An update on Streptococcus uberis mastitis and control

Streptococcus uberis is a common cause of intramammary infection in dairy cattle in the UK. It can cause subclinical and clinical mastitis in lactating animals, heifers and dry cows. Technologically, dairy farming, dairy medicine and dairy research have advanced dramatically in the past decades but the biology of S. uberis has largely remained the same and so has the control of S. uberis mastitis. S. uberis is widespread in cattle dung and hence in the dairy environment. Environmental hygiene is a key component of S. uberis mastitis prevention. In addition, the infected mammary gland is a source of S. uberis and contagious transmission must be prevented, for example through implementation of the 5-point plan. In comparison to Escherichia coli and Staphylococcus aureus, little is known about the host response to S. uberis infection. Natural infection does not cause immunity to re-infection and efforts to harness the host immune response through vaccination have not yet led to a vaccine. Response to antimicrobial treatment is quite variable, and may be linked to lactation stage and duration of infection, which has implications for diagnostics, treatment regimens and transmission. With adequate effort, both contagious and environmental S. uberis can be controlled on most farms.