Evaluation of the secretion of antimicrobial peptides and antimicrobial effect of skin wash in atopic and healthy dogs: a preliminary study

2018 ◽  
Vol 29 (5) ◽  
pp. 402-e132 ◽  
Author(s):  
Domenico Santoro
Keyword(s):  
Antimicrobial Peptides ◽  
Antimicrobial Effect ◽  
Healthy Dogs ◽  
Preliminary Study

scholarly journals Attacins: A Promising Class of Insect Antimicrobial Peptides

Antibiotics ◽  
2021 ◽  
Vol 10 (2) ◽  
pp. 212
Author(s):  
Francesco Buonocore ◽  
Anna Maria Fausto ◽  
Giulia Della Pelle ◽  
Tomislav Roncevic ◽  
Marco Gerdol ◽  
...  
Keyword(s):  
Antimicrobial Peptides ◽  
Antimicrobial Effect ◽  
Short Review ◽  
Microbial Pathogens ◽  
Special Focus ◽  
Gram Negative Bacteria ◽  
Physiological Importance ◽  
Related Proteins ◽  
Large Repertoire

Insects produce a large repertoire of antimicrobial peptides (AMPs) as the first line of defense against bacteria, viruses, fungi or parasites. These peptides are produced from a large precursor that contains a signal domain, which is cleaved in vivo to produce the mature protein with antimicrobial activity. At present, AMPs from insects include several families which can be classified as cecropins, ponericins, defensins, lebocins, drosocin, Metchnikowin, gloverins, diptericins and attacins according to their structure and/or function. This short review is focused on attacins, a class of glycine-rich peptides/proteins that have been first discovered in the cecropia moth (Hyalophora cecropia). They are a rather heterogeneous group of immunity-related proteins that exhibit an antimicrobial effect mainly against Gram-negative bacteria. Here, we discuss different attacin and attacin-like AMPs that have been discovered so far and analyze their structure and phylogeny. Special focus is given to the physiological importance and mechanism of action of attacins against microbial pathogens together with their potential pharmacological applications, emphasizing their roles as antimicrobials.

scholarly journals Antimicrobial effect of methylene blue formulations with oxygen carrier at different pHs: preliminary study

2019 ◽  
Vol 22 (1) ◽  
pp. Process
Author(s):  
Jessica Klöckner Knorst ◽  
Gabriela Scarton Barriquello ◽  
Marcos Antônio Villetti ◽  
Roberto Christ Vianna Santos ◽  
Karla Zanini Kantorski
Keyword(s):  
Methylene Blue ◽  
Pseudomonas Aeruginosa ◽  
Photodynamic Therapy ◽  
Oxygen Carrier ◽  
Statistical Significance ◽  
Antimicrobial Effect ◽  
Control Group ◽  
Preliminary Study ◽  
Post Hoc ◽  
Multispecies Biofilms

Objective: Evaluate methylene blue (MB) formulations containing oxygen carrier at different pHs in antimicrobial photodynamic therapy (aPDT). Material and Methods: Biofilms of Pseudomonas aeruginosa PA01 formed over acrylics specimens during five days were treated with aPDT using different formulations: MB/pH 7.4; MB/pH 5.6; MB/carrier pH 7.4; MB/carrier pH 5.6. Biofilms not exposed to treatment were used as a control. Blind examiner for the experimental groups performed the counting of colonies per ml suspension (CFU/ml). Two-way ANOVA was used to determine the effect of factors solvent (carrier vs water) and pH (7.4 vs 5.6). One-way ANOVA and post-hoc Tukey’s test was used to evaluate differences among the five groups (control; MB/carrier pH 7.4; MB pH 7.4; MB/carrier pH 5.6; MB pH 5.6). The Statistics 8.0 software was used (P<0.05). Results: All of photodynamic therapy groups showed significant reduction in P. aeruginosa compared to the control group. The solvent factor was not significant (P=0.18), while the pH factor presented statistical significance (P=0.01). When the carrier was used, MB formulation at pH 7.4 presented a statistically greater reduction of P. aeruginosa than the formulation with pH 5.6. Conclusion: The PDT using methylene blue formulations with oxygen carrier demonstrated potential for the treatment of localized infections by P. aeruginosa. MB formulations with oxygen carrier and pH 7.4 resulted in higher antimicrobial effect and should be considered for future studies with multispecies biofilms.  KeywordsAntimicrobial photodynamic therapy; biofilm; laser; Pseudomonas aeruginosa.

