Reducing Bacterial Colonization of 3-D Nanofiber Cell Scaffolds by Hierarchical Assembly of Microgels and an Antimicrobial Peptide

2012 ◽  
Vol 2 (5) ◽  
pp. 687-691 ◽  
Author(s):  
Qichen Wang ◽  
Xiaojun Yu ◽  
Matthew Libera
Keyword(s):  
Antimicrobial Peptide ◽  
Bacterial Colonization ◽  
Hierarchical Assembly ◽  
Cell Scaffolds

scholarly journals Developmental switch of intestinal antimicrobial peptide expression

2008 ◽  
Vol 205 (1) ◽  
pp. 183-193 ◽  
Author(s):  
Sandrine Ménard ◽  
Valentina Förster ◽  
Michael Lotz ◽  
Dominique Gütle ◽  
Claudia U. Duerr ◽  
...  
Keyword(s):  
Antimicrobial Peptide ◽  
High Performance ◽  
Bacterial Colonization ◽  
Paneth Cell ◽  
Active Form ◽  
Constitutive Expression ◽  
Postnatal Period ◽  
Enteric Infection ◽  
Immune Effector ◽  
Developmental Switch

Paneth cell–derived enteric antimicrobial peptides provide protection from intestinal infection and maintenance of enteric homeostasis. Paneth cells, however, evolve only after the neonatal period, and the antimicrobial mechanisms that protect the newborn intestine are ill defined. Using quantitative reverse transcription–polymerase chain reaction, immunohistology, reverse-phase high-performance liquid chromatography, and mass spectrometry, we analyzed the antimicrobial repertoire in intestinal epithelial cells during postnatal development. Surprisingly, constitutive expression of the cathelin-related antimicrobial peptide (CRAMP) was observed, and the processed, antimicrobially active form was identified in neonatal epithelium. Peptide synthesis was limited to the first two weeks after birth and gradually disappeared with the onset of increased stem cell proliferation and epithelial cell migration along the crypt–villus axis. CRAMP conferred significant protection from intestinal bacterial growth of the newborn enteric pathogen Listeria monocytogenes. Thus, we describe the first example of a complete developmental switch in innate immune effector expression and anatomical distribution. Epithelial CRAMP expression might contribute to bacterial colonization and the establishment of gut homeostasis, and provide protection from enteric infection during the postnatal period.

scholarly journals RELATION BETWEEN BACTERIAL COLONIZATION IN LUNGS AND LEVELS OF 25-HYDROXYVITAMIN D AND ANTIMICROBIAL PEPTIDE LL-37 IN CHILDREN WITH CYSTIC FIBROSIS

InterConf ◽  
2021 ◽  
pp. 278-282
Author(s):  
Veronika Dudnyk ◽  
Valeriia Demianyshyna
Keyword(s):  
Cystic Fibrosis ◽  
Antimicrobial Peptide ◽  
Bacterial Colonization ◽  
Hydroxyvitamin D ◽  
25 Hydroxyvitamin D ◽  
25 Hydroxycholecalciferol

The aim of the study was to assess the bacterial colonization in lungs of children with cystic fibrosis based on the antimicrobial peptide cathelicidin and 25-hydroxycholecalciferol in the serum. Study showed significant correlation between P. aeruginosa infection and cathelicidin and 25-hydroxycholecalciferol levels.

scholarly journals Multilayer Polyelectrolyte Films Functionalized by Insertion of Defensin: a New Approach to Protection of Implants from Bacterial Colonization

2004 ◽  
Vol 48 (10) ◽  
pp. 3662-3669 ◽  
Author(s):  
O. Etienne ◽  
C. Picart ◽  
C. Taddei ◽  
Y. Haikel ◽  
J. L. Dimarcq ◽  
...  
Keyword(s):  
Antimicrobial Peptide ◽  
Micrococcus Luteus ◽  
Bacterial Colonization ◽  
Streaming Potential ◽  
Multilayer Films ◽  
Microbial Infection ◽  
Host Protection ◽  
New Strategy ◽  
Local Host ◽  
Positively Charged

