scholarly journals Marine Macroalgae, a Source of Natural Inhibitors of Fungal Phytopathogens

2021 ◽  
Vol 7 (12) ◽  
pp. 1006
Author(s):  
Tânia F. L. Vicente ◽  
Marco F. L. Lemos ◽  
Rafael Félix ◽  
Patrícia Valentão ◽  
Carina Félix
Keyword(s):  
Fruits And Vegetables ◽  
Antimicrobial Agents ◽  
Industrial Applications ◽  
Marine Macroalgae ◽  
In Planta ◽  
Lipophilic Compounds ◽  
Wide Range ◽  
Fungal Phytopathogens

Fungal phytopathogens are a growing problem all over the world; their propagation causes significant crop losses, affecting the quality of fruits and vegetables, diminishing the availability of food, leading to the loss of billions of euros every year. To control fungal diseases, the use of synthetic chemical fungicides is widely applied; these substances are, however, environmentally damaging. Marine algae, one of the richest marine sources of compounds possessing a wide range of bioactivities, present an eco-friendly alternative in the search for diverse compounds with industrial applications. The synthesis of such bioactive compounds has been recognized as part of microalgal responsiveness to stress conditions, resulting in the production of polyphenols, polysaccharides, lipophilic compounds, and terpenoids, including halogenated compounds, already described as antimicrobial agents. Furthermore, many studies, in vitro or in planta, have demonstrated the inhibitory activity of these compounds with respect to fungal phytopathogens. This review aims to gather the maximum of information addressing macroalgae extracts with potential inhibition against fungal phytopathogens, including the best inhibitory results, while presenting some already reported mechanisms of action.

scholarly journals In VivoEfficacy of Anuran Trypsin Inhibitory Peptides against Staphylococcal Skin Infection and the Impact of Peptide Cyclization

2015 ◽  
Vol 59 (4) ◽  
pp. 2113-2121 ◽  
Author(s):  
U. Malik ◽  
O. N. Silva ◽  
I. C. M. Fensterseifer ◽  
L. Y. Chan ◽  
R. J. Clark ◽  
...  
Keyword(s):  
Antimicrobial Agents ◽  
Cyclic Peptide ◽  
Sequence Similarity ◽  
Infection Model ◽  
Content Type ◽  
Wide Range ◽  
Inhibitory Activities ◽  
The Impact

ABSTRACTStaphylococcus aureusis a virulent pathogen that is responsible for a wide range of superficial and invasive infections. Its resistance to existing antimicrobial drugs is a global problem, and the development of novel antimicrobial agents is crucial. Antimicrobial peptides from natural resources offer potential as new treatments against staphylococcal infections. In the current study, we have examined the antimicrobial properties of peptides isolated from anuran skin secretions and cyclized synthetic analogues of these peptides. The structures of the peptides were elucidated by nuclear magnetic resonance (NMR) spectroscopy, revealing high structural and sequence similarity with each other and with sunflower trypsin inhibitor 1 (SFTI-1). SFTI-1 is an ultrastable cyclic peptide isolated from sunflower seeds that has subnanomolar trypsin inhibitory activity, and this scaffold offers pharmaceutically relevant characteristics. The five anuran peptides were nonhemolytic and noncytotoxic and had trypsin inhibitory activities similar to that of SFTI-1. They demonstrated weakin vitroinhibitory activities againstS. aureus, but several had strong antibacterial activities againstS. aureusin anin vivomurine wound infection model. pYR, an immunomodulatory peptide fromRana sevosa, was the most potent, with complete bacterial clearance at 3 mg · kg−1. Cyclization of the peptides improved their stability but was associated with a concomitant decrease in antimicrobial activity. In summary, these anuran peptides are promising as novel therapeutic agents for treating infections from a clinically resistant pathogen.

scholarly journals Efficacy of Variable Tetraconazole Rates Against Cercospora beticola Isolates with Differing In Vitro Sensitivities to DMI Fungicides