scholarly journals Multiple Antimicrobial Effects of Hybrid Peptides Synthesized Based on the Sequence of Ribosomal S1 Protein from Staphylococcus aureus

2022 ◽  
Vol 23 (1) ◽  
pp. 524
Author(s):  
Sergey V. Kravchenko ◽  
Pavel A. Domnin ◽  
Sergei Y. Grishin ◽  
Alexander V. Panfilov ◽  
Viacheslav N. Azev ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Antimicrobial Peptides ◽  
Pathogenic Bacteria ◽  
Antimicrobial Effect ◽  
Cell Penetrating Peptide ◽  
Gram Negative Bacteria ◽  
Antimicrobial Effects ◽  
Bacterial Proteins ◽  
Hybrid Peptides ◽  
Successful Approach

The need to develop new antimicrobial peptides is due to the high resistance of pathogenic bacteria to traditional antibiotics now and in the future. The creation of synthetic peptide constructs is a common and successful approach to the development of new antimicrobial peptides. In this work, we use a simple, flexible, and scalable technique to create hybrid antimicrobial peptides containing amyloidogenic regions of the ribosomal S1 protein from Staphylococcus aureus. While the cell-penetrating peptide allows the peptide to enter the bacterial cell, the amyloidogenic site provides an antimicrobial effect by coaggregating with functional bacterial proteins. We have demonstrated the antimicrobial effects of the R23F, R23DI, and R23EI hybrid peptides against Staphylococcus aureus, methicillin-resistant S. aureus (MRSA), Pseudomonas aeruginosa, Escherichia coli, and Bacillus cereus. R23F, R23DI, and R23EI can be used as antimicrobial peptides against Gram-positive and Gram-negative bacteria resistant to traditional antibiotics.

scholarly journals SPS-neutralization in tissue samples for efficacy testing of antimicrobial peptides

2019 ◽  
Author(s):  
Gabrielle Dijksteel ◽  
Peter Nibbering ◽  
Magda Ulrich ◽  
Esther Middelkoop ◽  
Bouke Boekema
Keyword(s):  
Antimicrobial Activity ◽  
Antimicrobial Peptides ◽  
Antimicrobial Agents ◽  
Ex Vivo ◽  
Accurate Determination ◽  
Residual Activity ◽  
Antimicrobial Effect ◽  
Complete Recovery ◽  
Bacterial Killing ◽  
Tissue Samples

Abstract Background Accurate determination of the efficacy of antimicrobial agents requires neutralization of residual antimicrobial activity in the samples before microbiological assessment of the number of surviving bacteria. Sodium polyanethol sulfonate (SPS) is a known neutralizer for the antimicrobial activity of aminoglycosides and polymyxins. In this study, we evaluated the ability of SPS to neutralize residual antimicrobial activity of antimicrobial peptides [SAAP-148 and pexiganan; 1% (wt/v) in PBS], antibiotics [mupirocin (Bactroban) and fusidic acid (Fucidin) in ointments; 2% (wt/wt))] and disinfectants [2% (wt/wt) silver sulfadiazine cream (SSD) and 0.5% (v/v) chlorhexidine in 70% alcohol]. Methods Homogenates of human skin models that were exposed to various antimicrobial agents for 1 h were pipetted on top of Methicillin-resistant Staphylococcus aureus (MRSA) on agar plates to demonstrate the presence of residual antimicrobial activity in tissue samples. To determine the efficacy of SPS in neutralization, various antimicrobial agents were mixed with PBS, 0.05%, 0.1%, 0.5% or 1% (wt/v) SPS in PBS. Subsequently, 10^5 colony forming units (CFU) MRSA were added to the mixtures and these were incubated for 30 min to determine the antimicrobial effect. Ex vivo excision wound models were inoculated with 10^5 CFU MRSA for 1 h and exposed to SAAP-148, pexiganan, chlorhexidine or PBS for 1 h to study the effect of SPS-neutralization on the bacterial killing of these antimicrobials. To quantify the number of surviving bacteria, 10-fold serial dilutions of the homogenates were cultured overnight on agar plates. Results All tested antimicrobials displayed residual activity in tissue samples, resulting in a lower recovery of surviving bacteria on agar. SPS concentrations at ≥0.05% (wt/v) were able to neutralize the antimicrobial activity of SAAP-148, pexiganan and chlorhexidine, resulting in the complete recovery of bacteria. However, SPS did not neutralize the activity of SSD, Bactroban and Fucidin. Finally, SPS-neutralization in ex vivo efficacy tests of SAAP-148 (p<0.001), pexiganan (p<0.05) and chlorhexidine (p<0.01) resulted in at least 10-fold higher numbers of MRSA compared to control samples without SPS-neutralization. Conclusion SPS can be used for the neutralization of residual activity of different antimicrobials, including SAAP-148, pexiganan and chlorhexidine and this prevents an overestimation of their efficacy.

