title: Genomic fingerprinting and genotyping of Helicobacter pylori strains from patients with duodenal ulcer or gastric cancer from different geographic regions.
abstract: Continuing attempts have been made to classify pathogenic strains within bacterial populations based on DNA fingerprints and to identify virulence factors in H. pylori. We studied 287 H. pylori isolates from patients with duodenal ulcer or gastric cancer from three different geographic regions. DNA fingerprints were generated using REP-PCR and analyzed by cluster analysis. The status of three candidate virulence factors-vacA polymorphism, cagA and iceA,-were examined by PCR amplification. Cluster analysis of the REP-PCR fingerprints showed clustering by geographic region but not by disease presentation. cagA was detected in 91.3% of the isolates. Differences in vacA subtypes were observed among the three geographic regions. There was no association between iceA subtypes and clinical outcome. We conclude that geographic differences among the H. pylori strains exist in single gene allelic variants as well as in the conserved noncoding regions such as REP sequences throughout the entire bacterial genome. We did not detect any association between disease presentation and H. pylori genotypes using either DNA fingerprinting or candidate single gene virulence factors.
authors.affiliation: Veterans Affairs Medical Center and Baylor College of Medicine, Houston, Texas, USA.
authors.forename: Li
authors.initials: L
authors.lastname: Li
authors.forename: David Y
authors.initials: DY
authors.lastname: Graham
authors.forename: Oscar
authors.initials: O
authors.lastname: Gutierrez
authors.forename: Jong G
authors.initials: JG
authors.lastname: Kim
authors.forename: Robert M
authors.initials: RM
authors.lastname: Genta
authors.forename: Hala M T
authors.initials: HM
authors.lastname: El-Zimaity
authors.forename: Mae F
authors.initials: MF
authors.lastname: Go
mesh_terms: D000942:Antigens, Bacterial; D001426:Bacterial Proteins / Q000235:genetics; D016172:DNA Fingerprinting; D004269:DNA, Bacterial / Q000235:genetics; D003710:Demography; D004381:Duodenal Ulcer / Q000382:microbiology*; D005838:Genotype; D016481:Helicobacter Infections / Q000453:epidemiology / Q000382:microbiology*; D016480:Helicobacter pylori / Q000235:genetics* / Q000472:pathogenicity; D006801:Humans; D016133:Polymerase Chain Reaction / Q000379:methods; D012091:Repetitive Sequences, Nucleic Acid; D013274:Stomach Neoplasms / Q000382:microbiology*; D014774:Virulence
chemical_list: D000942:Antigens, Bacterial; D001426:Bacterial Proteins; D004269:DNA, Bacterial; C074689:VacA protein, Helicobacter pylori; C080866:cagA protein, Helicobacter pylori; C405087:iceA1 protein, Helicobacter pylori