title: Locally Confined Clonal Complexes of Mycobacterium ulcerans in Two Buruli Ulcer Endemic Regions of Cameroon.
abstract: BACKGROUND
  Mycobacterium ulcerans is the causative agent of the necrotizing skin disease Buruli ulcer (BU), which has been reported from over 30 countries worldwide. The majority of notified patients come from West African countries, such as Côte d'Ivoire, Ghana, Benin and Cameroon. All clinical isolates of M. ulcerans from these countries are closely related and their genomes differ only in a limited number of single nucleotide polymorphisms (SNPs).
  
  
  RESULTS
  We performed a molecular epidemiological study with clinical isolates from patients from two distinct BU endemic regions of Cameroon, the Nyong and the Mapé river basins. Whole genome sequencing of the M. ulcerans strains from these two BU endemic areas revealed the presence of two phylogenetically distinct clonal complexes. The strains from the Nyong river basin were genetically more diverse and less closely related to the M. ulcerans strain circulating in Ghana and Benin than the strains causing BU in the Mapé river basin.
  
  
  CONCLUSIONS
  Our comparative genomic analysis revealed that M. ulcerans clones diversify locally by the accumulation of SNPs. Case isolates coming from more recently emerging BU endemic areas, such as the Mapé river basin, may be less diverse than populations from longer standing disease foci, such as the Nyong river basin. Exchange of strains between distinct endemic areas seems to be rare and local clonal complexes can be easily distinguished by whole genome sequencing.
authors.affiliation: Swiss Tropical and Public Health Institute, Basel, Switzerland; University of Basel, Basel, Switzerland.
authors.forename: Miriam
authors.initials: M
authors.lastname: Bolz
authors.affiliation: Swiss Tropical and Public Health Institute, Basel, Switzerland; University of Basel, Basel, Switzerland.
authors.forename: Martin W
authors.initials: MW
authors.lastname: Bratschi
authors.affiliation: Swiss Tropical and Public Health Institute, Basel, Switzerland; University of Basel, Basel, Switzerland.
authors.forename: Sarah
authors.initials: S
authors.lastname: Kerber
authors.affiliation: Swiss Tropical and Public Health Institute, Basel, Switzerland; FAIRMED, Yaoundé, Cameroon.
authors.forename: Jacques C
authors.initials: JC
authors.lastname: Minyem
authors.affiliation: FAIRMED, Yaoundé, Cameroon.
authors.forename: Alphonse
authors.initials: A
authors.lastname: Um Boock
authors.affiliation: Section Clinical Tropical Medicine, Heidelberg University Hospital, Heidelberg, Germany.
authors.forename: Moritz
authors.initials: M
authors.lastname: Vogel
authors.affiliation: FAIRMED, Yaoundé, Cameroon.
authors.forename: Pierre Franklin
authors.initials: PF
authors.lastname: Bayi
authors.affiliation: Section Clinical Tropical Medicine, Heidelberg University Hospital, Heidelberg, Germany.
authors.forename: Thomas
authors.initials: T
authors.lastname: Junghanss
authors.affiliation: Swiss Tropical and Public Health Institute, Basel, Switzerland; University of Basel, Basel, Switzerland.
authors.forename: Daniela
authors.initials: D
authors.lastname: Brites
authors.affiliation: Wellcome Trust Sanger Institute, Wellcome Trust Genome Campus, Hinxton, Cambridge, United Kingdom.
authors.forename: Simon R
authors.initials: SR
authors.lastname: Harris
authors.affiliation: Wellcome Trust Sanger Institute, Wellcome Trust Genome Campus, Hinxton, Cambridge, United Kingdom.
authors.forename: Julian
authors.initials: J
authors.lastname: Parkhill
authors.affiliation: Swiss Tropical and Public Health Institute, Basel, Switzerland; University of Basel, Basel, Switzerland.
authors.forename: Gerd
authors.initials: G
authors.lastname: Pluschke
authors.affiliation: Swiss Tropical and Public Health Institute, Basel, Switzerland; University of Basel, Basel, Switzerland.
authors.forename: Araceli
authors.initials: A
authors.lastname: Lamelas Cabello
mesh_terms: D001483:Base Sequence; D054312:Buruli Ulcer / Q000453:epidemiology* / Q000382:microbiology*; D002163:Cameroon / Q000453:epidemiology; D014644:Genetic Variation; D006801:Humans; D016013:Likelihood Functions; D008957:Models, Genetic; D008969:Molecular Sequence Data; D019911:Mycobacterium ulcerans / Q000235:genetics*; D058069:Neglected Diseases / Q000453:epidemiology* / Q000382:microbiology*; D010802:Phylogeny; D020641:Polymorphism, Single Nucleotide / Q000235:genetics; D017422:Sequence Analysis, DNA