In vivo antimicrobial evaluation of an alanine-rich peptide derived from Pleuronectes americanus

AbstractIn several organisms, the first barrier against microbial infections consists of antimicrobial peptides (AMPs) which are molecules that act as components of the innate immune system. Recent studies have demonstrated that AMPs can perform various functions in different tissues or physiological conditions. In this view, this study was carried out in order to evaluate the multifunctional activity in vivo of an alanine-rich peptide, known as Pa-MAP, derived from the polar fish Pleuronectes americanus. Pa-MAP was evaluated in intraperitoneally infected mice with a sub-lethal concentration of Escherichia coli at standard concentrations of 1 and 5mgkg−1. At both concentrations, Pa-MAPs exhibited an ability to prevent E. coli infection and increase mice survival, similar to the result observed in mice treated with ampicillin at 2mgkg−1. In addition, mice were monitored for weight loss. The results showed that mice treated with Pa-MAPs at 1mgkg−1 gained 0.8% of body weight during the 72h of experiment. The same was observed with Pa-MAP at 5mgkg−1, which had a gain of 0.5% in body weight during the treatment. Mice treated with ampicillin at 2mgkg−1 show a significant weight loss of 5.6% of body weight. The untreated group exhibited a 5.5% loss of body weight. The immunomodulatory effects were also evaluated by the quantification of IL-10, IL-12, TNF-α, IFN-γ and nitric oxide cytokines in serum, but no immunomodulatory activity was observed. Data presented here suggest that Pa-MAP should be used as a novel antibiotic against infection control

Forensic Human Identification for Cutaneous Microbiome, a Brief Review

Forensic Science compounds many study areas in context of solving crimes, one of which is the forensic microbiology. Combined with genomic approaches, microbiology has shown strong performance in studies regarding the relationship between microorganisms present on human skin and environment. The Human Microbiome Project (HMP) has contributed significantly to characterization of microbial complexity and their connection to human being. The purpose of this work consists of a historical overview of scientific articles, demonstrating the growth and possibility of using skin microbiome in forensic identification. Studies about use of cutaneous microbiome in human identification, as well its forensic approaches, were looked into for writing of this review. Comparisons among cutaneous microbial communities and manipulated objects have been tested using 16S rRNA, as well as a thorough sequencing of the bacterial genome. From use of ecological measures of distance to genetic markers with nucleotide variants and predictive algorithms, research has shown promising results for advances in field of forensic identification. The development of metagenomic microbial panel markers, named hidSkinPlax for targeted sequencing has been designed and tested with great results. Research results show satisfactory potential in human identification by cutaneous microbiome and the possibility for contributive use in elucidating crimes

Resíduos sólidos de uva e compostos com capacidade oxi-redox favorável.

O objetivo deste estudo foi determinar a diferença existente entre os resíduos dos cultivares Isabel, Niágara, Chardonnay, Pinot Noir e uma mistura de cultivares em relação à concentração dos agentes oxi-redoxf para exploração industrial e comercial.Resumo

EcDBS1R4, an antimicrobial peptide effective against Escherichia coli with in vitro fusogenic ability

©2020 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open accessarticle distributed under the terms and conditions of the Creative Commons Attribution(CC BY) license (http://creativecommons.org/licenses/by/4.0/)Discovering antibiotic molecules able to hold the growing spread of antimicrobial resistance is one of the most urgent endeavors that public health must tackle. The case of Gram-negative bacterial pathogens is of special concern, as they are intrinsically resistant to many antibiotics, due to an outer membrane that constitutes an effective permeability barrier. Antimicrobial peptides (AMPs) have been pointed out as potential alternatives to conventional antibiotics, as their main mechanism of action is membrane disruption, arguably less prone to elicit resistance in pathogens. Here, we investigate the in vitro activity and selectivity of EcDBS1R4, a bioinspired AMP. To this purpose, we have used bacterial cells and model membrane systems mimicking both the inner and the outer membranes of Escherichia coli, and a variety of optical spectroscopic methodologies. EcDBS1R4 is effective against the Gram-negative E. coli, ineffective against the Gram-positive Staphylococcus aureus and noncytotoxic for human cells. EcDBS1R4 does not form stable pores in E. coli, as the peptide does not dissipate its membrane potential, suggesting an unusual mechanism of action. Interestingly, EcDBS1R4 promotes a hemi-fusion of vesicles mimicking the inner membrane of E. coli. This fusogenic ability of EcDBS1R4 requires the presence of phospholipids with a negative curvature and a negative charge. This finding suggests that EcDBS1R4 promotes a large lipid spatial reorganization able to reshape membrane curvature, with interesting biological implications herein discussed.This research was funded by Fundação para a Ciência e a Tecnologia—Ministério da Ciência, Tecnologia e Ensino Superior (FCT-MCTES, Portugal), Marie Skłodowska-Curie Research and Innovation Staff Exchange (MSCA-RISE, European Union) project INPACT (call H2020-MSCA-RISE-2014, grant agreement 644167), Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq, Brazil), Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES, Brazil), Fundação de Amparo a Pesquisa do Distrito Federal (FAPDF, Brazil) and Fundação de Apoio ao Desenvolvimento do Ensino, Ciência e Tecnologia do Estado de Mato Grosso do Sul (FUNDECT, Brazil). M.M. and M.R.F. also acknowledge FCT-MCTES fellowships SPRH/BD/128290/2017 and SPRH/BD/100517/2014, respectively.info:eu-repo/semantics/publishedVersio