scholarly journals Staphylococcus aureus Susceptibility to Innate Antimicrobial Peptides, β-Defensins and CAP18, Expressed by Human Keratinocytes

2003 ◽  
Vol 71 (7) ◽  
pp. 3730-3739 ◽  
Author(s):  
Kazushige Midorikawa ◽  
Kazuhisa Ouhara ◽  
Hitoshi Komatsuzawa ◽  
Toshihisa Kawai ◽  
Sakuo Yamada ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Antimicrobial Peptides ◽  
Bacterial Infection ◽  
Methicillin Resistance ◽  
Antimicrobial Effect ◽  
Human Keratinocytes ◽  
Innate Defense ◽  
Mrsa Strains ◽  
Insight Into ◽  
Increased Susceptibility

ABSTRACT The antimicrobial peptides human β-defensin-1 (hBD1), hBD2, hBD3, and CAP18 expressed by keratinocytes have been implicated in mediation of the innate defense against bacterial infection. To gain insight into Staphylococcus aureus infection, the susceptibility of S. aureus, including methicillin-resistant S. aureus (MRSA), to these antimicrobial peptides was examined. Based on quantitative PCR, expression of hBD2 mRNA by human keratinocytes was significantly induced by contact with S. aureus, and expression of hBD3 and CAP18 mRNA was slightly induced, while hBD1 mRNA was constitutively expressed irrespective of the presence of S. aureus. Ten clinical S. aureus isolates, including five MRSA isolates, induced various levels of expression of hBD2, hBD3, and CAP18 mRNA by human kertinocytes. The activities of hBD3 and CAP18 against S. aureus were found to be greater than those of hBD1 and hBD2. A total of 44 S. aureus clinical isolates, including 22 MRSA strains, were tested for susceptibility to hBD3 and CAP18. Twelve (55%) and 13 (59%) of the MRSA strains exhibited more than 20% survival in the presence of hBD3 (1 μg/ml) and CAP18 (0.5 μg/ml), respectively. However, only three (13%) and two (9%) of the methicillin-sensitive S. aureus isolates exhibited more than 20% survival with hBD3 and CAP18, respectively, suggesting that MRSA is more resistant to these peptides. A synergistic antimicrobial effect between suboptimal doses of methicillin and either hBD3 or CAP18 was observed with 10 MRSA strains. Furthermore, of several genes associated with methicillin resistance, inactivation of the fmtC gene in MRSA strain COL increased susceptibility to the antimicrobial effect mediated by hBD3 or CAP18.

scholarly journals Extracellular Vesicles in the Blood of Dogs with Cancer—A Preliminary Study

Animals ◽  
2019 ◽  
Vol 9 (8) ◽  
pp. 575 ◽  
Author(s):  
Magdalena Żmigrodzka ◽  
Olga Witkowska-Piłaszewicz ◽  
Alicja Rzepecka ◽  
Anna Cywińska ◽  
Dariusz Jagielski ◽  
...  
Keyword(s):  
Extracellular Vesicles ◽  
Cell Communication ◽  
Biological Marker ◽  
Annexin V ◽  
Absolute Number ◽  
Cellular Origin ◽  
Healthy Dogs ◽  
Preliminary Study ◽  
Cellular Markers ◽  
Abundant Population