ABSTRACT Infection of implanted materials by bacteria constitutes one of the most serious complications following prosthetic surgery. In the present study, we developed a new strategy based on the insertion of an antimicrobial peptide (defensin from Anopheles gambiae mosquitoes) into polyelectrolyte multilayer films built by the alternate deposition of polyanions and polycations. Quartz crystal microbalance and streaming potential measurements were used to follow step by step the construction of the multilayer films and embedding of the defensin within the films. Antimicrobial assays were performed with two strains: Micrococcus luteus (a gram-positive bacterium) and Escherichia coli D22 (a gram-negative bacterium). The inhibition of E. coli D22 growth at the surface of defensin-functionalized films was found to be 98% when 10 antimicrobial peptide layers were inserted in the film architecture. Noticeably, the biofunctionalization could be achieved only when positively charged poly(l-lysine) was the outermost layer of the film. On the basis of the results of bacterial adhesion experiments observed by confocal or electron microscopy, these observations could result from the close interaction of the bacteria with the positively charged ends of the films, which allows defensin to interact with the bacterial membrane structure. These results open new possibilities for the use of such easily built and functionalized architectures onto any type of implantable biomaterial. The modified surfaces are active against microbial infection and represent a novel means of local host protection.

scholarly journals Antimicrobial peptide coatings for hydroxyapatite: electrostatic and covalent attachment of antimicrobial peptides to surfaces

2017 ◽  
Vol 14 (126) ◽  
pp. 20160657 ◽  
Author(s):  
Leigh Townsend ◽  
Richard L. Williams ◽  
Olachi Anuforom ◽  
Matthew R. Berwick ◽  
Fenella Halstead ◽  
...  
Keyword(s):  
Antimicrobial Peptide ◽  
Cell Attachment ◽  
Bacterial Colonization ◽  
Covalent Attachment ◽  
Dual Approach ◽  
Covalently Bonded ◽  
Novel Method ◽  
Tissue Interface ◽  
Peptide Coatings ◽  
Implanted Devices

The interface between implanted devices and their host tissue is complex and is often optimized for maximal integration and cell adhesion. However, this also gives a surface suitable for bacterial colonization. We have developed a novel method of modifying the surface at the material–tissue interface with an antimicrobial peptide (AMP) coating to allow cell attachment while inhibiting bacterial colonization. The technology reported here is a dual AMP coating. The dual coating consists of AMPs covalently bonded to the hydroxyapatite surface, followed by deposition of electrostatically bound AMPs. The dual approach gives an efficacious coating which is stable for over 12 months and can prevent colonization of the surface by both Gram-positive and Gram-negative bacteria.

scholarly journals Subinhibitory concentrations of the cationic antimicrobial peptide colistin induce the pseudomonas quinolone signal in Pseudomonas aeruginosa

Microbiology ◽  
2009 ◽  
Vol 155 (9) ◽  
pp. 2826-2837 ◽  
Author(s):  
Joanne Cummins ◽  
F. Jerry Reen ◽  
Christine Baysse ◽  
Marlies J. Mooij ◽  
Fergal O'Gara
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Antimicrobial Peptide ◽  
Biofilm Formation ◽  
Bacterial Colonization ◽  
Central Component ◽  
Functional Genomic ◽  
Cationic Antimicrobial Peptide ◽  
Altered Expression ◽  
Pseudomonas Quinolone Signal ◽  
Subinhibitory Concentrations

Colistin is an important cationic antimicrobial peptide (CAMP) in the fight against Pseudomonas aeruginosa infection in cystic fibrosis (CF) lungs. The effects of subinhibitory concentrations of colistin on gene expression in P. aeruginosa were investigated by transcriptome and functional genomic approaches. Analysis revealed altered expression of 30 genes representing a variety of pathways associated with virulence and bacterial colonization in chronic infection. These included response to osmotic stress, motility, and biofilm formation, as well as genes associated with LPS modification and quorum sensing (QS). Most striking was the upregulation of Pseudomonas quinolone signal (PQS) biosynthesis genes, including pqsH, pqsB and pqsE, and the phenazine biosynthesis operon. Induction of this central component of the QS network following exposure to subinhibitory concentrations of colistin may represent a switch to a more robust population, with increased fitness in the competitive environment of the CF lung.

