Characterization of a highly conserved island in the otherwise divergent Bordetella holmesii and Bordetella pertussis genomes.
The recently discovered pathogen Bordetella holmesii has been isolated from the airways and blood of diseased humans. Genetic events contributing to the emergence of B. holmesii are not understood, and its phylogenetic position among the bordetellae remains unclear. To address these questions, B. holmesii strains were analyzed by comparative genomic hybridization (CGH) to a Bordetella pertussis microarray and by multilocus sequence typing. Both methods indicated substantial sequence divergence between B. pertussis and B. holmesii. However, CGH identified a putative pathogenicity island of 66 kb that is highly conserved between these species and contains several IS481 elements that may have been laterally transferred from B. pertussis to B. holmesii. This island contains, among other genes, a functional, iron-regulated locus encoding the biosynthesis, export, and uptake of the siderophore alcaligin. The acquisition of this genomic island by B. holmesii may have significantly contributed to its emergence as a human pathogen. Horizontal gene transfer between B. pertussis and B. holmesii may also explain the unusually high sequence identity of their 16S rRNA genes.
Diavatopoulos
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DA
Laboratory for Vaccine Preventable Diseases, National Institute of Public Health and the Environment, Antonie van Leeuwenhoeklaan 9, P.O. Box 1, 3720 BA Bilthoven, The Netherlands.
Cummings
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CA
van der Heide
H G J
HG
van Gent
M
M
Liew
S
S
Relman
D A
DA
Mooi
F R
FR
D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism; D001884:Bordetella / Q000145:classification* / Q000235:genetics* / Q000302:isolation & purification; D001886:Bordetella pertussis / Q000145:classification* / Q000235:genetics* / Q000302:isolation & purification; D019143:Evolution, Molecular; D016680:Genome, Bacterial; D044404:Genomic Islands / Q000235:genetics*; D006801:Humans; D006877:Hydroxamic Acids / Q000378:metabolism; D008969:Molecular Sequence Data; D009693:Nucleic Acid Hybridization; D020411:Oligonucleotide Array Sequence Analysis; D010802:Phylogeny; D017422:Sequence Analysis, DNA
D001426:Bacterial Proteins; D006877:Hydroxamic Acids; C092056:alcaligin