<i>Helicobacter pylori</i> Strain and the Pattern of Gastritis Among First‐Degree Relatives of Patients with Gastric Carcinoma

Li, Li; Genta, Robert M.; Go, Mae F.; Gutiérrez, Óscar; Kim, Jong G.; Graham, David Y.

doi:10.1046/j.1523-5378.2002.00108.x

Cited by 16 publications

(18 citation statements)

References 42 publications

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“…Indirect evidence of transmission within sibships has been reported from a low-income country by using concordance in urea breath tests (14). In addition, clustering of strains in sibships has been demonstrated before (16,20,22,38,39).…”

Section: Discussionmentioning

confidence: 88%

“…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: 95%

“…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).…”

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confidence: 97%

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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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Section: Discussionmentioning

confidence: 88%

Section: Discussionmentioning

confidence: 95%

mentioning

confidence: 97%

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Concordance ofHelicobacter pyloriStrains within Families

et al. 2003

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“…Together, these data make it very unlikely that the cag PAI is solely responsible for tropism to a particular region of the stomach, although it may affect colonization levels. Although it is not clear whether bacterial genotypes determine infection patterns (36), some strains have a specific and consistent tropism during animal infections (1). We were not able to find any genes that were present or absent exclusively in isolates obtained from a particular region of the stomach, although such negative results might have been expected given our small sample size.…”

Section: Discussionmentioning

confidence: 99%

Genetic Analysis of Helicobacter pylori Strain Populations Colonizing the Stomach at Different Times Postinfection

et al. 2007

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Genetic diversity of the human gastric pathogen Helicobacter pylori in an individual host has been observed; whether this diversity represents diversification of a founding strain or a mixed infection with distinct strain populations is not clear. To examine this issue, we analyzed multiple single-colony isolates from two to four separate stomach biopsies of eight adult and four pediatric patients from a high-incidence Mexican population. Eleven of the 12 patients contained isolates with identical random amplified polymorphic DNA, amplified fragment length polymorphism, and vacA allele molecular footprints, whereas a single adult patient had two distinct profiles. Comparative genomic hybridization using whole-genome microarrays (array CGH) revealed variation in 24 to 67 genes in isolates from patients with similar molecular footprints. The one patient with distinct profiles contained two strain populations differing at 113 gene loci, including the cag pathogenicity island virulence genes. The two strain populations in this single host had different spatial distributions in the stomach and exhibited very limited genetic exchange. The total genetic divergence and pairwise genetic divergence between isolates from adults and isolates from children were not statistically different. We also analyzed isolates obtained 15 and 90 days after experimental infection of humans and found no evidence of genetic divergence, indicating that transmission to a new host does not induce rapid genetic changes in the bacterial population in the human stomach. Our data suggest that humans are infected with a population of closely related strains that vary at a small number of gene loci, that this population of strains may already be present when an infection is acquired, and that even during superinfection genetic exchange among distinct strains is rare.

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“…H. pylori is acquired during childhood by intrafamilial transmission [3,4], and infection continues lifelong in the absence of antibiotic therapy. It has been postulated [5] that this lifelong association is accompanied by the selection of well-adapted, host-specific variants with particular patterns of expression of adhesins [6,7] and other surface molecules [8,9].…”

Section: Introductionmentioning

confidence: 99%

Gain and Loss of Multiple Genes During the Evolution of Helicobacter pylori

et al. 2005

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Sequence diversity and gene content distinguish most isolates of Helicobacter pylori. Even greater sequence differences differentiate distinct populations of H. pylori from different continents, but it was not clear whether these populations also differ in gene content. To address this question, we tested 56 globally representative strains of H. pylori and four strains of Helicobacter acinonychis with whole genome microarrays. Of the weighted average of 1,531 genes present in the two sequenced genomes, 25% are absent in at least one strain of H. pylori and 21% were absent or variable in H. acinonychis. We extrapolate that the core genome present in all isolates of H. pylori contains 1,111 genes. Variable genes tend to be small and possess unusual GC content; many of them have probably been imported by horizontal gene transfer. Phylogenetic trees based on the microarray data differ from those based on sequences of seven genes from the core genome. These discrepancies are due to homoplasies resulting from independent gene loss by deletion or recombination in multiple strains, which distort phylogenetic patterns. The patterns of these discrepancies versus population structure allow a reconstruction of the timing of the acquisition of variable genes within this species. Variable genes that are located within the cag pathogenicity island were apparently first acquired en bloc after speciation. In contrast, most other variable genes are of unknown function or encode restriction/modification enzymes, transposases, or outer membrane proteins. These seem to have been acquired prior to speciation of H. pylori and were subsequently lost by convergent evolution within individual strains. Thus, the use of microarrays can reveal patterns of gene gain or loss when examined within a phylogenetic context that is based on sequences of core genes.

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Helicobacter pylori Strain and the Pattern of Gastritis Among First‐Degree Relatives of Patients with Gastric Carcinoma

Abstract: The results of this study are not consistent with the hypothesis that specific virulence factors or similar H. pylori strains correlate with a specific histologic pattern or outcome even among those sharing the same environment in childhood.

Cited by 16 publications

References 42 publications

Concordance ofHelicobacter pyloriStrains within Families

Concordance ofHelicobacter pyloriStrains within Families

Genetic Analysis of Helicobacter pylori Strain Populations Colonizing the Stomach at Different Times Postinfection

Gain and Loss of Multiple Genes During the Evolution of Helicobacter pylori

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