A novel in silico antimicrobial peptide DP7 combats MDR Pseudomonas aeruginosa and related biofilm infections

2020 ◽  
Vol 75 (11) ◽  
pp. 3248-3259 ◽  
Author(s):  
Qi Yin ◽  
Siwen Wu ◽  
Lei Wu ◽  
Zhenling Wang ◽  
Yandong Mu ◽  
...  
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Antimicrobial Peptide ◽  
Genome Sequencing ◽  
Mode Of Action ◽  
In Silico ◽  
Bacterial Colonization ◽  
Outer Membrane Proteins ◽  
Antibiofilm Activity ◽  
Promising Alternative ◽  
Biofilm Infection

Abstract Background Antimicrobial peptides are promising alternative antimicrobial agents to combat MDR. DP7, an antimicrobial peptide designed in silico, possesses broad-spectrum antimicrobial activities and immunomodulatory effects. However, the effects of DP7 against Pseudomonas aeruginosa and biofilm infection remain largely unexplored. Objectives To assess (i) the antimicrobial activity of DP7 against MDR P. aeruginosa; and (ii) the antibiofilm activity against biofilm infection. Also, to preliminarily investigate the possible antimicrobial mode of action. Methods The MICs of DP7 for 104 clinical P. aeruginosa strains (including 57 MDR strains) and the antibiofilm activity were determined. RNA-Seq, genome sequencing and cell morphology were conducted. Both acute and chronic biofilm infection mouse models were established. Two mutants, resulting from point mutations associated with LPS and biofilms, were constructed to investigate the potential mode of action. Results DP7, at 8–32 mg/L, inhibited the growth of clinical P. aeruginosa strains and, at 64 mg/L, reduced biofilm formation by 43% to 68% in vitro. In acute lung infection, 0.5 mg/kg DP7 exhibited a 70% protection rate and reduced bacterial colonization by 50% in chronic infection. DP7 mainly suppressed gene expression involving LPS and outer membrane proteins and disrupted cell wall structure. Genome sequencing of the DP7-resistant strain DP7R revealed four SNPs controlling LPS and biofilm production. gshA44 and wbpJ139 mutants displayed LPS reduction and motility deficiency, conferring the reduction of LPS and biofilm biomass of strain DP7R and indicating that LPS was a potential target of DP7. Conclusions These results demonstrate that DP7 may hold potential as an effective antimicrobial agent against MDR P. aeruginosa and related infections.

scholarly journals Peptide Mediated Antimicrobial Dental Adhesive System

2019 ◽  
Vol 9 (3) ◽  
pp. 557 ◽  
Author(s):  
Sheng-Xue Xie ◽  
Kyle Boone ◽  
Sarah Kay VanOosten ◽  
Esra Yuca ◽  
Linyong Song ◽  
...  
Keyword(s):  
Antimicrobial Peptide ◽  
Bacterial Colonization ◽  
Antibacterial Properties ◽  
Adhesive System ◽  
Dental Composite ◽  
Material Degradation ◽  
Material Weakness ◽  
Food Preservative ◽  
Dental Adhesive ◽  
Adhesive Formulation

The most common cause for dental composite failures is secondary caries due to invasive bacterial colonization of the adhesive/dentin (a/d) interface. Innate material weakness often lead to an insufficient seal between the adhesive and dentin. Consequently, bacterial by-products invade the porous a/d interface leading to material degradation and dental caries. Current approaches to achieve antibacterial properties in these materials continue to raise concerns regarding hypersensitivity and antibiotic resistance. Herein, we have developed a multi-faceted, bio-functionalized approach to overcome the vulnerability of such interfaces. An antimicrobial adhesive formulation was designed using a combination of antimicrobial peptide and a ε-polylysine resin system. Effector molecules boasting innate immunity are brought together with a biopolymer offering a two-fold biomimetic design approach. The selection of ε-polylysine was inspired due to its non-toxic nature and common use as food preservative. Biomolecular characterization and functional activity of our engineered dental adhesive formulation were assessed and the combinatorial formulation demonstrated significant antimicrobial activity against Streptococcus mutans. Our antimicrobial peptide-hydrophilic adhesive hybrid system design offers advanced, biofunctional properties at the critical a/d interface.

scholarly journals High-fat diet modifies the PPAR-γ pathway leading to disruption of microbial and physiological ecosystem in murine small intestine

2016 ◽  
Vol 113 (40) ◽  
pp. E5934-E5943 ◽  
Author(s):  
Julie Tomas ◽  
Céline Mulet ◽  
Azadeh Saffarian ◽  
Jean-Baptiste Cavin ◽  
Robert Ducroc ◽  
...  
Keyword(s):  
Spatial Distribution ◽  
Small Intestine ◽  
Antimicrobial Peptide ◽  
Bacterial Colonization ◽  
Peroxisome Proliferator ◽  
High Fat ◽  
Peroxisome Proliferator Activated Receptor ◽  
Ppar Γ ◽  
Peptide Expression ◽  
Antimicrobial Peptide Expression

