Investigations into genome diversity of <it>Haemophilus influenzae</it> using whole genome sequencing of clinical isolates and laboratory transformants

• Main Authors: Power Peter M, Bentley Stephen D, Parkhill Julian, Moxon E, Hood Derek W
• Format: Article
• Language: English
• Published: BMC 2012-11-01
• Series: BMC Microbiology
• Subjects: <it>Haemophilus influenzae</it>; Genome sequence; Population structure; Transformation
• Online Access: http://www.biomedcentral.com/1471-2180/12/273

<p>Abstract</p> <p>Background</p> <p><it>Haemophilus influenzae</it> is an important human commensal pathogen associated with significant levels of disease. High-throughput DNA sequencing was used to investigate differences in genome content within this species.</p> <p>Results</p> <p>Genomic DNA sequence was obtained from 85 strains of <it>H. influenzae</it> and from other related species, selected based on geographical site of isolation, disease association and documented genotypic and phenotypic differences. When compared by Mauve alignment these indicated groupings of <it>H. influenzae</it> that were consistent with previously published analyses<b>; c</b>apsule expressing strains fell into two distinct groups and those of serotype b (Hib) were found in two closely positioned lineages. For 18 Hib strains representing both lineages we found many discrete regions (up to 40% of the total genome) displaying sequence variation when compared to a common reference strain. Evidence that this naturally occurring pattern of inter-strain variation in <it>H. influenzae</it> can be mediated by transformation was obtained through sequencing DNA obtained from a pool of 200 independent transformants of a recipient (strain Rd) using donor DNA from a heterologous Hib strain (Eagan).</p> <p>Conclusion</p> <p>Much of the inter-strain variation in genome sequence in <it>H. influenzae</it> is likely the result of inter-strain exchanges of DNA, most plausibly through transformation.</p>