s. aureus in a Petri dish with blood agar, production of various hemolysins

A) S. aureus with a wide zone of beta (complete) haemolysis on blood agar (sporadically beta-hemolytic colonies of Streptococcus agalactiae and nonhemolytic colonies of Enterococcus faecalis)

B) S. aureus can product multiple haemolysins with slightly different effects. This "double zone" shows the presence of a complete haemolysin (likely alpha-haemolysin) and an incomplete (likely beta-haemolysin) [note that the types of haemolysis (the visible effect) and haemolysins (the toxins themselves) are named differently]

Text: Eva van Dijk