Comparative analysis of selected methods for the assessment of antimicrobial and membrane-permeabilizing activity: a case study for lactoferricin derived peptides
Growing concerns about bacterial resistance to antibiotics have prompted the development of alternative therapies like those based on cationic antimicrobial peptides (APs). These compounds not only are bactericidal by themselves but also enhance the activity of antibiotics. Stud...
| Main Authors: | , , , , , , , , , |
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| Format: | info:eu-repo/semantics/article |
| Language: | eng |
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BioMed Central
2013
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| Online Access: | https://hdl.handle.net/10171/27572 |
| _version_ | 1793400053578072064 |
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| author | Sánchez-Gómez, S. (Susana) Lamata, M. (M.) Leiva, J. (José) Blondelle, S.E. (Sylvie E.) Jerala, R. (Roman) Andrä, J. (Jörg) Brandenburg, K. (Klaus) Lohner, K. (Karl) Moriyon, I. (Ignacio) Martinez-de-Tejada, G. (Guillermo) |
| author_facet | Sánchez-Gómez, S. (Susana) Lamata, M. (M.) Leiva, J. (José) Blondelle, S.E. (Sylvie E.) Jerala, R. (Roman) Andrä, J. (Jörg) Brandenburg, K. (Klaus) Lohner, K. (Karl) Moriyon, I. (Ignacio) Martinez-de-Tejada, G. (Guillermo) |
| author_sort | Sánchez-Gómez, S. (Susana) |
| collection | DSpace |
| description | Growing concerns about bacterial resistance to antibiotics have
prompted the development of alternative therapies like those based on cationic
antimicrobial peptides (APs). These compounds not only are bactericidal by
themselves but also enhance the activity of antibiotics. Studies focused on the
systematic characterization of APs are hampered by the lack of standard
guidelines for testing these compounds. We investigated whether the information
provided by methods commonly used for the biological characterization of APs is
comparable, as it is often assumed. For this purpose, we determined the
bacteriostatic, bactericidal, and permeability-increasing activity of synthetic
peptides (n = 57; 9-13 amino acid residues in length) analogous to the
lipopolysaccharide-binding region of human lactoferricin by a number of the most
frequently used methods and carried out a comparative analysis. RESULTS: While
the minimum inhibitory concentration determined by an automated
turbidimetry-based system (Bioscreen) or by conventional broth microdilution
methods did not differ significantly, bactericidal activity measured under static
conditions in a low-ionic strength solvent resulted in a vast overestimation of
antimicrobial activity. Under these conditions the degree of antagonism between
the peptides and the divalent cations differed greatly depending on the bacterial
strain tested. In contrast, the bioactivity of peptides was not affected by the
type of plasticware (polypropylene vs. polystyrene). Susceptibility testing of
APs using cation adjusted Mueller-Hinton was the most stringent screening method,
although it may overlook potentially interesting peptides. Permeability assays
based on sensitization to hydrophobic antibiotics provided overall information
analogous - though not quantitatively comparable- to that of tests based on the
uptake of hydrophobic fluorescent probes. CONCLUSION: We demonstrate that subtle
changes in methods for testing cationic peptides bring about marked differences
in activity. Our results show that careful selection of the test strains for
susceptibility testing and for screenings of antibiotic-sensitizing activity is
of critical importance. A number of peptides proved to have potent
permeability-increasing activity at subinhibitory concentrations and efficiently
sensitized Pseudomonas aeruginosa both to hydrophilic and hydrophobic
antibiotics. |
| format | info:eu-repo/semantics/article |
| id | oai:dadun.unav.edu:10171-27572 |
| institution | Universidad de Navarra |
| language | eng |
| publishDate | 2013 |
| publisher | BioMed Central |
| record_format | dspace |
