Evidence of clonal variants of Helicobacter pylori in three generations of a duodenal ulcer disease family.

Nwokolo, CU; Bickley, J.; Attard, Alex R.; Owen, Robert J.; Costas, M.; Fraser, Ian

doi:10.1136/gut.33.10.1323

Cited by 61 publications

(27 citation statements)

References 19 publications

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“…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 (2,7,11,16,20,22,24,29,33,38,39). These observations are in line with familial transmission and an epidemic clonal population structure (37).…”

supporting

confidence: 64%

“…It has previously been suggested that children are colonized by the mother's strain more often than the father's (16). However, both father-offspring and mother-offspring strain concordances have been reported repeatedly by studies using molecular typing (2,7,11,16,20,22,24,33,38,39). Epidemiologic data also indicate that the father has some role in children's acquisition of H. pylori (30,35).…”

Section: Discussionmentioning

confidence: 98%

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Concordance ofHelicobacter pyloriStrains within Families

et al. 2003

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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...

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supporting

confidence: 64%

Section: Discussionmentioning

confidence: 98%

Concordance ofHelicobacter pyloriStrains within Families

et al. 2003

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“…Previous investigations using serological or histological diagnosis and/or the [ 13 C]urea breath test have demonstrated an intrafamilial clustering of H. pylori infections in Canada (8), the United States (18), Italy (7,27), and England (1,26). It has also been suggested that H. pylori is transmitted from infected parents, especially infected mothers, to children in Germany (4,28,29), the United States (10), and Japan (20,22).…”

Section: Discussionmentioning

confidence: 99%

Helicobacter pylori Intrafamilial Infections: Change in Source of Infection of a Child from Father to Mother after Eradication Therapy

Taneike

Tamura

Shimizu

et al. 2001

Clin Diagn Lab Immunol

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Biopsy specimens of the antrum and corpus were obtained from four Helicobacter pylori-infected members of a family and from the same boy (son 1) in whom the infection reappeared after simultaneous successful eradication treatment of three family members, excluding the mother. A total of 18 to 60 H. pylori isolates were obtained from each specimen and subjected to rRNA gene restriction pattern analysis. The father's isolates and the initial isolates from son 1 showed the same HindIII type, which was divided into three HaeIII subtypes. Isolates from the mother and a brother (son 2) and posttreatment isolates from son 1 showed a distinct HindIII type (with one minor subtype), which was divided into six HaeIII subtypes. All subtypes of the initial isolates from son 1 were present in the father's isolates, and all subtypes of the posttreatment isolates from son 1 were present in the mother's isolates but not in son 2's. Electron microscopic analysis of the biopsy specimens demonstrated extremely high levels of H. pylori colonization in the father's gastric mucosa. H. pylori adherence with a ruffle formation was also demonstrated. The findings suggest that son 1 was infected initially with the H. pylori strain of the father and son 2 was infected with the H. pylori strain of the mother and that after eradication therapy son 1 was reinfected with the H. pylori strain of the mother, who did not undergo eradication therapy.Helicobacter pylori colonizes the gastric mucosa via an oral route, and around 60% of individuals worldwide are infected with H. pylori (5). Children are at high risk for H. pylori infections (21, 34). H. pylori infection may persist for years or be lifelong (30,35), although spontaneous clearance is also common in childhood (15,19). H. pylori infection is closely associated with gastritis and peptic ulcers (14, 25), and it is also a bacterial risk factor for gastric cancer (16) and mucosa-associated lymphoid tissue lymphoma (2).The precise mechanisms of H. pylori transmission are not yet known. Previous investigations by Drumm et al. in 1990 (8), Malaty et al. in 1991 (18), and Oderda et al. in 1991 (27) suggested intrafamilial clustering of H. pylori infections. Molecular DNA analyses of familial strains of H. pylori were then performed by Nwokolo et al. in 1992 (26) and by Bamford et al. in 1993 (1), demonstrating intrafamilial infections due to a single H. pylori strain (or a common source of infection within the family). Now, transmission among family members is considered to constitute the main route of H. pylori infection (6).In intrafamilial H. pylori infection, the infected parents, particularly infected mothers, have been considered likely to play a key role in the transmission of H. pylori (4, 28). In contrast, in developing countries, environmental factors may be more important than intrafamilial transmission (29, 32).Those epidemiological studies, however, are not based on molecular biological analysis of H. pylori strains. In this study, we investigated the molecular basis of H. pylor...

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“…Hence, the organism has both the molecular machinery and the ecological setup for strain-to-strain spread of DNA to occur. It will clearly be important to study the potential importance of horizontal gene transfer in scenarios such as therapeutic treatment failures, drug resistance, mosaic gene structure, generation of antigenic diversity, persistent infections, and intrafamily strain variation (39).…”

Section: Discussionmentioning

confidence: 99%

Population genetic analysis of Helicobacter pylori by multilocus enzyme electrophoresis: extensive allelic diversity and recombinational population structure

et al. 1996

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Genetic diversity and relationships in 74 Helicobacter pylori isolates recovered from patients assigned to distinct clinical categories were estimated by examination of allelic variation in six genes encoding metabolic housekeeping enzymes by multilocus enzyme electrophoresis. Seventy-three distinct allele profiles, representing multilocus chromosomal genotypes, were identified. All six loci were highly polymorphic, with an average of 11.2 alleles per locus. The mean genetic diversity in the sample was 0.735, a value that exceeds the level of diversity recorded in virtually all bacterial species studied by multilocus enzyme electrophoresis. A high frequency of occurrence of null alleles (lack of enzyme activity) was identified and warrants further investigation at the molecular level. Lack of linkage disequilibrium (nonrandom association of alleles over loci) indicates that horizontal transfer and recombination of metabolic enzyme genes have contributed to the generation of chromosomal diversity in H. pylori. In this sample of isolates, there was no statistically significant association of multilocus enzyme electrophoretic types or cluster of related chromosomal types and disease category.

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Evidence of clonal variants of Helicobacter pylori in three generations of a duodenal ulcer disease family.

Cited by 61 publications

References 19 publications

Concordance ofHelicobacter pyloriStrains within Families

Concordance ofHelicobacter pyloriStrains within Families

Helicobacter pylori Intrafamilial Infections: Change in Source of Infection of a Child from Father to Mother after Eradication Therapy

Population genetic analysis of Helicobacter pylori by multilocus enzyme electrophoresis: extensive allelic diversity and recombinational population structure

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