title: Localization of H.pylori within the vacuole of Candida yeast by direct immunofluorescence technique.
abstract: BACKGROUND
  Reports indicate that H.pylori is able to invade the eukaryotic cells and establish inside their vacuoles. In this study, FITC-conjugated IgY-Hp was used to localize H.pylori inside the vacuole of Candida yeast. Presence of intracellular H.pylori inside the new generations of yeast cells was also examined by light microscopy and Live/Dead BacLight staining method.
  
  
  METHODS
  A single colony of fresh yeast culture was cultivated in a 100-µl medium containing yeast extract and N-acetylglucoseamine supplemented with fetal bovine serum. After 12-hr incubation at 37℃, FITC-conjugated IgY-Hp was added. After 3 hours, 10 µL of yeast suspension was smeared on a glass slide, air-dried and examined by fluorescent microscopy. Wet mounts of yeast culture and Live/Dead BacLight stained preparations were examined by light and fluorescent microscopy, respectively. Photographs were taken from the fast-moving H.pylori inside the yeast vacuoles.
  
  
  RESULTS
  Fluorescent microscopy showed that FITC-conjugated IgY-Hp could enter yeast cells and specifically react with H.pylori, localizing the bacterium inside the yeast vacuole. Photographs taken from wet mounts observed by  light and fluorescent microscopy showed fast-moving H.pylori cells in the vacuole of mother as well as daughter yeast cells. The intravacuolar H.pylori cells stained green, showing their viability.
  
  
  CONCLUSIONS
  Intracellular life of prokaryotes inside eukaryotes has been described as an evolutionary phenomenon with a great impact on bacterial persistence despite environmental stresses. Results of this study demonstrated the specific interaction of FITC-conjugated IgY-Hp with H.pylori cells and the bacterial localization inside the Candida yeast vacuole. The intracellular bacteria were viable and existed in the vacuole of next generations of yeast cells. It appears that H.pylori is well-equipped to dwell within the vacuole of eukaryotic cells where it is protected from stressful conditions, including antibacterial therapy. Presence of H.pylori inside the vacuole of new generations of yeasts demonstrates the intimate relationship between the two microorganisms, resulting in bacterial inheritance as part of the vacuolar content of yeast cells.
authors: Department of Microbiology, School of Biology, University College of Sciences, University of Tehran, Tehran, Iran.siavoshi@khayam.ut.ac.ir.
authors: Parastoo
authors: P
authors: Saniee
authors: Department of Microbiology, School of Biology, University College of Sciences, University of Tehran, Tehran, Iran.
authors: Farideh
authors: F
authors: Siavoshi
authors: Department of Microbiology and Immunology, Faculty of Veterinary Medicine, University of Tehran, Tehran, Iran.
authors: Gholamreza
authors: G
authors: Nikbakht Broujeni
authors: Department of Microbiology and Immunology, Faculty of Veterinary Medicine, University of Tehran, Tehran, Iran.
authors: Mahmood
authors: M
authors: Khormali
authors: Department of Immunology, School of Public Health, Tehran University of Medical Sciences, Tehran, Iran.
authors: Abdolfatah
authors: A
authors: Sarrafnejad
authors: Digestive Disease Research Institute, Tehran University of Medical Sciences, Tehran, Iran.
authors: Reza
authors: R
authors: Malekzadeh
mesh_terms: D002175:Candida / Q000648:ultrastructure; D016650:Fluorescein-5-isothiocyanate; D019085:Fluorescent Antibody Technique, Direct; D016480:Helicobacter pylori / Q000737:chemistry / Q000302:isolation & purification*; D007136:Immunoglobulins / Q000032:analysis; D050296:Microbial Viability; D008856:Microscopy, Fluorescence; D014617:Vacuoles / Q000382:microbiology*
chemical_list: C016512:IgY; D007136:Immunoglobulins; D016650:Fluorescein-5-isothiocyanate