| spelling | oai:dadun.unav.edu:10171-275722020-12-02T17:12:34Z Comparative analysis of selected methods for the assessment of antimicrobial and membrane-permeabilizing activity: a case study for lactoferricin derived peptides Sánchez-Gómez, S. (Susana) Lamata, M. (M.) Leiva, J. (José) Blondelle, S.E. (Sylvie E.) Jerala, R. (Roman) Andrä, J. (Jörg) Brandenburg, K. (Klaus) Lohner, K. (Karl) Moriyon, I. (Ignacio) Martinez-de-Tejada, G. (Guillermo) Anti-Bacterial Agents/pharmacology Antimicrobial Cationic Peptides/pharmacology Bacteria/drug effects/growth & development Growing concerns about bacterial resistance to antibiotics have prompted the development of alternative therapies like those based on cationic antimicrobial peptides (APs). These compounds not only are bactericidal by themselves but also enhance the activity of antibiotics. Studies focused on the systematic characterization of APs are hampered by the lack of standard guidelines for testing these compounds. We investigated whether the information provided by methods commonly used for the biological characterization of APs is comparable, as it is often assumed. For this purpose, we determined the bacteriostatic, bactericidal, and permeability-increasing activity of synthetic peptides (n = 57; 9-13 amino acid residues in length) analogous to the lipopolysaccharide-binding region of human lactoferricin by a number of the most frequently used methods and carried out a comparative analysis. RESULTS: While the minimum inhibitory concentration determined by an automated turbidimetry-based system (Bioscreen) or by conventional broth microdilution methods did not differ significantly, bactericidal activity measured under static conditions in a low-ionic strength solvent resulted in a vast overestimation of antimicrobial activity. Under these conditions the degree of antagonism between the peptides and the divalent cations differed greatly depending on the bacterial strain tested. In contrast, the bioactivity of peptides was not affected by the type of plasticware (polypropylene vs. polystyrene). Susceptibility testing of APs using cation adjusted Mueller-Hinton was the most stringent screening method, although it may overlook potentially interesting peptides. Permeability assays based on sensitization to hydrophobic antibiotics provided overall information analogous - though not quantitatively comparable- to that of tests based on the uptake of hydrophobic fluorescent probes. CONCLUSION: We demonstrate that subtle changes in methods for testing cationic peptides bring about marked differences in activity. Our results show that careful selection of the test strains for susceptibility testing and for screenings of antibiotic-sensitizing activity is of critical importance. A number of peptides proved to have potent permeability-increasing activity at subinhibitory concentrations and efficiently sensitized Pseudomonas aeruginosa both to hydrophilic and hydrophobic antibiotics. 2013-01-08T17:28:10Z 2013-01-08T17:28:10Z 2008 info:eu-repo/semantics/article https://hdl.handle.net/10171/27572 eng http://www.biomedcentral.com/content/pdf/1471-2180-8-196.pdf info:eu-repo/semantics/openAccess application/pdf BioMed Central |
| spellingShingle | Anti-Bacterial Agents/pharmacology Antimicrobial Cationic Peptides/pharmacology Bacteria/drug effects/growth & development Sánchez-Gómez, S. (Susana) Lamata, M. (M.) Leiva, J. (José) Blondelle, S.E. (Sylvie E.) Jerala, R. (Roman) Andrä, J. (Jörg) Brandenburg, K. (Klaus) Lohner, K. (Karl) Moriyon, I. (Ignacio) Martinez-de-Tejada, G. (Guillermo) Comparative analysis of selected methods for the assessment of antimicrobial and membrane-permeabilizing activity: a case study for lactoferricin derived peptides |
| title | Comparative analysis of selected methods for the assessment of antimicrobial and membrane-permeabilizing activity: a case study for lactoferricin derived peptides |
| title_full | Comparative analysis of selected methods for the assessment of antimicrobial and membrane-permeabilizing activity: a case study for lactoferricin derived peptides |
| title_fullStr | Comparative analysis of selected methods for the assessment of antimicrobial and membrane-permeabilizing activity: a case study for lactoferricin derived peptides |
| title_full_unstemmed | Comparative analysis of selected methods for the assessment of antimicrobial and membrane-permeabilizing activity: a case study for lactoferricin derived peptides |
| title_short | Comparative analysis of selected methods for the assessment of antimicrobial and membrane-permeabilizing activity: a case study for lactoferricin derived peptides |
| title_sort | comparative analysis of selected methods for the assessment of antimicrobial and membrane-permeabilizing activity: a case study for lactoferricin derived peptides |
| topic | Anti-Bacterial Agents/pharmacology Antimicrobial Cationic Peptides/pharmacology Bacteria/drug effects/growth & development |
| url | https://hdl.handle.net/10171/27572 |
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