Helicobacter pylori genotypes in Israeli children: the significance of geography.

BACKGROUND

There is substantial genetic variation among different isolates of Helicobacter pylori, which may affect the clinical outcome. The aims of this study were to find the common H. pylori genotypes in Israeli children and to look for a possible genotype-phenotype correlation.

METHODS

Ninety-eight H. pylori cultures were isolated from antral biopsy specimens of symptomatic Israeli children and were analyzed for vacA and iceA genotype and cagA and cagE status by polymerase chain reaction.

RESULTS

cagA and cagE genes were present in only 25.5% and 24.5%, respectively. The common vacA genotype was s2m2, which was found in 65%. Eleven specimens (11%) contained multiple vacA genotypes. iceA1 was found in 37% and iceA2 in 52% of cases. Both iceA alleles were found in 11%. Increased prevalence of iceA1 and cagE were observed in children with duodenal disease, although it did not reach significance.

CONCLUSIONS

The low prevalence of cagA and the high prevalence of vacA genotype s2m2 in Israeli pediatric patients are different from the genotype prevalence reported globally. However, similar findings have been reported in Egypt, indicating a possible geographic influence. There is a possible correlation between duodenal ulcer and cag E and ice A1 genotype, but the power of the study was too low to prove it.