Outer Membrane Vesicles Released From Aeromonas Strains Are Involved in the Biofilm Formation
Aeromonas spp. are Gram-negative rod-shaped bacteria ubiquitously distributed in diverse water sources. Several Aeromonas spp. are known as human and fish pathogens. Recently, attention has been focused on the relationship between bacterial biofilm formation and pathogenicity or drug resistance. How...
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| Format: | Article |
| Language: | English |
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Frontiers Media S.A.
2021-01-01
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| Series: | Frontiers in Microbiology |
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| Online Access: | https://www.frontiersin.org/articles/10.3389/fmicb.2020.613650/full |
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| author | Soshi Seike Hidetomo Kobayashi Mitsunobu Ueda Eizo Takahashi Keinosuke Okamoto Hiroyasu Yamanaka |
| author_facet | Soshi Seike Hidetomo Kobayashi Mitsunobu Ueda Eizo Takahashi Keinosuke Okamoto Hiroyasu Yamanaka |
| author_sort | Soshi Seike |
| collection | DOAJ |
| description | Aeromonas spp. are Gram-negative rod-shaped bacteria ubiquitously distributed in diverse water sources. Several Aeromonas spp. are known as human and fish pathogens. Recently, attention has been focused on the relationship between bacterial biofilm formation and pathogenicity or drug resistance. However, there have been few reports on biofilm formation by Aeromonas. This study is the first to examine the in vitro formation and components of the biofilm of several Aeromonas clinical and environmental strains. A biofilm formation assay using 1% crystal violet on a polystyrene plate revealed that most Aeromonas strains used in this study formed biofilms but one strain did not. Analysis of the basic components contained in the biofilms formed by Aeromonas strains confirmed that they contained polysaccharides containing GlcNAc, extracellular nucleic acids, and proteins, as previously reported for the biofilms of other bacterial species. Among these components, we focused on several proteins fractionated by SDS-PAGE and determined their amino acid sequences. The results showed that some proteins existing in the Aeromonas biofilms have amino acid sequences homologous to functional proteins present in the outer membrane of Gram-negative bacteria. This result suggests that outer membrane components may affect the biofilm formation of Aeromonas strains. It is known that Gram-negative bacteria often release extracellular membrane vesicles from the outer membrane, so we think that the outer membrane-derived proteins found in the Aeromonas biofilms may be derived from such membrane vesicles. To examine this idea, we next investigated the ability of Aeromonas strains to form outer membrane vesicles (OMVs). Electron microscopic analysis revealed that most Aeromonas strains released OMVs outside the cells. Finally, we purified OMVs from several Aeromonas strains and examined their effect on the biofilm formation. We found that the addition of OMVs dose-dependently promoted biofilm formation, except for one strain that did not form biofilms. These results suggest that the OMVs released from the bacterial cells are closely related to the biofilm formation of Aeromonas strains. |
| first_indexed | 2024-12-20T12:20:47Z |
| format | Article |
| id | doaj.art-3b1e1f500ed549beb596ff4da2e06065 |
| institution | Directory Open Access Journal |
| issn | 1664-302X |
| language | English |
| last_indexed | 2024-12-20T12:20:47Z |
| publishDate | 2021-01-01 |
| publisher | Frontiers Media S.A. |
| record_format | Article |
| series | Frontiers in Microbiology |
