title: Proteomannans in biofilm of Helicobacter pylori ATCC 43504.
abstract: BACKGROUND
  The human bacterial pathogen Helicobacter pylori forms biofilms. However, the constituents of the biofilm have not been extensively investigated. In this study, we analyzed the carbohydrate and protein components of biofilm formed by H. pylori strain ATCC 43504 (NCTC 11637).
  
  
  METHODS
  Development of H. pylori biofilm was analyzed using scanning electron microscopy (SEM) and quantified using crystal violet staining. The extracted extracellular polysaccharide (EPS) matrix was analyzed using GC-MS and nuclear magnetic resonance (NMR) analyses. Proteomic profiles of biofilms were examined by SDS-PAGE while deletion mutants of upregulated biofilm proteins were constructed and characterized.
  
  
  RESULTS
  Formation of H. pylori biofilm is time dependent as shown by crystal violet staining assay and SEM. NMR reveals the prevalence of 1,4-mannosyl linkages in both developing and mature biofilms. Proteomic analysis of the biofilm indicates the upregulation of neutrophil-activating protein A (NapA) and several stress-induced proteins. Interestingly, the isogenic mutant napA revealed a different biofilm phenotype that showed reduced aggregated colonial structure when compared to the wild type.
  
  
  CONCLUSIONS
  This in vitro study shows that mannose-related proteoglycans (proteomannans) are involved in the process of H. pylori biofilm formation while the presence of upregulated NapA in the biofilm implies the potency to increase adhesiveness of H. pylori biofilm. Being a complex matrix of proteins and carbohydrates, which are probably interdependent, the H. pylori biofilm could possibly offer a protective haven for the survival of this gastric bacterial pathogen in the extragastric environments.
authors: Institute of Biological Chemistry, Academia Sinica, Taipei 115, Taiwan.
authors: Feng-Ling
authors: FL
authors: Yang
authors: Ammar Mansoor
authors: AM
authors: Hassanbhai
authors: Hong-Yu
authors: HY
authors: Chen
authors: Zih-You
authors: ZY
authors: Huang
authors: Tzu-Lung
authors: TL
authors: Lin
authors: Shih-Hsiung
authors: SH
authors: Wu
authors: Bow
authors: B
authors: Ho
mesh_terms: D018441:Biofilms / Q000254:growth & development*; D002850:Chromatography, Gel; D004591:Electrophoresis, Polyacrylamide Gel; D016480:Helicobacter pylori / Q000254:growth & development / Q000378:metabolism* / Q000648:ultrastructure; D009682:Magnetic Resonance Spectroscopy; D008358:Mannose / Q000737:chemistry*; D018625:Microscopy, Atomic Force; D011134:Polysaccharides / Q000737:chemistry / Q000378:metabolism*
chemical_list: D011134:Polysaccharides; D008358:Mannose