Bacteria photos: Staphylococcus aureus

Staphylococcus aureus yellow colonies on sheep blood agar

S.aureus yellow colonies on blood agar, beta-hemolysis

Typical colonies of Staphylococcus aureus on blood agar (CAP agar) after 24 hours, aerobic atmosphere, 37°C. Yellow colonies are surroundend by a zone of beta-hemolysis.

Some strains of S. aureus are capable of producing staphyloxanthin - a golden coloured carotenoid pigment. This pigment acts as a virulence factor, primarily by being a bacterial antioxidant which helps the microbe evade the reactive oxygen species which the host immune system uses to kill pathogens.

Text: Wikipedia