Colonies of four bacteria: Escherichia coli (Gram-negative bacilli), Pseudomonas aeruginosa (Gram-negative bacilli), Staphylococcus aureus (Gram-positive cocci; colony surrounded by a zone of beta-hemolysis) and Staphylococcus epidermidis (Gram-positive cocci) on blood agar.

Cultivation 24 hours, 37°C in an aerobic atmosphere.