scholarly journals Antimicrobial Peptides With Antibiofilm Activity Against Xylella fastidiosa

2021 ◽  
Vol 12 ◽  
Author(s):  
Luís Moll ◽  
Esther Badosa ◽  
Marta Planas ◽  
Lidia Feliu ◽  
Emilio Montesinos ◽  
...  
Keyword(s):  
Antimicrobial Peptides ◽  
Control Strategies ◽  
Research Effort ◽  
Xylella Fastidiosa ◽  
Mediterranean Area ◽  
Antibiofilm Activity ◽  
Negative Bacterium ◽  
Moderate Growth ◽  
Low Toxicity ◽  
New Treatments

Xylella fastidiosa is a plant pathogen that was recently introduced in Europe and is causing havoc to its agriculture. This Gram-negative bacterium invades the host xylem, multiplies, and forms biofilm occluding the vessels and killing its host. In spite of the great research effort, there is no method that effectively prevents or cures hosts from infections. The main control strategies up to now are eradication, vector control, and pathogen-free plant material. Antimicrobial peptides have arisen as promising candidates to combat this bacterium due to their broad spectrum of activity and low environmental impact. In this work, peptides previously reported in the literature and newly designed analogs were studied for its bactericidal and antibiofilm activity against X. fastidiosa. Also, their hemolytic activity and effect on tobacco leaves when infiltrated were determined. To assess the activity of peptides, the strain IVIA 5387.2 with moderate growth, able to produce biofilm and susceptible to antimicrobial peptides, was selected among six representative strains found in the Mediterranean area (DD1, CFBP 8173, Temecula, IVIA 5387.2, IVIA 5770, and IVIA 5901.2). Two interesting groups of peptides were identified with bactericidal and/or antibiofilm activity and low-moderate toxicity. The peptides 1036 and RIJK2 with dual (bactericidal–antibiofilm) activity against the pathogen and moderate toxicity stand out as the best candidates to control X. fastidiosa diseases. Nevertheless, peptides with only antibiofilm activity and low toxicity are also promising agents as they could prevent the occlusion of xylem vessels caused by the pathogen. The present work contributes to provide novel compounds with antimicrobial and antibiofilm activity that could lead to the development of new treatments against diseases caused by X. fastidiosa.

scholarly journals Controlling the Spatial Spread of a Xylella Epidemic

2021 ◽  
Vol 83 (4) ◽  
Author(s):  
Sebastian Aniţa ◽  
Vincenzo Capasso ◽  
Simone Scacchi
Keyword(s):  
Spatial Structure ◽  
Numerical Simulations ◽  
Control Strategies ◽  
Xylella Fastidiosa ◽  
Cost Effective ◽  
Olive Tree ◽  
Control Measures ◽  
Weed Biomass ◽  
Spatial Spread ◽  
Olive Trees

AbstractIn a recent paper by one of the authors and collaborators, motivated by the Olive Quick Decline Syndrome (OQDS) outbreak, which has been ongoing in Southern Italy since 2013, a simple epidemiological model describing this epidemic was presented. Beside the bacterium Xylella fastidiosa, the main players considered in the model are its insect vectors, Philaenus spumarius, and the host plants (olive trees and weeds) of the insects and of the bacterium. The model was based on a system of ordinary differential equations, the analysis of which provided interesting results about possible equilibria of the epidemic system and guidelines for its numerical simulations. Although the model presented there was mathematically rather simplified, its analysis has highlighted threshold parameters that could be the target of control strategies within an integrated pest management framework, not requiring the removal of the productive resource represented by the olive trees. Indeed, numerical simulations support the outcomes of the mathematical analysis, according to which the removal of a suitable amount of weed biomass (reservoir of Xylella fastidiosa) from olive orchards and surrounding areas resulted in the most efficient strategy to control the spread of the OQDS. In addition, as expected, the adoption of more resistant olive tree cultivars has been shown to be a good strategy, though less cost-effective, in controlling the pathogen. In this paper for a more realistic description and a clearer interpretation of the proposed control measures, a spatial structure of the epidemic system has been included, but, in order to keep mathematical technicalities to a minimum, only two players have been described in a dynamical way, trees and insects, while the weed biomass is taken to be a given quantity. The control measures have been introduced only on a subregion of the whole habitat, in order to contain costs of intervention. We show that such a practice can lead to the eradication of an epidemic outbreak. Numerical simulations confirm both the results of the previous paper and the theoretical results of the model with a spatial structure, though subject to regional control only.

scholarly journals Novel Virulent Bacteriophages Infecting Mediterranean Isolates of the Plant Pest Xylella fastidiosa and Xanthomonas albilineans

