Generation of genic diversity among Streptococcus pneumoniae strains via horizontal gene transfer during a chronic polyclonal pediatric infection

N. Luisa Hiller, Azad Ahmed, Evan Powell, Darren P. Martin, Rory Eutsey, Josh Earl, Benjamin Janto, Robert J. Boissy, Justin Hogg, Karen Barbadora, Rangarajan Sampath, Shaun Lonergan, J. Christopher Post, Fen Z. Hu, Garth D. Ehrlich

Research output: Contribution to journalArticle

105 Citations (Scopus)

Abstract

Although there is tremendous interest in understanding the evolutionary roles of horizontal gene transfer (HGT) processes that occur during chronic polyclonal infections, to date there have been few studies that directly address this topic. We have characterized multiple HGT events that most likely occurred during polyclonal infection among nasopharyngeal strains of Streptococcus pneumoniae recovered from a child suffering from chronic upper respiratory and middle-ear infections. Whole genome sequencing and comparative genomics were performed on six isolates collected during symptomatic episodes over a period of seven months. From these comparisons we determined that five of the isolates were genetically highly similar and likely represented a dominant lineage. We analyzed all genic and allelic differences among all six isolates and found that all differences tended to occur within contiguous genomic blocks, suggestive of strain evolution by homologous recombination. From these analyses we identified three strains (two of which were recovered on two different occasions) that appear to have been derived sequentially, one from the next, each by multiple recombination events. We also identified a fourth strain that contains many of the genomic segments that differentiate the three highly related strains from one another, and have hypothesized that this fourth strain may have served as a donor multiple times in the evolution of the dominant strain line. The variations among the parent, daughter, and grand-daughter recombinant strains collectively cover greater than seven percent of the genome and are grouped into 23 chromosomal clusters. While capturing in vivo HGT, these data support the distributed genome hypothesis and suggest that a single competence event in pneumococci can result in the replacement of DNA at multiple non-adjacent loci.

Original languageEnglish (US)
Article numbere01108
JournalPLoS pathogens
Volume6
Issue number9
DOIs
StatePublished - Sep 1 2010

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Horizontal Gene Transfer
Streptococcus pneumoniae
Genome
Pediatrics
Nuclear Family
Infection
Homologous Recombination
Middle Ear
Genomics
Mental Competency
Genetic Recombination
Tissue Donors
DNA

ASJC Scopus subject areas

  • Parasitology
  • Microbiology
  • Immunology
  • Molecular Biology
  • Genetics
  • Virology

Cite this

Generation of genic diversity among Streptococcus pneumoniae strains via horizontal gene transfer during a chronic polyclonal pediatric infection. / Hiller, N. Luisa; Ahmed, Azad; Powell, Evan; Martin, Darren P.; Eutsey, Rory; Earl, Josh; Janto, Benjamin; Boissy, Robert J.; Hogg, Justin; Barbadora, Karen; Sampath, Rangarajan; Lonergan, Shaun; Post, J. Christopher; Hu, Fen Z.; Ehrlich, Garth D.

In: PLoS pathogens, Vol. 6, No. 9, e01108, 01.09.2010.

Research output: Contribution to journalArticle

Hiller, NL, Ahmed, A, Powell, E, Martin, DP, Eutsey, R, Earl, J, Janto, B, Boissy, RJ, Hogg, J, Barbadora, K, Sampath, R, Lonergan, S, Post, JC, Hu, FZ & Ehrlich, GD 2010, 'Generation of genic diversity among Streptococcus pneumoniae strains via horizontal gene transfer during a chronic polyclonal pediatric infection', PLoS pathogens, vol. 6, no. 9, e01108. https://doi.org/10.1371/journal.ppat.1001108
Hiller, N. Luisa ; Ahmed, Azad ; Powell, Evan ; Martin, Darren P. ; Eutsey, Rory ; Earl, Josh ; Janto, Benjamin ; Boissy, Robert J. ; Hogg, Justin ; Barbadora, Karen ; Sampath, Rangarajan ; Lonergan, Shaun ; Post, J. Christopher ; Hu, Fen Z. ; Ehrlich, Garth D. / Generation of genic diversity among Streptococcus pneumoniae strains via horizontal gene transfer during a chronic polyclonal pediatric infection. In: PLoS pathogens. 2010 ; Vol. 6, No. 9.
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