Plant Disease ◽  
2012 ◽  
Vol 96 (12) ◽  
pp. 1749-1756 ◽  
Author(s):  
Melvin D. Bolton ◽  
Viviana Rivera-Varas ◽  
Luis E. del Río Mendoza ◽  
Mohamed F. R. Khan ◽  
Gary A. Secor
Keyword(s):  
Sugar Beet ◽  
Disease Severity ◽  
Cercospora Beticola ◽  
In Planta ◽  
Sensitivity Testing ◽  
In Vitro Sensitivity ◽  
Wide Range ◽  
Fungicide Efficacy ◽  
Dmi Fungicides

Cercospora leaf spot (CLS) of sugar beet is caused by the fungus Cercospora beticola. CLS management practices include the application of the sterol demethylation inhibitor (DMI) fungicides tetraconazole, difenoconazole, and prothioconazole. Evaluating resistance to DMIs is a major focus for CLS fungicide resistance management. Isolates were collected in 1997 and 1998 (baseline sensitivity to tetraconazole, prothioconazole, or difenoconazole) and 2007 through 2010 from the major sugar-beet-growing regions of Minnesota and North Dakota and assessed for in vitro sensitivity to two or three DMI fungicides. Most (47%) isolates collected in 1997–98 exhibited 50% effective concentration (EC50) values for tetraconazole of <0.01 μg ml–1, whereas no isolates could be found in this EC50 range in 2010. Since 2007, annual median and mean tetraconazole EC50 values have generally been increasing, and the frequency of isolates with EC50 values >0.11 μg ml–1 increased from 2008 to 2010. In contrast, the frequency of isolates with EC50 values for prothioconazole of >1.0 μg ml–1 has been decreasing since 2007. Annual median difenoconazole EC50 values appears to be stable, although annual mean EC50 values generally have been increasing for this fungicide. Although EC50 values are important for gauging fungicide sensitivity trends, a rigorous comparison of the relationship between in vitro EC50 values and loss of fungicide efficacy in planta has not been conducted for C. beticola. To explore this, 12 isolates exhibiting a wide range of tetraconazole EC50 values were inoculated to sugar beet but no tetraconazole was applied. No relationship was found between isolate EC50 value and disease severity. To assess whether EC50 values are related to fungicide efficacy in planta, sugar beet plants were sprayed with various dilutions of Eminent, the commercial formulation of tetraconazole, and subsequently inoculated with isolates that exhibited very low, medium, or high tetraconazole EC50 values. The high EC50 isolate caused significantly more disease than isolates with medium or very low EC50 values at the field application rate and most reduced rates. Because in vitro sensitivity testing is typically carried out with the active ingredient of the commercial fungicide, we investigated whether loss of disease control was the same for tetraconazole as for the commercial product Eminent. The high EC50 isolate caused more disease on plants treated with tetraconazole than Eminent but disease severity was not different between plants inoculated with the very low EC50 isolate.

scholarly journals Apotransferrin in Combination with Ciprofloxacin Slows Bacterial Replication, Prevents Resistance Amplification, and Increases Antimicrobial Regimen Effect

2019 ◽  
Vol 63 (5) ◽  
Author(s):  
Paul G. Ambrose ◽  
Brian D. VanScoy ◽  
Brian M. Luna ◽  
Jun Yan ◽  
Amber Ulhaq ◽  
...  
Keyword(s):  
Antimicrobial Agents ◽  
Bactericidal Effect ◽  
Bacterial Density ◽  
Infection Model ◽  
Time Curve ◽  
Content Type ◽  
Wide Range ◽  
Bacterial Replication ◽  
The Impact

