Protein ◽  
Protein Encoding

scholarly journals Droplet-based microfluidics platform for antifungal analysis against filamentous fungi

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Sehrish Iftikhar ◽  
Aurélie Vigne ◽  
Julia Elisa Sepulveda-Diaz
Keyword(s):  
Fungal Pathogens ◽  
Antimicrobial Agents ◽  
Pearson Correlation ◽  
Hyphal Growth ◽  
Bulk Analysis ◽  
Single Spore ◽  
Microfluidic Platform ◽  
Viability Assay ◽  
Wide Range ◽  
Potential Applications

AbstractFungicides are extensively used in agriculture to control fungal pathogens which are responsible for significant economic impact on plant yield and quality. The conventional antifungal screening techniques, such as water agar and 96-well plates, are based on laborious protocols and bulk analysis, restricting the analysis at the single spore level and are time consuming. In this study, we present a droplet-based microfluidic platform that enables antifungal analysis of single spores of filamentous fungus Alternaria alternata. A droplet-based viability assay was developed, allowing the germination and hyphal growth of single A. alternata spores within droplets. The viability was demonstrated over a period of 24 h and the antifungal screening was achieved using Kunshi/Tezuma as antifungal agent. The efficacy results of the droplet-based antifungal analysis were compared and validated with the results obtained from conventional protocols. The percentage inhibitions assessed by the droplet-based platform were equivalent with those obtained by the other two methods, and the Pearson correlation analysis showed high correlation between the three assays. Taken together, this droplet-based microfluidic platform provides a wide range of potential applications for the analysis of fungicide resistance development as well as combinatorial screening of other antimicrobial agents and even antagonistic fungi.

scholarly journals Resorbable Beads Provide Extended Release of Antifungal Medication: In Vitro and In Vivo Analyses

Pharmaceutics ◽  
2019 ◽  
Vol 11 (11) ◽  
pp. 550 ◽  
Author(s):  
Yung-Heng Hsu ◽  
Huang-Yu Chen ◽  
Jin-Chung Chen ◽  
Yi-Hsun Yu ◽  
Ying-Chao Chou ◽  
...  
Keyword(s):  
High Performance ◽  
Antifungal Agents ◽  
High Dose ◽  
Molding Method ◽  
Potential Applications ◽  
Radical Debridement ◽  
Fungal Osteomyelitis ◽  
High Level

Fungal osteomyelitis has been difficult to treat, with first-line treatments consisting of implant excision, radical debridement, and local release of high-dose antifungal agents. Locally impregnated antifungal beads are another popular treatment option. This study aimed to develop biodegradable antifungal-agent-loaded Poly(d,l-lactide-co-glycolide) (PLGA) beads and evaluate the in vitro/in vivo release patterns of amphotericin B and fluconazole from the beads. Beads of different sizes were formed using a compression-molding method, and their morphology was evaluated via scanning electron microscopy. Intrabead incorporation of antifungal agents was evaluated via Fourier-transform infrared spectroscopy, and in vitro fluconazole liberation curves of PLGA beads were inspected via high-performance liquid chromatography. When we implanted the drug-incorporated beads into the bone cavity of rabbits, we found that a high level of fluconazole (beyond the minimum therapeutic concentration [MTC]) was released for more than 49 d in vivo. Our results indicate that compression-molded PLGA/fluconazole beads have potential applications in treating bone infections.

scholarly journals Certain Aspects of Silver and Silver Nanoparticles in Wound Care: A Minireview

2016 ◽  
Vol 2016 ◽  
pp. 1-10 ◽  
Author(s):  
Marek Konop ◽  
Tatsiana Damps ◽  
Aleksandra Misicka ◽  
Lidia Rudnicka
Keyword(s):  
Silver Nanoparticles ◽  
Clinical Practice ◽  
Pathogenic Bacteria ◽  
Antimicrobial Agents ◽  
Antifungal Agents ◽  
Wound Care ◽  
Wound Dressings ◽  
Major Health Problem ◽  
Major Health ◽  
Bactericidal Effects

