Preparation of Antibacterial Polypeptides with Different Topologies and Their Antibacterial Properties

2022 ◽  
Author(s):  
Xiaodan Wang ◽  
FangPing Yang ◽  
Huawei Yang ◽  
Xu Zhang ◽  
Haoyu Tang ◽  
...  
Keyword(s):  
Antimicrobial Peptides ◽  
Bacterial Infections ◽  
Antimicrobial Agents ◽  
Antibacterial Properties ◽  
Conventional Antibiotics

Antimicrobial peptides (AMPs) are attractive antimicrobial agents used to combat bacterial infections and have been advanced to be one of the most promising alternatives to conventional antibiotics. They stand out...

scholarly journals Loxosceles gaucho Spider Venom: An Untapped Source of Antimicrobial Agents

Toxins ◽  
2018 ◽  
Vol 10 (12) ◽  
pp. 522 ◽  
Author(s):  
Paula Segura-Ramírez ◽  
Pedro Silva Júnior
Keyword(s):  
Bacterial Infections ◽  
High Performance ◽  
Antimicrobial Agents ◽  
Chemical Properties ◽  
Carcinoma Cells ◽  
Promising Candidate ◽  
Human Red Blood Cells ◽  
New Antibiotics ◽  
Conventional Antibiotics ◽  
Human Cervical Carcinoma Cells

The remarkable ability of microorganisms to develop resistance to conventional antibiotics is one of the biggest challenges that the pharmaceutical industry currently faces. Recent studies suggest that antimicrobial peptides discovered in spider venoms may be useful resources for the design of structurally new anti-infective agents effective against drug-resistant microorganisms. In this work, we found an anionic antibacterial peptide named U1-SCRTX-Lg1a in the venom of the spider Loxosceles gaucho. The peptide was purified using high-performance liquid chromatography (HPLC), its antimicrobial activity was tested through liquid growth inhibition assays, and its chemical properties were characterized using mass spectrometry. U1-SCRTX-Lg1a was found to show a monoisotopic mass of 1695.75 Da, activity against Gram-negative bacteria, a lack of hemolytic effects against human red blood cells, and a lack of cytotoxicity against human cervical carcinoma cells (HeLa). Besides this, the sequence of the peptide exhibited great similarity to specific regions of phospholipases D from different species of Loxosceles spiders, leading to the hypothesis that U1-SCRTX-Lg1a may have originated from a limited proteolytic cleavage. Our data suggest that U1-SCRTX-Lg1a is a promising candidate for the development of new antibiotics that could help fight bacterial infections and represents an exciting discovery for Loxosceles spiders.

Development and Characterization of Hydroxyapatite Containing Silver by Precipitation and Immersion Methods

2014 ◽  
Vol 631 ◽  
pp. 216-221
Author(s):  
M.F. Santos ◽  
L.C.O. Vercik ◽  
A. Vercik ◽  
E.C.S. Rigo
Keyword(s):  
Bacterial Infections ◽  
Antibacterial Properties ◽  
Silver Ions ◽  
Antimicrobial Effect ◽  
Bone Substitutes ◽  
Precipitation Method ◽  
Precipitation Process ◽  
X Ray Diffraction ◽  
Ionic Groups ◽  
Conventional Antibiotics

The use of bone substitutes for recovery of lost function is a constant search within the medical field. So biomaterials have received a very large attention from the scientific community, including the materials the basis of calcium phosphate. Hydroxyapatite (HA) has been studied as apart from representing the natural constitution of the mass of bones and teeth in 30 to 70 %, has properties of bioactivity and osteoconductivity, encouraging and assisting the growth of bone tissue. In contrast, bacterial infections can arise after implantation causing the loss of functionality in the short and medium term. Several alternatives are being tested, usually associated with the use of conventional antibiotics incorporated into biomaterials. An alternative to antibiotics would be use such metals that possess antibacterial properties. Silver (Ag) is known as a bactericidal metal and so gained a prominent place among the studies as an important ally in the control of post-surgical infections. This work aimed to synthesize, characterize and evaluate the antimicrobial effect of the addition of silver ions into hydroxyapatite. The hydroxyapatites containing silver were obtained by the precipitation method in aqueous solution containing AgNO3 and by immersing the powder after the precipitation process in aqueous solutions containing AgNO3. At this stage of the work, were analyzed and characterized the crystalline phases and the ionic groups present in HA, HA precipitates with Ag and immersed in a solution of Ag. X-ray diffraction (XRD) spectra showed that regardless of the method used, precipitation (room temperature or 90°C) or by immersion, the metallic Ag was present in the structure of HA. Additionally, it was observed that the peaks indicated in the XRD pattern for HA corresponding to the diffraction pattern of plugs JPCDS 09-0432 (Joint Committee on Powder Diffraction Standards). No peaks related to the phases being observed β-TCP and CaO, respectively, indicating that the conditions adopted for obtaining HA Ag, only HA phase is present and that methods, precipitation and immersion are efficient to occur doping of HA with Ag