ABSTRACT There has been renewed interest in combining traditional small-molecule antimicrobial agents with nontraditional therapies to potentiate antimicrobial effects. Apotransferrin, which decreases iron availability to microbes, is one such approach. We conducted a 48-h one-compartment in vitro infection model to explore the impact of apotransferrin on the bactericidal activity of ciprofloxacin. The challenge panel included four Klebsiella pneumoniae isolates with ciprofloxacin MIC values ranging from 0.08 to 32 mg/liter. Each challenge isolate was subjected to an ineffective ciprofloxacin monotherapy exposure (free-drug area under the concentration-time curve over 24 h divided by the MIC [AUC/MIC ratio] ranging from 0.19 to 96.6) with and without apotransferrin. As expected, the no-treatment and apotransferrin control arms showed unaltered prototypical logarithmic bacterial growth. We identified relationships between exposure and change in bacterial density for ciprofloxacin alone (R2 = 0.64) and ciprofloxacin in combination with apotransferrin (R2 = 0.84). Addition of apotransferrin to ciprofloxacin enabled a remarkable reduction in bacterial density across a wide range of ciprofloxacin exposures. For instance, at a ciprofloxacin AUC/MIC ratio of 20, ciprofloxacin monotherapy resulted in nearly 2 log10 CFU increase in bacterial density, while the combination of apotransferrin and ciprofloxacin resulted in 2 log10 CFU reduction in bacterial density. Furthermore, addition of apotransferrin significantly reduced the emergence of ciprofloxacin-resistant subpopulations compared to monotherapy. These data demonstrate that decreasing the rate of bacterial replication with apotransferrin in combination with antimicrobial therapy represents an opportunity to increase the magnitude of the bactericidal effect and to suppress the growth rate of drug-resistant subpopulations.

scholarly journals Applications of Melatonin in Female Reproduction in the Context of Oxidative Stress

2021 ◽  
Vol 2021 ◽  
pp. 1-11
Author(s):  
Yonghui Jiang ◽  
Huangcong Shi ◽  
Yue Liu ◽  
Shigang Zhao ◽  
Han Zhao
Keyword(s):  
Oxidative Stress ◽  
Polycystic Ovary ◽  
Oocyte Quality ◽  
Early Embryo ◽  
Female Reproduction ◽  
Adverse Conditions ◽  
Wide Range

Oxidative stress has been recognized as one of the causal mediators of female infertility by affecting the oocyte quality and early embryo development. Improving oxidative stress is essential for reproductive health. Melatonin, a self-secreted antioxidant, has a wide range of effects by improving mitochondrial function and reducing the damage of reactive oxygen species (ROS). This minireview illustrates the applications of melatonin in reproduction from four aspects: physiological ovarian aging, vitrification freezing, in vitro maturation (IVM), and oxidative stress homeostasis imbalance associated with polycystic ovary syndrome (PCOS), emphasising the role of melatonin in improving the quality of oocytes in assisted reproduction and other adverse conditions.

scholarly journals Identification of a putative DNA-binding protein in Arabidopsis that acts as a susceptibility hub and interacts with multiple Pseudomonas syringae effectors

2020 ◽  
Author(s):  
Karl Schreiber ◽  
Jennifer D Lewis
Keyword(s):  
Pseudomonas Syringae ◽  
Transcriptional Profiling ◽  
Effector Proteins ◽  
Ribosomal Protein Genes ◽  
Loss Of Function ◽  
Wild Type ◽  
In Planta ◽  
Arabidopsis Protein ◽  
Wide Range

Phytopathogens use secreted effector proteins to suppress host immunity and promote pathogen virulence, and there is increasing evidence that the host-pathogen interactome comprises a complex network. In an effort to identify novel interactors of the Pseudomonas syringae effector HopZ1a, we performed a yeast two-hybrid screen that identified a previously uncharacterized Arabidopsis protein that we designate HopZ1a Interactor 1 (ZIN1). Additional analyses in yeast and in planta revealed that ZIN1 also interacts with several other P. syringae effectors. We show that an Arabidopsis loss-of-function zin1 mutant is less susceptible to infection by certain strains of P. syringae, while overexpression of ZIN1 results in enhanced susceptibility. Functionally, ZIN1 exhibits topoisomerase-like activity in vitro. Transcriptional profiling of wild-type and zin1 Arabidopsis plants inoculated with P. syringae indicated that while ZIN1 regulates a wide range of pathogen-responsive biological processes, the list of genes more highly expressed in zin1 versus wild-type plants was particularly enriched for ribosomal protein genes. Altogether, these data illuminate ZIN1 as a potential susceptibility hub that interacts with multiple effectors to influence the outcome of plant-microbe interactions.

