Overview Haemophilus influenzae chocolate agar factor V (NAD+) factor X (hematin, a precursor of hemin) Neisseria gonorrhoeae Thayer-Martin (VPN) media selects for N. gonorrhoeae growth only vancomycin inhibits gram-positive organisms polymyxin inhibits gram-negative organisms nystatin inhibits fungi Mycoplasma cholesterol Salt Staphylococcus aureus can grow in high levels of salt Vibrio spp. requires NaCl to grow and grows in 6.5% NaCl Enterococci (group D streptococci) grows in 6.5% NaCl differentiates from non-enterococcal group D strepococci (S. bovis) Bile group D streptococci can grow in bile (both Streptococcus bovis and Enterococci) Klebsiella can grow in bile Mycobacterium tuberculosis Löwenstein-Jensen agar Mycoplasma pneumoniae Eaton's agar Mycoplasma must be given a long time to grow Bordetella pertussis collect culture with calcium alginate swab Regan-Lowe medium Bordet-Gengou (potato) agar "BORDETella" Corynebacterium diphtheriae Cysteine-tellurite agar forms metachromatic granules detected with methylene blue stain Löffler's media Fungi Sabouraud's agar especially used for dermatophytes fungi causing systemic infections must be given a long time to grow! e.g. Blastomyces, Histoplasma, Coccidioides Legionella charcoal yeast extract agar with cysteine and iron Cysteine required Francisella Brucella Legionella Pasteurella Lactose-fermenting enterics MacConkey's agar pink colonies due to acid production by fermentation contains bile to inhibit growth of unwanted organisms EMB agar (eosin-methylene blue) also used to differentiate lactose-fermenting bacteria Escherichia coli appears with metallic green sheen