Viruses ◽  
2021 ◽  
Vol 13 (5) ◽  
pp. 725
Author(s):  
Fernando Clavijo-Coppens ◽  
Nicolas Ginet ◽  
Sophie Cesbron ◽  
Martial Briand ◽  
Marie-Agnès Jacques ◽  
...  
Keyword(s):  
Phage Therapy ◽  
Xylella Fastidiosa ◽  
Infected Plant ◽  
Mediterranean Area ◽  
Genomic Features ◽  
Phylogeny Analysis ◽  
Plant Pest ◽  
European Regulations ◽  
Surrogate Host

Xylella fastidiosa (Xf) is a plant pathogen causing significant losses in agriculture worldwide. Originating from America, this bacterium caused recent epidemics in southern Europe and is thus considered an emerging pathogen. As the European regulations do not authorize antibiotic treatment in plants, alternative treatments are urgently needed to control the spread of the pathogen and eventually to cure infected crops. One such alternative is the use of phage therapy, developed more than 100 years ago to cure human dysentery and nowadays adapted to agriculture. The first step towards phage therapy is the isolation of the appropriate bacteriophages. With this goal, we searched for phages able to infect Xf strains that are endemic in the Mediterranean area. However, as Xf is truly a fastidious organism, we chose the phylogenetically closest and relatively fast-growing organism X. albineans as a surrogate host for the isolation step. Our results showed the isolation from various sources and preliminary characterization of several phages active on different Xf strains, namely, from the fastidiosa (Xff), multiplex (Xfm), and pauca (Xfp) subspecies, as well as on X. albilineans. We sequenced their genomes, described their genomic features, and provided a phylogeny analysis that allowed us to propose new taxonomic elements. Among the 14 genomes sequenced, we could identify two new phage species, belonging to two new genera of the Caudoviricetes order, namely, Usmevirus (Podoviridae family) and Subavirus (Siphoviridae family). Interestingly, no specific phages could be isolated from infected plant samples, whereas one was isolated from vector insects captured in a contaminated area, and several from surface and sewage waters from the Marseille area.

scholarly journals Antimicrobial and Antibiofilm Peptides

Biomolecules ◽  
2020 ◽  
Vol 10 (4) ◽  
pp. 652 ◽  
Author(s):  
Angela Di Somma ◽  
Antonio Moretta ◽  
Carolina Canè ◽  
Arianna Cirillo ◽  
Angela Duilio
Keyword(s):  
Antimicrobial Peptides ◽  
Biofilm Formation ◽  
Bacterial Resistance ◽  
Antimicrobial Agents ◽  
Multidrug Resistant ◽  
Resistant Bacteria ◽  
Antibiofilm Activity ◽  
Chronic Infections ◽  
Planktonic Bacteria ◽  
Hostile Environments

The increasing onset of multidrug-resistant bacteria has propelled microbiology research towards antimicrobial peptides as new possible antibiotics from natural sources. Antimicrobial peptides are short peptides endowed with a broad range of activity against both Gram-positive and Gram-negative bacteria and are less prone to trigger resistance. Besides their activity against planktonic bacteria, many antimicrobial peptides also show antibiofilm activity. Biofilms are ubiquitous in nature, having the ability to adhere to virtually any surface, either biotic or abiotic, including medical devices, causing chronic infections that are difficult to eradicate. The biofilm matrix protects bacteria from hostile environments, thus contributing to the bacterial resistance to antimicrobial agents. Biofilms are very difficult to treat, with options restricted to the use of large doses of antibiotics or the removal of the infected device. Antimicrobial peptides could represent good candidates to develop new antibiofilm drugs as they can act at different stages of biofilm formation, on disparate molecular targets and with various mechanisms of action. These include inhibition of biofilm formation and adhesion, downregulation of quorum sensing factors, and disruption of the pre-formed biofilm. This review focuses on the proprieties of antimicrobial and antibiofilm peptides, with a particular emphasis on their mechanism of action, reporting several examples of peptides that over time have been shown to have activity against biofilm.

scholarly journals From Old-Generation to Next-Generation Nematicides

Agronomy ◽  
2020 ◽  
Vol 10 (9) ◽  
pp. 1387
Author(s):  
Yuji Oka
Keyword(s):  
Control Strategies ◽  
Intensive Agriculture ◽  
Control Methods ◽  
Nematode Control ◽  
Next Generation ◽  
Control Efficacy ◽  
Cash Crops ◽  
Low Toxicity ◽  
High Control ◽  
Soil Fumigants