Diet is among the most important factors contributing to intestinal homeostasis, and basic functions performed by the small intestine need to be tightly preserved to maintain health. Little is known about the direct impact of high-fat (HF) diet on small-intestinal mucosal defenses and spatial distribution of the microbiota during the early phase of its administration. We observed that only 30 d after HF diet initiation, the intervillous zone of the ileum—which is usually described as free of bacteria—became occupied by a dense microbiota. In addition to affecting its spatial distribution, HF diet also drastically affected microbiota composition with a profile characterized by the expansion of Firmicutes (appearance ofErysipelotrichi), Proteobacteria (Desulfovibrionales) and Verrucomicrobia, and decrease of Bacteroidetes (family S24-7) andCandidatus arthromitus. A decrease in antimicrobial peptide expression was predominantly observed in the ileum where bacterial density appeared highest. In addition, HF diet increased intestinal permeability and decreased cystic fibrosis transmembrane conductance regulator (Cftr) and the Na-K-2Cl cotransporter 1 (Nkcc1) gene and protein expressions, leading to a decrease in ileal secretion of chloride, likely responsible for massive alteration in mucus phenotype. This complex phenotype triggered by HF diet at the interface between the microbiota and the mucosal surface was reversed when the diet was switched back to standard composition or when mice were treated for 1 wk with rosiglitazone, a specific agonist of peroxisome proliferator-activated receptor-γ (PPAR-γ). Moreover, weaker expression of antimicrobial peptide-encoding genes and intervillous bacterial colonization were observed inPpar-γ–deficient mice, highlighting the major role of lipids in modulation of mucosal immune defenses.

scholarly journals Adhesive Antimicrobial Peptides Containing 3,4-Dihydroxy-L-Phenylalanine Residues for Direct One-Step Surface Coating

2021 ◽  
Vol 22 (21) ◽  
pp. 11915
Author(s):  
Young Eun Hwang ◽  
Seonghun Im ◽  
Hyun Kim ◽  
Jung-Hoon Sohn ◽  
Byung-Kwan Cho ◽  
...  
Keyword(s):  
Antimicrobial Peptides ◽  
Antimicrobial Peptide ◽  
Surface Coating ◽  
Bacterial Colonization ◽  
Substrate Surface ◽  
Antibacterial Properties ◽  
Antimicrobial Properties ◽  
Coating Agent ◽  
C Terminus ◽  
One Step

Bacterial colonization and transmission via surfaces increase the risk of infection. In this study, we design and employ novel adhesive antimicrobial peptides to prevent bacterial contamination of surfaces. Repeats of 3,4-dihydroxy-L-phenylalanine (DOPA) were added to the C-terminus of NKC, a potent synthetic antimicrobial peptide, and the adhesiveness and antibacterial properties of the resulting peptides are evaluated. The peptide is successfully immobilized on polystyrene, titanium, and polydimethylsiloxane surfaces within 10 min in a one-step coating process with no prior surface functionalization. The antibacterial effectiveness of the NKC-DOPA5-coated polystyrene, titanium, and polydimethylsiloxane surfaces is confirmed by complete inhibition of the growth of Escherichia coli, Pseudomonas aeruginosa, and Staphylococcus aureus within 2 h. The stability of the peptide coated on the substrate surface is maintained for 84 days, as confirmed by its bactericidal activity. Additionally, the NKC-DOPA5-coated polystyrene, titanium, and polydimethylsiloxane surfaces show no cytotoxicity toward the human keratinocyte cell line HaCaT. The antimicrobial properties of the peptide-coated surfaces are confirmed in a subcutaneous implantation animal model. The adhesive antimicrobial peptide developed in this study exhibits potential as an antimicrobial surface-coating agent for efficiently killing a broad spectrum of bacteria on contact.

The Human Endogenous Antimicrobial Peptide Ll-37 Stimulates Airway Epithelial Repair

Pneumologie ◽  
2006 ◽  
Vol 59 (12) ◽  
Author(s):  
R Shaykhiev ◽  
C Beißwenger ◽  
K Kändler ◽  
J Senske ◽  
A Püchner ◽  
...  
Keyword(s):  
Antimicrobial Peptide ◽  
Airway Epithelial ◽  
Epithelial Repair
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