Staphylococcus aureus is a facultatively anaerobic, Gram-positive coccus.
Strains are responsible for food poisoning through the production of an enterotoxin, and pathogenicity is also associated with coagulase positivity.
Staphylococcus aureus may occur as a commensal on skin; it also occurs in the nose frequently (in about a third of the population) and the throat less commonly. The occurrence of Staphylococcus aureus under these circumstances does not always indicate infection and, therefore, does not always require treatment (indeed, treatment may be ineffective and recolonisation may occur).
It can survive on domesticated animals, such as dogs, cats, and horses, and can cause bumblefoot in chickens.
Staphylococcus aureus (Wikipedia)