Temporal analysis of French Bordetella pertussis isolates by comparative whole-genome hybridization.
Bordetella pertussis, a gram-negative beta-proteobacterium, is the agent of whooping cough in humans. Whooping cough remains a public health problem worldwide, despite well-implemented infant/child vaccination programs. It continues to be endemic and is observed cyclically in vaccinated populations. Classical molecular subtyping methods indicate that genome diversity among B. pertussis isolates is limited. Although the whole bacterial genome has been studied by pulsed-field gel electrophoresis, the genes implicated in the diversity have not been identified. We developed a B. pertussis whole-genome DNA microarray representing over 91% of the predicted coding sequences of the sequenced strain Tohama I. Genomic DNA from clinical isolates with various pulsed-field gel electrophoresis profile patterns was competitively hybridized with the DNA microarray and coding sequences were classified as present, absent or duplicated. Our data strongly suggest that the B. pertussis population is dynamic. In France, with highly vaccinated population, the genetic diversity is low and decreasing with time, and clonal expansion correlates with cycles of the disease. This decrease in diversity is essentially due to loss of genes and pseudogenes. The genes deleted are most of the time flanked by insertion sequences.
Caro
Valérie
V
Molecular Prevention and Therapy of Human Diseases Unit, Institut Pasteur, FRE-CNRS 2849, National Center of Reference of Whooping Cough and other Bordetelloses, 25 rue du Dr Roux, 75724 Paris Cedex 15, France. vcaro@pasteur.fr
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David
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Guigon
Ghislaine
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Hubans
Christine
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Mathilde
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Soubigou
Guillaume
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Renauld-Mongénie
Geneviève
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Antoine
Rudy
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Locht
Camille
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Lemoine
Yves
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Guiso
Nicole
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D001886:Bordetella pertussis / Q000145:classification* / Q000235:genetics* / Q000302:isolation & purification; D004251:DNA Transposable Elements; D004269:DNA, Bacterial / Q000235:genetics; D019143:Evolution, Molecular; D005602:France; D017353:Gene Deletion; D014644:Genetic Variation; D016680:Genome, Bacterial; D017720:Molecular Epidemiology; D009693:Nucleic Acid Hybridization / Q000379:methods*; D020411:Oligonucleotide Array Sequence Analysis; D013997:Time Factors; D014917:Whooping Cough / Q000382:microbiology*
D004251:DNA Transposable Elements; D004269:DNA, Bacterial