scholarly journals The flavin monooxygenase Bs3 triggers cell death in plants, impairs growth in yeast and produces H2O2 in vitro

PLoS ONE ◽  
2021 ◽  
Vol 16 (8) ◽  
pp. e0256217
Author(s):  
Christina Krönauer ◽  
Thomas Lahaye
Keyword(s):  
Nadph Oxidase ◽  
Oxidation State ◽  
Transcriptional Activation ◽  
Oxidase Activity ◽  
Plant Immunity ◽  
Striking Similarity ◽  
In Planta ◽  
Nadph Oxidase Activity ◽  
Wide Range

The pepper resistance gene Bs3 triggers a hypersensitive response (HR) upon transcriptional activation by the corresponding effector protein AvrBs3 from the bacterial pathogen Xanthomonas. Expression of Bs3 in yeast inhibited proliferation, demonstrating that Bs3 function is not restricted to the plant kingdom. The Bs3 sequence shows striking similarity to flavin monooxygenases (FMOs), an FAD- and NADPH-containing enzyme class that is known for the oxygenation of a wide range of substrates and their potential to produce H2O2. Since H2O2 is a hallmark metabolite in plant immunity, we analyzed the role of H2O2 during Bs3 HR. We purified recombinant Bs3 protein from E. coli and confirmed the FMO function of Bs3 with FAD binding and NADPH oxidase activity in vitro. Translational fusion of Bs3 to the redox reporter roGFP2 indicated that the Bs3-dependent HR induces an increase of the intracellular oxidation state in planta. To test if the NADPH oxidation and putative H2O2 production of Bs3 is sufficient to induce HR, we adapted previous studies which have uncovered mutations in the NADPH binding site of FMOs that result in higher NADPH oxidase activity. In vitro studies demonstrated that recombinant Bs3S211A protein has twofold higher NADPH oxidase activity than wildtype Bs3. Translational fusions to roGFP2 showed that Bs3S211A also increased the intracellular oxidation state in planta. Interestingly, while the mutant derivative Bs3S211A had an increase in NADPH oxidase capacity, it did not trigger HR in planta, ultimately revealing that H2O2 produced by Bs3 on its own is not sufficient to trigger HR.

scholarly journals Microbiological and Chemical Quality of Portuguese Lettuce—Results of a Case Study

Foods ◽  
2020 ◽  
Vol 9 (9) ◽  
pp. 1274
Author(s):  
Catarina Ferreira ◽  
Filipa Lopes ◽  
Reginaldo Costa ◽  
Norton Komora ◽  
Vânia Ferreira ◽  
...  
Keyword(s):  
Fruits And Vegetables ◽  
Organophosphorus Pesticides ◽  
Indicator Organisms ◽  
Salmonella Spp ◽  
Chemical Safety ◽  
Limit Of Quantification ◽  
Wide Range ◽  
Maximum Residue Levels ◽  
Yeasts And Molds

