title: Prevalence, diversity and disease association of Helicobacter pylori in dyspeptic patients from Pakistan.
abstract: BACKGROUND
  The etiological association of Helicobacter pylori with gastric ulcer (GU), gastric cancer (GC), and duodenal ulcer (DU) is well-known. Understanding the epidemiology of H. pylori facilitates the estimation of disease burden in a certain population. This study presents the diversity of H. pylori genotypes and their association with different clinical outcomes among dyspeptic patients in Pakistan over a period of four years.
  
  
  METHODS
  Gastric biopsy samples from a total of 450 dyspeptic individualswere subjected to PCR, genotypingand histology.
  
  
  RESULTS
  A total of 201 (45%) cases were found positive for H. pylori. The detection rate was high in GU (91%), DU (86%) and GC (83%) cases compared with those cases who had intact gastric mucosa (18%). Histology revealed the presence of infection in 68% of cases of mild/chronic nonspecific gastritis with others belonging to the GU sequel. cagA gene carriage was observed in 104 (51%) cases or mostly from DU, GU and GC groups, of which 97 were Western type strains while 3 were East-Asian type strains that are rarely observed in South Asia. vacA allelic variant s1am1 was most commonly observed, followed by s1am2, and s1bm1, with direct correlation in diseased cases (gastritis, GU, DU and GC). Prevalent genotypic combinations were s1am1/cagA- in gastritis and s1am1/cagA+ in DU, GU, and GC.
  
  
  CONCLUSIONS
  Our study indicates the predominant circulation of Western type cagA and vacAs1am1 type H. pylori strains in Pakistan.
authors.affiliation: Immunology and Infectious Diseases Research Laboratory, Department of Microbiology, University of Karachi, Pakistan. adnankh@uok.edu.pk
authors.forename: Adnan
authors.initials: A
authors.lastname: Khan
authors.forename: Amber
authors.initials: A
authors.lastname: Farooqui
authors.forename: Yasir
authors.initials: Y
authors.lastname: Raza
authors.forename: Faisal
authors.initials: F
authors.lastname: Rasheed
authors.forename: Hamid
authors.initials: H
authors.lastname: Manzoor
authors.forename: Syed Shakeel
authors.initials: SS
authors.lastname: Akhtar
authors.forename: Muhammad Saeed
authors.initials: MS
authors.lastname: Quraishy
authors.forename: Salvatore
authors.initials: S
authors.lastname: Rubino
authors.forename: Shahana U
authors.initials: SU
authors.lastname: Kazmi
authors.forename: Bianca
authors.initials: B
authors.lastname: Paglietti
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001706:Biopsy; D002648:Child; D005260:Female; D005753:Gastric Mucosa / Q000382:microbiology / Q000473:pathology; D014644:Genetic Variation; D005838:Genotype; D016481:Helicobacter Infections / Q000453:epidemiology* / Q000382:microbiology* / Q000473:pathology; D016480:Helicobacter pylori / Q000145:classification / Q000235:genetics* / Q000302:isolation & purification*; D006651:Histocytochemistry; D006801:Humans; D008297:Male; D008875:Middle Aged; D017720:Molecular Epidemiology; D010154:Pakistan / Q000453:epidemiology; D016133:Polymerase Chain Reaction; D015995:Prevalence; D037521:Virulence Factors / Q000235:genetics; D055815:Young Adult
chemical_list: D037521:Virulence Factors