scholarly journals Design, Overproduction and Purification of the Chimeric Phage Lysin MLTphg Fighting against Staphylococcus aureus

Processes ◽  
2020 ◽  
Vol 8 (12) ◽  
pp. 1587
Author(s):  
Feng Wang ◽  
Xiaohang Liu ◽  
Zhengyu Deng ◽  
Yao Zhang ◽  
Xinyu Ji ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Bacterial Infections ◽  
Antimicrobial Agents ◽  
Multidrug Resistant ◽  
Resistant Bacteria ◽  
Antibiotic Resistant ◽  
E Coli ◽  
Conventional Antibiotics ◽  
Phage Lysin ◽  
Shed Light

With the increasing spread of multidrug-resistant bacterial pathogens, it is of great importance to develop alternatives to conventional antibiotics. Here, we report the generation of a chimeric phage lysin, MLTphg, which was assembled by joining the lysins derived from Meiothermus bacteriophage MMP7 and Thermus bacteriophage TSP4 with a flexible linker via chimeolysin engineering. As a potential antimicrobial agent, MLTphg can be obtained by overproduction in Escherichia coli BL21(DE3) cells and the following Ni-affinity chromatography. Finally, we recovered about 40 ± 1.9 mg of MLTphg from 1 L of the host E. coli BL21(DE3) culture. The purified MLTphg showed peak activity against Staphylococcus aureus ATCC6538 between 35 and 40 °C, and maintained approximately 44.5 ± 2.1% activity at room temperature (25 °C). Moreover, as a produced chimera, it exhibited considerably improved bactericidal activity against Staphylococcus aureus (2.9 ± 0.1 log10 reduction was observed upon 40 nM MLTphg treatment at 37 °C for 30 min) and also a group of antibiotic-resistant bacteria compared to its parental lysins, TSPphg and MMPphg. In the current age of growing antibiotic resistance, our results provide an engineering basis for developing phage lysins as novel antimicrobial agents and shed light on bacteriophage-based strategies to tackle bacterial infections.

scholarly journals An Update on Antimicrobial Peptides (AMPs) and Their Delivery Strategies for Wound Infections

Pharmaceutics ◽  
2020 ◽  
Vol 12 (9) ◽  
pp. 840 ◽  
Author(s):  
Viorica Patrulea ◽  
Gerrit Borchard ◽  
Olivier Jordan
Keyword(s):  
Antimicrobial Peptides ◽  
Bacterial Infections ◽  
Antimicrobial Agents ◽  
New Technologies ◽  
Multidrug Resistant ◽  
Inorganic Nanoparticles ◽  
Wound Dressings ◽  
Wound Infections ◽  
Clinical Phase ◽  
Delivery Strategies

Bacterial infections occur when wound healing fails to reach the final stage of healing, which is usually hindered by the presence of different pathogens. Different topical antimicrobial agents are used to inhibit bacterial growth due to antibiotic failure in reaching the infected site, which is accompanied very often by increased drug resistance and other side effects. In this review, we focus on antimicrobial peptides (AMPs), especially those with a high potential of efficacy against multidrug-resistant and biofilm-forming bacteria and fungi present in wound infections. Currently, different AMPs undergo preclinical and clinical phase to combat infection-related diseases. AMP dendrimers (AMPDs) have been mentioned as potent microbial agents. Various AMP delivery strategies that are used to combat infection and modulate the healing rate—such as polymers, scaffolds, films and wound dressings, and organic and inorganic nanoparticles—have been discussed as well. New technologies such as Clustered Regularly Interspaced Short Palindromic Repeat (CRISPR)-associated protein (CRISPR-Cas) are taken into consideration as potential future tools for AMP delivery in skin therapy.

