Iron is a signal for Stenotrophomonas maltophilia biofilm formation, oxidative stress response, OMPs expression and virulence
Stenotrophomonas maltophilia is an emerging nosocomial pathogen. In many bacteria iron availability regulates, trough the Fur system, not only iron homeostasis but also virulence. The aim of this work was to assess the role of iron on S. maltophilia biofilm formation, EPS production, oxidative stres...
| Main Authors: | , , , |
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| Format: | Article |
| Language: | English |
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Frontiers Media S.A.
2015-09-01
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| Series: | Frontiers in Microbiology |
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| Online Access: | http://journal.frontiersin.org/Journal/10.3389/fmicb.2015.00926/full |
| _version_ | 1811335311468265472 |
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| author | Carlos Adrian Garcia Eliana Sabrina Alcaraz Mirta Aurora Franco Beatriz Noemí Passerini De Rossi |
| author_facet | Carlos Adrian Garcia Eliana Sabrina Alcaraz Mirta Aurora Franco Beatriz Noemí Passerini De Rossi |
| author_sort | Carlos Adrian Garcia |
| collection | DOAJ |
| description | Stenotrophomonas maltophilia is an emerging nosocomial pathogen. In many bacteria iron availability regulates, trough the Fur system, not only iron homeostasis but also virulence. The aim of this work was to assess the role of iron on S. maltophilia biofilm formation, EPS production, oxidative stress response, OMPs regulation, quorum sensing (QS), and virulence. Studies were done on K279 and its isogenic fur mutant F60 cultured in the presence or absence of dipyridyl. This is the first report of spontaneous fur mutants obtained in S. maltophilia. F60 produced higher amounts of biofilms than K279a and CLSM analysis demonstrated improved adherence and biofilm organization. Under iron restricted conditions, K279a produced biofilms with more biomass and enhanced thickness. In addition, F60 produced higher amounts of EPS than K279a but with a similar composition, as revealed by ATR-FTIR spectroscopy. With respect to the oxidative stress response, MnSOD was the only SOD isoenzyme detected in K279a. F60 presented higher SOD activity than the wt strain in planktonic and biofilm cultures, and iron deprivation increased K279a SOD activity. Under iron starvation, SDS-PAGE profile from K279a presented two iron-repressed proteins. Mass spectrometry analysis revealed homology with FepA and another putative TonB-dependent siderophore receptor of K279a. In silico analysis allowed the detection of potential Fur boxes in the respective coding genes. K279a encodes the QS diffusible signal factor (DSF). Under iron restriction K279a produced higher amounts of DSF than under iron rich condition. Finally, F60 was more virulent than K279a in the Galleria mellonella killing assay. These results put in evidence that iron levels regulate, likely through the Fur system, S. maltophilia biofilm formation, oxidative stress response, OMPs expression, DSF production and virulence. |
| first_indexed | 2024-04-13T17:22:15Z |
| format | Article |
| id | doaj.art-6394700698c040868d3260c0d70391fd |
| institution | Directory Open Access Journal |
| issn | 1664-302X |
| language | English |
| last_indexed | 2024-04-13T17:22:15Z |
| publishDate | 2015-09-01 |
| publisher | Frontiers Media S.A. |
| record_format | Article |
| series | Frontiers in Microbiology |
| spelling | doaj.art-6394700698c040868d3260c0d70391fd2022-12-22T02:37:56ZengFrontiers Media S.A.Frontiers in Microbiology1664-302X2015-09-01610.3389/fmicb.2015.00926159746Iron is a signal for Stenotrophomonas maltophilia biofilm formation, oxidative stress response, OMPs expression and virulenceCarlos Adrian Garcia0Eliana Sabrina Alcaraz1Mirta Aurora Franco2Beatriz Noemí Passerini De Rossi3Universidad de Buenos AiresUniversidad de Buenos AiresUniversidad de Buenos AiresUniversidad de Buenos AiresStenotrophomonas maltophilia is an emerging nosocomial pathogen. In many bacteria iron availability regulates, trough the Fur system, not only iron homeostasis but also virulence. The aim of this work was to assess the role of iron on S. maltophilia biofilm formation, EPS production, oxidative stress response, OMPs regulation, quorum sensing (QS), and virulence. Studies were done on K279 and its isogenic fur mutant F60 cultured in the presence or absence of dipyridyl. This is the first report of spontaneous fur mutants obtained in S. maltophilia. F60 produced higher amounts of biofilms than K279a and CLSM analysis demonstrated improved adherence and biofilm organization. Under iron restricted conditions, K279a produced biofilms with more biomass and enhanced thickness. In addition, F60 produced higher amounts of EPS than K279a but with a similar composition, as revealed by ATR-FTIR spectroscopy. With respect to the oxidative stress response, MnSOD was the only SOD isoenzyme detected in K279a. F60 presented higher SOD activity than the wt strain in planktonic and biofilm cultures, and iron deprivation increased K279a SOD activity. Under iron starvation, SDS-PAGE profile from K279a presented two iron-repressed proteins. Mass spectrometry analysis revealed homology with FepA and another putative TonB-dependent siderophore receptor of K279a. In silico analysis allowed the detection of potential Fur boxes in the respective coding genes. K279a encodes the QS diffusible signal factor (DSF). Under iron restriction K279a produced higher amounts of DSF than under iron rich condition. Finally, F60 was more virulent than K279a in the Galleria mellonella killing assay. These results put in evidence that iron levels regulate, likely through the Fur system, S. maltophilia biofilm formation, oxidative stress response, OMPs expression, DSF production and virulence.http://journal.frontiersin.org/Journal/10.3389/fmicb.2015.00926/fullBiofilmsIronStenotrophomonas maltophiliaVirulenceFuroxidative stress response |
| spellingShingle | Carlos Adrian Garcia Eliana Sabrina Alcaraz Mirta Aurora Franco Beatriz Noemí Passerini De Rossi Iron is a signal for Stenotrophomonas maltophilia biofilm formation, oxidative stress response, OMPs expression and virulence Frontiers in Microbiology Biofilms Iron Stenotrophomonas maltophilia Virulence Fur oxidative stress response |
| title | Iron is a signal for Stenotrophomonas maltophilia biofilm formation, oxidative stress response, OMPs expression and virulence |
| title_full | Iron is a signal for Stenotrophomonas maltophilia biofilm formation, oxidative stress response, OMPs expression and virulence |
| title_fullStr | Iron is a signal for Stenotrophomonas maltophilia biofilm formation, oxidative stress response, OMPs expression and virulence |
| title_full_unstemmed | Iron is a signal for Stenotrophomonas maltophilia biofilm formation, oxidative stress response, OMPs expression and virulence |
| title_short | Iron is a signal for Stenotrophomonas maltophilia biofilm formation, oxidative stress response, OMPs expression and virulence |
| title_sort | iron is a signal for stenotrophomonas maltophilia biofilm formation oxidative stress response omps expression and virulence |
| topic | Biofilms Iron Stenotrophomonas maltophilia Virulence Fur oxidative stress response |
| url | http://journal.frontiersin.org/Journal/10.3389/fmicb.2015.00926/full |
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