Concordance ofHelicobacter pyloriStrains within Families

Abstract

Helicobacter pylori infection is typically acquired in early childhood, and a predominantly intrafamilial transmission has been postulated. To what extent family members share the same strains is poorly documented. Our aim was to explore patterns of shared strains within families by using molecular typing. Family members of H. pylori-infected 10-to 12-year-old index children identified in a school survey were invited to undergo gastroscopy. Bacterial isolates were typed with random amplified polymorphic DNA and PCRrestriction fragment length polymorphism of the genes ureA-B, glmM, or flaA. The presence or absence of the cag pathogenicity island, a bacterial virulence factor, was determined by PCR. GelCompar II software, supplemented with visual inspection, was used in the cluster analysis. In 39 families, 104 individuals contributed 208 bacterial isolates from the antrum and corpus. A large proportion, 29 of 36 (81%) of the offspring in a sibship, harbored the same strain as at least one sibling. Mother-offspring strain concordance was detected in 10 of 18 (56%) of the families. Of 17 investigated father-offspring relations in eight families, none were strain concordant. Spouses were infected with the same strains in 5 of 23 (22%) of the couples. Different strains in the antrum and corpus were found in 8 of 104 (8%) of the subjects. Our family-based fingerprinting study demonstrates a high proportion of shared strains among siblings. Transmission between spouses seems to be appreciable. The data support mother-child and sib-sib transmission as the primary transmission pathways of H. pylori.Helicobacter pylori colonizes half of the world's population, and the infection is associated with chronic gastritis, peptic ulcer, gastric cancer, and gastric lymphoma. In-depth knowledge of the transmission patterns may constitute important information for future intervention strategies.In the absence of consistent and verified environmental reservoirs, a predominantly person-to-person transmission has been postulated. H. pylori infection is associated with poor living conditions, and possible transmission routes are fecaloral, oral-oral, or gastro-oral, but firm evidence is lacking (36). The infection clusters in families and is usually acquired in early childhood. A child's risk of being infected is largely determined by the presence or absence of infected family members. Having an infected mother has been suggested to be a more prominent risk factor than having an infected father (30,35). Indications of sib-sib transmission have been reported (14). Transmission between spouses occurs but its significance is unclear (5, 9, 19).Molecular typing of pathogens can corroborate and further characterize the transmission pathways suggested by epidemiologic data based on infection status. Shared strains among individuals indicate person-to-person transmission or acquisition from a common source. Unrelated individuals harbor distinct H. pylori isolates (1), while clonal lineages can be discerned within families (2,7,11,16,20,22,24,2...

Prevalence and Risk Factors of Helicobacter pylori Infection in Muong Children in Vietnam

“…The importance of both infected siblings and mothers was recently corroborated in a Brazilian high-prevalence community [41]. The findings are substantiated by a previous report of H. pylori strain concordance between mothers and offspring and amongst siblings, demonstrated by using bacterial molecular typing in a subset of the currently studied families [40]. Aguemon et al also reported the higher infection rate in children whose parents were both infected or only infected mother.…”

“…Malaty et al also provided data demonstrating an increased prevalence of infected children to infected parents [4,39]. The higher prevalence of infection due to H. pylori in parents of infected children suggests person-to-person transmission within the family [5,40]. The H. pylori status of the mother was found to be a strong determinant for childhood infection and more predictive than the status of the father [13,14,36].…”

“…By using logistic regression analysis, sharing bed (OR, 95% CI: 3.85, 1.53-9.67, p 0.003) and infected mothers (OR, 95% CI: 9.82, 4.13-23.31, p<0.001) were independent predictors for H. pylori infection [42]. Family contact with infected persons and crowded living conditions were associated with increased risk of infection [5,37,40]. In the present study, we found higher rates of seropositivity among children who had H. pylori positive mothers, siblings or grandfather compared to those whose family members were negative.…”

Distinguishing human ethnic groups by means of sequences from Helicobacter pylori : Lessons from Ladakh

“…pylori are highly genetically diverse, providing Ϸ1,400 informative sites within 4.5 kb of sequence, and their global genetic structure parallels that of humans (28). Moreover, epidemiological studies have shown that transmission occurs predominantly within families (29)(30)(31)(32). This point is critical because vertical transmission is more likely to reflect human migrations than is the horizontal transmission that is typical of many microbes.…”

Acquisition of Helicobacter pylori Infection in Rhesus Macaques Is Most Consistent with Oral-Oral Transmission

“…Epidemiological and molecular fingerprinting data suggest that the transmission of Helicobacter pylori occurs from person to person during childhood, without an animal or environmental reservoir (2,9,10,(16)(17)(18). The relative importance of fecaloral transmission versus that of oral-oral transmission is controversial (7,13,14).…”