Charcoal Blood Agar Base is recommended for the cultivation of Bordetella pertussis for vaccine production and also for the maintenance of stock cultures. Addition of sterile defibrinated horse blood provides enrichment to the media. Penicillin inhbits contaminanting bacteria. Cephalexin inhibits gram-positive organisms. Bordetella bronchiseptica, Bordetella parapertussis and Bordetella pertussis grows luxuriantlly on this medium while Staphylococcus aureus and Klebsiella pneumoniae are inhibited.