title: Geographic divergence of bovine and human Shiga toxin–producing Escherichia coli O157:H7 genotypes, New Zealand.
abstract: Shiga toxin-producing Escherichia coli (STEC)O157:H7 is a zoonotic pathogen of public health concern worldwide. To compare the local and large-scale geographic distributions of genotypes of STEC O157:H7 isolates obtained from various bovine and human sources during 2008–2011, we used pulsed-field gel electrophoresis and Shiga toxin–encoding bacteriophage insertion (SBI) typing. Using multivariate methods, we compared isolates from the North and South Islands of New Zealand with isolates from Australia and the United States. The STEC O157:H7 population structure differed substantially between the 2 islands and showed evidence of finer scale spatial structuring, which is consistent with highly localized transmission rather than disseminated foodborne outbreaks. The distribution of SBI types differed markedly among isolates from New Zealand, Australia, and the United States. Our findings also provide evidence for the historic introduction into New Zealand of a subset of globally circulating STEC O157:H7 strains that have continued to evolve and be transmitted locally between cattle and humans.
authors.affiliation: Massey University, Palmerston North, New Zealand.
authors.forename: Patricia
authors.initials: P
authors.lastname: Jaros
authors.forename: Adrian L
authors.initials: AL
authors.lastname: Cookson
authors.forename: Donald M
authors.initials: DM
authors.lastname: Campbell
authors.forename: Gail E
authors.initials: GE
authors.lastname: Duncan
authors.forename: Deborah
authors.initials: D
authors.lastname: Prattley
authors.forename: Philip
authors.initials: P
authors.lastname: Carter
authors.forename: Thomas E
authors.initials: TE
authors.lastname: Besser
authors.forename: Smriti
authors.initials: S
authors.lastname: Shringi
authors.forename: Steve
authors.initials: S
authors.lastname: Hathaway
authors.forename: Jonathan C
authors.initials: JC
authors.lastname: Marshall
authors.forename: Nigel P
authors.initials: NP
authors.lastname: French
mesh_terms: D000818:Animals; D001315:Australia / Q000453:epidemiology; D002417:Cattle; D002418:Cattle Diseases / Q000453:epidemiology / Q000382:microbiology* / Q000635:transmission; D004927:Escherichia coli Infections / Q000453:epidemiology / Q000382:microbiology* / Q000635:transmission; D019453:Escherichia coli O157 / Q000145:classification / Q000235:genetics*; D014644:Genetic Variation; D005838:Genotype; D006801:Humans; D058885:Multilocus Sequence Typing; D009520:New Zealand / Q000453:epidemiology; D010802:Phylogeny; D058974:Phylogeography; D014481:United States / Q000453:epidemiology; D014774:Virulence / Q000235:genetics; D037521:Virulence Factors / Q000235:genetics
chemical_list: D037521:Virulence Factors