Analysis of vacA, cagA, and IS605 genotypes and those determined by PCR amplification of DNA between repetitive sequences of Helicobacter pylori strains isolated from patients with nonulcer dyspepsia or mucosa-associated lymphoid tissue lymphoma.

The vacA s and m genotypes and the presence of cagA and IS605 were determined in Helicobacter pylori strains from patients with mono- and multiple infections. Surprisingly, these genetic markers were not associated with nonulcer dyspepsia or mucosa-associated lymphoid tissue lymphoma. The presence of cagA correlated with the presence of the vacA s1 allele (P < 0.05), whereas the presence of IS605 was associated with the presence of the s2 allele (P < 0.05).