| spelling | doaj.art-3b1e1f500ed549beb596ff4da2e060652022-12-21T19:41:00ZengFrontiers Media S.A.Frontiers in Microbiology1664-302X2021-01-011110.3389/fmicb.2020.613650613650Outer Membrane Vesicles Released From Aeromonas Strains Are Involved in the Biofilm FormationSoshi Seike0Hidetomo Kobayashi1Mitsunobu Ueda2Eizo Takahashi3Keinosuke Okamoto4Hiroyasu Yamanaka5Laboratory of Molecular Microbiological Science, Faculty of Pharmaceutical Sciences, Hiroshima International University, Hiroshima, JapanLaboratory of Molecular Microbiological Science, Faculty of Pharmaceutical Sciences, Hiroshima International University, Hiroshima, JapanLaboratory of Molecular Microbiological Science, Faculty of Pharmaceutical Sciences, Hiroshima International University, Hiroshima, JapanLaboratory of Medical Microbiology, Department of Health Pharmacy, Yokohama University of Pharmacy, Yokohama, JapanCollaborative Research Center of Okayama University for Infectious Diseases in India, National Institute of Cholera and Enteric Diseases, Kolkata, IndiaLaboratory of Molecular Microbiological Science, Faculty of Pharmaceutical Sciences, Hiroshima International University, Hiroshima, JapanAeromonas spp. are Gram-negative rod-shaped bacteria ubiquitously distributed in diverse water sources. Several Aeromonas spp. are known as human and fish pathogens. Recently, attention has been focused on the relationship between bacterial biofilm formation and pathogenicity or drug resistance. However, there have been few reports on biofilm formation by Aeromonas. This study is the first to examine the in vitro formation and components of the biofilm of several Aeromonas clinical and environmental strains. A biofilm formation assay using 1% crystal violet on a polystyrene plate revealed that most Aeromonas strains used in this study formed biofilms but one strain did not. Analysis of the basic components contained in the biofilms formed by Aeromonas strains confirmed that they contained polysaccharides containing GlcNAc, extracellular nucleic acids, and proteins, as previously reported for the biofilms of other bacterial species. Among these components, we focused on several proteins fractionated by SDS-PAGE and determined their amino acid sequences. The results showed that some proteins existing in the Aeromonas biofilms have amino acid sequences homologous to functional proteins present in the outer membrane of Gram-negative bacteria. This result suggests that outer membrane components may affect the biofilm formation of Aeromonas strains. It is known that Gram-negative bacteria often release extracellular membrane vesicles from the outer membrane, so we think that the outer membrane-derived proteins found in the Aeromonas biofilms may be derived from such membrane vesicles. To examine this idea, we next investigated the ability of Aeromonas strains to form outer membrane vesicles (OMVs). Electron microscopic analysis revealed that most Aeromonas strains released OMVs outside the cells. Finally, we purified OMVs from several Aeromonas strains and examined their effect on the biofilm formation. We found that the addition of OMVs dose-dependently promoted biofilm formation, except for one strain that did not form biofilms. These results suggest that the OMVs released from the bacterial cells are closely related to the biofilm formation of Aeromonas strains.https://www.frontiersin.org/articles/10.3389/fmicb.2020.613650/fullAeromonasbiofilmouter membrane vesicles (OMVs)extracellular polymeric substances (EPS)extracellular matrix (ECM) |
| spellingShingle | Soshi Seike Hidetomo Kobayashi Mitsunobu Ueda Eizo Takahashi Keinosuke Okamoto Hiroyasu Yamanaka Outer Membrane Vesicles Released From Aeromonas Strains Are Involved in the Biofilm Formation Frontiers in Microbiology Aeromonas biofilm outer membrane vesicles (OMVs) extracellular polymeric substances (EPS) extracellular matrix (ECM) |
| title | Outer Membrane Vesicles Released From Aeromonas Strains Are Involved in the Biofilm Formation |
| title_full | Outer Membrane Vesicles Released From Aeromonas Strains Are Involved in the Biofilm Formation |
| title_fullStr | Outer Membrane Vesicles Released From Aeromonas Strains Are Involved in the Biofilm Formation |
| title_full_unstemmed | Outer Membrane Vesicles Released From Aeromonas Strains Are Involved in the Biofilm Formation |
| title_short | Outer Membrane Vesicles Released From Aeromonas Strains Are Involved in the Biofilm Formation |
| title_sort | outer membrane vesicles released from aeromonas strains are involved in the biofilm formation |
| topic | Aeromonas biofilm outer membrane vesicles (OMVs) extracellular polymeric substances (EPS) extracellular matrix (ECM) |
| url | https://www.frontiersin.org/articles/10.3389/fmicb.2020.613650/full |
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