CagA C-terminal variations in Helicobacter pylori strains from Colombian patients with gastric precancerous lesions.
Clin Microbiol Infect
; 16(4): 369-78, 2010 Apr.
Article
in En
| MEDLINE
| ID: mdl-19456839
ABSTRACT
The C-terminus of the Helicobacter pylori CagA protein is polymorphic, bearing different EPIYA sequences (EPIYA-A, B, C or D), and one or more CagA multimerization (CM) motifs. The number of EPIYA-C motifs is associated with precancerous lesions and gastric cancer (GC). The relationship between EPIYA, CM motifs and gastric lesions was examined in H. pylori-infected Colombian patients from areas of high and low risk for GC. Genomic DNA was extracted from H. pylori strains cultured from gastric biopsies from 80 adults with dyspeptic symptoms. Sixty-seven (83.8%) of 80 strains were cagA positive. The 3' region of cagA was sequenced, and EPIYA and CM motifs were identified. CagA proteins contained one (64.2%), two (34.3%) or three EPIYA-C motifs (1.5%), all with Western type CagA-specific sequences. Strains with one EPIYA-C motif were associated with less severe gastric lesions (non-atrophic and multifocal atrophic gastritis), whereas strains with multiple EPIYA-C motifs were associated with more severe lesions (intestinal metaplasia and dysplasia) (p <0.001). In 54 strains, the CM motifs were identical to those common in Western strains. Thirteen strains from the low-risk area contained two different CM motifs one of Western type located within the EPIYA-C segment and another following the EPIYA-C segment and resembling the CM motif found in East Asian strains. These strains induced significantly shorter projections in AGS cells and an attenuated reduction in levels of CagA upon immunodepletion of SHP-2 than strains possessing Western/Western motifs. This novel finding may partially explain the difference in GC incidence in these populations.
Full text:
1
Collection:
01-internacional
Database:
MEDLINE
Main subject:
Precancerous Conditions
/
Stomach Neoplasms
/
Bacterial Proteins
/
Helicobacter pylori
/
Helicobacter Infections
/
Antigens, Bacterial
Type of study:
Prognostic_studies
Limits:
Adult
/
Humans
/
Male
/
Middle aged
Country/Region as subject:
America do sul
/
Colombia
Language:
En
Journal:
Clin Microbiol Infect
Journal subject:
DOENCAS TRANSMISSIVEIS
/
MICROBIOLOGIA
Year:
2010
Document type:
Article
Affiliation country: