Cargando…

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, through 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 stre...

Descripción completa

Detalles Bibliográficos
Autores principales: García, Carlos A., Alcaraz, Eliana S., Franco, Mirta A., Passerini de Rossi, Beatriz N.
Formato: Online Artículo Texto
Lenguaje:English
Publicado: Frontiers Media S.A. 2015
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4559654/
https://www.ncbi.nlm.nih.gov/pubmed/26388863
http://dx.doi.org/10.3389/fmicb.2015.00926
_version_ 1782388812477890560
author García, Carlos A.
Alcaraz, Eliana S.
Franco, Mirta A.
Passerini de Rossi, Beatriz N.
author_facet García, Carlos A.
Alcaraz, Eliana S.
Franco, Mirta A.
Passerini de Rossi, Beatriz N.
author_sort García, Carlos A.
collection PubMed
description Stenotrophomonas maltophilia is an emerging nosocomial pathogen. In many bacteria iron availability regulates, through 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 K279a 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.
format Online
Article
Text
id pubmed-4559654
institution National Center for Biotechnology Information
language English
publishDate 2015
publisher Frontiers Media S.A.
record_format MEDLINE/PubMed
spelling pubmed-45596542015-09-18 Iron is a signal for Stenotrophomonas maltophilia biofilm formation, oxidative stress response, OMPs expression, and virulence García, Carlos A. Alcaraz, Eliana S. Franco, Mirta A. Passerini de Rossi, Beatriz N. Front Microbiol Public Health Stenotrophomonas maltophilia is an emerging nosocomial pathogen. In many bacteria iron availability regulates, through 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 K279a 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. Frontiers Media S.A. 2015-09-04 /pmc/articles/PMC4559654/ /pubmed/26388863 http://dx.doi.org/10.3389/fmicb.2015.00926 Text en Copyright © 2015 García, Alcaraz, Franco and Passerini de Rossi. http://creativecommons.org/licenses/by/4.0/ This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) or licensor are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.
spellingShingle Public Health
García, Carlos A.
Alcaraz, Eliana S.
Franco, Mirta A.
Passerini de Rossi, Beatriz N.
Iron is a signal for Stenotrophomonas maltophilia biofilm formation, oxidative stress response, OMPs expression, and virulence
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 Public Health
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4559654/
https://www.ncbi.nlm.nih.gov/pubmed/26388863
http://dx.doi.org/10.3389/fmicb.2015.00926
work_keys_str_mv AT garciacarlosa ironisasignalforstenotrophomonasmaltophiliabiofilmformationoxidativestressresponseompsexpressionandvirulence
AT alcarazelianas ironisasignalforstenotrophomonasmaltophiliabiofilmformationoxidativestressresponseompsexpressionandvirulence
AT francomirtaa ironisasignalforstenotrophomonasmaltophiliabiofilmformationoxidativestressresponseompsexpressionandvirulence
AT passeriniderossibeatrizn ironisasignalforstenotrophomonasmaltophiliabiofilmformationoxidativestressresponseompsexpressionandvirulence