title: Milk of livestock as a possible transmission route of Helicobacter pylori infection.
abstract: OBJECTIVE
  The current investigation aimed to evaluate ruminant raw milk as a reservoir source of Helicobacter pylori and analyze the diversity of cagA and vacA genotypes as H. pylori virulence factors to find any relationship between these genotypes in human and animal H. pylori strains.
  
  
  BACKGROUND
  The way of transmission of Helicobacter pylori as one of the most controversial bacteria in the world, which colonizes the human gastric tissue and is responsible for several gastric diseases is still unknown. The possibility of zoonotic transmission of H. pylori is feasible, but is not proven in ruminant reservoirs.
  
  
  METHODS
  Overall 210 cows, sheep, goats, camels and buffalos' raw milk samples and 100 human gastric biopsies were collected in this survey. We applied PCR assays to identify H. pylori, vacA and cagA genes. Statistical tests were applied for data analysis.
  
  
  RESULTS
  Totally 12(16%) cow, 8(13.79%) sheep, 2 (4.76%) goat, 2(13.33%), buffalo 4(20%) and 82 (82%) of human specimens were confirmed to be H. pylori positive. Among which s1a/m2 genotype was more frequent in isolated H. pylori strains and statistically significant between strains. Based on statistical analyses the s1b allele of sheep had a significant association with human strains.
  
  
  CONCLUSIONS
  The current survey was prompted by our previous report. According to both results we can conclude that sheep may act as a reservoir for H. pylori and transmit this bacterium to human via its milk. Extended assessments in other geographical regions and other animals are recommended.
authors.affiliation: Shahid Modaress Hospital, Faculty of Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran.
authors.forename: Ramin
authors.initials: R
authors.lastname: Talaei
authors.affiliation: Young Researchers and Elite Club, Islamic Azad University, Central Tehran Branch, Tehran, Iran.
authors.forename: Negar
authors.initials: N
authors.lastname: Souod
authors.affiliation: Department of Microbiology, Faculty of Veterinary Medicine, Islamic Azad University, ShahreKord Branch, ShahreKord, Iran.
authors.forename: Hassan
authors.initials: H
authors.lastname: Momtaz
authors.affiliation: Department of Clinical Microbiology, Faculty of Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran.
authors.forename: Hossein
authors.initials: H
authors.lastname: Dabiri
keywords: Helicobacter pylori; Human; Milk; Ruminant; Virulence factors