Cargando…

Extracellular DNA release confers heterogeneity in Candida albicans biofilm formation

BACKGROUND: Biofilm formation by Candida albicans has shown to be highly variable and is directly associated with pathogenicity and poor clinical outcomes in patients at risk. The aim of this study was to test the hypotheses that the extracellular DNA release by C. albicans is strain dependent and i...

Descripción completa

Detalles Bibliográficos
Autores principales: Rajendran, Ranjith, Sherry, Leighann, Lappin, David F, Nile, Chris J, Smith, Karen, Williams, Craig, Munro, Carol A, Ramage, Gordon
Formato: Online Artículo Texto
Lenguaje:English
Publicado: BioMed Central 2014
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4262977/
https://www.ncbi.nlm.nih.gov/pubmed/25476750
http://dx.doi.org/10.1186/s12866-014-0303-6
_version_ 1782348483153362944
author Rajendran, Ranjith
Sherry, Leighann
Lappin, David F
Nile, Chris J
Smith, Karen
Williams, Craig
Munro, Carol A
Ramage, Gordon
author_facet Rajendran, Ranjith
Sherry, Leighann
Lappin, David F
Nile, Chris J
Smith, Karen
Williams, Craig
Munro, Carol A
Ramage, Gordon
author_sort Rajendran, Ranjith
collection PubMed
description BACKGROUND: Biofilm formation by Candida albicans has shown to be highly variable and is directly associated with pathogenicity and poor clinical outcomes in patients at risk. The aim of this study was to test the hypotheses that the extracellular DNA release by C. albicans is strain dependent and is associated with biofilm heterogeneity. RESULTS: Initially, biofilm formed by C. albicans high biofilm formers (HBF) or low biofilm formers (LBF) were treated with DNase to find whether eDNA play a role in their biofilm formation. Digestion of biofilm eDNA significantly reduced the HBF biofilm biomass by five fold compared to untreated controls. In addition, quantification of eDNA over the period of biofilm formation by SYBR green assay demonstrate a significantly higher level of 2 to 6 fold in HBF compared to LBF. Biochemical and transcriptional analyses showed that chitinase activity and mRNA levels of chitinase genes, a marker of autolysis, were upregulated in 24 h biofilm formation by HBF compared to LBF, indicating autolysis pathway possibly involved in causing variation. The biofilm biomass and eDNA release by single (∆cht2, ∆cht3) and double knockout (∆cht2/∆cht3) chitinase mutants were significantly less compared to their parental strain CA14, confirming the role of chitinases in eDNA release and biofilm formation. Correlation analysis found a positive correlation between chitinases and HWP1, suggesting eDNA may release during the hyphal growth. Finally, we showed a combinational treatment of biofilms with DNase or chitinase inhibitor (acetazolamide) plus amphotericin B significantly improved antifungal susceptibility by 2 to 8 fold. CONCLUSIONS: Collectively, these data show that eDNA release by C. albicans clinical isolates is variable and is associated with differential biofilm formation. Digestion of biofilm eDNA by DNase may provide a novel therapeutic strategies to destabilise biofilm growth and improves antifungal sensitivity. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1186/s12866-014-0303-6) contains supplementary material, which is available to authorized users.
format Online
Article
Text
id pubmed-4262977
institution National Center for Biotechnology Information
language English
publishDate 2014
publisher BioMed Central
record_format MEDLINE/PubMed
