title: Linkage disequilibrium between minisatellite loci supports clonal evolution of Mycobacterium tuberculosis in a high tuberculosis incidence area.
abstract: Deciphering the structure of pathogen populations is instrumental for the understanding of the epidemiology and history of infectious diseases and for their control. Although Mycobacterium tuberculosis is the most widespread infectious agent in humans, its actual population structure has remained hypothetical until now because: (i) its structural genes are poorly polymorphic; (ii) adequate samples and appropriate statistics for population genetic analysis have not been considered. To investigate this structure, we analysed the statistical associations (linkage disequilibrium) between 12 independent M. tuberculosis minisatellite-like loci by high-throughput genotyping within a model population of 209 isolates representative of the genetic diversity in an area with a very high incidence of tuberculosis. These loci contain variable number tandem repeats (VNTRs) of genetic elements named mycobacterial interspersed repetitive units (MIRUs). Highly significant linkage disequilibrium was detected among the MIRU-VNTR loci in this model. This linkage disequilibrium was also evident when the MIRU-VNTR types were compared with the IS6110 restriction fragment length polymorphism types. These results support a predominant clonal evolution of M. tuberculosis.
authors.affiliation: Laboratoire des Mécanismes Moléculaires de la Pathogenèse Bactérienne, INSERM U447, Institut Pasteur de Lille, Cedex, France. philip.supply@pasteur-lille.fr
authors.forename: Philip
authors.initials: P
authors.lastname: Supply
authors.forename: Robin M
authors.initials: RM
authors.lastname: Warren
authors.forename: Anne-Laure
authors.initials: AL
authors.lastname: Bañuls
authors.forename: Sarah
authors.initials: S
authors.lastname: Lesjean
authors.forename: Gian D
authors.initials: GD
authors.lastname: Van Der Spuy
authors.forename: Lee-Anne
authors.initials: LA
authors.lastname: Lewis
authors.forename: Michel
authors.initials: M
authors.lastname: Tibayrenc
authors.forename: Paul D
authors.initials: PD
authors.lastname: Van Helden
authors.forename: Camille
authors.initials: C
authors.lastname: Locht
mesh_terms: D015373:Bacterial Typing Techniques; D004251:DNA Transposable Elements; D019143:Evolution, Molecular; D014644:Genetic Variation; D006801:Humans; D015810:Linkage Disequilibrium; D018598:Minisatellite Repeats / Q000235:genetics*; D009169:Mycobacterium tuberculosis / Q000145:classification* / Q000235:genetics; D012150:Polymorphism, Restriction Fragment Length; D013019:South Africa / Q000453:epidemiology; D014397:Tuberculosis, Pulmonary / Q000453:epidemiology / Q000382:microbiology
chemical_list: D004251:DNA Transposable Elements