scholarly journals A Uniform In Vitro Efficacy Dataset to Guide Antimicrobial Peptide Design

Data ◽  
2019 ◽  
Vol 4 (1) ◽  
pp. 27 ◽  
Author(s):  
Deepesh Nagarajan ◽  
Tushar Nagarajan ◽  
Neha Nanajkar ◽  
Nagasuma Chandra
Keyword(s):  
Antimicrobial Peptides ◽  
Antimicrobial Peptide ◽  
Antimicrobial Agents ◽  
Multi Drug Resistance ◽  
Peptide Design ◽  
Drug Candidates ◽  
The Face ◽  
Conventional Antibiotics ◽  
Different Sources

Antimicrobial peptides are ubiquitous molecules that form the innate immune system of organisms across all kingdoms of life. Despite their prevalence and early origins, they continue to remain potent natural antimicrobial agents. Antimicrobial peptides are therefore promising drug candidates in the face of overwhelming multi-drug resistance to conventional antibiotics. Over the past few decades, thousands of antimicrobial peptides have been characterized in vitro, and their efficacy data are now available in a multitude of public databases. Computational antimicrobial peptide design attempts typically use such data. However, utilizing heterogenous data aggregated from different sources presents significant drawbacks. In this report, we present a uniform dataset containing 20 antimicrobial peptides assayed against 30 organisms of Gram-negative, Gram-positive, mycobacterial, and fungal origin. We also present circular dichroism spectra for all antimicrobial peptides. We draw simple inferences from this data, and we discuss what characteristics are essential for antimicrobial peptide efficacy. We expect our uniform dataset to be useful for future projects involving computational antimicrobial peptide design.

Combating bacterial resistance by combination of antibiotics with antimicrobial peptides

2019 ◽  
Vol 91 (2) ◽  
pp. 199-209 ◽  
Author(s):  
Dean E. Sheard ◽  
Neil M. O’Brien-Simpson ◽  
John D. Wade ◽  
Frances Separovic
Keyword(s):  
Antimicrobial Peptides ◽  
Bacterial Infections ◽  
Bacterial Resistance ◽  
Synergistic Effects ◽  
Resistance Mechanisms ◽  
Bacterial Strains ◽  
Diverse Range ◽  
Recent Emergence ◽  
Agricultural Industries ◽  
Conventional Antibiotics

Abstract The overuse of antibiotics in the healthcare and agricultural industries has led to the worldwide spread of bacterial resistance. The recent emergence of multidrug resistant (MDR) bacteria has resulted in a call for the development of novel strategies to address this global issue. Research on a diverse range of antimicrobial peptides (AMPs) has shown promising activity against several resistant strains. Increased understanding of the mode of action of AMPs has shown similarity and complementarity to conventional antibiotics and the combination of both has led to synergistic effects in some cases. Combination therapy has been widely used to combat MDR bacterial infections and the recent focus on their application with AMPs may allow antibiotics to be effective against resistant bacterial strains. By conjugation of an antibiotic onto an AMP, a compound may be produced with possibly greater activity and with reduced side-effects and toxicity. The AMP in these conjugates may also act as a unique adjuvant for the antibiotic by disrupting the resistance mechanisms used by bacteria thus allowing the antibiotic to once again be effective. This mini-review outlines some of the current and past work in combining AMPs with conventional antibiotics as strategies to address bacterial resistance.

scholarly journals Potential of Nanoparticles Integrated with Antibacterial Properties in Preventing Biofilm and Antibiotic Resistance