In addition to environmental pollution issues, social concerns about the sustainability, safety, and quality of conventionally grown fruits and vegetables have been increasing. In order to evaluate if there were any microbiological differences between samples of organic and conventional lettuce, a wide range of parameters were tested, including pathogens and indicator organisms: the enumeration of Escherichia coli; the detection of Salmonella spp.; the detection/enumeration of Listeria monocytogenes; the enumeration of lactic acid bacteria, Pseudomonas spp. yeasts and molds, and Enterobacteriaceae. This study also evaluated the chemical safety of the lettuce samples, quantifying the nitrate concentration and 20 pesticides (14 organochlorine and 6 organophosphorus pesticides). Significant differences (p < 0.05) between the conventional and organic samples were only detected for the counts of total microorganisms at 30 °C. Pathogens were absent in all the samples. The analytical method, using the quick, easy, cheap, effective, rugged, and safe (QuEChERS) approach for pesticide extraction, was suitable for detecting the targeted analytes; the limit of quantification (LOQ) was between 0.6 and 1.8 µg/kg (lower than the Maximum Residue Levels (MRLs) established by EU legislation). In three organic lettuce samples, one organochlorine pesticide (α-HCH) was observed below the MRLs. For the samples analyzed and for the parameters investigated, except for the total mesophilic counts, the organic and conventional lettuces were not different.

scholarly journals Synthesis and evaluation of newly1-substituted-(2H)-2-thio-4-(3-substitutedthiocarbamido-1-yl)-6-(2-imino-4-thio-5- substitutedbiureto-1-yl) 1, 2-dihydro-S-triazines as potent antimicrobial agents

2020 ◽  
Vol 13 (3) ◽  
pp. 109-112
Author(s):  
ME Shelke
Keyword(s):  
Antimicrobial Agents ◽  
Sodium Bicarbonate Solution ◽  
Antimicrobial Activities ◽  
Industrial Applications ◽  
Diffusion Method ◽  
Chemical Action ◽  
Research Areas ◽  
Wide Range ◽  
The World ◽  
Biological Tool

The search for novel antibiotics is of immense importance in research areas around the world for agricultural, pharmaceutical, and industrial applications. The s-triazines are widely used as an important biological tool for the production of a wide range of novel secondary metabolites. In the present study, the series of 1-substituted-(2H)-2-thio-4-(3- substitutedthiocarbamido-1-yl)-6-(2-imino-4-thio- 5- substitutedbiureto-1-yl) 1,2-dihydro-s-triazine [4a(i) to 4f(iii)] have been obtained by the isomerisation of 2-(2-imino-4-thio-5- substitutedbiureto-1-yl)-4-(3- substitutedthio-carbamido-1-yl)-6- substitutedimino-1,3,5-thiadiazine [3a(i) to 3f(iii)] in presence of ethanolic sodium bicarbonate solution. The later were synthesized by the chemical action of 1, 3-bis-(N-phenylamidinothiocarbamido)-thiocarbamide and aryl/alkylisocyanodichlorides. On the basis of IR, PMR spectrum data and elemental analysis, the structures of all these compounds were established. The synthesized s-triazine were analyzed for antimicrobial activities by cup plate diffusion method and exhibited a broad spectrum of antimicrobial activity against test pathogens. The isolate was tested for the ability to grow in the presence of antibiotic, such as ciprofloxacin at the same concentration. Thus, the study concludes with the eco-friendly route for synthesizing s-triazine with antibacterial activity against clinically important pathogens.

scholarly journals Book review: “It Starts with the Egg” by Rebecca Fett

2019 ◽  
Vol 13 (3) ◽  
pp. 255-260
Author(s):  
A. D. Makatsariya
Keyword(s):  
Polycystic Ovary ◽  
Recurrent Miscarriage ◽  
Action Plan ◽  
Reproductive Function ◽  
Poor Quality ◽  
Vitro Fertilization ◽  
Wide Range ◽  
Based Medicine