Extracellular vesicles (EVs) are a heterogeneous population of submicron-sized structures released during the activation, proliferation, or apoptosis of various types of cells. Due to their size, their role in cell-to-cell communication in cancer is currently being discussed. In blood, the most abundant population of EVs is platelet-derived EVs (PEVs). The aim of this study was to estimate the absolute number and the origin of EVs in the blood of healthy dogs and of dogs with various types of cancer. The EV absolute number and cellular origin were examined by flow cytometry technique. EVs were classified on the basis of surface annexin V expression (phosphatidylserine PS+) and co-expression of specific cellular markers (CD61, CD45, CD3, CD21). The number of PEVs was significantly higher in dogs with cancer (median: 409/µL, range: 42–2748/µL vs. median: 170/µL, range: 101–449/µL in controls). The numbers of EVs derived from leukocytes (control median: 86/µL, range: 40–240/µL; cancer median: 443/µL, range: 44–3 352/µL) and T cells (control median: 5/µL, range: 2–66/µL; cancer median: 108/µL, range: 3–1735/µL) were higher in dogs with neoplasia compared to healthy controls. The estimation of PEV and leukocyte-derived EV counts may provide a useful biological marker in dogs with cancer.

scholarly journals Immobilization Reduces the Activity of Surface-Bound Cationic Antimicrobial Peptides with No Influence upon the Activity Spectrum

2008 ◽  
Vol 53 (3) ◽  
pp. 1132-1141 ◽  
Author(s):  
Mojtaba Bagheri ◽  
Michael Beyermann ◽  
Margitta Dathe
Keyword(s):  
Antimicrobial Activity ◽  
Antimicrobial Peptides ◽  
Solid Phase ◽  
Solid Phase Peptide Synthesis ◽  
Antimicrobial Effect ◽  
Side Chain ◽  
Surface Immobilization ◽  
Spacer Length ◽  
Biological Targets ◽  
Coupling Parameters

ABSTRACT Early studies of immobilized peptides mainly focused upon the relationship between structural properties and the activity of soluble and surface-tethered sequences. The intention of this study was to analyze the influence of immobilization parameters upon the activity profile of peptides. Resin beads (TentaGel S NH2, HypoGel 400 NH2, and HypoGel 200 NH2) with polyethylene glycol spacers of different lengths were rendered antimicrobial by linkage of an amphipathic model KLAL peptide and magainin-derived MK5E. Standard solid-phase peptide synthesis, thioalkylation, and ligation strategies were used to immobilize the peptides at the C and N termini and via different side-chain positions. Depending upon the resin capacity and the coupling strategies, peptide loading ranged between 0.1 and 0.25 μmol/mg for C-terminally and around 0.03 μmol/mg for N-terminally and side-chain-immobilized peptides. Tethering conserved the activity spectra of the soluble peptides at reduced concentrations. The resin-bound peptides were antimicrobial toward Escherichia coli and Bacillus subtilis in the millimolar range compared to the results seen with micromolar concentrations of the free peptides. B. subtilis was more susceptible than E. coli. The antimicrobial activity distinctly decreased with reduction of the spacer length. Slight differences in the antimicrobial effect of KLAL and MK5E bound at different chain positions on TentaGel S NH2 suggest that the activity is less dependent upon the position of immobilization. Soluble KLAL was active toward red blood cells, whereas MK5E was nonhemolytic at up to about 400 μM. Resin-induced hemolysis hampered the determination of the hemolytic effect of the immobilized peptides. TentaGel S NH2-bound peptides enhanced the permeability of the POPC (1-palmitoyl-2-oleoyl-sn-glycero-3-phospho-choline) and mixed POPC/1-palmitoyl-2-oleoyl-sn-glycero-3-[phospho-rac-(1-glycerol)] (POPC/POPG) bilayers used to model the charge properties of the biological targets. The results suggest that surface immobilization of the cationic amphipathic antimicrobial peptides does not influence the membrane-permeabilizing mode of action. Peptide insertion into the target membrane and likely the exchange of membrane-stabilizing bivalent cations contribute to the antimicrobial effect. In conclusion, reasonable antimicrobial activity of surface-bound peptides requires the optimization of the coupling parameters, with the length of the spacer and the amount of target-accessible peptide being the most important factors.

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