Comparison of the virulence factors of Helicobacter pylori isolated in stomach and saliva in Iran.
BACKGROUND
Helicobacter pylori is a microaerophilic, spiral-shaped motile bacterium that is strongly associated with gastroduodenal diseases, but recently, dental plaque and saliva have been implicated as possible sources of H pylori infection. Two virulence factors that are expressed by the alleles of the cytotoxin genes, cagA and vacA, have been identified. The aim of this study was to compare cagA and vacA genotypes of H pylori between stomach and saliva in a same patient.


METHODS
This study was performed on antrum gastric biopsy specimens and saliva samples, which were obtained from 250 patients undergoing upper gastrointestinal tract endoscopy in Hagar Hospital of Shahrekord Township in Iran. Initially, H pylori strains were identified by rapid urease test; then, we applied polymerase chain reaction assay to analyze cagA and vacA genotypes of H pylori from both gastric and saliva specimens.


RESULTS
One hundred eighty-nine (75.6%) and 36 (14.4%) samples were H pylori positive in gastric and saliva samples, respectively. Evaluation of virulence factors in the 36 patients whose saliva and gastric samples were both positive for H pylori showed a great deal of cytotoxin genotypic diversity between stomach and saliva in the same patient; in fact, 14 patients (38.8%) had different H pylori strains in their saliva and gastric samples.


CONCLUSIONS
The data suggest that >1 H pylori strain may exist in stomach and saliva in the same patient.
Department of Microbiology, Islamic Azad University, Shahrekord Branch, Shahrekord, Iran. hamomtaz@iaushk.ac.ir
Hassan
H
Momtaz
Negar
N
Souod
Hossein
H
Dabiri
D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000942:Antigens, Bacterial / Q000235:genetics; D001426:Bacterial Proteins / Q000032:analysis* / Q000235:genetics; D001706:Biopsy; D005838:Genotype; D016481:Helicobacter Infections; D016480:Helicobacter pylori / Q000737:chemistry* / Q000235:genetics / Q000472:pathogenicity*; D006801:Humans; D007492:Iran; D008297:Male; D008875:Middle Aged; D012463:Saliva / Q000737:chemistry* / Q000382:microbiology; D013270:Stomach / Q000737:chemistry* / Q000382:microbiology; D055815:Young Adult
D000942:Antigens, Bacterial; D001426:Bacterial Proteins; C074689:VacA protein, Helicobacter pylori; C080866:cagA protein, Helicobacter pylori