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.

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.

scholarly journals Activities of Antimicrobial Peptides and Synergy with Enrofloxacin against Mycoplasma pulmonis

2006 ◽  
Vol 51 (2) ◽  
pp. 468-474 ◽  
Author(s):  
Lina Fassi Fehri ◽  
Henri Wróblewski ◽  
Alain Blanchard
Keyword(s):  
Antimicrobial Peptides ◽  
Antimicrobial Agents ◽  
Cell Concentration ◽  
Synergistic Effects ◽  
Minimal Bactericidal Concentration ◽  
In Vitro Susceptibility ◽  
Gramicidin S ◽  
Mycoplasma Cell ◽  
Conventional Antibiotics

ABSTRACT We showed in a previous study that associations of antimicrobial peptides (AMPs), which are key components of the innate immune systems of all living species, with the fluoroquinolone enrofloxacin can successfully cure HeLa cell cultures of Mycoplasma fermentans and M. hyorhinis contamination. In the present work, the in vitro susceptibility of M. pulmonis, a murine pathogen, to enrofloxacin and four AMPs (alamethicin, globomycin, gramicidin S, and surfactin) was investigated, with special reference to synergistic associations and the effect of the mycoplasma cell concentration. Enrofloxacin and globomycin displayed the lowest MICs (0.4 μM), followed by gramicidin S (3.12 μM), alamethicin (6.25 μM), and surfactin (25 μM). When the mycoplasma cell concentration was varied from 104 to 108 CFU/ml, the MICs of enrofloxacin and globomycin increased while those of the three other molecules remained essentially constant. The minimal bactericidal concentration of enrofloxacin (0.8 μM) was also lower than those of the peptides (6.25 to 100 μM), but the latter killed the mycoplasma cells much faster than enrofloxacin (2 h versus 1 day). The use of the AMPs in association with enrofloxacin revealed synergistic effects with alamethicin and surfactin. Interestingly, the mycoplasma-killing activities of the two combinations enrofloxacin (MIC/2) plus alamethicin (MIC/4) and enrofloxacin (MIC/2) plus surfactin (MIC/16) were about 2 orders of magnitude higher than those of the three molecules used separately. These results support the interest devoted to AMPs as a novel class of antimicrobial agents and pinpoint their ability to potentiate the activities of conventional antibiotics, such as fluoroquinolones.

scholarly journals In Vitro Efficiency of Antimicrobial Peptides against Staphylococcal Pathogens Associated with Canine Pyoderma

Animals ◽  
2020 ◽  
Vol 10 (3) ◽  
pp. 470
Author(s):  
Małgorzata Jarosiewicz ◽  
Katarzyna Garbacz ◽  
Damian Neubauer ◽  
Wojciech Kamysz
Keyword(s):  
Antimicrobial Peptides ◽  
Antimicrobial Agents ◽  
Solid Phase ◽  
In Vitro Study ◽  
Phase Method ◽  
Promising Alternative ◽  
Microdilution Method ◽  
Broth Microdilution Method ◽  
Conventional Antibiotics

The emergence of staphylococcal canine pathogens resistant to multiple antimicrobial agents is a growing and urgent problem in veterinary practice. Antimicrobial peptides (AMPs) seem to be a promising alternative to conventional antibiotics. The aim of this in vitro study was to evaluate the antimicrobial activity of selected AMPs against pathogenic staphylococcal strains, including multidrug- and methicillin-resistant strains isolated from canine pyoderma cases. Seven antimicrobial peptides (aurein 1.2, CAMEL, citropin 1.1, protegrin-1, pexiganan, temporin A and uperin 3.6) synthesized by the 9-fluorenylmethoxycarbonyl (Fmoc) solid-phase method were tested. The minimal inhibitory and minimal bactericidal concentrations (MIC and MBC) were determined by the broth microdilution method. The study showed that analyzed AMPs exerted an extensive effect against canine pathogens, with the most active peptide being uperin 3.6. The tested AMPs were equally efficient against both resistant- and susceptible staphylococcal strains and were more efficient against Staphylococcus pseudintermedius than against Staphylococcus aureus strains. Our findings are particularly interesting from a clinical perspective, as they point to AMPs as potential therapeutic topical agents in canine pyoderma cases associated with antimicrobial resistance of staphylococci.

