ABSTRACT
BACKGROUND: Acute tonsillopharyngitis or sore throat is an initial sign of viral respiratory tract infection (RTI) and an optimal indicator for early antiviral and anti-inflammatory intervention. Both of these actions have been attributed to Echinacea purpurea and Salvia officinalis. METHODS: 74 patients (age 13-69 years) with acute sore throat symptoms (<48 h) were treated with five Echinacea/Salvia lozenges per day (4,000 mg Echinacea purpurea extract [Echinaforce®] and 1,893 mg Salvia officinalis extract [A. Vogel AG, Switzerland] daily) for 4 days. Symptom intensities were recorded in a diary and oropharyngeal swab samples collected for virus detection and quantification via RT-qPCR. RESULTS: The treatment was exceptionally well tolerated, no complicated RTI developed, and no antibiotic treatment was required. A single lozenge reduced throat pain by 48% (p < 0.001) and tonsillopharyngitis symptoms by 34% (p < 0.001). Eighteen patients tested virus positive at inclusion. Viral loads in these patients was reduced by 62% (p < 0.03) after intake of a single lozenge and by 96% (p < 0.02) after 4 days of treatment compared to pre-treatment. CONCLUSIONS: Echinacea/Salvia lozenges represent a valuable and safe option for the early treatment of acute sore throats capable to alleviate symptoms and contribute to reducing viral loads in the throat.
Subject(s)
Echinacea , Pharyngitis , Salvia officinalis , Salvia , Adolescent , Adult , Aged , Humans , Middle Aged , Young Adult , Pain , Pharyngitis/drug therapy , Pharyngitis/diagnosis , Pharyngitis/etiology , Viral LoadABSTRACT
Background: Due to the frequency and severity of cold symptoms in children, and the risk of associated complications, effective treatments are urgently needed. Here we evaluated the safety profile and treatment benefits of Echinacea in children with acute cold and flu symptoms. Methods: A total of 79 children (4-12 years) were randomized to a treatment regimen of three or five times daily Echinaforce Junior tablets (total of 1200 or 2000 mg Echinacea extract, EFJ) for the prospective treatment of upcoming cold and flu episodes at first signs. Parents recorded respiratory symptoms daily during episodes in their child and physicians and parents subjectively rated tolerability. Results: EFJ was used to treat 130 cold episodes in 68 children and was very well tolerated by more than 96% positive physician's ratings. EFJ-treated cold episodes lasted 7.5 days on average, with nine out of 10 episodes being fully resolved after 10 days. Five EFJ tablets daily reduced the average episode duration by up to 1.7 days (p < 0.02) in comparison to three EFJ tablets daily regimen. Effective symptom resolution finally contributed to a low antibiotic prescription rate in this study of 4.6%. Conclusions: EFJ tablets present a valuable option for the treatment of acute cold episodes in children showing a wide safety margin and increased therapeutic benefits at five tablets daily.
ABSTRACT
Progressive antibiotic resistance is a serious condition adding to the challenges associated with skin wound treatment, and antibacterial wound dressings with alternatives to antibiotics are urgently needed. Cellulose-based membranes are increasingly considered as wound dressings, necessitating further functionalization steps. A bifunctional peptide, combining an antimicrobial peptide (AMP) and a cellulose binding peptide (CBP), is designed. AMPs affect bacteria via multiple modes of action, thereby reducing the evolutionary pressure selecting for antibiotic resistance. The bifunctional peptide is successfully immobilized on cellulose membranes of bacterial origin or electrospun fibers of plant-derived cellulose, with tight control over peptide concentrations (0.2 ± 0.1 to 4.6 ± 1.6 µg mm-2 ). With this approach, new materials with antibacterial activity against Staphylococcus aureus (log4 reduction) and Pseudomonas aeruginosa (log1 reduction) are developed. Furthermore, membranes are cytocompatible in cultures of human fibroblasts. Additionally, a cell adhesive CBP-RGD peptide is designed and immobilized on membranes, inducing a 2.2-fold increased cell spreading compared to pristine cellulose. The versatile concept provides a toolbox for the functionalization of cellulose membranes of different origins and architectures with a broad choice in peptides. Functionalization in tris-buffered saline avoids further purification steps, allowing for translational research and multiple applications outside the field of wound dressings.
