To investigate the prevalence of the vacA, cagA, cagE, iceA, and babA2 genotypes in
Helicobacter pylori strains isolated from Thai dyspeptic patients, and to determine
whether any correlation exists between these genotypes and clinical manifestations.
Helicobacter pylori was examined in 112 patients (62 with non-ulcer dyspepsia (gastritis),
34 with peptic ulcer disease, and 16 with gastric cancer (GCA)), detected by culture
or direct detection from gastric biopsies. Allelic variants of the vacA, cagA, cagE,
iceA, and babA2 genotypes were identified by using the polymerase chain reaction.
The positive rates for the vacAs1, vacAs2, cagA, cagE, iceA1, iceA2, and babA2 genes
in H. pylori of dyspeptic patients were 100%, 0%, 98.2%, 88.4%, 45.5%, 33.1%, and
92%, respectively. The allelic variant vacAs1m1 was more prevalent (58%) than vacAs1m2
(42%). The cagA and cagE genes were commonly found together (87.5%). The most predominant
genotypes were vacAs1m1, cagA, cagE, iceA1, and babA2. The various genes alone or
in combination had no statistically significant association with the clinical outcomes
(p>0.05).
Neither single gene nor combination of vacA, cagA, cagE, iceA, and babA2 genes was
significantly helpful in predicting the clinical outcome of H. pylori infection in
Thai patients. The high prevalence of these genes in H. pylori isolated from Thai
patient groups suggests that H. pylori strains are geographically dependent.