Mastitis is characterized by increased sodium and decreased potassium in milk, and the effect of this on bacterial growth was examined. Colonies of Staphylococcus aureus, Streptococcus uberis, and Escherichia coli were grown in tryptone broth containing 0−75 mM Na or 0−40 mM K. For S. aureus, the total viable count (TVC) growth rate decreased as Na increased from the normal level to that typica...

The objectives of this study are to determine the occurrence of antimicrobial resistance (AMR) genes using whole-genome sequence (WGS) of Streptococcus uberis (S. uberis) and Streptococcus dysgalactiae (S. dysgalactiae) isolates, recovered from dairy cows in the Canadian Maritime Provinces. A secondary objective included the exploration of the association between phenotypic AMR and the genomic ...

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...

Streptococcus uberis is one of the most important mastitis-causing pathogens. Although pathogenesis and virulence factors required for intramammary infection development are not yet well established, several putative virulence-associated genes have been described. This work aimed to investigate presence ten known in S. isolated from subclinical or clinical mastitis its closely related species p...

BACKGROUND Objectives of the study were to document the impact of some management factors on the occurrence of clinical mastitis in primiparous dairy cows and to identify common udder pathogens of clinical mastitis in freshly calved heifers and multiparous cows on the day of calving. METHODS A one-year study was conducted during 2004 and 2005 in 11 selected Estonian dairy herds. Data consiste...