Subject(s)
Anti-Infective Agents , Cellulose , Anti-Bacterial Agents/pharmacology , Bandages , Humans , PeptidesABSTRACT
Resistance to antibiotics has posed a high demand for novel strategies to fight bacterial infections. Antimicrobial peptides (AMPs) are a promising alternative to conventional antibiotics. However, their poor solubility in water and sensitivity to degradation has limited their application. Here, we report the design of a smart, pH-responsive antimicrobial nanobiocomposite material based on the AMP nisin and 2,2,6,6-tetramethyl-1-piperidinyloxyl-oxidized nanofibrillated cellulose (TONFC). Morphological transformations of the nanoscale structure of nisin functionalized-TONFC fibrils were discovered at pH values between 5.8 and 8.0 using small-angle X-ray scattering. Complementary ζ potential measurements indicate that electrostatic attractions between the negatively charged TONFC surface and the positively charged nisin molecules are responsible for the integration of nisin. Modification of the pH level or increasing the ionic strength reduces the nisin binding capacity of TONFC. Biological evaluation studies using a bioluminescence-based reporter strain of Bacillus subtilis and a clinically relevant strain of Staphylococcus aureus indicated a significantly higher antimicrobial activity of the TONFC-nisin biocomposite compared to the pure nisin against both strains under physiological pH and ionic strength conditions. The in-depth characterization of this new class of antimicrobial biocomposite material based on nanocellulose and nisin may guide the rational design of sustainable antimicrobial materials.
ABSTRACT
Organisms are either heterotrophic or autotrophic, meaning that they cover their carbon requirements by assimilating organic compounds or by fixing inorganic carbon dioxide (CO2). The conversion of a heterotrophic organism into an autotrophic one by metabolic engineering is a long-standing goal in synthetic biology and biotechnology, because it ultimately allows for the production of value-added compounds from CO2. The heterotrophic Alphaproteobacterium Methylobacterium extorquens AM1 is a platform organism for a future C1-based bioeconomy. Here we show that M. extorquens AM1 provides unique advantages for establishing synthetic autotrophy, because energy metabolism and biomass formation can be effectively separated from each other in the organism. We designed and realized an engineered strain of M. extorquens AM1 that can use the C1 compound methanol for energy acquisition and forms biomass from CO2 by implementation of a heterologous Calvin-Benson-Bassham (CBB) cycle. We demonstrate that the heterologous CBB cycle is active, confers a distinct phenotype, and strongly increases viability of the engineered strain. Metabolic 13C-tracer analysis demonstrates the functional operation of the heterologous CBB cycle in M. extorquens AM1 and comparative proteomics of the engineered strain show that the host cell reacts to the implementation of the CBB cycle in a plastic way. While the heterologous CBB cycle is not able to support full autotrophic growth of M. extorquens AM1, our study represents a further advancement in the design and realization of synthetic autotrophic organisms.
Subject(s)
Carbon Dioxide/metabolism , Metabolic Engineering , Methylobacterium extorquens , Photosynthesis , Methylobacterium extorquens/genetics , Methylobacterium extorquens/metabolismABSTRACT
Controlled and efficient immobilization of specific biomolecules is a key technology to introduce new, favorable functions to materials suitable for biomedical applications. Here, we describe an innovative and efficient, two-step methodology for the stable immobilization of various biomolecules, including small peptides and enzymes onto TEMPO oxidized nanofibrillated cellulose (TO-NFC). The introduction of carboxylate groups to NFC by TEMPO oxidation provided a high surface density of negative charges able to drive the adsorption of biomolecules and take part in covalent cross-linking reactions with 1-ethyl-3-[3-(dimethylamino)propyl]carbodiimide (EDAC) and glutaraldehyde (Ga) chemistry. Up to 0.27 µmol of different biomolecules per mg of TO-NFC could be reversibly immobilized by electrostatic interaction. An additional chemical cross-linking step prevented desorption of more than 80% of these molecules. Using the cysteine-protease papain as model, a highly active papain-TO-NFC conjugate was achieved. Once papain was immobilized, 40% of the initial enzymatic activity was retained, with an increase in kcat from 213 to >700 s(-1) for the covalently immobilized enzymes. The methodology presented in this work expands the range of application for TO-NFC in the biomedical field by enabling well-defined hybrid biomaterials with a high density of functionalization.
Subject(s)
Cellulose, Oxidized/chemistry , Cyclic N-Oxides/chemistry , Drug Carriers/chemistry , Nanofibers/chemistry , Biocompatible Materials/chemistry , Carbodiimides/chemistry , Carboxylic Acids/chemistry , Enzymes, Immobilized/chemistry , Glutaral/chemistry , Hydrogen-Ion Concentration , Papain/chemistry , Surface PropertiesABSTRACT
The discipline of synthetic biology requires standardized tools and genetic elements to construct novel functionalities in microorganisms; yet, many model systems still lack such tools. Here, we describe a novel set of vectors that allows the convenient construction of synthetic operons in Methylobacterium extorquens AM1, an important alphaproteobacterial model organism for methylotrophy and a promising platform organism for methanol-based biotechnology. In addition, we provide a set of constitutive alphaproteobacterial promoters of different strengths that were characterized in detail by two approaches: on the single-cell scale and on the cell population level. Finally, we describe a straightforward strategy to deliver synthetic constructs to the genome of M. extorquens AM1 and other Alphaproteobacteria. This study defines a new standard to systematically characterize genetic parts for their use in M. extorquens AM1 by using single-cell fluorescence microscopy and opens the toolbox for synthetic biological applications in M. extorquens AM1 and other alphaproteobacterial model systems.
