The severity of staphylococcal infection is highly variable, ranging from subclinical to gangrenous mastitis.

Staphylococcus aureus mastitis in dairy sheep ranges from subclinical mastitis to lethal gangrenous mastitis.

Here, two S. aureus strains were isolated from curds formed within the udder of two ewes suffering from gangrenous mastitis.

A genomic comparison of two strains, one responsible for subclinical mastitis and one for lethal gangrenous mastitis, was performed using multi-strain DNA microarrays.