Introduction: The spread of Helicobacter pylori infection is still
a subject of research. Family transmission is the most
important transmission way in developed countries.
Aim: To assess of transmission within family on the base of
genetic typing of H. pylori strains isolated from family
members.
Material and methods: Altogether 55 members from
22 families with diagnosed gastritis connected with H. pylori
infection were included into the study. Bacteria genetic
material was isolated from the stomach biopsy specimens
with the use of NucleoSpin®Tissue kit (Macherey-Nagel).
Genes: glmM, cagA, cagE, iceA underwent polymerase chain
reaction during analysis of H. pylori strains and multiplex PCR
reaction for vacA (s1/s2 + m1/m2) was performed.
Results: Gastritis caused by H. pylori infection was diagnosed
in 55 members of 22 families, including 13 mothers, 11 fathers
and 30 offspring. Parents’ age varied from 31 to 54 years
(mean age 39.1 years), but offspring’s age varied from 4 to 26
years (mean age 11.9 years). Unanimity of H. pylori genetic
types were found only in 18 from 44 pairs of persons who are
the members of the same family (40.9%). Most often
infection with the same genetic type of H. pylori was proved
in pairs mother-child (70.6%). Only one of seven married
couples was infected with the same genetic type of bacteria
(14.3%). Infection with the same H. pylori type was observed
similarly rarely between father and his child (27.3%), but also
among siblings (22.2%). Only in three among 11 families with
three persons infected with H. pylori all family members
included in the study (mother and two children two times,mother-father-son once) were infected with the same genetic
type of bacteria. The presence of cagA gene was found in
45 persons of 55 family members (81.8%) infected with
H. pylori, cagE gene was noted in 13 of them (23.6%), iceA
gene – in 7 of them (12.7%), vacAs gene – in 17 of them
(30.9%), but vasAm gene – in 7 of them (12.7%).
Conclusions:
1) Genetic typing of H. pylori strains isolated from family
members confirms essential role of mother in infection
transmission to children.
2) Infection of other family members, but particularly married
couples seem to be less important in infection
transmission