Abstract
Multiple
Helicobacter pylori
strains may colonize an individual host. Using enzyme-linked immunosorbent assay and line probe assay (LiPA) techniques, we analyzed the prevalence of mixed
H. pylori
colonization in 127 subjects from Venezuela, a country of high
H. pylori
prevalence, from three regions representing different population groups: the Andes (Merida), where Caucasian mestizos predominate, a major city near the coast (Caracas), where Amerindian-Caucasian-African mestizos predominate, and an Amazonian community (Puerto Ayacucho), where Amerindians predominate and mestizos reflect Amerindian and Caucasian ancestry. Among 121
H. pylori
-positive persons, the prevalence of
cagA
-positive strains varied from 50% (Merida) to 86% (Puerto Ayacucho) by LiPA. Rates of mixed colonization also varied, as assessed by LiPA of the
vacA s
(mean, 49%) and
m
(mean, 26%) regions. In total, 55% of the individuals had genotypic evidence of mixed colonization.
vacA s1c
, a marker of Amerindian (East Asian) origin, was present in all three populations, especially from Puerto Ayacucho (86%). These results demonstrate the high prevalence of mixed colonization and indicate that the
H. pylori
East Asian
vacA
genotype has survived in all three populations tested.