The aim of this study was to determine the presence of
Helicobacter pylori
cytotoxin-associated gene (
cagA)/vacuolating cytotoxin gene (
vacA) among patients with chronic gastritis in Cuba and Venezuela.
Gastric antrum biopsies were taken for culture, DNA extraction and PCR analysis. Amplification of
vacA and
cagA segments was performed
using two regions of
cagA: 349 bp were amplified with the F1/B1 primers and the remaining 335 bp were amplified with the B7629/B7628 primers.
The VA1-F/VA1-R set of primers was used to amplify the 259-bp (s1) or 286-bp (s2) product and the VAG-R/VAG-F set of primers was used to
amplify the 567-bp (m1) or 642-bp (m2) regions of
vacA.
cagA was detected in 87% of the antral samples from Cuban patients and
80.3% of those from Venezuelan patients. All possible combinations of
vacA regions were found, with the exception of s2/m1.
The predominant combination found in both countries was s1/m1. The percentage of
cagA
+ strains was increased by the use of a second
set of primers and a greater number of strains was amplified with the B7629/B7628 primers in the Cuban patients (p = 0.0001).
There was no significant difference between the presence of the allelic variants of
vacA and
cagA in both populations.
The predominant genotype was
cagA
+/s1m1 in both countries. The results support the necessary investigation of isolates circulating among
the human population in each region.
