title: Intrafamilial transmission of Helicobacter pylori: genotyping of faecal samples.
abstract: BACKGROUND
  After more than 20 years of research, there is a little information about the detailed routes of Helicobacter pylori transmission. The aim of this study was to explore intrafamilial transmission of H. pylori in children who had indication for upper gastrointestinal endoscopy and their parents.
  
  
  METHODS
  Children (aged up to 15 years) were studied during September 2012 to October 2013. The parents of those with positive urea breath test results were asked to provide faecal and blood samples after giving informed consent. Non-invasive tests such as immunoassay for serological antibodies against H. pylori and detection of its antigen in faeces were measured. The genetic similarity of the family strains was investigated by the random amplification of polymorphic DNA (RAPD-PCR) genotyping method.
  
  
  RESULTS
  According to the genotyping results of 30 families, in 10 (33.3%) children related H. pylori genotypes to their mothers were found, while only 2 children (6.7%) had similar genotypes to their fathers. Interestingly, children with similar H. pylori genotype with their mothers had higher IgA (35.7 ± 10.8) and IgM antibody titres (87.23 ± 19.15) than other children. In addition, in these children, lower titres of IgG antibodies (9.93 ± 3.31) were found rather than children who had no H. pylori in their faeces or had no similarities with their parents (30.28 ± 6.15).
  
  
  CONCLUSIONS
  In conclusion, mother-to-child transmission is the main route of intrafamilial transmission of H. pylori in Iranian families. Molecular typing of H. pylori can be useful in identifying a high-risk population.
authors.affiliation: a Department of Pediatric Infectious Disease, Pediatrics Center of Excellence, Children's Medical Center , Tehran University of Medical Sciences , Tehran , Iran.|b Pediatric Infectious Diseases Research Center , Tehran University of Medical Sciences , Tehran , Iran.
authors.forename: Setareh
authors.initials: S
authors.lastname: Mamishi
authors.affiliation: a Department of Pediatric Infectious Disease, Pediatrics Center of Excellence, Children's Medical Center , Tehran University of Medical Sciences , Tehran , Iran.
authors.forename: Hamid
authors.initials: H
authors.lastname: Eshaghi
authors.affiliation: b Pediatric Infectious Diseases Research Center , Tehran University of Medical Sciences , Tehran , Iran.
authors.forename: Shima
authors.initials: S
authors.lastname: Mahmoudi
authors.affiliation: c Department of Microbiology, School of Medicine , Tehran University of Medical Sciences , Tehran , Iran.
authors.forename: Abbas
authors.initials: A
authors.lastname: Bahador
authors.affiliation: b Pediatric Infectious Diseases Research Center , Tehran University of Medical Sciences , Tehran , Iran.
authors.forename: Reihaneh
authors.initials: R
authors.lastname: Hosseinpour Sadeghi
authors.affiliation: d Department of Pediatric Gastroenterology, School of Medicine , Tehran University of Medical Sciences , Tehran , Iran.
authors.forename: Mehri
authors.initials: M
authors.lastname: Najafi
authors.affiliation: d Department of Pediatric Gastroenterology, School of Medicine , Tehran University of Medical Sciences , Tehran , Iran.
authors.forename: Fatemeh
authors.initials: F
authors.lastname: Farahmand
authors.affiliation: d Department of Pediatric Gastroenterology, School of Medicine , Tehran University of Medical Sciences , Tehran , Iran.
authors.forename: Ahmad
authors.initials: A
authors.lastname: Khodadad
authors.affiliation: b Pediatric Infectious Diseases Research Center , Tehran University of Medical Sciences , Tehran , Iran.
authors.forename: Babak
authors.initials: B
authors.lastname: Pourakbari
mesh_terms: D000293:Adolescent; D000328:Adult; D000907:Antibodies, Bacterial / Q000097:blood; D015415:Biomarkers / Q000097:blood; D001944:Breath Tests; D002648:Child; D004269:DNA, Bacterial / Q000235:genetics* / Q000302:isolation & purification; D016099:Endoscopy, Gastrointestinal; D005220:Fathers; D005243:Feces / Q000382:microbiology*; D005260:Female; D005838:Genotype; D016481:Helicobacter Infections / Q000097:blood / Q000175:diagnosis / Q000382:microbiology* / Q000635:transmission*; D016480:Helicobacter pylori / Q000235:genetics* / Q000276:immunology / Q000302:isolation & purification; D006801:Humans; D007070:Immunoglobulin A / Q000097:blood; D007075:Immunoglobulin M / Q000097:blood; D018445:Infectious Disease Transmission, Vertical; D007492:Iran; D008297:Male; D008875:Middle Aged; D009035:Mothers; D016133:Polymerase Chain Reaction; D011237:Predictive Value of Tests; D012307:Risk Factors
chemical_list: D000907:Antibodies, Bacterial; D015415:Biomarkers; D004269:DNA, Bacterial; D007070:Immunoglobulin A; D007075:Immunoglobulin M
keywords: Helicobacter pylori; genotyping; intrafamilial transmission