| Article ID | Journal | Published Year | Pages | File Type |
|---|---|---|---|---|
| 4483792 | Water Research | 2012 | 9 Pages |
Legionella pneumophila is a ubiquitous environmental microorganism found in freshwater that can cause an acute form of pneumonia known as Legionnaires’ disease. Despite widespread use of chlorine to ensure drinking water quality and awareness that L. pneumophila may escape these treatments, little is known about its effects on L. pneumophila. The aim of this study was to investigate the L. pneumophila transcriptional response induced by chlorine treatment. Transcriptome analysis, using DNA arrays, showed that a sublethal dose of chlorine induces a differential expression of 391 genes involved in stress response, virulence, general metabolism, information pathways and transport. Many of the stress response genes were significantly upregulated, whereas a significant number of virulence genes were repressed. In particular, exposure of L. pneumophila to chlorine induced the expression of cellular antioxidant proteins, stress proteins and transcriptional regulators. In addition, glutathione S-transferase specific activity was enhanced following chlorine treatment. Our results clearly indicate that chlorine induces expression of proteins involved in cellular defence mechanisms against oxidative stress that might be involved in adaptation or resistance to chlorine treatment.
Graphical abstractFigure optionsDownload full-size imageDownload high-quality image (53 K)Download as PowerPoint slideHighlights► Chlorine treatment induced gene expression modifications in Legionella pneumophila. ► Chlorine initiates a bacterial stress response related to the induction of cellular protective processes. ► The virulence potential of chlorine-treated bacteria seems to be attenuated. ► L. pneumophila mechanisms involved in adaptation or resistance to chlorine treatment are identified.
