Question: is streptococcus agalactiae resistant to bacitracin?
Answer: With the bacitracin test, a disk of bacitracin is added to the blood agar. Strep agalactiae is bacitracin resistant, so the colonies remain intact, whereas Strep pyogenes is bacitracin sensitive, so the colonies die off. With the CAMP test, Strep agalactiae is grown with Staphylococcus aureus on the same blood agar.