The phaseout of methyl bromide and the ban on, or withdrawal of, other toxic soil fumigants and non-fumigant nematicides belonging to the organophosphate and carbamate groups are leading to changes in nematode-control strategies. Sustainable nematode-control methods are available and preferred, but not always effective enough, especially for cash crops in intensive agriculture. A few non-fumigant nematicides, which have a relatively high control efficacy with a low toxicity to non-target organisms, have been released to the market or are in the process of being registered for use. Fluensulfone, fluopyram, and fluazaindolizine are the three main and most promising next-generation nematicides. In this paper, several aspects of these non-fumigant nematicides are reviewed, along with a brief history and problems of old-generation nematicides.

scholarly journals In Silico Study of Coumarins and Quinolines Derivatives as Potent Inhibitors of SARS-CoV-2 Main Protease

2021 ◽  
Vol 8 ◽  
Author(s):  
Osvaldo Yañez ◽  
Manuel Isaías Osorio ◽  
Eugenio Uriarte ◽  
Carlos Areche ◽  
William Tiznado ◽  
...  
Keyword(s):  
Experimental Studies ◽  
Ligand Efficiency ◽  
Infected People ◽  
High Affinity ◽  
Main Protease ◽  
In Silico Study ◽  
The World ◽  
Low Toxicity ◽  
Viral Maturation ◽  
New Treatments

The pandemic that started in Wuhan (China) in 2019 has caused a large number of deaths, and infected people around the world due to the absence of effective therapy against coronavirus 2 of the severe acute respiratory syndrome (SARS-CoV-2). Viral maturation requires the activity of the main viral protease (Mpro), so its inhibition stops the progress of the disease. To evaluate possible inhibitors, a computational model of the SARS-CoV-2 enzyme Mpro was constructed in complex with 26 synthetic ligands derived from coumarins and quinolines. Analysis of simulations of molecular dynamics and molecular docking of the models show a high affinity for the enzyme (∆Ebinding between −5.1 and 7.1 kcal mol−1). The six compounds with the highest affinity show Kd between 6.26 × 10–6 and 17.2 × 10–6, with binding affinity between −20 and −25 kcal mol−1, with ligand efficiency less than 0.3 associated with possible inhibitory candidates. In addition to the high affinity of these compounds for SARS-CoV-2 Mpro, low toxicity is expected considering the Lipinski, Veber and Pfizer rules. Therefore, this novel study provides candidate inhibitors that would allow experimental studies which can lead to the development of new treatments for SARS-CoV-2.

scholarly journals Influence of ecological factors on larvae hatching of cystogenous species of nematodes

2016 ◽  
Author(s):  
L. Pylypenko ◽  
K. Kalatur
Keyword(s):  
Control Strategies ◽  
Research Effort ◽  
Inorganic Compounds ◽  
Ecological Factors ◽  
Nematode Species ◽  
Control Measures ◽  
Parasitic Nematodes ◽  
Cyst Nematodes ◽  
Wide Range ◽  
Hatching Process

Understanding hatching process in plant parasitic nematodes has the potential to lead to new control strategies of these devistating pathogens, causing up to10–20% or $80 billion of crop loss globally (Nicol et al, 2011; Каплин, 2012). Although much research effort has been extended in elucidating the hatching factors, there has been no successful control strategy using their analogues to induce hatch in the field. This review examines development on this subject, focusing on the root diffusate, natural and inorganic compounds, as well as abiotic hatching factors (environmental temperature, moisture, aeration). They are assumed to have different impact on the hatching process of various cyst nematodes species despite of similarities in their biological features and life strategies. Notably, soil temperature and moisture play the vital role for species with a wide range of host plants whereas host plant diffusate is a key factor for highly specialized cyst nematode species. Appropriately investigated, it can favour development of control measures specified against targeted nematode species and boost their application in practice.

scholarly journals Clinical Trials Supporting the Role of the IL-17/IL-23 Axis in Axial Spondyloarthritis

2021 ◽  
Vol 12 ◽  
Author(s):  
Angela Ceribelli ◽  
Francesca Motta ◽  
Matteo Vecellio ◽  
Natasa Isailovic ◽  
Francesco Ciccia ◽  
...  
Keyword(s):  
Musculoskeletal Diseases ◽  
Research Effort ◽  
Axial Skeleton ◽  
Thoracic Wall ◽  
Inflammatory Back Pain ◽  
Comprehensive Overview ◽  
X Ray Imaging ◽  
Significant Research ◽  
Inflammatory Bowel ◽  
New Treatments

