title: Water-induced modulation of Helicobacter pylori virulence properties.
abstract: While the influence of water in Helicobacter pylori culturability and membrane integrity has been extensively studied, there are little data concerning the effect of this environment on virulence properties. Therefore, we studied the culturability of water-exposed H. pylori and determined whether there was any relation with the bacterium's ability to adhere, produce functional components of pathogenicity and induce inflammation and alterations in apoptosis in an experimental model of human gastric epithelial cells. H. pylori partially retained the ability to adhere to epithelial cells even after complete loss of culturability. However, the microorganism is no longer effective in eliciting in vitro host cell inflammation and apoptosis, possibly due to the non-functionality of the cag type IV secretion system. These H. pylori-induced host cell responses, which are lost along with culturability, are known to increase epithelial cell turnover and, consequently, could have a deleterious effect on the initial H. pylori colonisation process. The fact that adhesion is maintained by H. pylori to the detriment of other factors involved in later infection stages appears to point to a modulation of the physiology of the pathogen after water exposure and might provide the microorganism with the necessary means to, at least transiently, colonise the human stomach.
authors: Institute of Molecular Pathology and Immunology, Medical Faculty, University of Porto, Porto, Portugal.
authors: Nuno M
authors: NM
authors: Guimarães
authors: Institute for Biotechnology and Bioengineering, Centre of Biological Engineering, University of Minho, Braga, Portugal.
authors: Nuno F
authors: NF
authors: Azevedo
authors: Institute for Biotechnology and Bioengineering, Centre of Biological Engineering, University of Minho, Braga, Portugal.
authors: Maria J
authors: MJ
authors: Vieira
authors: Institute of Molecular Pathology and Immunology, Medical Faculty, University of Porto, Porto, Portugal.
authors: Ceu
authors: C
authors: Figueiredo
mesh_terms: D000942:Antigens, Bacterial / Q000502:physiology; D001422:Bacterial Adhesion / Q000502:physiology*; D001426:Bacterial Proteins / Q000502:physiology; D058947:Bacterial Secretion Systems; D004847:Epithelial Cells / Q000382:microbiology*; D005753:Gastric Mucosa / Q000166:cytology; D016480:Helicobacter pylori / Q000254:growth & development / Q000472:pathogenicity*; D054884:Host-Pathogen Interactions; D006801:Humans; D014774:Virulence / Q000502:physiology; D014867:Water
chemical_list: D000942:Antigens, Bacterial; D001426:Bacterial Proteins; D058947:Bacterial Secretion Systems; C080866:cagA protein, Helicobacter pylori; D014867:Water