Dataset Information

Helicobacter pylori genome variability in a framework of familial transmission.

ABSTRACT:

Background

Helicobacter pylori infection is exceptionally prevalent and is considered to be acquired primarily early in life through person-to-person transmission within the family. H. pylori is a genetically diverse bacterial species, which may facilitate adaptation to new hosts and persistence for decades. The present study aimed to explore the genetic diversity of clonal isolates from a mother and her three children in order to shed light on H. pylori transmission and host adaptation.

Results

Two different H. pylori strains and strain variants were identified in the family members by PCR-based molecular typing and sequencing of five loci. Genome diversity was further assessed for 15 isolates by comparative microarray hybridizations. The microarray consisted of 1,745 oligonucleotides representing the genes of two previously sequenced H. pylori strains. The microarray analysis detected a limited mean number (+/- standard error) of divergent genes between clonal isolates from the same and different individuals (1 +/- 0.4, 0.1%, and 3 +/- 0.3, 0.2%, respectively). There was considerable variability between the two different strains in the family members (147 +/- 4, 8%) and for all isolates relative to the two sequenced reference strains (314 +/- 16, 18%). The diversity between different strains was associated with gene functional classes related to DNA metabolism and the cell envelope.

Conclusion

The present data from clonal H. pylori isolates of family members do not support that transmission and host adaptation are associated with substantial sequence diversity in the bacterial genome. However, important phenotypic modifications may be determined by additional genetic mechanisms, such as phase-variation. Our findings can aid further exploration of H. pylori genetic diversity and adaptation.

SUBMITTER: Kivi M

PROVIDER: S-EPMC1899507 | biostudies-literature | 2007 Jun

REPOSITORIES: biostudies-literature

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Publications

Helicobacter pylori genome variability in a framework of familial transmission.

Kivi Mårten M Rodin Sandra S Kupershmidt Ilya I Lundin Annelie A Tindberg Ylva Y Granström Marta M Engstrand Lars L

BMC microbiology 20070611

<h4>Background</h4>Helicobacter pylori infection is exceptionally prevalent and is considered to be acquired primarily early in life through person-to-person transmission within the family. H. pylori is a genetically diverse bacterial species, which may facilitate adaptation to new hosts and persistence for decades. The present study aimed to explore the genetic diversity of clonal isolates from a mother and her three children in order to shed light on H. pylori transmission and host adaptation. ...[more]

PMID: 17562007

Similar Datasets

Project description:Transmission of Helicobacter pylori is thought to occur mainly during childhood, and predominantly within families. However, due to the difficulty of obtaining H. pylori isolates from large population samples and to the extensive genetic diversity between isolates, the transmission and spread of H. pylori remain poorly understood. We studied the genetic relationships of H. pylori isolated from 52 individuals of two large families living in a rural community in South Africa and from 43 individuals of 11 families living in urban settings in the United Kingdom, the United States, Korea, and Colombia. A 3,406 bp multilocus sequence haplotype was determined for a total of 142 H. pylori isolates. Isolates were assigned to biogeographic populations, and recent transmission was measured as the occurrence of non-unique isolates, i.e., isolates whose sequences were identical to those of other isolates. Members of urban families were almost always infected with isolates from the biogeographic population that is common in their location. Non-unique isolates were frequent in urban families, consistent with familial transmission between parents and children or between siblings. In contrast, the diversity of H. pylori in the South African families was much more extensive, and four distinct biogeographic populations circulated in this area. Non-unique isolates were less frequent in South African families, and there was no significant correlation between kinship and similarity of H. pylori sequences. However, individuals who lived in the same household did have an increased probability of carrying the same non-unique isolates of H. pylori, independent of kinship. We conclude that patterns of spread of H. pylori under conditions of high prevalence, such as the rural South African families, differ from those in developed countries. Horizontal transmission occurs frequently between persons who do not belong to a core family, blurring the pattern of familial transmission that is typical of developed countries. Predominantly familial transmission in urban societies is likely a result of modern living conditions with good sanitation and where physical contact between persons outside the core family is limited and regulated by societal rules. The patterns observed in rural South African families may be representative of large parts of the developing world.

Dataset Information

Helicobacter pylori genome variability in a framework of familial transmission.

Background

Results

Conclusion

Publications

Helicobacter pylori genome variability in a framework of familial transmission.

Similar Datasets

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