The term spondyloarthritis (SpA) encompasses a heterogeneous group of inflammatory musculoskeletal diseases with several common genetic background and clinical features, including the possible involvement of the axial skeleton with peripheral mono- or oligo- arthritis and frequently coexisting skin, eye and intestinal manifestations. When the sacroiliac joints or other parts of the spine or thoracic wall are predominantly affected at magnetic resonance or X-ray imaging with inflammatory back pain, the disease is classified as axial SpA and the therapeutic choices are significantly different compared to cases of peripheral arthritis. Moving from the narrow effectiveness and safety profiles of non-steroidal anti-inflammatory drugs, there has been a significant research effort aimed at identifying new treatments based on our better understanding of the pathogenesis of SpA. Indeed, in parallel with the solid data demonstrating that IL-17 and IL-23 are key cytokines in the development of enthesitis and spondylitis, monoclonal antibodies interfering with this pathway have been developed for the treatment of axial SpA. Furthermore, the IL-17/IL-23 axis is key to extra-articular manifestations such as inflammatory bowel disease, uveitis, and psoriasis which are frequent comorbidities of SpA. Currently available drugs act through these mechanisms recognizing IL-23 and targeting IL-17, such as secukinumab and ixekizumab. These therapeutic approaches are now envisioned in the international treatment recommendations for psoriatic arthritis with an axial phenotype as well as for ankylosing spondylitis (AS). We will provide herein a concise comprehensive overview of the clinical evidence supporting the use of these and other drugs acting on IL-23 and IL-17 in axial SpA.

scholarly journals Genetic characterization of Xylella fastidiosa isolated from citrus and coffee plants

2007 ◽  
Vol 64 (5) ◽  
pp. 482-485 ◽  
Author(s):  
Vicente Savonitti Miranda ◽  
Paulo Roberto Silva Farias ◽  
Sérgio Rufo Roberto ◽  
Pedro Magalhães Lacava
Keyword(s):  
Genetic Characterization ◽  
Xylella Fastidiosa ◽  
Random Amplified Polymorphic Dna ◽  
Negative Bacterium ◽  
Similarity Coefficients ◽  
Gram Negative ◽  
Coffee Plants ◽  
The Many ◽  
Group D

The Citrus Variegated Chlorosis and the Coffee Leaf Scorch are some of the many destructive diseases caused by Xylella fastidiosa, a gram-negative bacterium limited to the xylem of affected plants. As its genetic characterization is still not well established, different isolates of X. fastidiosa from citrus and coffee were evaluated through RAPD (Random Amplified Polymorphic DNA) technique to characterize and classify these isolates based on similarity coefficients. Sixteen isolates of X. fastidiosa were used on this trial, obtained from citrus, coffee and almond. The genetic polymorphism evaluation was performed using six arbitrary 10-base primer pairs. It was possible to establish a dendogram in which the isolates were classified into five groups (A, B, C, D and E). A prevalence of citrus isolates in groups A and D was observed. In groups B and C, there was a prevalence of coffee isolates meanwhile the group D consisted of the almond isolate, solely.

scholarly journals Mini Review on Antimicrobial Peptides, Sources, Mechanism and Recent Applications

2019 ◽  
Vol 27 (1) ◽  
pp. 4-16 ◽  
Author(s):  
Jaspreet Kaur Boparai ◽  
Pushpender Kumar Sharma
Keyword(s):  
Antimicrobial Peptides ◽  
Biological Diversity ◽  
Therapeutic Potential ◽  
High Specificity ◽  
New Era ◽  
Therapeutic Drugs ◽  
Therapeutic Peptides ◽  
Low Toxicity ◽  
Pharmaceutical Industries ◽  
Micro Organisms

Antimicrobial peptides in recent years have gained increased interest among scientists, health professionals and the pharmaceutical companies owing to their therapeutic potential. These are low molecular weight proteins with broad range antimicrobial and immuno modulatory activities against infectious bacteria (Gram positive and Gram negative), viruses and fungi. Inability of micro-organisms to develop resistance against most of the antimicrobial peptide has made them as an efficient product which can greatly impact the new era of antimicrobials. In addition to this these peptides also demonstrates increased efficacy, high specificity, decreased drug interaction, low toxicity, biological diversity and direct attacking properties. Pharmaceutical industries are therefore conducting appropriate clinical trials to develop these peptides as potential therapeutic drugs. More than 60 peptide drugs have already reached the market and several hundreds of novel therapeutic peptides are in preclinical and clinical development. Rational designing can be used further to modify the chemical and physical properties of existing peptides. This mini review will discuss the sources, mechanism and recent therapeutic applications of antimicrobial peptides in treatment of infectious diseases.

ANTIBIOFILM ACTIVITY OF Β-HAIPRIN ANTIMICROBIAL PEPTIDES FROM MARINE POLYCHAETA

2021 ◽  
Vol 1 (19) ◽  
pp. 171-173
Author(s):  
P.V. Panteleev ◽  
T.V. Ovchinnikova
Keyword(s):  
Antimicrobial Peptides ◽  
Antibiofilm Activity ◽  
Capitella Teleta

Recombinant β-hairpin antimicrobial peptides were obtained from marine polychaeta Capitella teleta and Abarenicola pacifica, and their antibiofilm activity was studied.

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