Recent Advances in the Development of Antimicrobial Peptides (AMPs): Attempts for Sustainable Medicine?

2018 ◽  
Vol 25 (21) ◽  
pp. 2503-2519 ◽  
Author(s):  
Anne Kokel ◽  
Marianna Torok
Keyword(s):  
Side Effects ◽  
Antimicrobial Peptides ◽  
Potential Drug ◽  
Green Technologies ◽  
Specific Antibodies ◽  
Structural Modifications ◽  
Drug Candidates ◽  
Induce Resistance ◽  
Conventional Antibiotics

Background: Since the first isolation of antimicrobial peptides (AMPs) they have attracted extensive interest in medicinal chemistry. However, only a few AMP-based drugs are currently available on the market. Despite their effectiveness, biodegradability, and versatile mode of action that is less likely to induce resistance compared to conventional antibiotics, AMPs suffer from major issues that need to be addressed to broaden their use. Notably, AMPs can lack selectivity leading to side effects and cytotoxicity, and also exhibit in vivo instability. Several strategies are being actively considered to overcome the limitations that restrain the success of AMPs. Methods: In the current work, recent strategies reported for improving AMPs in the context of drug design and delivery were surveyed, and also their possible impact on patients and the environment was assessed. Results: As a major advantage AMPs possess an easily tunable skeleton offering opportunities to improve their properties. Strategic structural modifications and the beneficial properties of cyclic or branched AMPs in term of stability have been reported. The conjugation of AMPs with nanoparticles has also been explored to increase their in vivo stability. Other techniques such as the coupling of AMPs with specific antibodies aim to increase the selectivity of the potential drug towards the target. These strategies were evaluated for their effect on the environment highlighting green technologies. Conclusion: Although further research is needed taking into account both environmental and human health consequences of novel AMPs, several of these compounds are promising drug candidates for use in sustainable medicine.

Antimicrobial Peptides: A Promising Avenue for Human Healthcare

2020 ◽  
Vol 21 (2) ◽  
pp. 90-96 ◽  
Author(s):  
Girish M. Bhopale
Keyword(s):  
Antimicrobial Peptides ◽  
Antimicrobial Peptide ◽  
Antimicrobial Agents ◽  
Current Status ◽  
Antimicrobial Drugs ◽  
Spectrum Activity ◽  
Low Levels ◽  
Human Healthcare ◽  
Broad Spectrum Activity ◽  
Promising Avenue

Antimicrobial drugs resistant microbes have been observed worldwide and therefore alternative development of antimicrobial peptides has gained interest in human healthcare. Enormous progress has been made in the development of antimicrobial peptide during the last decade due to major advantages of AMPs such as broad-spectrum activity and low levels of induced resistance over the current antimicrobial agents. This review briefly provides various categories of AMP, their physicochemical properties and mechanism of action which governs their penetration into microbial cell. Further, the recent information on current status of antimicrobial peptide development, their applications and perspective in human healthcare are also described.

scholarly journals Beneficial Impacts of Incorporating the Non-Natural Amino Acid Azulenyl-Alanine into the Trp-Rich Antimicrobial Peptide buCATHL4B

Biomolecules ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 421
Author(s):  
Areetha R. D’Souza ◽  
Matthew R. Necelis ◽  
Alona Kulesha ◽  
Gregory A. Caputo ◽  
Olga V. Makhlynets
Keyword(s):  
Amino Acid ◽  
Antimicrobial Peptides ◽  
Antimicrobial Peptide ◽  
Mechanism Of Action ◽  
Bactericidal Activity ◽  
Antimicrobial Agents ◽  
Human Cells ◽  
Side Chains ◽  
Natural Amino Acid ◽  
Proteolytic Stability

Antimicrobial peptides (AMPs) present a promising scaffold for the development of potent antimicrobial agents. Substitution of tryptophan by non-natural amino acid Azulenyl-Alanine (AzAla) would allow studying the mechanism of action of AMPs by using unique properties of this amino acid, such as ability to be excited separately from tryptophan in a multi-Trp AMPs and environmental insensitivity. In this work, we investigate the effect of Trp→AzAla substitution in antimicrobial peptide buCATHL4B (contains three Trp side chains). We found that antimicrobial and bactericidal activity of the original peptide was preserved, while cytocompatibility with human cells and proteolytic stability was improved. We envision that AzAla will find applications as a tool for studies of the mechanism of action of AMPs. In addition, incorporation of this non-natural amino acid into AMP sequences could enhance their application properties.