Antibiotics ◽  
2021 ◽  
Vol 10 (11) ◽  
pp. 1338
Author(s):  
Maheswary Thambirajoo ◽  
Manira Maarof ◽  
Yogeswaran Lokanathan ◽  
Haliza Katas ◽  
Nur Fatiha Ghazalli ◽  
...  
Keyword(s):  
Antibiotic Resistance ◽  
Bacterial Infections ◽  
Antimicrobial Agents ◽  
Antibacterial Properties ◽  
Alternative Methods ◽  
Bacterial Biofilms ◽  
High Morbidity ◽  
Different Types ◽  
Other Substances ◽  
Potential Use

Nanotechnology has become an emerging technology in the medical field and is widely applicable for various clinical applications. The potential use of nanoparticles as antimicrobial agents is greatly explored and taken into consideration as alternative methods to overcome the challenges faced by healthcare workers and patients in preventing infections caused by pathogenic microorganisms. Among microorganisms, bacterial infections remain a major hurdle and are responsible for high morbidity and mortality globally, especially involving those with medical conditions and elderly populations. Over time, these groups are more vulnerable to developing resistance to antibiotics, as bacterial biofilms are difficult to destroy or eliminate via antibiotics; thus, treatment becomes unsuccessful or ineffective. Mostly, bacterial biofilms and other microbes can be found on medical devices and wounds where they disperse their contents which cause infections. To inhibit biofilm formations and overcome antibiotic resistance, antimicrobial-loaded nanoparticles alone or combined with other substances could enhance the bactericidal activity of nanomaterials. This includes killing the pathogens effectively without harming other cells or causing any adverse effects to living cells. This review summarises the mechanisms of actions employed by the different types of nanoparticles which counteract infectious agents in reducing biofilm formation and improve antibiotic therapy for clinical usage.

scholarly journals Anti-bacterial properties and GC-MS analysis of extracts and essential oils of selected plant product

2018 ◽  
Vol 16 (1) ◽  
pp. 44-58
Author(s):  
OMBUNA DINAH NYAITONDI ◽  
RUTH NDUTA WANJAU ◽  
HUDSON NYAMBAKA ◽  
AHMED HASSANALI
Keyword(s):  
Antibacterial Activity ◽  
Essential Oils ◽  
Bacterial Infections ◽  
Antimicrobial Agents ◽  
Antibacterial Properties ◽  
Salmonella Typhi ◽  
Retention Indices ◽  
Methanol Extracts ◽  
Plant Product ◽  
Ms Analysis

Nyaitondi OD, Wanjau R, Nyambaka H, Hassanali A. 2018. Anti-bacterial properties and GC-MS analysis of extracts and essential oils of selected plant product. Biofarmasi J Nat Prod Biochem 16: 44-58. Plants are traditionally used for the treatment of bacterial infections though they are not clinically regulated due to lack of awareness and sufficient data to support the reported therapeutic claims. Some plants used as food and vegetables are hardly considered in such studies. This study aimed to investigate the antibacterial properties associated with garlic, ginger, turmeric, lemon, and onion in the form of juices, methanol extracts, and essential oils. These materials were tested against Staphylococcus aureus, Pseudomonas aeruginosa, Escherichia coli, and Salmonella typhi. Identification of suspected antibacterial compounds was made by comparison of retention indices and the mass spectra with those in National Institute of Standards and Technology (NIST) libraries using GC-MS analyses. Garlic juice was bactericidal against all tested strains. Lemon/garlic juice exhibited significantly higher activity against E. coli and S. typhi. Turmeric/lemon/garlic methanol extracts blend was most active against S. aureus. Preliminary screening of the essential oils indicated significant antibacterial activity of lemon/garlic essential oil blend against P. aeruginosa. GC-MS analysis of the active samples confirmed the presence of compounds containing-OOH,-OH,-N,-Cl,-F,-NH2 and-S groups which are associated with bacterial inhibition in conventional antibiotics. The 10 major constituents obtained from samples suspected to contain antibacterial activity, include limonene; 3-vinyl-1,2-dithiacyclohex-4- ene; α-zingiberene; diallyl disulphide; 2-butanone,4-(-hydroxy-3-methoxyphenyl); 3-chlorothiophene; methanehydrazonic acid,N-[3- (methylthio)-1,-2,4-thiadiazol-5-yl]-,ethyl ester; n-hexadecanoic acid; γ-sitosterol and propanamide,2-amino-3-phenyl. Juices of garlic, lemon and lemon/garlic blend were found to be active against one or more of the bacteria tested unlike methanol extracts and essential oils, and they should be used in raw form as heating and drying is likely to render them inactive. Further studies on methanol extract and fresh juice of lemon/garlic blend need to be undertaken to elucidate the active principles in these extracts and may lead to the discovery of novel antimicrobial agents and models for the new generation of synthetic antibiotics.

