title: High frequency variations of Helicobacter pylori isolates in individual hosts in a Chinese population.
abstract: BACKGROUND
  Colonization of individual hosts by multiple Helicobacter pylori genotypes may be one reason why this infection is persistent and difficult to eradicate.
  
  
  METHODS
  In order to study the diversity of H. pylori in individuals, a modified randomly amplified polymorphic DNA (RAPD) method was applied using primary culture isolates instead of passaged cultures.
  
  
  RESULTS
  The results showed that variations in H. pylori were prevalent among individuals in the Chinese population, and the incidence of multiple colonization was 99.1% (115/116), significantly higher than in other reports. Moreover, the number of RAPD genotypes was found to be significantly associated with the process of disease development (p<0.05). Indeed, a trend for a higher number of RAPD genotypes within a single host (up to five genotypes) was observed as the disease developed or became more serious. After subculturing for three generations in our experiment, some genotypes present in the primary cultures were lost. The different genotypes in one patient may have originated from a single ancestral strain, as determined by analysis of six H. pylori housekeeping gene alleles, most of which were shown to be identical.
  
  
  CONCLUSIONS
  These results suggest that investigating isolates of the primary culture will better reflect the H. pylori diversity in individuals. Also, they indicate that continuous variation of one strain in the gastric microenvironment may be the main cause of H. pylori diversity in individuals in the Chinese population.
authors.affiliation: Department of Clinical Microbiology and Immunology, Faculty of Laboratory Medicine and College of Pharmacy, the Third Military Medical University, Chongqing, 400038, China.
authors.forename: L
authors.initials: L
authors.lastname: Ren
authors.forename: Y L
authors.initials: YL
authors.lastname: Liao
authors.forename: Y
authors.initials: Y
authors.lastname: Song
authors.forename: Y
authors.initials: Y
authors.lastname: Guo
authors.forename: X H
authors.initials: XH
authors.lastname: Mao
authors.forename: Q H
authors.initials: QH
authors.lastname: Xie
authors.forename: W J
authors.initials: WJ
authors.lastname: Zhang
authors.forename: G
authors.initials: G
authors.lastname: Guo
authors.forename: Q M
authors.initials: QM
authors.lastname: Zou
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000595:Amino Acid Sequence; D044466:Asian People; D001426:Bacterial Proteins / Q000235:genetics; D015373:Bacterial Typing Techniques; D004381:Duodenal Ulcer / Q000382:microbiology; D005260:Female; D005756:Gastritis / Q000382:microbiology; D014644:Genetic Variation; D005838:Genotype; D016481:Helicobacter Infections / Q000382:microbiology*; D016480:Helicobacter pylori / Q000235:genetics* / Q000302:isolation & purification; D006801:Humans; D008297:Male; D008875:Middle Aged; D008969:Molecular Sequence Data; D058885:Multilocus Sequence Typing; D019105:Random Amplified Polymorphic DNA Technique; D013276:Stomach Ulcer / Q000382:microbiology
chemical_list: D001426:Bacterial Proteins