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

2019 ◽  
Vol 19 (1) ◽  
Author(s):  
Gabrielle Sherella Dijksteel ◽  
Peter H. Nibbering ◽  
Magda M. W. Ulrich ◽  
Esther Middelkoop ◽  
Bouke K. H. L. Boekema
Keyword(s):  
Antimicrobial Activity ◽  
Antimicrobial Peptides ◽  
Antimicrobial Agents ◽  
Ex Vivo ◽  
Residual Activity ◽  
Gram Negative Bacteria ◽  
Tissue Samples ◽  
Gram Negative ◽  
Viable Bacteria

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 had been exposed to various antimicrobial agents for 1 h were pipetted on top of Methicillin-resistant Staphylococcus aureus (MRSA) on agar plates to determine whether the antimicrobial agents display residual activity. To determine the optimal concentration of SPS for neutralization, antimicrobial agents were mixed with PBS or increasing doses of SPS in PBS (0.05–1% wt/v) and then 105 colony forming units (CFU)/mL MRSA were added. After 30 min incubation, the number of viable bacteria was assessed. Next, the in vitro efficacy of SAAP-148 against various gram-positive and gram-negative bacteria was determined using PBS or 0.05% (wt/v) SPS immediately after 30 min incubation of the mixture. Additionally, ex vivo excision wound models were inoculated with 105 CFU MRSA for 1 h and exposed to SAAP-148, pexiganan, chlorhexidine or PBS for 1 h. Subsequently, samples were homogenized in PBS or 0.05% (wt/v) SPS and the number of viable bacteria was assessed. 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, but not of SSD, Bactroban and Fucidin. Finally, SPS-neutralization in in vitro and ex vivo efficacy tests of SAAP-148, pexiganan and chlorhexidine against gram-positive and gram-negative bacteria resulted in significantly higher numbers of CFU compared to control samples without SPS-neutralization. Conclusions SPS was successfully used to neutralize residual activity of SAAP-148, pexiganan and chlorhexidine and this prevented an overestimation of their efficacy.

scholarly journals Bacterial Cellulose Containing Combinations of Antimicrobial Peptides with Various QQ Enzymes as a Prototype of an “Enhanced Antibacterial” Dressing: In Silico and In Vitro Data

Pharmaceutics ◽  
2020 ◽  
Vol 12 (12) ◽  
pp. 1155
Author(s):  
Aysel Aslanli ◽  
Ilya Lyagin ◽  
Nikolay Stepanov ◽  
Denis Presnov ◽  
Elena Efremenko
Keyword(s):  
Antimicrobial Peptides ◽  
Bacterial Cellulose ◽  
In Silico ◽  
Antimicrobial Agents ◽  
Penicillin Acylase ◽  
Signal Molecules ◽  
Bacterial Cells ◽  
Gram Positive ◽  
Gram Negative

To improve the action of already in use antibiotics or new antimicrobial agents against different bacteria, the development of effective combinations of antimicrobial peptides (AMPs) with enzymes that can quench the quorum (QQ) sensing of bacterial cells was undertaken. Enzymes hydrolyzing N-acyl homoserine lactones (AHLs) and peptides that are signal molecules of Gram-negative and Gram-positive bacterial cells, respectively, were estimated as “partners” for antibiotics and antimicrobial peptides in newly designed antimicrobial–enzymatic combinations. The molecular docking of six antimicrobial agents to the surface of 10 different QQ enzyme molecules was simulated in silico. This made it possible to choose the best variants among the target combinations. Further, bacterial cellulose (BC) was applied as a carrier for uploading such combinations to generally compose prototypes of effective dressing materials with morphology, providing good absorbance. The in vitro analysis of antibacterial activity of prepared BC samples confirmed the significantly enhanced efficiency of the action of AMPs (including polymyxin B and colistin, which are antibiotics of last resort) in combination with AHL-hydrolyzing enzymes (penicillin acylase and His6-tagged organophosphorus hydrolase) against both Gram-negative and Gram-positive cells.

