title: Identification of Streptococcus uberis multilocus sequence types highly associated with mastitis.
abstract: Multilocus sequence typing analysis of Streptococcus uberis has identified a cluster of isolates associated with clinical and subclinical mastitis and a cluster associated with cows with low somatic cell counts in their milk. Specific groups of genotypes (global clonal complex [GCC] sequence type 5s [ST5s] and GCC ST143s) were highly associated (P = 0.006) with clinical and subclinical mastitis and may represent a lineage of virulent isolates, whereas isolates belonging to GCC ST86 were associated with low-cell-count cows. This study has, for the first time, demonstrated the occurrence of identical sequence types (ST60 and ST184) between different continents (Australasia and Europe) and different countries (Australia and New Zealand). The standardized index of association and the empirical estimation of the rate of recombination showed substantial recombination within the S. uberis population in Australia, consistent with previous multilocus sequence type analyses.
authors.affiliation: Department of Biotechnology and Environmental Biology, RMIT University, Bundoora West Campus, Bundoora, Melbourne, Victoria 3083, Australia.
authors.forename: Takehiro
authors.initials: T
authors.lastname: Tomita
authors.forename: Brian
authors.initials: B
authors.lastname: Meehan
authors.forename: Nalin
authors.initials: N
authors.lastname: Wongkattiya
authors.forename: Jakob
authors.initials: J
authors.lastname: Malmo
authors.forename: Gillian
authors.initials: G
authors.lastname: Pullinger
authors.forename: James
authors.initials: J
authors.lastname: Leigh
authors.forename: Margaret
authors.initials: M
authors.lastname: Deighton
mesh_terms: D000818:Animals; D015373:Bacterial Typing Techniques; D002417:Cattle; D016000:Cluster Analysis; D004269:DNA, Bacterial / Q000737:chemistry / Q000235:genetics*; D005838:Genotype; D008414:Mastitis, Bovine / Q000453:epidemiology / Q000382:microbiology*; D017720:Molecular Epidemiology; D008969:Molecular Sequence Data; D009520:New Zealand / Q000453:epidemiology; D017422:Sequence Analysis, DNA; D013290:Streptococcal Infections / Q000453:epidemiology / Q000382:microbiology* / Q000662:veterinary*; D013291:Streptococcus / Q000145:classification* / Q000235:genetics* / Q000302:isolation & purification
chemical_list: D004269:DNA, Bacterial