Activity of Specialized Biomolecules against Gram-Positive and Gram-Negative Bacteria
The increased resistance of bacteria against conventional pharmaceutical solutions, the antibiotics, has raised serious health concerns. This has stimulated interest in the development of bio-based therapeutics with limited resistance, namely, essential oils (EOs) or antimicrobial peptides (AMPs). T...
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| Format: | Article |
| Language: | English |
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MDPI AG
2020-06-01
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| Series: | Antibiotics |
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| Online Access: | https://www.mdpi.com/2079-6382/9/6/314 |
| _version_ | 1797565688559173632 |
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| author | Tânia D. Tavares Joana C. Antunes Jorge Padrão Ana I. Ribeiro Andrea Zille M. Teresa P. Amorim Fernando Ferreira Helena P. Felgueiras |
| author_facet | Tânia D. Tavares Joana C. Antunes Jorge Padrão Ana I. Ribeiro Andrea Zille M. Teresa P. Amorim Fernando Ferreira Helena P. Felgueiras |
| author_sort | Tânia D. Tavares |
| collection | DOAJ |
| description | The increased resistance of bacteria against conventional pharmaceutical solutions, the antibiotics, has raised serious health concerns. This has stimulated interest in the development of bio-based therapeutics with limited resistance, namely, essential oils (EOs) or antimicrobial peptides (AMPs). This study envisaged the evaluation of the antimicrobial efficacy of selected biomolecules, namely LL37, pexiganan, tea tree oil (TTO), cinnamon leaf oil (CLO) and niaouli oil (NO), against four bacteria commonly associated to nosocomial infections: <i>Staphylococcus aureus</i>, <i>Staphylococcus epidermidis</i>, <i>Escherichia coli</i> and <i>Pseudomonas aeruginosa</i>. The antibiotic vancomycin and silver nanoparticles (AgNPs) were used as control compounds for comparison purposes. The biomolecules were initially screened for their antibacterial efficacy using the agar-diffusion test, followed by the determination of minimal inhibitory concentrations (MICs), kill-time kinetics and the evaluation of the cell morphology upon 24 h exposure. All agents were effective against the selected bacteria. Interestingly, the AgNPs required a higher concentration (4000–1250 μg/mL) to induce the same effects as the AMPs (500–7.8 μg/mL) or EOs (365.2–19.7 μg/mL). Pexiganan and CLO were the most effective biomolecules, requiring lower concentrations to kill both Gram-positive and Gram-negative bacteria (62.5–7.8 μg/mL and 39.3–19.7 μg/mL, respectively), within a short period of time (averaging 2 h 15 min for all bacteria). Most biomolecules apparently disrupted the bacteria membrane stability due to the observed cell morphology deformation and by effecting on the intracellular space. AMPs were observed to induce morphological deformations and cellular content release, while EOs were seen to split and completely envelope bacteria. Data unraveled more of the potential of these new biomolecules as replacements for the conventional antibiotics and allowed us to take a step forward in the understanding of their mechanisms of action against infection-related bacteria. |
| first_indexed | 2024-03-10T19:16:35Z |
| format | Article |
| id | doaj.art-041d8ebfbe2e4767b76c69e4ea50557c |
| institution | Directory Open Access Journal |
| issn | 2079-6382 |
| language | English |
| last_indexed | 2024-03-10T19:16:35Z |
| publishDate | 2020-06-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Antibiotics |
| spelling | doaj.art-041d8ebfbe2e4767b76c69e4ea50557c2023-11-20T03:19:08ZengMDPI AGAntibiotics2079-63822020-06-019631410.3390/antibiotics9060314Activity of Specialized Biomolecules against Gram-Positive and Gram-Negative BacteriaTânia D. Tavares0Joana C. Antunes1Jorge Padrão2Ana I. Ribeiro3Andrea Zille4M. Teresa P. Amorim5Fernando Ferreira6Helena P. Felgueiras7Centre for Textile Science and Technology (2C2T), Department of Textile Engineering, University of Minho, Campus of Azurém, 4800-058 Guimarães, PortugalCentre for Textile Science and Technology (2C2T), Department of Textile Engineering, University of Minho, Campus of Azurém, 4800-058 Guimarães, PortugalCentre