scholarly journals Lipocalin 2: A New Antimicrobial in Mast Cells

2019 ◽  
Vol 20 (10) ◽  
pp. 2380 ◽  
Author(s):  
Yu-Ling Chang ◽  
Zhenping Wang ◽  
Satomi Igawa ◽  
Jae Eun Choi ◽  
Tyler Werbel ◽  
...  
Keyword(s):  
Mast Cells ◽  
Antimicrobial Peptides ◽  
Antimicrobial Peptide ◽  
Bacterial Growth ◽  
Immune Defense ◽  
Lipocalin 2 ◽  
Vitro Assay ◽  
E Coli ◽  
Sphingosine 1 Phosphate

Mast cells (MCs) play a significant role in the innate immune defense against bacterial infection through the release of cytokines and antimicrobial peptides. However, their antimicrobial function is still only partially described. We therefore hypothesized that MCs express additional antimicrobial peptides. In this study, we used FANTOM 5 transcriptome data to identify for the first time that MCs express lipocalin 2 (LCN2), a known inhibitor of bacterial growth. Using MCs derived from mice which were deficient in LCN2, we showed that this antimicrobial peptide is an important component of the MCs’ antimicrobial activity against Escherichia coli (E. coli). Since sphingosine-1-phosphate receptors (S1PRs) on MCs are known to regulate their function during infections, we hypothesized that S1P could activate LCN2 production in MCs. Using an in vitro assay, we demonstrated that S1P enhances MCs antimicrobial peptide production and increases the capacity of MCs to directly kill S. aureus and E. coli via an LCN2 release. In conclusion, we showed that LCN2 is expressed by MCs and plays a role in their capacity to inhibit bacterial growth.

scholarly journals SSD1 Is Integral to Host Defense Peptide Resistance in Candida albicans

2008 ◽  
Vol 7 (8) ◽  
pp. 1318-1327 ◽  
Author(s):  
Kimberly D. Gank ◽  
Michael R. Yeaman ◽  
Satoshi Kojima ◽  
Nannette Y. Yount ◽  
Hyunsook Park ◽  
...  
Keyword(s):  
Candida Albicans ◽  
Antimicrobial Peptides ◽  
Antimicrobial Peptide ◽  
Host Defense ◽  
Genomic Library ◽  
Inflammatory Responses ◽  
Host Defense Peptides ◽  
Antimicrobial Peptide Resistance ◽  
Null Mutants

ABSTRACT Candida albicans is usually a harmless human commensal. Because inflammatory responses are not normally induced by colonization, antimicrobial peptides are likely integral to first-line host defense against invasive candidiasis. Thus, C. albicans must have mechanisms to tolerate or circumvent molecular effectors of innate immunity and thereby colonize human tissues. Prior studies demonstrated that an antimicrobial peptide-resistant strain of C. albicans, 36082R, is hypervirulent in animal models versus its susceptible counterpart (36082S). The current study aimed to identify a genetic basis for antimicrobial peptide resistance in C. albicans. Screening of a C. albicans genomic library identified SSD1 as capable of conferring peptide resistance to a susceptible surrogate, Saccharomyces cerevisiae. Sequencing confirmed that the predicted translation products of 36082S and 36082R SSD1 genes were identical. However, Northern analyses corroborated that SSD1 is expressed at higher levels in 36082R than in 36082S. In isogenic backgrounds, ssd1Δ/ssd1Δ null mutants were significantly more susceptible to antimicrobial peptides than parental strains but had equivalent susceptibilities to nonpeptide stressors. Moreover, SSD1 complementation of ssd1Δ/ssd1Δ mutants restored parental antimicrobial peptide resistance phenotypes, and overexpression of SSD1 conferred enhanced peptide resistance. Consistent with these in vitro findings, ssd1 null mutants were significantly less virulent in a murine model of disseminated candidiasis than were their parental or complemented strains. Collectively, these results indicate that SSD1 is integral to C. albicans resistance to host defense peptides, a phenotype that appears to enhance the virulence of this organism in vivo.

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