DNA-level characterization of Helicobacter pylori strains from patients with overt disease and with benign infections in Bangladesh.
The complex relation between the genotype of Helicobacter pylori and its association with clinical outcome is not well understood. Studies in the West have showed that strains expressing certain virulence factors (vacAs1, vacAm1, and cagA) are associated with duodenal ulcer disease. However, the H. pylori genotype is known to vary with geographic region. In the present study, we compared several virulence markers (cagA, vacA, and iceA) and neutral markers (IS605, IS606, and IS608) in H. pylori strains isolated from 65 adult patients with peptic ulcer (PU) and 50 patients with nonulcer dyspepsia (NUD). PCR tests indicated that cagA is present in 75% of the strains from patients with PU compared to 55% in patients with NUD, and 80% of the isolates from patients with PU carried potentially toxigenic vacAs1 alleles of the vacuolating cytotoxin gene (vacA) compared to 60% in isolates from patients with NUD. However, no significant difference in any other virulence marker was observed in isolates from both groups. Phylogenetic analysis of the vacA middle region and the 5' end of the cagA gene indicates that Bangladeshi isolates are more closely related to H. pylori isolates from India and are different from isolates from East Asia.
International Centre for Diarrhoeal Disease Research, Dhaka, Bangladesh.
Motiur
M
Rahman
Asish K
AK
Mukhopadhyay
Shamsun
S
Nahar
Simanti
S
Datta
Milan Mashhud
MM
Ahmad
Safique
S
Sarker
Ibna M
IM
Masud
Lars
L
Engstrand
M John
MJ
Albert
G Balakrish
GB
Nair
Douglas E
DE
Berg
D000328:Adult; D000483:Alleles; D000942:Antigens, Bacterial / Q000235:genetics; D001425:Bacterial Outer Membrane Proteins / Q000235:genetics; D001426:Bacterial Proteins / Q000235:genetics; D001459:Bangladesh; D001483:Base Sequence; D004269:DNA, Bacterial / Q000235:genetics*; D004415:Dyspepsia / Q000382:microbiology; D005260:Female; D005798:Genes, Bacterial; D016481:Helicobacter Infections / Q000382:microbiology*; D016480:Helicobacter pylori / Q000235:genetics* / Q000302:isolation & purification* / Q000472:pathogenicity; D006801:Humans; D008297:Male; D008875:Middle Aged; D008969:Molecular Sequence Data; D010437:Peptic Ulcer / Q000382:microbiology; D010802:Phylogeny; D014774:Virulence / Q000235:genetics
D000942:Antigens, Bacterial; D001425:Bacterial Outer Membrane Proteins; D001426:Bacterial Proteins; D004269:DNA, Bacterial; C074689:VacA protein, Helicobacter pylori; C080866:cagA protein, Helicobacter pylori; C063113:ice nucleation protein