title: Gastric mucosal infiltration by Helicobacter pylori favours bacterial survival after treatment.
abstract: BACKGROUND
  Although a number of patient and bacterial factors have been identified as predictors of treatment failure in Helicobacter pylori-associated gastritis, the causes of lack of response to treatment have not been fully elucidated. We hypothesized that bacterial infiltration of the gastric mucosa might be one of the factors responsible for treatment failure in patients harbouring the bacterium.
  
  
  METHODS
  We studied 182 patients with gastritis who underwent anti-H. pylori treatment with different drugs. Gastric biopsies obtained at endoscopy, were examined for electron microscopic features of infiltration and damage. Patients were assigned to different treatment groups, and endoscopy, evaluation of H. pylori status and electron microscopy were repeated at least 4 weeks after the end of treatment.
  
  
  RESULTS
  The overall H. pylori eradication rate was 65%. Eradication was achieved more frequently in patients without electron microscopic features of infiltration (85%), than in those patients with the bacteria deeply embedded into the gastric mucosa (45%; P < 0.0001). No treatment appeared to be clearly superior for patients with the highest degree of mucosal infiltration.
  
  
  CONCLUSIONS
  Bacterial mucosal infiltration may facilitate the survival of H. pylori during antibacterial treatment; moreover, electron microscopy may be helpful to identify patients potentially unresponsive to anti-H. pylori treatment.
authors.affiliation: Department of Gastroenterology, S. Timoteo Hospital, Termoli, Italy.
authors.forename: M
authors.initials: M
authors.lastname: Neri
authors.forename: D
authors.initials: D
authors.lastname: Susi
authors.forename: I
authors.initials: I
authors.lastname: Bovani
authors.forename: F
authors.initials: F
authors.lastname: Laterza
authors.forename: E
authors.initials: E
authors.lastname: Porreca
authors.forename: F
authors.initials: F
authors.lastname: Cuccurullo
mesh_terms: D000293:Adolescent; D000328:Adult; D000900:Anti-Bacterial Agents; D004359:Drug Therapy, Combination / Q000627:therapeutic use*; D005260:Female; D005753:Gastric Mucosa / Q000382:microbiology* / Q000473:pathology; D016481:Helicobacter Infections / Q000188:drug therapy*; D016480:Helicobacter pylori / Q000187:drug effects* / Q000648:ultrastructure; D006801:Humans; D008297:Male; D008875:Middle Aged; D017211:Treatment Failure; D016896:Treatment Outcome
chemical_list: D000900:Anti-Bacterial Agents