Streptococcus uberis isolated from clinical mastitis cases on a southeastern Queensland dairy

A genomic comparison of Streptococcus uberis isolates was made to investigate potential sources (environment, cow) of udder quarter infections on one southeastern Queensland dairy property. Strep. uberis was cultured from milk samples obtained over several years from the quarters of cows exhibiting clinical signs of mastitis. Twenty-two samples from recurrent and one-of cases from different lactations and different seasons were included. The identities of the isolated organisms were initially determined by standard methods used in a diagnostic microbiology laboratory. Comparison of subsequently obtained genomic sequences did not identify any pattern consistent with a cow-to-cow spread, season, or lactation number. The data appears to support an environmental location as the primary source of the detected organisms