The licensed edition of Rebecca Fett's book, “It Starts with the Egg” has been published in Russian. Given its medical contents, it seems important to evaluate the information contained in the book from the perspective of a practicing obstetrician-gynecologist, focusing on the problem of miscarriage and pregravid preparation. Importantly, the book is based on evidence-based medicine: although the book is intended for a wide scope of readers, it contains a list of primary references similarly to that in peer-reviewed journals.The author analyzed and summarized the data from over 60 scientific articles. Although based on primary academic sources, the author used a simple and understandable language to explain the complex pathogenesis of infertility and the manipulations used in the assisted reproductive technology (ART).The book consists of 3 parts; each of them contains several chapters reviewing the causes of reproductive disorders and the ways to correct them. The first part addresses the reasons for poor quality of women’s eggs. The second part describes nutraceuticals and dietary supplements that can improve the quality of eggs. The third part of the book examines the diet, which helps improve this quality. A step-by-step action plan for improving reproductive function is also presented. The basic plan is suitable for those who are just thinking about pregnancy and those who have no reason to expect any difficulties, as well as for couples who have been struggling with infertility for several years. The mid-level plan is intended for those who already have some concerns about conceiving, but are not yet aware of personal problems with their reproductive function, as well as for women with polycystic ovary syndrome (PCOS) or irregular ovulation. The plan for those having serious problems is intended for women with recurrent miscarriage, as well as for couples with a decrease in the ovarian reserve who are trying to get pregnant using in vitro fertilization (IVF).Despite some remarks regarding the role of vitamin D and magnesium in pregravid preparation, the book contains a large number of useful and balanced recommendations that can improve the woman’s health and increase her chances to get pregnant and give birth to a healthy baby. Therefore, the book can be recommended for a wide range of readers.

scholarly journals Rearing substrate impacts growth and macronutrient composition of Hermetia illucens (L.) (Diptera: Stratiomyidae) larvae produced at an industrial scale

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Andrea Scala ◽  
Jonathan A. Cammack ◽  
Rosanna Salvia ◽  
Carmen Scieuzo ◽  
Antonio Franco ◽  
...  
Keyword(s):  
Organic Waste ◽  
Fruits And Vegetables ◽  
Industrial Applications ◽  
Biodiesel Production ◽  
Industrial Scale ◽  
Waste Valorization ◽  
Black Soldier Fly ◽  
Hermetia Illucens ◽  
Wide Range ◽  
Spent Grain

Abstract Organic waste is a rapidly increasing problem due to the growth of the agricultural production needed to meet global food demands. Development of sustainable waste management solutions is essential. Black soldier fly, Hermetia illucens (L.) (Diptera: Stratiomyidae) (BSF), larvae are voracious consumers of a wide range of organic materials ranging from fruits and vegetables to animal remains, and manure. Thanks to this ability and considering the larval high protein and lipid content, BSF larvae are a useful additive in animal feeds and biodiesel production. Unfortunately, the feasibility of using the black soldier fly as a tool for waste valorization and feed production has primarily been investigated at the benchtop scale. Thus, mobilization of current practices to an industrial scale is challenging because scaling up from small laboratory studies to large industrial studies is not necessarily linear. The goal of this study was to demonstrate the ability of the BSF to recycle organic waste at an industrial scale. To accomplish this goal, three organic waste streams were used (e.g., apples, bananas, and spent grain from a brewery) to test six diet treatments (1) apple, (2) banana, (3) spent grain, (4) apple and banana, (5) apple and spent grain, and (6) banana and spent grain. Working at scale of 10,000 BSF larvae life history traits, waste valorization, protein and lipid profiles were measured for each diet treatment. Differences were recorded across all variables, except substrate conversion, for larvae fed on fruit and spent grain (alone or with fruit). Growth rate significantly differed across treatments; larvae reared on spent grain grew twice as fast as those fed apples alone, but those reared on the apple and spent grain mixture produced twice as much insect biomass. However, it should be noted that larvae resulting from the apple diet contained 50% more fat than larvae fed the fruit and spent grain mixtures. Commonly-available organic wastes were successfully used at an industrial scale to produce BSF larvae that have the potential to substitute other sources of protein and lipids in different industrial applications. Industrialization efforts are encouraged to assess these impacts when integrating diverse ingredients into larval diets as a means to more precisely predict output, such as larval development time and final larval biomass.

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