for Textile Science and Technology (2C2T), Department of Textile Engineering, University of Minho, Campus of Azurém, 4800-058 Guimarães, PortugalCentre for Textile Science and Technology (2C2T), Department of Textile Engineering, University of Minho, Campus of Azurém, 4800-058 Guimarães, PortugalCentre for Textile Science and Technology (2C2T), Department of Textile Engineering, University of Minho, Campus of Azurém, 4800-058 Guimarães, PortugalCentre for Textile Science and Technology (2C2T), Department of Textile Engineering, University of Minho, Campus of Azurém, 4800-058 Guimarães, PortugalCentre for Textile Science and Technology (2C2T), Department of Textile Engineering, University of Minho, Campus of Azurém, 4800-058 Guimarães, PortugalCentre for Textile Science and Technology (2C2T), Department of Textile Engineering, University of Minho, Campus of Azurém, 4800-058 Guimarães, PortugalThe increased resistance of bacteria against conventional pharmaceutical solutions, the antibiotics, has raised serious health concerns. This has stimulated interest in the development of bio-based therapeutics with limited resistance, namely, essential oils (EOs) or antimicrobial peptides (AMPs). This study envisaged the evaluation of the antimicrobial efficacy of selected biomolecules, namely LL37, pexiganan, tea tree oil (TTO), cinnamon leaf oil (CLO) and niaouli oil (NO), against four bacteria commonly associated to nosocomial infections: <i>Staphylococcus aureus</i>, <i>Staphylococcus epidermidis</i>, <i>Escherichia coli</i> and <i>Pseudomonas aeruginosa</i>. The antibiotic vancomycin and silver nanoparticles (AgNPs) were used as control compounds for comparison purposes. The biomolecules were initially screened for their antibacterial efficacy using the agar-diffusion test, followed by the determination of minimal inhibitory concentrations (MICs), kill-time kinetics and the evaluation of the cell morphology upon 24 h exposure. All agents were effective against the selected bacteria. Interestingly, the AgNPs required a higher concentration (4000–1250 μg/mL) to induce the same effects as the AMPs (500–7.8 μg/mL) or EOs (365.2–19.7 μg/mL). Pexiganan and CLO were the most effective biomolecules, requiring lower concentrations to kill both Gram-positive and Gram-negative bacteria (62.5–7.8 μg/mL and 39.3–19.7 μg/mL, respectively), within a short period of time (averaging 2 h 15 min for all bacteria). Most biomolecules apparently disrupted the bacteria membrane stability due to the observed cell morphology deformation and by effecting on the intracellular space. AMPs were observed to induce morphological deformations and cellular content release, while EOs were seen to split and completely envelope bacteria. Data unraveled more of the potential of these new biomolecules as replacements for the conventional antibiotics and allowed us to take a step forward in the understanding of their mechanisms of action against infection-related bacteria.https://www.mdpi.com/2079-6382/9/6/314antimicrobial peptidesessential oilsminimum inhibitory concentrationbactericidalnosocomial |
| spellingShingle | Tânia D. Tavares Joana C. Antunes Jorge Padrão Ana I. Ribeiro Andrea Zille M. Teresa P. Amorim Fernando Ferreira Helena P. Felgueiras Activity of Specialized Biomolecules against Gram-Positive and Gram-Negative Bacteria Antibiotics antimicrobial peptides essential oils minimum inhibitory concentration bactericidal nosocomial |
| title | Activity of Specialized Biomolecules against Gram-Positive and Gram-Negative Bacteria |
| title_full | Activity of Specialized Biomolecules against Gram-Positive and Gram-Negative Bacteria |
| title_fullStr | Activity of Specialized Biomolecules against Gram-Positive and Gram-Negative Bacteria |
| title_full_unstemmed | Activity of Specialized Biomolecules against Gram-Positive and Gram-Negative Bacteria |
| title_short | Activity of Specialized Biomolecules against Gram-Positive and Gram-Negative Bacteria |
| title_sort | activity of specialized biomolecules against gram positive and gram negative bacteria |
| topic | antimicrobial peptides essential oils minimum inhibitory concentration bactericidal nosocomial |
| url | https://www.mdpi.com/2079-6382/9/6/314 |
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