87 MOLECULAR TYPING OF HELICOBACTER PYLORI STRAINS ISOLATED AMONGST INFECTED FAMILY MEMBERS

Abstract

The aim of this study was to investigate the spread of Helicobacter Pylori (HP) infection amongst the members of the families of infected individuals, using a direct DNA amplification technique and restriction pattern analysis (REA-PCR). Eleven symptomatic index patients (7 children aged 6-14 years, 4 adults) seropositive for HP antibodies, and their 18 (out of 25) seropositive for HP antibodies family members were found to be HP positive by histology and culture. Biopsy specimens were taken from the duodenum, pylorus, antrum and fundus of the above patients to assess the possibility of multiple HP strains infection. Amplification by PCR of UreA and UreB genes of HP, followed by restriction pattern analysis was used for the comparison of HP strains isolated in the index patients and their family members. The results of our study were the following: 1) in 3 out of 6 families the children and their parents were infected by different HP strains. 2) In 4 out of 8 couples different HP strains were found in each spouse. 3) In 5 out of 11 families 2-4 different HP strains were found in each family. 4) In only one patient were 2 different HP strains isolated in the antrum and fundus. In conclusion vertical and/or horizontal transmission of HP within families is possible, although a common source of infection cannot be precluded. However in 50% of the families different sources of HP infection of the family members can be suspected. Infected individuals by multiple HP strains can be found, but this is a rather rare phenomenon.