BACKGROUND: The genes @entity2757 and vacA encode @entity1534 virulence factors. AIM: To genotype these genes in @entity1534 strains isolated from @entity1 with @entity344 . MATERIAL AND METHODS: We studied 50 @entity1 who underwent an upper @entity344 , with positive culture for @entity1534 . Detection of @entity2757 and vacA genotyping was done using polymerase chain reactions. RESULTS: The gene @entity2757 was detected in 19 samples (38%). Signal sequences s1 and s2 of vacA gene were detected in 16 samples each (32%). There was simultaneous amplification of s1 and s2 in 6 samples and they were not detected in 9 samples. The middle region of vacA was m1 in 9 samples, m2 in 29 samples and there was simultaneous amplification of m1 and m2 in 12 samples. In 16 samples (32%), more than one type of signal sequence or medial region was detected. Of those @entity1 in whom vacA was the only genotype detected, 15 were s2/m2, 7 were s1/m1, 4 were s1/ @entity25089 was s2/m1. CONCLUSIONS: In these @entity1 , the infection with @entity2757 - @entity1534 strains, predominates, the prevalence of infection with s1 or s2 strains is similar and the predominant medial region is m2.

[ XXXX : @entity2757 analysis and vacA genotyping in Chile. Detection of a s2/m1 strain].

@entity1 :: ('9606', 'Species') :: ['patients'] @entity344 :: ('MESH:D005767', 'Disease') :: ['gastrointestinal endoscopy', 'upper gastrointestinal symptoms'] @entity25089 :: ('100507027', 'Gene') :: ['m2 and 1'] @entity1534 :: ('210', 'Species') :: ['H pylori'] @entity2757 :: ('6279', 'Gene') :: ['cagA']
@entity1534 :: (210,Species) :: ['Helicobacter pylori']