scholarly journals A uniform in vitro efficacy dataset to guide antimicrobial peptide design

2018 ◽  
Author(s):  
Deepesh Nagarajan ◽  
Tushar Nagarajan ◽  
Neha Nanajkar ◽  
Nagasuma Chandra
Keyword(s):  
Antimicrobial Peptides ◽  
Antimicrobial Peptide ◽  
Antimicrobial Agents ◽  
Multi Drug Resistance ◽  
Peptide Design ◽  
Drug Candidates ◽  
The Face ◽  
Conventional Antibiotics ◽  
Different Sources

ABSTRACTAntimicrobial peptides are ubiquitous molecules that form the innate immune system of organisms across all kingdoms of life. Despite their prevalence and early origins, they continue to remain potent natural antimicrobial agents. Antimicrobial peptides are therefore promising drug candidates in the face of overwhelming multi-drug resistance to conventional antibiotics. Over the past few decades, thousands of antimicrobial peptides have been characterized in vitro, and their efficacy data is now available in a multitude of public databases. Computational antimicrobial peptide design attempts typically use such data. However, utilizing heterogenous data aggregated from different sources presents significant drawbacks. In this report, we present a uniform dataset containing 20 antimicrobial peptides assayed against 30 organisms spanning gram positive, gram negative, fungal, and mycobacterial origin. We draw inferences from the results of 600 individual MIC assays, and discuss what characteristics are essential for antimicrobial peptide efficacy. We expect our uniform dataset to be useful for future projects involving computational antimicrobial peptide design.

Synergism between Host Defence Peptides and Antibiotics Against Bacterial Infections

2020 ◽  
Vol 20 (14) ◽  
pp. 1238-1263 ◽  
Author(s):  
Jiarui Li ◽  
Pablo Fernández-Millán ◽  
Ester Boix
Keyword(s):  
Bacterial Infections ◽  
Bacterial Resistance ◽  
Antimicrobial Agents ◽  
Resistance Mechanisms ◽  
Adjuvant Activity ◽  
Biofilm Growth ◽  
Intracellular Target ◽  
Conventional Antibiotics ◽  
Available Information ◽  
Toxic Concentrations

Background: Antimicrobial resistance (AMR) to conventional antibiotics is becoming one of the main global health threats and novel alternative strategies are urging. Antimicrobial peptides (AMPs), once forgotten, are coming back into the scene as promising tools to overcome bacterial resistance. Recent findings have attracted attention to the potentiality of AMPs to work as antibiotic adjuvants. Methods: In this review, we have tried to collect the currently available information on the mechanism of action of AMPs in synergy with other antimicrobial agents. In particular, we have focused on the mechanisms of action that mediate the inhibition of the emergence of bacterial resistance by AMPs. Results and Conclusion: We find in the literature many examples where AMPs can significantly reduce the antibiotic effective concentration. Mainly, the peptides work at the bacterial cell wall and thereby facilitate the drug access to its intracellular target. Complementarily, AMPs can also contribute to permeate the exopolysaccharide layer of biofilm communities, or even prevent bacterial adhesion and biofilm growth. Secondly, we find other peptides that can directly block the emergence of bacterial resistance mechanisms or interfere with the community quorum-sensing systems. Interestingly, the effective peptide concentrations for adjuvant activity and inhibition of bacterial resistance are much lower than the required for direct antimicrobial action. Finally, many AMPs expressed by innate immune cells are endowed with immunomodulatory properties and can participate in the host response against infection. Recent studies in animal models confirm that AMPs work as adjuvants at non-toxic concentrations and can be safely administrated for novel combined chemotherapies.

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