Structural studies of a lipid-binding peptide from tunicate hemocytes with anti-biofilm activity

This work is licensed under a Creative Commons Attribution 4.0 International License. The images or other third party material in this article are included in the article’s Creative Commons license, unless indicated otherwise in the credit line; if the material is not included under the Creative Commons license, users will need to obtain permission from the license holder to reproduce the material. To view a copy of this license, visit http://creativecommons.org/licenses/by/4.0/Clavanins is a class of peptides (23aa) histidine-rich, free of post-translational modifications. Clavanins have been studied largely for their ability to disrupt bacterial membranes. In the present study, the interaction of clavanin A with membranes was assessed by dynamic light scattering, zeta potential and permeabilization assays. We observed through those assays that clavanin A lysis bacterial cells at concentrations corresponding to its MIC. Further, the structure and function of clavanin A was investigated. To better understand how clavanin interacted with bacteria, its NMR structure was elucidated. The solution state NMR structure of clavanin A in the presence of TFE-d3 indicated an α-helical conformation. Secondary structures, based on circular dichroism measurements in anionic sodium dodecyl sulfate (SDS) and TFE (2,2,2-trifluorethanol), in silico lipid-peptide docking and molecular simulations with lipids DPPC and DOPC revealed that clavanin A can adopt a variety of folds, possibly influencing its different functions. Microcalorimetry assays revealed that clavanin A was capable of discriminating between different lipids. Finally, clavanin A was found to eradicate bacterial biofilms representing a previously unrecognized function.We would like to thank CNPq, CAPES (Ciências sem Fronteiras), FAPDF and FUNDECT. D.G. acknowledges Fundação para a Ciência e a Tecnologia - Ministério da Educação e Ciência (FCT-MEC, Portugal) for fellowship SFRH/BPD/73500/2010 and A.S.V. for funding within the FCT Investigator Programme (IF/00803/2012).info:eu-repo/semantics/publishedVersio

An anti-infective synthetic peptide with dual antimicrobial and immunomodulatory activities

Antibiotic-resistant infections are predicted to kill 10 million people per year by 2050, costing the global economy $100 trillion. Therefore, there is an urgent need to develop alternative technologies. We have engineered a synthetic peptide called clavanin-MO, derived from a marine tunicate antimicrobial peptide, which exhibits potent antimicrobial and immunomodulatory properties both in vitro and in vivo. The peptide effectively killed a panel of representative bacterial strains, including multidrug-resistant hospital isolates. Antimicrobial activity of the peptide was demonstrated in animal models, reducing bacterial counts by six orders of magnitude, and contributing to infection clearance. In addition, clavanin-MO was capable of modulating innate immunity by stimulating leukocyte recruitment to the site of infection, and production of immune mediators GM-CSF, IFN-γ and MCP-1, while suppressing an excessive and potentially harmful inflammatory response by increasing synthesis of anti-inflammatory cytokines such as IL-10 and repressing the levels of pro-inflammatory cytokines IL-12 and TNF-α. Finally, treatment with the peptide protected mice against otherwise lethal infections caused by both Gram-negative and -positive drug-resistant strains. The peptide presented here directly kills bacteria and further helps resolve infections through its immune modulatory properties. Peptide anti-infective therapeutics with combined antimicrobial and immunomodulatory properties represent a new approach to treat antibiotic-resistant infections