title: Immunodetection of Helicobacter pylori-specific proteins in oral and gastric Candida yeasts.
abstract: BACKGROUND
  Human gastric epithelium and immunocytes have been recognized as the sole specialized eukaryotic cells that host Helicobacter pylori (H. pylori). The aim of this study was to provide further evidence for our previous proposal regarding the occurrence of H.pylori inside the yeast vacuole, verifying the viability of the intravacuolar H.pylori by western blotting.
  
  
  METHODS
  Light microscopy and polymerase chain reaction (PCR) were used for primary detection of nonculturable H.pylori in 11 Candida yeasts (six oral and five gastric). Boiling was used for extraction of proteins from yeasts and the control H.pylori. Western blot analysis was recruited to assess the occurrence of H.pylori-specific proteins in protein pool of yeasts, using IgY-Hp raised in hens and IgG1-Hp raised in mice.
  
  
  RESULTS
  The fast-moving bacterium-like bodies (BLBs) were identified as H.pylori by amplification of H.pylori 16S rRNA, ureAB, vacA s1, and ahpC genes from the whole DNA of yeasts. Analysis of the sequenced products of 16S rRNA gene amplified from the yeast and H.pylori isolates of patient #2 showed 100 % homology with the corresponding sequences of the reference H. pylori strains in GenBank. According to published data, it was plausible to assign the H.pylori-specific proteins, detected by western blot analysis, as thiol peroxidase (21 kDa), peroxiredoxin (AhpC) (26 kDa), urease-A subunit (UreA) (32 kDa), vacuolating cytotoxin A (VacA) small subunit (36 kDa), and VacA large subunit (56 kDa).
  
  
  CONCLUSIONS
  Results of this study show that inside yeast, H.pylori expresses proteins and is viable. These proteins appear to serve as powerful tools to help H.pylori to establish in the vacuole of yeast where it can reach nutrients and multiply. The intimate relationship between H.pylori and Candida yeast which began long time ago, could have led to the establishment of H.pylori inside the yeast vacuole before invading human cells.
authors.affiliation: Department of Microbiology, School of Biology, University College of Sciences, University of Tehran, Tehran, Iran. Siavoshi@khayam.ut.ac.ir.
authors.forename: Parastoo
authors.initials: P
authors.lastname: Saniee
authors.forename: Farideh
authors.initials: F
authors.lastname: Siavoshi
authors.forename: Gholamreza
authors.initials: G
authors.lastname: Nikbakht Broujeni
authors.forename: Mahmood
authors.initials: M
authors.lastname: Khormali
authors.forename: Abdolfatah
authors.initials: A
authors.lastname: Sarrafnejad
authors.forename: Reza
authors.initials: R
authors.lastname: Malekzadeh
mesh_terms: D001426:Bacterial Proteins / Q000032:analysis* / Q000235:genetics; D015153:Blotting, Western; D002175:Candida / Q000737:chemistry*; D004269:DNA, Bacterial / Q000032:analysis*; D005753:Gastric Mucosa / Q000382:microbiology; D016480:Helicobacter pylori / Q000235:genetics / Q000302:isolation & purification*; D006801:Humans; D009061:Mouth Mucosa / Q000382:microbiology; D010544:Peroxidases / Q000235:genetics; D016133:Polymerase Chain Reaction; D012336:RNA, Ribosomal, 16S / Q000235:genetics
chemical_list: D001426:Bacterial Proteins; D004269:DNA, Bacterial; D012336:RNA, Ribosomal, 16S; C074689:VacA protein, Helicobacter pylori; D010544:Peroxidases; C508531:ahpC protein, Helicobacter pylori