title: Massive dispersal ofCoxiella burnetiiamong cattle across the United States.
abstract: Q-fever is an underreported disease caused by the bacteriumCoxiella burnetii, which is highly infectious and has the ability to disperse great distances. It is a completely clonal pathogen with low genetic diversity and requires whole-genome analysis to identify discriminating features among closely related isolates.C. burnetii, and in particular one genotype (ST20), is commonly found in cow's milk across the entire dairy industry of the USA. This single genotype dominance is suggestive of host-specific adaptation, rapid dispersal and persistence within cattle. We used a comparative genomic approach to identify SNPs for high-resolution and high-throughput genotyping assays to better describe the dispersal of ST20 across the USA. We genotyped 507 ST20 cow milk samples and discovered three subgenotypes, all of which were present across the entire country and over the complete time period studied. Only one of these sub-genotypes was observed in a single dairy herd. The temporal and geographic distribution of these sub-genotypes is consistent with a model of large-scale, rapid, frequent and continuous dissemination on a continental scale. The distribution of subgenotypes is not consistent with wind-based dispersal alone, and it is likely that animal husbandry and transportation practices, including pooling of milk from multiple herds, have also shaped the patterns. On the scale of an entire country, there appear to be few barriers to rapid, frequent and large-scale dissemination of the ST20 subgenotypes.
authors.affiliation: 1​Center for Microbial Genetics and Genomics, Northern Arizona University, PO Box 4073, Flagstaff, AZ 86011, USA.
authors.forename: Sonora
authors.initials: S
authors.lastname: Olivas
authors.affiliation: 1​Center for Microbial Genetics and Genomics, Northern Arizona University, PO Box 4073, Flagstaff, AZ 86011, USA.
authors.forename: Heidie
authors.initials: H
authors.lastname: Hornstra
authors.affiliation: 2​Rickettsial Zoonoses Branch, Centers for Disease Control and Prevention, 1600 Clifton Rd, Atlanta, GA 30333, USA.
authors.forename: Rachael A
authors.initials: RA
authors.lastname: Priestley
authors.affiliation: 1​Center for Microbial Genetics and Genomics, Northern Arizona University, PO Box 4073, Flagstaff, AZ 86011, USA.
authors.forename: Emily
authors.initials: E
authors.lastname: Kaufman
authors.affiliation: 1​Center for Microbial Genetics and Genomics, Northern Arizona University, PO Box 4073, Flagstaff, AZ 86011, USA.|3​Informatics and Computing Program, Northern Arizona University, PO Box 5717, Flagstaff, AZ 86011, USA.
authors.forename: Crystal
authors.initials: C
authors.lastname: Hepp
authors.affiliation: 4​Department of Mathematics and Statistics, Northern Arizona University, PO Box 5717, Flagstaff, AZ 86011, USA.
authors.forename: Derek L
authors.initials: DL
authors.lastname: Sonderegger
authors.affiliation: 1​Center for Microbial Genetics and Genomics, Northern Arizona University, PO Box 4073, Flagstaff, AZ 86011, USA.
authors.forename: Karthik
authors.initials: K
authors.lastname: Handady
authors.affiliation: 2​Rickettsial Zoonoses Branch, Centers for Disease Control and Prevention, 1600 Clifton Rd, Atlanta, GA 30333, USA.
authors.forename: Robert F
authors.initials: RF
authors.lastname: Massung
authors.affiliation: 1​Center for Microbial Genetics and Genomics, Northern Arizona University, PO Box 4073, Flagstaff, AZ 86011, USA.|5​Pathogen Genomics Division, Translational Genomics Research Institute, Phoenix, Arizona, USA.
authors.forename: Paul
authors.initials: P
authors.lastname: Keim
authors.affiliation: 2​Rickettsial Zoonoses Branch, Centers for Disease Control and Prevention, 1600 Clifton Rd, Atlanta, GA 30333, USA.
authors.forename: Gilbert J
authors.initials: GJ
authors.lastname: Kersh
authors.affiliation: 1​Center for Microbial Genetics and Genomics, Northern Arizona University, PO Box 4073, Flagstaff, AZ 86011, USA.
authors.forename: Talima
authors.initials: T
authors.lastname: Pearson
mesh_terms: D000818:Animals; D002417:Cattle; D002418:Cattle Diseases / Q000453:epidemiology / Q000382:microbiology* / Q000635:transmission; D016997:Coxiella burnetii / Q000235:genetics / Q000502:physiology*; D003612:Dairying; D005260:Female; D005838:Genotype; D008892:Milk / Q000382:microbiology; D020641:Polymorphism, Single Nucleotide / Q000235:genetics; D011778:Q Fever / Q000453:epidemiology / Q000382:microbiology / Q000635:transmission / Q000662:veterinary*; D014186:Transportation; D014481:United States / Q000453:epidemiology
keywords: Coxiella burnetii; Phylogeography; Q fever, genotyping; SNP typing; canSNP; dairy cattle