Morphological analysis of Helicobacter pylori from gastric biopsies and dental plaque by scanning electron microscopy

Helicobacter pylori is rarely cultured from sites other than the gastric mu cosa. The morphology of ii pylori in the stomach and dental plaque of adult dyspeptic patients was investigated to determine whether a difference in m orphology at these sites could explain the inability to culture the organis m from the oral cavity. Five adult patients attending for an upper gastroin testinal endoscopy were investigated. Dental plaque and gastric antral biop sy samples were analysed by culture and polymerase chain reaction (PCR) bot h before and after immunomagnetic separation using polyclonal rabbit anti-H . pylori IgG. Bead:bacteria aggregates were then examined by scanning elect ron microscopy (SEM). Rod and coccoid forms of H pylori were seen by SEM in all oral and gastric samples which were H pylori PCR positive. Although ro d and coccoid forms have previously been shown to be associated with the ga stric mucosa, this is the first time H pylori cells have been visualized in dental plaque.