title: Extended Multilocus Sequence Analysis to Describe the Global Population Structure of the GenusBrucella: Phylogeography and Relationship to Biovars.
abstract: An extended multilocus sequence analysis (MLSA) scheme applicable to theBrucella, an expanding genus that includes zoonotic pathogens that severely impact animal and human health across large parts of the globe, was developed. The scheme, which extends a previously described nine locus scheme by examining sequences at 21 independent genetic loci in order to increase discriminatory power, was applied to a globally and temporally diverse collection of over 500 isolates representing all 12 knownBrucellaspecies providing an expanded and detailed understanding of the population genetic structure of the group. Over 100 sequence types (STs) were identified and analysis of data provided insights into both the global evolutionary history of the genus, suggesting that early emergingBrucella abortuslineages might be confined to Africa while some later lineages have spread worldwide, and further evidence of the existence of lineages with restricted host or geographical ranges. The relationship between biovar, long used as a crude epidemiological marker, and genotype was also examined and showed decreasing congruence in the orderBrucella suis>B. abortus>Brucella melitensis. Both the previously described nine locus scheme and the extended 21 locus scheme have been made available at http://pubmlst.org/brucella/ to allow the community to interrogate existing data and compare with newly generated data.
authors.affiliation: FAO/WHO Collaborating Centre for Reference and Research in Brucellosis and OIE Brucellosis Reference Laboratory, Department of Bacteriology, Animal and Plant Health Agency Addlestone, UK.
authors.forename: Adrian M
authors.initials: AM
authors.lastname: Whatmore
authors.affiliation: FAO/WHO Collaborating Centre for Reference and Research in Brucellosis and OIE Brucellosis Reference Laboratory, Department of Bacteriology, Animal and Plant Health Agency Addlestone, UK.
authors.forename: Mark S
authors.initials: MS
authors.lastname: Koylass
authors.affiliation: FAO/WHO Collaborating Centre for Reference and Research in Brucellosis and OIE Brucellosis Reference Laboratory, Department of Bacteriology, Animal and Plant Health Agency Addlestone, UK.
authors.forename: Jakub
authors.initials: J
authors.lastname: Muchowski
authors.affiliation: FAO/WHO Collaborating Centre for Reference and Research in Brucellosis and OIE Brucellosis Reference Laboratory, Department of Bacteriology, Animal and Plant Health Agency Addlestone, UK.
authors.forename: James
authors.initials: J
authors.lastname: Edwards-Smallbone
authors.affiliation: FAO/WHO Collaborating Centre for Reference and Research in Brucellosis and OIE Brucellosis Reference Laboratory, Department of Bacteriology, Animal and Plant Health Agency Addlestone, UK.
authors.forename: Krishna K
authors.initials: KK
authors.lastname: Gopaul
authors.affiliation: FAO/WHO Collaborating Centre for Reference and Research in Brucellosis and OIE Brucellosis Reference Laboratory, Department of Bacteriology, Animal and Plant Health Agency Addlestone, UK.
authors.forename: Lorraine L
authors.initials: LL
authors.lastname: Perrett
keywords: Brucella; brucellosis; molecular typing; multilocus sequence; zoonosis