spelling pubmed-42629772014-12-12 Extracellular DNA release confers heterogeneity in Candida albicans biofilm formation Rajendran, Ranjith Sherry, Leighann Lappin, David F Nile, Chris J Smith, Karen Williams, Craig Munro, Carol A Ramage, Gordon BMC Microbiol Research Article BACKGROUND: Biofilm formation by Candida albicans has shown to be highly variable and is directly associated with pathogenicity and poor clinical outcomes in patients at risk. The aim of this study was to test the hypotheses that the extracellular DNA release by C. albicans is strain dependent and is associated with biofilm heterogeneity. RESULTS: Initially, biofilm formed by C. albicans high biofilm formers (HBF) or low biofilm formers (LBF) were treated with DNase to find whether eDNA play a role in their biofilm formation. Digestion of biofilm eDNA significantly reduced the HBF biofilm biomass by five fold compared to untreated controls. In addition, quantification of eDNA over the period of biofilm formation by SYBR green assay demonstrate a significantly higher level of 2 to 6 fold in HBF compared to LBF. Biochemical and transcriptional analyses showed that chitinase activity and mRNA levels of chitinase genes, a marker of autolysis, were upregulated in 24 h biofilm formation by HBF compared to LBF, indicating autolysis pathway possibly involved in causing variation. The biofilm biomass and eDNA release by single (∆cht2, ∆cht3) and double knockout (∆cht2/∆cht3) chitinase mutants were significantly less compared to their parental strain CA14, confirming the role of chitinases in eDNA release and biofilm formation. Correlation analysis found a positive correlation between chitinases and HWP1, suggesting eDNA may release during the hyphal growth. Finally, we showed a combinational treatment of biofilms with DNase or chitinase inhibitor (acetazolamide) plus amphotericin B significantly improved antifungal susceptibility by 2 to 8 fold. CONCLUSIONS: Collectively, these data show that eDNA release by C. albicans clinical isolates is variable and is associated with differential biofilm formation. Digestion of biofilm eDNA by DNase may provide a novel therapeutic strategies to destabilise biofilm growth and improves antifungal sensitivity. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1186/s12866-014-0303-6) contains supplementary material, which is available to authorized users. BioMed Central 2014-12-05 /pmc/articles/PMC4262977/ /pubmed/25476750 http://dx.doi.org/10.1186/s12866-014-0303-6 Text en © Rajendran et al.; licensee BioMed Central Ltd. 2014 This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly credited. The Creative Commons Public Domain Dedication waiver (http://creativecommons.org/publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise stated.
spellingShingle Research Article
Rajendran, Ranjith
Sherry, Leighann
Lappin, David F
Nile, Chris J
Smith, Karen
Williams, Craig
Munro, Carol A
Ramage, Gordon
Extracellular DNA release confers heterogeneity in Candida albicans biofilm formation
title Extracellular DNA release confers heterogeneity in Candida albicans biofilm formation
title_full Extracellular DNA release confers heterogeneity in Candida albicans biofilm formation
title_fullStr Extracellular DNA release confers heterogeneity in Candida albicans biofilm formation
title_full_unstemmed Extracellular DNA release confers heterogeneity in Candida albicans biofilm formation
title_short Extracellular DNA release confers heterogeneity in Candida albicans biofilm formation
title_sort extracellular dna release confers heterogeneity in candida albicans biofilm formation
topic Research Article
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4262977/
https://www.ncbi.nlm.nih.gov/pubmed/25476750
http://dx.doi.org/10.1186/s12866-014-0303-6
work_keys_str_mv AT rajendranranjith extracellulardnareleaseconfersheterogeneityincandidaalbicansbiofilmformation
AT sherryleighann extracellulardnareleaseconfersheterogeneityincandidaalbicansbiofilmformation
AT lappindavidf extracellulardnareleaseconfersheterogeneityincandidaalbicansbiofilmformation
AT nilechrisj extracellulardnareleaseconfersheterogeneityincandidaalbicansbiofilmformation
AT smithkaren extracellulardnareleaseconfersheterogeneityincandidaalbicansbiofilmformation
AT williamscraig extracellulardnareleaseconfersheterogeneityincandidaalbicansbiofilmformation
AT munrocarola extracellulardnareleaseconfersheterogeneityincandidaalbicansbiofilmformation
AT ramagegordon extracellulardnareleaseconfersheterogeneityincandidaalbicansbiofilmformation