Resistance to antimicrobial agents by pathogenic bacteria has emerged in recent years and is a major health problem. In this context silver and silver nanoparticles (AgNP) have been known to have inhibitory and bactericidal effects and was used throughout history for treatment of skin ulcer, bone fracture, and supporting wound healing. In all of these applications prevention and treatment of bacterial colonized/infected wounds are critical. In this context silver and its derivatives play an important role in health care. Silver is widely used in clinical practice in the form of silver nitrate and/or silver sulfadiazine. In the last few years silver nanoparticles entered into clinical practice as both antimicrobial and antifungal agents. In addition, nanosilver is used in coating medical devices (catheters) and as component of wound dressings. In this paper we present summarized information about silver and nanoparticles made of silver in the context of their useful properties, especially antibacterial ones, being of a great interest for researchers and clinicians.

scholarly journals Saccharomyces paradoxus Transcriptional Alterations in Cells of Distinct Phenotype and Viral dsRNA Content

2020 ◽  
Vol 8 (12) ◽  
pp. 1902
Author(s):  
Bazilė Ravoitytė ◽  
Juliana Lukša ◽  
Vyacheslav Yurchenko ◽  
Saulius Serva ◽  
Elena Servienė
Keyword(s):  
Food Industry ◽  
Antifungal Agents ◽  
Acid Biosynthesis ◽  
Viral Dsrna ◽  
Saccharomyces Paradoxus ◽  
Distinct Phenotype ◽  
Transcriptional Alterations ◽  
Potential Applications ◽  
Dsrna Viruses ◽  
First Time

Killer yeasts are attractive antifungal agents with great potential applications in the food industry. Natural Saccharomyces paradoxus isolates provide new dsRNA-based killer systems available for investigation. The presence of viral dsRNA may alter transcriptional profile of S. paradoxus. To test this possibility, a high-throughput RNA sequencing was employed to compare the transcriptomes of S. paradoxus AML 15-66 K66 killer strains after curing them of either M-66 alone or both M-66 and L-A-66 dsRNA viruses. The S. paradoxus cells cured of viral dsRNA(s) showed respiration deficient or altered sporulation patterns. We have identified numerous changes in the transcription profile of genes including those linked to ribosomes and amino acid biosynthesis, as well as mitochondrial function. Our work advance studies of transcriptional adaptations of Saccharomyces spp. induced by changes in phenotype and set of dsRNA viruses, reported for the first time.

scholarly journals Antifungal Agents: Mode of Action, Mechanisms of Resistance, and Correlation of These Mechanisms with Bacterial Resistance

1999 ◽  
Vol 12 (4) ◽  
pp. 501-517 ◽  
Author(s):  
Mahmoud A. Ghannoum ◽  
Louis B. Rice
Keyword(s):  
Mode Of Action ◽  
Drug Target ◽  
Bacterial Resistance ◽  
Antifungal Agents ◽  
Mechanisms Of Resistance ◽  
Development Of Resistance ◽  
Action Mechanisms ◽  
Membrane Pumps ◽  
Antibacterial And Antifungal ◽  
And Control

SUMMARY The increased use of antibacterial and antifungal agents in recent years has resulted in the development of resistance to these drugs. The significant clinical implication of resistance has led to heightened interest in the study of antimicrobial resistance from different angles. Areas addressed include mechanisms underlying this resistance, improved methods to detect resistance when it occurs, alternate options for the treatment of infections caused by resistant organisms, and strategies to prevent and control the emergence and spread of resistance. In this review, the mode of action of antifungals and their mechanisms of resistance are discussed. Additionally, an attempt is made to discuss the correlation between fungal and bacterial resistance. Antifungals can be grouped into three classes based on their site of action: azoles, which inhibit the synthesis of ergosterol (the main fungal sterol); polyenes, which interact with fungal membrane sterols physicochemically; and 5-fluorocytosine, which inhibits macromolecular synthesis. Many different types of mechanisms contribute to the development of resistance to antifungals. These mechanisms include alteration in drug target, alteration in sterol biosynthesis, reduction in the intercellular concentration of target enzyme, and overexpression of the antifungal drug target. Although the comparison between the mechanisms of resistance to antifungals and antibacterials is necessarily limited by several factors defined in the review, a correlation between the two exists. For example, modification of enzymes which serve as targets for antimicrobial action and the involvement of membrane pumps in the extrusion of drugs are well characterized in both the eukaryotic and prokaryotic cells.

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