The functional status of the Helicobacter pylori sabB adhesin gene as a putative marker for disease outcome.
BACKGROUND
Helicobacter pylori factors that contribute to disease outcome are largely unknown, but intimate contact with host cells mediated by outer membrane proteins is thought to play an important role. Expression of the outer membrane proteins OipA, HopZ, SabA, and SabB is regulated by phase-variable dinucleotide repeats in the coding regions of the respective genes. We have evaluated the correlation between the expression status of these four genes and disease outcome of H. pylori infection in a Dutch patient population.


METHODS
H. pylori strains, isolated from 96 Dutch patients with gastritis (n = 29), duodenal ulcer (n = 28), gastric ulcer (n = 21), gastric carcinoma (n = 9), and lymphoma (n = 9), were analyzed for the 'on/off' expression status of the H. pylori genes oipA, hopZ, sabA, and sabB by direct DNA sequence analysis of amplified fragments.


RESULTS
The off-status of sabB was significantly associated with duodenal ulcer (p =.036), but not with gastric ulcer. In contrast, the expression status of oipA, hopZ, and sabA did not correlate with disease outcome. Furthermore, lymphoma strains appeared to express a significantly smaller amount of putative adhesins when compared to gastritis, gastric ulcer, duodenal ulcer and gastric carcinoma strains (p <.02 for all groups tested).


CONCLUSIONS
The off-status of sabB was found to be associated with duodenal ulcer disease, and thus represents a putative marker for disease outcome. Assuming that SabB is involved in bacterial adhesion, this association suggests that adherent H. pylori are more prone to elimination by the host immune system.
de Jonge
Ramon
R
Department of Gastroenterology and Hepatology, Erasmus MC-University Medical Center Rotterdam, Rotterdam, The Netherlands.
Pot
Raymond G J
RG
Loffeld
Ruud J L F
RJ
van Vliet
Arnoud H M
AH
Kuipers
Ernst J
EJ
Kusters
Johannes G
JG
D018829:Adhesins, Bacterial / Q000235:genetics* / Q000502:physiology; D000595:Amino Acid Sequence; D000942:Antigens, Bacterial / Q000235:genetics; D001425:Bacterial Outer Membrane Proteins / Q000235:genetics*; D001426:Bacterial Proteins / Q000235:genetics; D001483:Base Sequence; D004269:DNA, Bacterial / Q000737:chemistry / Q000302:isolation & purification; D018900:Dinucleotide Repeats; D004381:Duodenal Ulcer / Q000382:microbiology; D005756:Gastritis / Q000382:microbiology; D015870:Gene Expression; D005798:Genes, Bacterial; D044404:Genomic Islands / Q000235:genetics; D016481:Helicobacter Infections / Q000382:microbiology* / Q000473:pathology; D016480:Helicobacter pylori / Q000235:genetics* / Q000472:pathogenicity*; D006801:Humans; D018442:Lymphoma, B-Cell, Marginal Zone / Q000382:microbiology; D008969:Molecular Sequence Data; D010437:Peptic Ulcer / Q000382:microbiology; D013274:Stomach Neoplasms / Q000382:microbiology
D018829:Adhesins, Bacterial; D000942:Antigens, Bacterial; D001425:Bacterial Outer Membrane Proteins; D001426:Bacterial Proteins; D004269:DNA, Bacterial; C121269:HopZ protein, Helicobacter pylori; C103937:PicB protein, Helicobacter pylori; C080866:cagA protein, Helicobacter pylori