Molecular Epidemiology and Population Structure of Bovine Streptococcus uberis

Pulsed-field gel electrophoresis (PFGE) profiles of SmaI-digested genomic DNA from Streptococcus uberis subclinical mastitis isolates collected at 6 Portuguese dairy herds. Ladder = Lambda PFGE ladder marker (New England BioLabs, Beverly, MA). A) PFGE type-subtype patterns of isolates from farm F and K; B) PFGE type-subtype patterns of isolates from farms C, D, I, and J; C) PFGE type-subtype patterns of 1 isolate from farm F.

Dendrogram of the pulsed-field gel electrophoresis (PFGE) profiles of Streptococcus uberis subclinical mastitis isolates collected at 6 Portuguese dairy herds, novel multilocus sequence types (ST) and clonal complexes. Isolate code, farm code, and date of isolation of each strain are also represented in the dendrogram. The dendrogram was produced by using Dice coefficients and an unweighted pair group method using arithmetic averages (UPGMA). Default clustering settings of 0.00% optimization (i.e., the relative distance an entire lane is allowed to shift in matching attempts) and 1.5% band position tolerance were used.

e-BURST diagram determined by eBURSTv3 software (http://eburst.mlst.net/) using 1 example of each sequence type (ST) assigned in the Streptococcus uberis multilocus sequence typing (MLST) database (http://pubmlst.org/suberis/info/protocol.shtml). Only ST-287 (circled) from the present work was assigned to the major clonal complex described as group 1, which includes 107 ST of Strep. uberis MLST database; ST-287 is a single locus variant of the predicted founder (ST-184).